Patent Publication Number: US-2022218389-A1

Title: Medical Devices and Kits Useful for Performing Treatment under Magnetic Resonance Imaging and Related Methods

Description:
RELATED APPLICATIONS 
     This application claims priority to U.S. Provisional Application No. 63/135,801, filed Jan. 11, 2021. The entire contents of this related application are hereby incorporated by reference into this disclosure. 
    
    
     FIELD 
     The disclosure relates generally to the field of medical devices. More particularly, the disclosure relates to medical devices useful in performing treatment under magnetic resonance imaging (MRI), kits useful in performing treatment under MRI, and methods of performing interventional medical treatment under MRI. 
     BACKGROUND 
     The field of interventional MRI is gaining wider acceptance and seeing an increase in the number of procedures that can be performed. Interventional procedures conducted under MRI have several benefits over X-Ray-guided interventions. For example, the patient is not exposed to ionizing radiation. Also, MRI provides the ability to characterize tissue and functional flow during an interventional procedure. 
     The development of interventional procedures conducted under MRI has been limited as a result of the tools needed to perform these procedures being unavailable. Therefore, patients are required to make multiple visits to treatment facilities to visualize, diagnose, and treat various conditions. In addition, multiple imaging modalities are often needed, which impacts the accuracy of utilizing a magnetic resonance image in directing intervention. For example, when addressing prostate cancer, visualization, biopsy, and treatment are currently completed over the course of three patient visits. At a first visit, a scan is completed using a magnetic resonance scanner to produce an image showing the prostate and any abnormalities. The patient then leaves the facility and awaits a review of the image. If abnormalities exist, a second patient visit will occur such that a biopsy sample of the abnormal tissue can be completed. Currently, software is used to fuse the magnetic resonance image with the procedural ultrasound to provide guidance in conducting the biopsy. This fusion decreases the value of the diagnostic magnetic resonance image. The patient then leaves the facility again and awaits a review of the biopsy sample to determine whether further treatment is required (e.g., if the review results in a positive prostate cancer diagnosis). If further treatment is required, the patient will visit the facility a third time such that treatment can be performed. Completion of these three patient visits can take months, prevents the patient from receiving rapid treatment, and increases the overall costs associated with treatment. Furthermore, software used to fuse magnetic resonance images with other images (e.g., those obtained via ultrasound) have drawbacks, such as potential image overlay issues and the potential for compression shifting of tissues (e.g., prostate). 
     A need exists, therefore, for new and improved medical devices useful in performing treatment under MRI, kits useful in performing treatment under MRI, and methods of performing interventional medical treatment under MRI. 
     Summary of Selected Example Embodiments 
     Various example medical devices useful in performing treatment under MRI, kits useful in performing treatment under MRI, and methods of performing interventional medical treatment under MRI are described herein. 
     An example medical device useful in performing treatment under MRI includes a cannula and a plug. The cannula has a proximal end, a distal end, a first portion, a second portion, and a main body that defines a lumen and a passageway. The first portion extends from the distal end toward the proximal end. The second portion extends from the first portion toward the proximal end. The first portion is formed of a first material. The second portion is formed of a second material that is different than the first material. The lumen extends from the proximal end to the distal end. The passageway is defined on the second portion and extends through the main body and is in fluid communication with the lumen. The plug is disposed within the passageway. The plug has a main body that defines a passageway in fluid communication with the lumen defined by the cannula. The plug is formed of a third material that is different than the second material. 
     An example method of performing an interventional medical treatment under MRI comprises positioning a patient within a magnetic resonance scanner; scanning a first portion of the patient using the magnetic resonance scanner; obtaining a magnetic resonance image of the first portion of the patient; identifying a tissue that has predefined characteristics using the magnetic resonance image; while the patient remains positioned within the magnetic resonance scanner used to scan the first portion of the patient, advancing a medical device into a bodily passage and to the tissue while scanning a second portion of the patient that includes the medical device using the magnetic resonance scanner; obtaining a magnetic resonance image of the second portion of the patient that includes the medical device; confirming the position of the medical device within the bodily passage; advancing a biopsy device through the medical device and to the tissue while scanning a third portion of the patient that includes the biopsy device using the magnetic resonance scanner; obtaining a magnetic resonance image of the third portion of the patient that includes the biopsy device; confirming the position of the biopsy device; collecting a tissue sample from the tissue using the biopsy device while scanning a fourth portion of the patient that includes the biopsy device and the tissue using the magnetic resonance scanner; obtaining a magnetic resonance image of the fourth portion of the patient that includes the biopsy device; confirming the tissue sample has been collected; withdrawing the biopsy device and the tissue sample through the medical device; and determining whether the tissue sample meets a predefined criterion. 
     Another example method of performing an interventional medical treatment comprises positioning a patient within a magnetic resonance scanner; scanning a first portion of the patient using the magnetic resonance scanner; obtaining a magnetic resonance image of the first portion of the patient; identifying a tissue that has predefined characteristics using the magnetic resonance image; while the patient remains positioned within the magnetic resonance scanner used to scan the first portion of the patient, advancing a medical device into a bodily passage and to the tissue while scanning a second portion of the patient that includes the medical device using the magnetic resonance scanner; obtaining a magnetic resonance image of the second portion of the patient that includes the medical device; confirming the position of the medical device within the bodily passage; advancing a biopsy device through the medical device and to the tissue while scanning a third portion of the patient that includes the biopsy device using the magnetic resonance scanner; obtaining a magnetic resonance image of the third portion of the patient that includes the biopsy device; confirming the position of the biopsy device; collecting a tissue sample from the tissue using the biopsy device while scanning a fourth portion of the patient that includes the biopsy device and the tissue using the magnetic resonance scanner; obtaining a magnetic resonance image of the fourth portion of the patient that includes the biopsy device; confirming the tissue sample has been collected; withdrawing the biopsy device and the tissue sample through the medical device; determining whether the tissue sample meets a predefined criterion; if the tissue sample does not meet the predefined criterion, additional steps comprise withdrawing the medical device from the bodily passage and removing the patient from the magnetic resonance scanner; if the tissue sample meets the predefined criterion, advancing an anchor member through the medical device through which the biopsy device was advanced and to the tissue while the patient remains positioned within the magnetic resonance scanner; securing the anchor member to retain the position of the medical device relative to the tissue; advancing a first inner sheath over the medical device and toward the tissue to dilate the bodily passage; advancing a second inner sheath over the first inner sheath and toward the tissue to dilate the bodily passage; advancing an outer sheath over the second inner sheath and toward the tissue to dilate the bodily passage; removing the anchor member from the tissue; withdrawing the anchor member from the bodily passage; withdrawing the medical device from the bodily passage; withdrawing the first inner sheath from the bodily passage; withdrawing the second inner sheath from the bodily passage; advancing a treatment device through the outer sheath and to the tissue; manipulating the tissue using the treatment device; withdrawing the treatment device from the outer sheath; and withdrawing the outer sheath from the bodily passage. 
     An example method of performing treatment on a prostate under MRI comprises positioning a patient within a magnetic resonance scanner; scanning a prostate and surrounding tissue of the patient using the magnetic resonance scanner; obtaining a magnetic resonance image of the prostate and surrounding tissue of the patient; identifying a tissue within the magnetic resonance image that has predefined characteristics; while the patient remains positioned within the magnetic resonance scanner used to scan the prostate and surrounding tissue, advancing a medical device into a bodily passage and to the tissue while scanning a first portion of the patient that includes the medical device using the magnetic resonance scanner; obtaining a magnetic resonance image of the second portion of the patient that includes the medical device; confirming the position of the medical device within the bodily passage; advancing a biopsy device through the medical device and to the tissue while scanning a third portion of the patient that includes the biopsy device using the magnetic resonance scanner; obtaining a magnetic resonance image of the third portion of the patient that includes the biopsy device; confirming the position of the biopsy device; collecting a tissue sample from the tissue using the biopsy device while scanning a fourth portion of the patient that includes the biopsy device and the tissue using the magnetic resonance scanner; obtaining a magnetic resonance image of the fourth portion of the patient that includes the biopsy device; confirming the tissue sample has been collected; withdrawing the biopsy device and the tissue sample through the medical device; determining whether the tissue sample meets a predefined criterion; if the tissue sample meets the predefined criterion, advancing an anchor member through the medical device through which the biopsy device was advanced and to the tissue while the patient remains positioned within the magnetic resonance scanner; securing the anchor member to the tissue to retain the position of the medical device relative to the tissue; advancing a first inner sheath over the medical device and toward the tissue to dilate the bodily passage; advancing a second inner sheath over the first inner sheath and toward the tissue to dilate the bodily passage; advancing an outer sheath over the second inner sheath and toward the tissue to dilate the bodily passage; removing the anchor member from the tissue; withdrawing the anchor member from the bodily passage; withdrawing the medical device from the bodily passage; withdrawing the first inner sheath from the bodily passage; withdrawing the second inner sheath from the bodily passage; advancing a treatment device through the outer sheath and to the tissue; manipulating the tissue using the treatment device; withdrawing the treatment device from the outer sheath; withdrawing the outer sheath from the bodily passage. 
     Another example method of performing an interventional medical treatment comprises positioning a patient within a magnetic resonance scanner; scanning a first portion of the patient using the magnetic resonance scanner; obtaining a magnetic resonance image of the first portion of the patient; identifying a tissue that has predefined characteristics using the magnetic resonance image; while the patient remains positioned within the magnetic resonance scanner used to scan a portion of the patient, advancing a medical device into a bodily passage and to the tissue while scanning a second portion of the patient that includes the medical device using the magnetic resonance scanner; obtaining a magnetic resonance image of the second portion of the patient that includes the medical device; confirming the position of the medical device within the bodily passage; advancing an anchor member through the medical device and to the tissue while the patient remains positioned within the magnetic resonance scanner; securing the anchor member to the tissue to retain the position of the anchor member relative to the tissue; withdrawing the medical device from the bodily passage; advancing a first inner sheath over the anchor member and toward the tissue to dilate the bodily passage; advancing a second inner sheath over the first inner sheath and toward the tissue to dilate the bodily passage; advancing an outer sheath over the second inner sheath and toward the tissue to dilate the bodily passage; withdrawing the first inner sheath from the bodily passage; withdrawing the second inner sheath from the bodily passage; removing the anchor member from the tissue; withdrawing the anchor member from the bodily passage; advancing a biopsy device through the outer sheath and to the tissue while scanning a third portion of the patient that includes the biopsy device using the magnetic resonance scanner; obtaining a magnetic resonance image of the third portion of the patient that includes the biopsy device; confirming the position of the biopsy device; collecting a tissue sample from the tissue using the biopsy device while scanning a fourth portion of the patient that includes the biopsy device and the tissue using the magnetic resonance scanner; obtaining a magnetic resonance image of the fourth portion of the patient that includes the biopsy device; confirming the tissue sample has been collected; withdrawing the biopsy device and the tissue sample through the outer sheath; determining whether the tissue sample meets a predefined criterion; if the tissue sample does not meet the predefined criterion, withdrawing the outer sheath from the bodily passage; removing the patient from the magnetic resonance scanner; if the tissue sample meets the predefined criterion, advancing a treatment device through the outer sheath and to the tissue; manipulating the tissue using the treatment device; withdrawing the treatment device from the outer sheath; withdrawing the outer sheath from the bodily passage; removing the patient from the magnetic resonance scanner. 
     An example kit useful in performing treatment under magnetic resonance includes a cannula, a first inner sheath, a second inner sheath, an outer sheath, an anchor member, and a treatment device. 
     Additional understanding of these example medical devices, kits, and methods can be obtained by review of the detailed description, below, and the appended drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a partial elevation view of a first example medical device. 
         FIG. 2  is a partial elevation view of the first medical device illustrated in  FIG. 1  disposed through a first inner sheath, a second inner sheath, and an outer sheath. 
         FIG. 3  is a partial elevation view of the outer sheath illustrated in  FIG. 2 . 
         FIG. 4  is a partial perspective view of a second example medical device. 
         FIG. 5  is a partial perspective view of a third example medical device. 
         FIG. 6  is a partial perspective exploded view of a fourth example medical device. 
         FIG. 7  is an elevation view of a fifth example medical device. 
         FIG. 8  is a partial elevation view of a sixth example medical device. 
         FIG. 9  is a partial sectional view of a seventh example medical device. The anchor member is shown in a first position. 
         FIG. 10  is another partial sectional view of the medical device shown in  FIG. 9 . The anchor member is shown in a second position. 
         FIG. 11  is another partial sectional view of the medical device shown in  FIG. 9 . The anchor member is shown in a third position. 
         FIG. 12  is a partial top view of the cannula of the medical device shown in  FIG. 9 . 
         FIG. 13  is a partial elevation view of the cannula of the medical device shown in  FIG. 9 . 
         FIG. 14  is a partial top view of the anchor member of the medical device shown in  FIG. 9 . 
         FIG. 15  is a partial top view of an eighth example medical device. The anchor member is shown in a first position. 
         FIG. 16  is another partial top view of the medical device shown in  FIG. 15 . The anchor member is shown in a second position. 
         FIG. 17  is another partial top view of the medical device shown in  FIG. 15 . The anchor member is shown in a third position. 
         FIG. 18  is a partial elevation view of a ninth example medical device. The anchor member is shown in a first position. 
         FIG. 19  is another partial elevation view of the medical device shown in  FIG. 18 . The anchor member is shown in a second position. 
         FIG. 20  is another partial elevation view of the medical device shown in  FIG. 18 . The anchor member is shown in a third position. 
         FIG. 21  is a schematic illustration of an example method of performing treatment under MRI. 
         FIGS. 22A and 22B  show another schematic illustration of an example method of performing treatment under MRI. 
         FIG. 23  is a partial perspective view of a tenth example medical device. 
         FIGS. 24A and 24B  show another schematic illustration of an example method of performing treatment under MRI. 
         FIG. 25  illustrates an example kit that includes example medical devices, an example first inner sheath, an example second inner sheath, an example outer sheath, and an example treatment device. 
         FIGS. 26A and 26B  show another schematic illustration of an example method of performing treatment under MRI. 
     
    
    
     DETAILED DESCRIPTION OF SELECTED EXAMPLES 
     The following detailed description and the appended drawings describe and illustrate various example medical devices useful in performing treatment under MRI, kits useful in performing treatment under MRI, and methods of performing interventional medical treatment under MRI. The description and illustration of these examples are provided to enable one skilled in the art to make and use a medical device, a kit, and to practice a method of performing an interventional medical treatment under MRI. They are not intended to limit the scope of the invention, or the protection sought, in any manner. The invention is capable of being practiced or carried out in various ways and the examples described and illustrated herein are merely selected examples of the various ways of practicing or carrying out the invention and are not considered exhaustive. 
     As used herein, the term “attached” refers to one member being secured to another member such that the members do not completely separate from each other during use performed in accordance with the intended use of an item that includes the members in their attached form. 
     As used herein, the term “plug” refers to a member having a size and configuration suitable for disposition within a hole, cavity, passageway, or void in another member. The term does not require any particular size or configuration, and the size and configuration of a particular plug will depend on the size and configuration of the hole, cavity, passageway, or void into which the plug is intended to be disposed. 
       FIGS. 1, 2, and 3  illustrate a first example medical device  10 . In this example, the medical device  10  is a cannula  12 . As shown in  FIG. 2 , the cannula  12  can be used with a first inner sheath  14 , a second inner sheath  16 , and an outer sheath  18  to accomplish sequential dilation of a bodily passage to provide access to the bodily passage. 
     The cannula  12  has a proximal end  20 , a distal end  22 , and a main body  24  that defines a lumen  26  and a distal tapered tip  28  with a cutting edge  30 . The lumen  26  extends from the proximal end  20  to the distal end  22  such that one or more devices can be passed into, and through, the cannula  12 . In the illustrated embodiment, the main body  24  has a first portion  32  formed of a first material and a second portion  34  formed of a second material. The first portion  32  extends from the distal end  22  toward the proximal end  20  and the second portion  34  extends from the first portion  32  toward the proximal end  20 . The first material and the second material can comprise any suitable MRI compatible material. For example, a first portion can comprise a magnetically susceptible material, such as a paramagnetic material or a ferromagnetic material, and the second portion can comprise a non-ferromagnetic material, such as an austentic nickel-chromium based alloy, such as Inconel, a brand for a family of austenitic nickel-chromium-based superalloys from Special Metals Corporation. Advantageously, the second material comprises a paramagnetic material. Particularly advantageously, the second material comprises a non-magnetically susceptible material. In the embodiment illustrated, the first material comprises 304 stainless steel and the second material comprises Inconel. Use of these materials results in the first portion acting as a passive marker when using MRI to create a magnetic resonance image. 
     While the cannula  12  has been illustrated as including a distal tapered tip  28  with a cutting edge  30 , a cannula can include any suitable structural configuration, such as those with blunted, or non-tapered, distal tips. While the cannula  12  has been illustrated as including a first portion  32  that extends from the distal end  22  toward the proximal end  20  and a second portion  34  that extends from the first portion  32  toward the proximal end  20 , a first portion and/or second portion of a cannula can be positioned at any suitable location on a cannula, such as between a proximal end and a distal end of a cannula, such that it extends from a proximal end toward a distal end, such that it extends from a distal end toward a proximal end, such that a second portion extends from a first portion and to a proximal end, and any other location considered suitable for a particular embodiment. 
     The first inner sheath  14  has a proximal end  40 , a distal end  42 , and a main body  44  that defines a lumen  46  and a tapered distal tip  48 . The second inner sheath  16  has a proximal end  50 , a distal end  52 , and a main body  54  that defines a lumen  56  and a tapered distal tip  58 . The outer sheath  18  has a proximal end  60 , a distal end  62 , and a main body  64  that defines a lumen  66  and a tapered distal tip  68 . 
     While the cannula  12  has been illustrated as being used with a first inner sheath  14 , a second inner sheath  16 , and an outer sheath  18  to accomplish sequential dilation, a cannula can be used with any suitable number of inner and/or outer sheaths. Selection of a suitable number of inner sheaths and/or outer sheaths to utilize when completing sequential dilation can be based on the bodily passage within which a sequential dilation is being completed. Examples of numbers of inner sheaths and/or outer sheaths considered suitable to include when completing sequential dilation include one, two, a plurality, three, four, more than four, and any other number considered suitable for a particular embodiment. 
     A cannula, an inner sheath, and an outer sheath can be formed of any suitable MRI compatible material and selection of a suitable material can be based on various considerations, including the intended use of the cannula, inner sheath, and/or outer sheath. Examples of MRI compatible materials considered suitable to form a cannula include biocompatible materials, materials that can be made biocompatible, metals, electrically insulating materials, electrically non-conducting materials, shape memory alloys, including nickel-titanium alloys such as Nitinol, stainless steel, including Austenitic stainless steel, stainless steel containing Iron, stainless steel including Inconel, cobalt chromium, cobalt chromium alloys, Inconel, titanium, polymers, PEEK, carbon-filled PEEK, ceramics, the materials described herein, combinations of the described herein, and any other material considered suitable for a particular embodiment. Examples of materials considered suitable to form an inner sheath and/or an outer sheath include biocompatible materials, materials that can be made biocompatible, metals, electrically insulating materials, electrically non-conducting materials, shape memory alloys, including nickel-titanium alloys such as Nitinol, Inconel, plastics, polymers, PEEK, carbon-filled PEEK, polyethylene, such as high-density polyethylene (HDPE), polypropylene, polycarbonates, silicone, Delrin, ceramics, transparent materials, opaque materials, the materials described herein, combinations of the materials described herein, and any other material considered suitable for a particular embodiment. 
       FIG. 4  illustrates a second example medical device  110 . In this example, the medical device  110  is a cannula  112 . The cannula  112  is similar to the cannula  12  illustrated in  FIGS. 1, 2, and 3  and described above, except as detailed below. In the illustrated embodiment, the cannula  112  has a proximal end  120 , a distal end  122 , and a main body  124  that defines a lumen  126  and a distal tapered tip  128  with a cutting edge  130 . The main body  124  is formed of a nickel-chromium based alloy, such as an Inconel brand alloy. The lumen  126  extends from the proximal end  120  to the distal end  122  such that one or more devices can be passed into, and through, the cannula  112 . A hub member  132  is disposed on the proximal end  120  of the cannula  112  such that other devices can be attached to the cannula  112 . 
     In the illustrated embodiment, the main body  124  of the cannula  112  defines a wall  136  that has inner  138  and outer  140  opposing surfaces. A wall thickness extends between the inner  138  and outer  140  surfaces. The main body  124  of the cannula  112  defines a passageway  142  that extends through the entire thickness of the wall  136  and from the inner surface  138  to the outer surface  140 . Alternatively, a passageway can extend only partially through the thickness of a wall, either from an inner surface toward an outer surface or from an outer surface toward an inner surface. 
     The cannula  112  includes a plurality of markers  144 . In the illustrated embodiment, a first marker  146  of the plurality of makers  144  is disposed between the proximal end  120  and the distal end  122  of the cannula  112  and a second marker  148  of the plurality of markers  144  is disposed between the first marker  146  and the proximal end  120  of the cannula  112 . Each marker of the plurality of markers  144  is attached to the cannula  112  and is formed of a magnetically susceptible material, such as a paramagnetic material or a ferromagnetic material. The first marker  146  is disposed circumferentially about main body  124  of the cannula  112  and comprises a stainless steel marker band. The second marker  148  is a plug  150  disposed within the passageway  142 . The plug  150  is formed of stainless steel and has a main body  152  that defines a passageway  154  that extends through the plug  150 . Alternative embodiments, however, can include a plug that does not define a passageway that extends through the plug such that the plug is a solid member that prevents access to a lumen defined by a cannula. The passageway  154  is in fluid communication with the lumen  126  defined by the cannula  112 . The second marker  148  is flush with the inner surface  138  and the outer surface  140  and, in the embodiment illustrated, has been pressed into the passageway  142 . Additional securement can be used, if desired. For example, a marker can be laser welded to a wall of a cannula to secure the marker in a passageway. Forming the first and second markers  146 ,  148  of stainless steel results in the cannula  112  that has two passive markers that can be viewed when using MRI to create a magnetic resonance image. Each marker of the plurality of markers  144  has properties that produce visual artifacts during MRI procedures in which the medical device  110  is imaged. These visual artifacts can be used to determine placement of the medical device  110  relative to other portions of an MRI image, such as portions of a bodily passage into which the medical device  110  has been advanced. 
     A passageway can be created in a cannula using any suitable technique, such as laser drilling, or electric discharge machining (EDM). A marker included on a cannula can be attached to the cannula using any suitable technique and be formed of any suitable material. Examples of techniques considered suitable to attach a marker to a cannula include pressing, welding, using adhesives, and any other technique considered suitable for a particular embodiment. Examples of materials considered suitable to form a marker include biocompatible materials, materials that can be made biocompatible, MRI compatible materials, metals, electrically insulating materials, electrically non-conducting materials, magnetically susceptible materials, including paramagnetic and ferromagnetic materials, ferromagnetic passive materials, Ferritic Stainless Steel, Ferritic Stainless Steel 430L powder, shape memory alloys, including nickel-titanium alloys such as Nitinol, stainless steel, including Austenitic stainless steel, stainless steel containing Iron, stainless steel including Inconel, cobalt chromium, cobalt chromium alloys, Inconel, titanium, materials (e.g., Stainless Steel) having a hardness of about 192 KSI, the materials described herein, combinations of the described herein, and any other material considered suitable for a particular embodiment. While the first marker  146  has been illustrated as a marker band (e.g., circumferential marker) and the second marker  148  has been illustrated as a plug, a marker can comprise any suitable structure attached to a cannula or any suitable treatment imparted on a cannula. For example, a marker can include bands of material, magnetic inks, sputtered magnetite marks of varying shapes and/or configurations, and/or dimpling or peening the material that forms a cannula (e.g., annealed 304 stainless steel). Any suitable marker can be included in a medical device, such as those described herein. Examples of markers considered suitable to include in a medical device are described in U.S. patent application Ser. No. 16/454,905, filed on Jun. 27, 2019, which is hereby incorporated by reference in its entirety for the purpose of describing markers considered suitable to include in a medical device. Each marker of the plurality of markers  144  can have any suitable configuration. Circumferential markers can be disposed around the entire circumference of the main body  124  of the medical device  110 . Alternatively, a marker that defines a partial circumference can be disposed around a main body of a medical device according to an embodiment such that the marker extends around only a portion of the circumference of the main body. 
     Any suitable number of markers can be used in a medical device according to an embodiment. While the medical device  110  includes two markers  146 ,  148 , it is to be appreciated that a medical device according to an embodiment can include any number of markers considered suitable for the intended use of the particular medical device. Examples of suitable numbers of markers for inclusion in a medical device according to an embodiment include one marker, two markers, more than two markers, three markers, a plurality of markers, four markers, five markers, six markers, seven markers, eight markers, nine markers, ten markers, and more than ten markers. Furthermore, in embodiments that include two or more markers, the markers can be spaced from each other by a desired distance. It should be noted, though, that, because the markers produce visual artifacts and their utility in the medical device is based on this production of visual artifacts in MRI procedures, it is desirable to space markers from each other by a distance that does not result in overlapping or nearly overlapping visual artifacts. 
       FIG. 5  illustrates a third example medical device  210 . In this example, the medical device  210  is a cannula  212 . The cannula  212  is similar to the cannula  112  illustrated in  FIG. 4  and described above, except as detailed below. In the illustrated embodiment, the cannula  212  has a proximal end  220 , a distal end  222 , and a main body  224  that defines a lumen  226  and a distal tapered tip  228  with a cutting edge  230 . The lumen  226  extends from the proximal end  220  to the distal end  222  such that one or more devices can be passed into, and through, the cannula  212 . 
     In the illustrated embodiment, the main body  224  of the cannula  212  defines a wall  236  that has inner  238  and outer  240  opposing surfaces. The main body  224  of the cannula  212  defines a plurality of passageways  242 . Each passageway of the plurality of passageways extends through the entire thickness of the wall  236  and from the inner surface  238  to the outer surface  240 . 
     The cannula  212  includes a plurality of markers  244 . In the illustrated embodiment, the plurality of markers  244  is arranged in a helical configuration about the circumference of the cannula  212 . Each marker of the plurality of markers  244  is attached to the cannula  212  and comprises a plug  250  disposed within a passageway of the plurality of passageways  242 . Each plug  250  has a main body  252  that defines a passageway  254  that extends through the plug  250 . The passageway  254  is in fluid communication with the lumen  226  defined by the cannula  212 . 
       FIG. 6  illustrates a fourth example medical device  310 . In this example, the medical device  310  is a cannula  312 . The cannula  312  is similar to the cannula  312  illustrated in  FIG. 4  and described above, except as detailed below. In the illustrated embodiment, the cannula  312  has a proximal end  320 , a distal end  322 , and a main body  324  that defines a lumen  326  and a distal tapered tip  328  with a cutting edge  330 . The lumen  326  extends from the proximal end  320  to the distal end  322  such that one or more devices can be passed into, and through, the cannula  312 . 
     In the illustrated embodiment, the main body  324  of the cannula  312  defines a wall  336  that has inner  338  and outer  340  opposing surfaces. The main body  324  of the cannula  312  defines a passageway  342  that extends through the entire thickness of the wall  336  and from the inner surface  338  to the outer surface  340 . 
     The cannula  312  includes a marker  344 . In the illustrated embodiment, the marker  344  is a plug  350  disposed within the passageway  342 . The plug  350  has a main body  352  that defines a passageway  354  that extends through the plug  350 . The passageway  354  is in fluid communication with the lumen  326  defined by the cannula  312 . As such, the marker  344  is attached to the cannula  312 . 
       FIG. 7  illustrates a fifth example medical device  510 . In this example, the medical device  510  is a cannula  512  with an attached handle  513 . The cannula  512  is similar to the cannula  12  illustrated in  FIGS. 1, 2 , and and described above, except as detailed below. In the illustrated embodiment, the cannula  512  has a proximal end  520 , a distal end  522 , and a main body  524  that defines a lumen  526  and a blunted distal tip  528 . The lumen  526  extends from the proximal end  520  to the distal end  522  such that one or more devices can be passed into, and through, the cannula  512 . The blunted distal tip  528  is created by grinding a non-cutting atraumatic tip on the distal end  522  of the cannula  512 . 
     In the illustrated embodiment, the handle  513  is releasably attached to the cannula  512  and comprises a luer-lock hub  560  that includes sealing members and a clamping member  564 . The sealing members can be adjusted by rotating the cap of the luer-lock hub  560 . The clamping member  564  is moveable between a first configuration and a second configuration. In the first configuration, the clamping member  564  attaches the luer-lock hub  560  to the cannula  512 . In the second configuration, the clamping member  564  is free of attachment to the cannula  512  such that the luer-lock hub  560  can be moved along the axial length of the cannula  512 . While a male luer-lock hub has been illustrated, alternative embodiments can include a female luer-lock hub. A handle, such as handle  513 , can be included on any medical device described herein. 
       FIG. 8  illustrates a sixth example medical device  610 . In this example, the medical device  610  is an anchor member  612 . The anchor member  612  has a proximal end  614 , a distal end  616 , and a main body  618  that defines a coil  620  and a distal tapered tip  622  with a cutting edge  624 . 
     In the illustrated embodiment, the coil  620  has a coil first end  626 , a coil second end  628 , and defines a plurality of coil turns that creates a conical coil. The coil has a first outside diameter  631  and a second outside diameter  633  that is less than the first outside diameter  631 . In the illustrated embodiment, the coil outside diameter tapers from the coil first end  626  to the coil second end  628 . 
       FIGS. 9, 10, 11, 12, 13, and 14  illustrate a seventh example medical device  710 . In this example, the medical device  710  includes a cannula  712  and an anchor member  713 . The cannula  712  is similar to the cannula  12  illustrated in  FIGS. 1, 2, and 3  and described above, except as detailed below. In the illustrated embodiment, the cannula  712  has a proximal end  720 , a distal end  722 , a length  723 , and a main body  724  that defines a lumen  726 , and a distal tapered tip  728  with a cutting edge  730 . The lumen  726  extends from the proximal end  720  to the distal end  722  such that one or more devices can be passed into, and through, the cannula  712 . 
     In the illustrated embodiment, the main body  724  of the cannula  712  defines a wall  736  that has inner  738  and outer  740  opposing surfaces. The main body  724  of the cannula  712  defines a first passageway  742  and a second passageway  744 . Each of the first passageway  742  and the second passageway  744  extends through the entire thickness of the wall  736 , from the inner surface  738  to the outer surface  740 , and has an oblong shape. 
     In the illustrated embodiment, the anchor member  713  is partially disposed within the lumen  726  defined by the cannula  712  and has a proximal end  750 , a distal end  752 , a length  753 , an elongate main body  754 , a first barb  756 , a second barb  758 , and a mechanical stop  760 . The length  753  of the anchor member is less than the length  723  of the cannula  712 . Each of the first barb  756  and the second barb  758  extends from the distal end  752  toward the proximal end  750  and away from the elongate main body  754 . The mechanical stop  760  is disposed on the proximal end  750  of the anchor member  713  and provides a mechanism for preventing the anchor member  713  from being advanced beyond the distal end  722  of the cannula  712 . 
     As shown in  FIGS. 9, 10, and 11 , the anchor member  713  is moveable within the cannula  712  such that it can be advanced into and withdrawn from the lumen  726  defined by the cannula  712 .  FIG. 9  shows the anchor member  713  in a first position in which the barbs  756 ,  758  are disposed within the lumen  726  defined by the cannula  712  and between the passageways  742 ,  744  and the proximal end  720  of the cannula  712 .  FIG. 10  shows the anchor member  713  in a second position in which the first barb  756  is disposed through the first passageway  742  and the second barb  758  is disposed through the second passageway  744 . When disposed within a bodily passage, the second configuration anchors the anchor member  713  within tissue such that the cannula  712  can be utilized to track additional medical devices to a point of treatment.  FIG. 11  shows the anchor member  713  in a third position in which the barbs  756 ,  758  are disposed between the passageways  742 ,  744  and the distal end  722  of the cannula  712 . In use, to move the anchor member  713  from the first position to the second position, a distally-directed force is applied to the anchor member  713  while maintaining the position of the cannula  712 . Alternatively, the position of the anchor member  713  can be maintained while applying a proximally-directed force on the cannula  712  or a distally-directed force can be applied to the anchor member  713  while applying a proximally-directed force on the cannula  712 . To move the anchor member  713  from the second position to the third position, a distally-directed force is applied to the anchor member  713  while maintaining the position of the cannula  712 . Alternatively, the position of the anchor member  713  can be maintained while applying a proximally-directed force on the cannula  712  or a distally-directed force can be applied to the anchor member  713  while applying a proximally-directed force on the cannula  712 . 
       FIGS. 15, 16, and 17  illustrate an eighth example medical device  810 . In this example, the medical device  810  includes a cannula  812  and an anchor member  813  disposed within the cannula  812 . The cannula  812  is similar to the cannula  12  illustrated in  FIGS. 1, 2, and 3  and described above, except as detailed below. In the illustrated embodiment, the cannula  812  has a proximal end  820 , a distal end  822 , and a main body  824  that defines a lumen  826 . The lumen  826  extends from the proximal end  820  to the distal end  822  such that one or more devices can be passed into, and through, the cannula  812 . 
     In the illustrated embodiment, the anchor member  813  has a proximal end  850 , a distal end  852 , an elongate main body  854 , and a distal tapered tip  856 . A distal portion  858  of the elongate main body  854  is biased to a curved configuration, as shown in  FIG. 17 , such that it defines a curve  860  when free of any structures (e.g., cannula  812 ) or any outside forces. The distal portion  858  of the elongate main body  854  has a substantially straight configuration when disposed within the lumen  826  defined by the cannula  812 . 
     As shown in  FIGS. 15, 16, and 17 , the anchor member  813  is moveable within the cannula  812  such that it can be advanced into and withdrawn from the lumen  826  defined by the cannula  812 .  FIG. 15  shows the anchor member  813  in a first position in which the distal tapered tip  856  is disposed outside of the lumen  826  defined by the cannula  812  and the distal portion  858  begins to define the curve  860  relative to the cannula  812 .  FIG. 16  shows the anchor member  813  in a second position in which the distal tapered tip  856  is disposed outside of the lumen  826  defined by the cannula  812  and the distal portion  858  defines a larger portion of the curve  860  relative to the portion of the curve  860  defined in the first position.  FIG. 17  shows the anchor member  813  in a third position in which the distal tapered tip  856  is disposed outside of the lumen  826  defined by the cannula  812  and the distal portion  858  defines the entire curve  860  outside of the lumen  826  defined by the cannula  812 . When the anchor member  813  is in the third configuration, the anchor member  813  is anchored within tissue such that the cannula  812  can be utilized to track additional medical devices to a point of treatment. In use, to move the anchor member  813  from the first position to the second position, and from the second position to the third position, a distally-directed force is applied to the anchor member  813  while maintaining the position of the cannula  812 . Alternatively, the position of the anchor member  813  can be maintained while applying a proximally-directed force on the cannula  812  or a distally-directed force can be applied to the anchor member  813  while applying a proximally-directed force on the cannula  812 . 
       FIGS. 18, 19, and 20  illustrate a ninth example medical device  910 . In this example, the medical device  910  is a cannula  912  and an anchor member  913 . The cannula  912  is similar to the cannula  12  illustrated in  FIGS. 1, 2, and 3  and described above, except as detailed below. In the illustrated embodiment, the cannula  912  has a proximal end  920 , a distal end  922 , and a main body  924  that defines a lumen  926 , and a blunted distal tip  928 . The lumen  926  extends from the proximal end  920  to the distal end  922  such that one or more devices can be passed into, and through, the cannula  912 . 
     In the illustrated embodiment, the main body  924  of the cannula  912  defines a wall  936  that has inner  938  and outer  940  opposing surfaces. The main body  924  of the cannula  912  defines a slot  942  that has a first portion  944  and a second portion  946 . The slot  942  extends through the entire thickness of the wall  936  and from the inner surface  938  to the outer surface  940 . The first portion  944  of the slot  942  extends from the distal end  922  of the cannula  912  and toward the proximal end  920  of the cannula  912 . The second portion  946  of the slot  942  extends from the first portion  944  of the slot  942  around a portion of the circumference of the wall  936  of the cannula  912  and toward the distal end  922  of the cannula  912  to a terminal end  948 . The first portion  944  and the second portion  946  of the slot  942  cooperatively define a j-shaped slot  942  that can receive a portion of the anchor member  913 , as described in more detail herein. 
     In the illustrated embodiment, the anchor member  913  has a proximal end  950 , a distal end  952 , an elongate main body  954 , and a barb  956 . The barb  956  extends from the distal end  952  toward the proximal end  950  and away from the elongate main body  954 . 
     As shown in  FIGS. 18, 19, and 20 , the anchor member  913  is moveable within the cannula  912  such that it can be advanced into and withdrawn from the lumen  926  defined by the cannula  912 .  FIG. 18  shows the anchor member  913  in a first position in which the barb  756  is disposed outside of the lumen  926  defined by the cannula  912  and distal to the distal end  922  of the cannula  912 . This configuration anchors the anchor member  913  within tissue such that the cannula  912  can be utilized to track additional medical devices to a point of treatment. Positioning the anchor member  913  in the first position can be accomplished by applying a distally-directed force on the anchor member  913  while maintaining the position of the cannula  912 . Alternatively, the position of the anchor member  913  can be maintained while applying a proximally-directed force on the cannula  912  or a distally-directed force can be applied to the anchor member  913  while applying a proximally-directed force on the cannula  912 .  FIG. 19  shows the anchor member  913  in a second position in which the barb  956  is partially disposed within the first portion  944  of the slot  942  defined by the cannula  912 . To move the anchor member  913  from the first position to the second position, a distally-directed force is applied on the cannula  913  while maintaining the position of the anchor member  913 . Optionally, depending on the orientation of the cannula  912  relative to the anchor member  913 , torque can be applied to the cannula  912  to position the slot in axial alignment with the barb  956 .  FIG. 20  shows the anchor member  913  in a third position in which the barb  956  is partially disposed within the second portion  946  of the slot  942  defined by the cannula  912 . To move the anchor member  913  from the second position to the third position, torque is applied to the cannula  913  while maintaining the position of the anchor member  913  to move the barb  956  from the first portion  944  of the slot  942  to the second portion  946  of the slot  942 . To fully advance the barb  956  into the lumen  926  defined by the cannula  912 , a proximally-directed force is applied to the cannula  912  while maintaining the position of the anchor member  913  and the barb  956  is positioned the second portion  946  of the slot  942  until the barb  956  is disposed within the lumen  926  defined by the cannula  912 . Alternatively, to fully advance the barb  956  into the lumen  926  defined by the cannula  912 , while the barb  956  is positioned the second portion  946  of the slot  942  a distally-directed force can be applied to the anchor member  913  while maintaining the position of the cannula  912  or a distally-directed force on the anchor member  913  while applying a proximally-directed force on the cannula  912  until the barb  956  is disposed within the lumen  926  defined by the cannula  912 . 
     Various methods of performing interventional medical treatment under MRI are described herein. While the methods described herein are shown and described as a series of acts, it is to be understood and appreciated that the methods are not limited by the order of acts, as some acts may in accordance with these methods may be omitted, occur in the order shown and/or described, occur in different orders, and/or occur concurrently with other acts described herein. 
       FIG. 21  illustrates a schematic illustration of an example method  1000  of performing treatment under MRI. 
     An initial step  1002  comprises positioning a patient within a magnetic resonance scanner. Another step  1004  comprises scanning a first portion of the patient using the magnetic resonance scanner. Another step  1006  comprises obtaining a magnetic resonance image of the first portion of the patient. Another step  1008  comprises identifying a tissue that has predefined characteristics using the magnetic resonance image. While the patient remains positioned within the magnetic resonance scanner used to scan a portion of the patient, another step  1010  comprises advancing a medical device into a bodily passage and to the tissue while scanning a second portion of the patient that includes the medical device using the magnetic resonance scanner. Another step  1012  comprises obtaining a magnetic resonance image of the second portion of the patient that includes the medical device. Another step  1014  comprises confirming the position of the medical device within the bodily passage. Another step  1016  comprises advancing a biopsy device through the medical device and to the tissue while scanning a third portion of the patient that includes the biopsy device using the magnetic resonance scanner. Another step  1018  comprises obtaining a magnetic resonance image of the third portion of the patient that includes the biopsy device. Another step  1020  comprises confirming the position of the biopsy device. Another step  1022  comprises collecting a tissue sample from the tissue using the biopsy device while scanning a fourth portion of the patient that includes the biopsy device and the tissue using the magnetic resonance scanner. Another step  1024  comprises obtaining a magnetic resonance image of the fourth portion of the patient that includes the biopsy device. Another step  1026  comprises confirming the tissue sample has been collected. Another step  1028  comprises withdrawing the biopsy device and the tissue sample through the medical device. Another step  1030  comprises determining whether the tissue sample meets a predefined criterion. 
     Step  1002  can be accomplished by positioning a patient within any suitable magnetic resonance scanner, such as conventional magnetic resonance scanners, magnetic resonance scanners that utilize 0.55 T fields, 1.5 T fields, 3 T fields, fields between about 0.055 T and 1.5 T, fields less than 1 T, and any other magnetic resonance scanner considered suitable for a particular embodiment. 
     Step  1004  can be accomplished by scanning any suitable portion of a patient and selection of a suitable portion of a patient to scan can be based on various considerations, including the treatment intended to be performed. Examples of portions of a patient considered suitable to scan include the extremities (e.g., arms, legs), chest, breast, spine, neck, head, abdomen, pelvis, prostate, peri-prostatic structures, tissues surrounding the portions of a patient described herein, and/or any other portion of the patient considered suitable for a particular embodiment. 
     Step  1006  can be accomplished by obtaining the magnetic resonance image from the magnetic resonance scanner used in step  1002 . 
     Step  1008  can be accomplished by reviewing the magnetic resonance image obtained in step  1006  and utilizing conventional techniques and/or methods to determine whether tissue has predefined characteristics (e.g., tissue has characteristics indicative of cancer, is a lesion, abnormal mass). Furthermore, the margins of any tissue (e.g., abnormal mass) can be identified and used in further steps, as described herein, to remove and/or treat the tissue. 
     Step  1010  can be accomplished using any suitable medical device, such as the medical devices and/or cannulas described herein, or incorporated by reference. Step  1010  can be accomplished by applying a distally-directed force on the medical device such that a distal end of the medical device is advanced into a bodily passage and to, within, or adjacent to, the tissue that has been identified as having the predefined characteristics. A bodily passage can include any suitable portion of a body, including existing bodily passages, bodily lumens, and/or bodily passages created through tissues layers and/or fascia using a device described herein. Step  1010  can be accomplished by scanning any suitable portion of a patient and selection of a suitable portion of a patient to scan can be based on various considerations, including the location of the tissue that has predefined characteristics. Examples of portions of a patient considered suitable to scan include portions that include the tissue that has predefined characteristics, portions that include the medical device, portions that include the tissue that has predefined characteristics and the medical device, and any other portion of the patient considered suitable for a particular embodiment. For example, a second portion of the patient can be the same as, or different than, the first portion of the patient. 
     Step  1012  can be accomplished by obtaining the magnetic resonance image from the magnetic resonance scanner used in step  1002 . 
     Step  1014  can be accomplished by reviewing the magnetic resonance image obtained in step  1012  and confirming the medical device is positioned at a desired location within the bodily passage (e.g., at, within, or adjacent to, the tissue that has been identified as having the predefined characteristics). This can be accomplished by visualizing one or more markers included on the medical device, as described herein. If the medical device is not positioned at a desired location, an optional step comprises manipulating the position of the medical device. 
     Step  1016  can be accomplished by applying a distally-directed force on the biopsy device such that a distal end of the biopsy device is advanced into a lumen defined by the medical device, through the lumen defined by the medical device, and to the tissue that has been identified as having the predefined characteristics. Step  1016  can be accomplished by scanning any suitable portion of a patient and selection of a suitable portion of a patient to scan can be based on various considerations, including the location of the tissue that has predefined characteristics. Examples of portions of a patient considered suitable to scan include portions that include the tissue that has predefined characteristics, portions that include the biopsy device, portions that include the tissue that has predefined characteristics and the biopsy device, and any other portion of the patient considered suitable for a particular embodiment. For example, a third portion of the patient can be the same as, or different than, the first portion of the patient and/or the second portion of the patient. 
     Step  1016 , step  1022 , and step  1028  can be accomplished using any suitable biopsy device, such as MRI compatible biopsy devices, the Echotip ProCore provided by Cook Medical, the Echotip Ultra provided by Cook Medical, and any other biopsy device considered suitable for a particular embodiment. Alternatively, step  1016 , step  1022 , and step  1028  can be completed using a biopsy device that is not MRI compatible. This alternative step can comprise advancing the biopsy device through the medical device and to the tissue without scanning a portion of the patient that includes the biopsy device using the magnetic resonance scanner. An alternative to step  1028  can comprise collecting a tissue sample using the biopsy device without scanning a portion of the patient that includes the biopsy device and the tissue using the magnetic resonance scanner. 
     Step  1018  can be accomplished by obtaining the magnetic resonance image from the magnetic resonance scanner used in step  1002 . 
     Step  1020  can be accomplished by reviewing the magnetic resonance image obtained in step  1018  and confirming the biopsy device is positioned at a desired location within the bodily passage (e.g., at, within, or adjacent to, the tissue that has been identified as having the predefined characteristics). If the biopsy device is not positioned at a desired location, an optional step comprises manipulating the position of the biopsy device. 
     Step  1022  can be accomplished using the biopsy device and conventional methods of obtaining a sample using a biopsy device. Step  1022  can be accomplished by scanning any suitable portion of a patient and selection of a suitable portion of a patient to scan can be based on various considerations, including the location of the tissue that has predefined characteristics. Examples of portions of a patient considered suitable to scan include portions that include the tissue that has predefined characteristics, portions that include the biopsy device, portions that include the tissue that has predefined characteristics and the biopsy device, and any other portion of the patient considered suitable for a particular embodiment. For example, a fourth portion of the patient can be the same as, or different than, the first portion of the patient, the second portion of the patient, and/or the third portion of the patient. 
     Step  1010 , step  1016 , and/or step  1022  can optionally be conducted in combination with performing an ultrasound on the portion of the patient that includes the medical device and/or biopsy device. In embodiments in which an ultrasound image is obtained, the magnetic resonance image obtained can be electronically fused with a real-time ultrasound image (e.g., transrectal ultrasound image of a prostate). 
     Step  1024  can be accomplished by obtaining the magnetic resonance image from the magnetic resonance scanner used in step  1002 . 
     Step  1026  can be accomplished by reviewing the magnetic resonance image obtained in step  1024  and confirming the biopsy device has collected the tissue sample (e.g., the tissue that has been identified as having the predefined characteristics). If the biopsy device has not collected the tissue sample, optional steps comprise repeating step  1016 , step  1018 , step  1020 , step  1022 , step  1024 , and/or step  1026 . 
     Step  1006 , step  1012 , step  1018 , and/or step  1024  can comprise obtaining a single still image. Alternatively, step  1004 , step  1010 , step  1016 , and/or step  1022  can be repeated any desired number of times such that step  1006 , step  1012 , step  1018 , and/or step  1024  comprises obtaining multiple magnetic resonance images of a portion that can be grouped as a cine to show motion. 
     Step  1028  can be accomplished by applying a proximally-directed force on the biopsy device such that it is withdrawn from the lumen defined by the medical device. In an alternative embodiment, step  1016 , step  1018 , step  1020 , step  1022 , step  1024 , step  1026 , and step  1028  can be omitted from method  1000 , and other methods described herein, and the medical device advanced in step  1010  can be utilized to obtain a biopsy and steps similar to those described with respect to a biopsy device can be completed utilizing the medical device. In another alternative embodiment, an anchor can be placed, as described herein, the medical device withdrawn, and the anchor used to track a biopsy device to the tissue. 
     Step  1030  can be accomplished using any technique or method considered suitable to determine whether tissue meets predefined criterion. For example, step  1030  can utilize conventional techniques and methods for determining whether a tissue sample is malignant, such as frozen section and/or other cytological methods. 
     Each of step  1006 , step  1008 , step  1010 , step  1012 , step  1014 , step  1016 , step  1018 , step  1020 , step  1022 , step  1024 , step  1026 , step  1028 , and/or step  1030  can be accomplished without removing the patient from the magnetic resonance scanner within which the patient is positioned in step  1002 . 
     Method  1000  is considered advantageous at least because each step of method  1000  can be performed during a single patient visit and using the same magnetic resonance scanner, which increases efficiency and reduces the number of patient visits and procedures performed. This results in a set of procedures in which a physician can visualize, diagnose, and treat a patient in a single patient visit. While some steps have been described as being completed while scanning a portion of the patient using a magnetic resonance scanner and other steps have not been described as being performed while scanning a portion of the patient using a magnetic resonance scanner, any step described herein can be completed while scanning a portion of a patient using the magnetic resonance scanner, and/or an ultrasound device or without scanning a portion of a patient using a magnetic resonance scanner. In embodiments in which an ultrasound image is obtained, the magnetic resonance image obtained can be electronically fused with a real-time ultrasound image (e.g., transrectal ultrasound image of a prostate). While some steps have been described as being completed while scanning a portion of the patient using a magnetic resonance scanner, this step can be broken into two separate steps such that a subsequent step of scanning a portion of a patient using the magnetic resonance scanner can be accomplished. Furthermore, any step which is completed while scanning a portion of the patient using the magnetic resonance scanner can comprise obtaining a single still image and be repeated any desired number of times to obtain multiple magnetic resonance images that can be grouped as a cine to show motion and/or any step which is completed while scanning a portion of the patient using the magnetic resonance scanner can comprise obtaining a live image, such as being completed under live real-time MRI visualization. 
       FIGS. 22A and 22B  illustrate another schematic illustration of an example method  1100  of performing treatment under MRI. 
     An initial step  1102  comprises positioning a patient within a magnetic resonance scanner. Another step  1104  comprises scanning a first portion of the patient using the magnetic resonance scanner. Another step  1106  comprises obtaining a magnetic resonance image of the first portion of the patient. Another step  1108  comprises identifying a tissue that has predefined characteristics using the magnetic resonance image. While the patient remains positioned within the magnetic resonance scanner used to scan a portion of the patient, another step  1110  comprises advancing a medical device into a bodily passage and to, within, or adjacent to, the tissue while scanning a second portion of the patient that includes the medical device using the magnetic resonance scanner. Another step  1112  comprises obtaining a magnetic resonance image of the second portion of the patient that includes the medical device. Another step  1114  comprises confirming the position of the medical device within the bodily passage. Another step  1116  comprises advancing a biopsy device through the medical device and to the tissue while scanning a third portion of the patient that includes the biopsy device using the magnetic resonance scanner. Another step  1118  comprises obtaining a magnetic resonance image of the third portion of the patient that includes the biopsy device. Another step  1120  comprises confirming the position of the biopsy device. Another step  1122  comprises collecting a tissue sample from the tissue using the biopsy device while scanning a fourth portion of the patient that includes the biopsy device and the tissue using the magnetic resonance scanner. Another step  1124  comprises obtaining a magnetic resonance image of the fourth portion of the patient that includes the biopsy device. Another step  1126  comprises confirming the tissue sample has been collected. Another step  1128  comprises withdrawing the biopsy device and the tissue sample through the medical device. Another step  1130  comprises determining whether the tissue sample meets a predefined criterion. If the tissue sample does not meet the predefined criterion, additional steps comprise  1132  withdrawing the medical device from the bodily passage and  1134  removing the patient from the magnetic resonance scanner. If the tissue sample meets the predefined criterion, another step  1136  comprises advancing an anchor member through the medical device through which the biopsy device was advanced and to the tissue while the patient remains positioned within the magnetic resonance scanner. Another step  1138  comprises securing the anchor member to the tissue to retain the position of the medical device relative to the tissue. Another step  1140  comprises advancing a first inner sheath over the medical device and toward the tissue to dilate the bodily passage. Another step  1142  comprises advancing a second inner sheath over the first inner sheath and toward the tissue to dilate the bodily passage. Another step  1144  comprises advancing an outer sheath over the second inner sheath and toward the tissue to dilate the bodily passage. Another step  1146  comprises removing the anchor member from the tissue. Another step  1148  comprises withdrawing the anchor member from the bodily passage. Another step  1150  comprises withdrawing the medical device from the bodily passage. Another step  1152  comprises withdrawing the first inner sheath from the bodily passage. Another step  1154  comprises withdrawing the second inner sheath from the bodily passage. Another step  1156  comprises advancing a treatment device through the outer sheath and to the tissue. Another step  1158  comprises manipulating the tissue using the treatment device. Another step  1160  comprises withdrawing the treatment device from the outer sheath. Another step  1162  comprises withdrawing the outer sheath from the bodily passage. 
     Step  1102  can be completed as described herein with respect to step  1002 . Step  1104  can be completed as described herein with respect to step  1004 . Step  1106  can be completed as described herein with respect to step  1006 . Step  1108  can be completed as described herein with respect to step  1008 . Step  1110  can be completed as described herein with respect to step  1010 . Step  1112  can be completed as described herein with respect to step  1012 . Step  1114  can be completed as described herein with respect to step  1014 . Step  1116  can be completed as described herein with respect to step  1016 . Step  1118  can be completed as described herein with respect to step  1018 . Step  1120  can be completed as described herein with respect to step  1020 . Step  1122  can be completed as described herein with respect to step  1022 . Step  1124  can be completed as described herein with respect to step  1024 . Step  1126  can be completed as described herein with respect to step  1026 . Step  1128  can be completed as described herein with respect to step  1028 . Step  1130  can be completed as described herein with respect to step  1030 . 
     Step  1132  can be accomplished by applying a proximally-directed force on the medical device until it is withdrawn from the bodily passage. Step  1134  can be accomplished by withdrawing the patient from the magnetic resonance scanner such that the patient is free of the magnetic resonance scanner. 
     Step  1136  can be accomplished using any suitable anchor member, such as the anchor members described herein. Step  1136  can be accomplished by applying a distally-directed force on the anchor member such that a distal end of the anchor member is advanced into a lumen defined by the medical device, through the lumen defined by the medical device, and to the tissue, within the tissue, or adjacent to the tissue. Optionally, step  1136  can be completed while scanning a fifth portion of the patient that includes the anchor member using the magnetic resonance scanner and additional steps that can be completed subsequent to this optional step include obtaining a magnetic resonance image of the fifth portion of the patient that includes the anchor member, and confirming the position of the anchor member. In embodiments in which it is desired to utilize the magnetic resonance scanner on a second patient that is different from the patient, optional steps that can be completed subsequent to step  1128  include removing the patient from the magnetic resonance scanner while maintaining the position of the patient on a surface, positioning a second patient within the magnetic resonance scanner, scanning a portion of the second patient using the magnetic resonance scanner, obtaining a magnetic resonance image of the portion of the second patient, removing the second patient from the magnetic resonance scanner, and repositioning the patient within the magnetic resonance scanner. 
     Completion of step  1138  of securing the anchor member into the tissue will depend on the structural configuration of the anchor member. Examples of suitable actions that can be performed for this step include, but are not limited to, axially advancing the anchoring member through a lumen defined by a medical device until a portion of the anchor member (e.g., barb) becomes disposed within the tissue, or applying torque on the anchoring member until a portion of the anchor member becomes disposed within the tissue. Alternatively, step  1138  can comprise anchoring the anchor member into a second, different tissue disposed within or adjacent to the tissue. Step  1138  allows for the medical device to be utilized as a guide rail to a target site such that one or more other devices can be advanced over the medical device to a treatment site. Optionally, step  1138  can be completed while scanning a sixth portion of the patient that includes the anchor member using the magnetic resonance scanner and additional steps that can be completed subsequent to this optional step include obtaining a magnetic resonance image of the sixth portion of the patient that includes the anchor member, and confirming the position of the anchor member. Step  1138  allows for site retention such that the medical device and/or anchor member stays positioned relative to the tissue after biopsy and prior to treatment and can be used to direct a treatment device to the tissue, as described in more detail herein. 
     Step  1140  can be accomplished by applying a distally-directed force on the first inner sheath such that a distal end of the first inner sheath is advanced over the medical device and to the tissue. Optionally, step  1140  can be completed while scanning a seventh portion of the patient that includes the first inner sheath using the magnetic resonance scanner and additional steps that can be completed subsequent to this optional step include obtaining a magnetic resonance image of the seventh portion of the patient that includes the first inner sheath, and confirming the position of the first inner sheath. 
     Step  1142  can be accomplished by applying a distally-directed force on the second inner sheath such that a distal end of the second inner sheath is advanced over the first inner sheath and to the tissue. Optionally, step  1142  can be completed while scanning an eighth portion of the patient that includes the second inner sheath using the magnetic resonance scanner and additional steps that can be completed subsequent to this optional step include obtaining a magnetic resonance image of the eighth portion of the patient that includes the second inner sheath, and confirming the position of the second inner sheath. 
     Step  1144  can be accomplished by applying a distally-directed force on the outer sheath such that a distal end of the outer sheath is advanced over the second inner sheath and to the tissue. Optionally, step  1144  can be completed while scanning a ninth portion of the patient that includes the outer sheath using the magnetic resonance scanner and additional steps that can be completed subsequent to this optional step include obtaining a magnetic resonance image of the ninth portion of the patient that includes the outer sheath, and confirming the position of the outer sheath. 
     Completion of step  1140 , step  1142 , and  1144  results in sequential dilation of the bodily passage under MRI. While only first and second inner sheaths and a single outer sheath has been described as accomplishing sequential dilation, any suitable number of inner sheaths and/or outer sheaths can be used to complete sequential dilation of a bodily passage. Examples of numbers of inner sheaths and/or outer sheaths considered suitable to accomplish sequential dilation includes one, two, a plurality, three, four, and any other number considered suitable for a particular embodiment. In embodiment in which sequential dilation is not desired, step  1140  can alternatively comprise advancing a dilator over the medical device and toward the tissue to dilate the bodily passage and step  1142  and step  1144  can be omitted from method  1100 . In this alternative step, step  1140  can be accomplished using any suitable dilator, such as conventional dilators, and/or the dilators described herein. 
     Completion of step  1146  of removing the anchor member from the tissue will depend on the structural configuration of the anchor member. Examples of suitable actions that can be performed for this step include, but are not limited to, applying a proximally-directed force on the anchor member such that it is withdrawn through the lumen defined by a medical device until a portion of the anchor member (e.g., barb) becomes free of the tissue (e.g., in embodiments in which anchor member  813  is being utilized), applying torque to the anchoring member until the portion of the anchor member disposed within the tissue becomes free of the tissue (e.g., in embodiments in which anchor member  612  is being utilized), or applying a distally-directed force on the anchor member such that it is advanced within the lumen defined by a medical device until a portion of the anchor member (e.g., barb) becomes free of the tissue (e.g., in embodiments in which anchor member  713  is being utilized). Any of the steps described herein relative to a particular anchor member can be used to introduce and/or withdraw an anchor member from the tissue. Alternatively, step  1146  can comprise removing the anchor member from a tissue disposed within or adjacent to the tissue. Optionally, step  1146  can be completed while scanning a tenth portion of the patient that includes the anchor member using the magnetic resonance scanner and additional steps that can be completed subsequent to this optional step include obtaining a magnetic resonance image of the tenth portion of the patient that includes the anchor member, and confirming the position of the anchor member. 
     Step  1148  can be accomplished by applying a proximally-directed force on the anchor member such that it is withdrawn from the lumen defined by the medical device. In an alternative embodiment, a medical device, such as medical device  500 , can be advanced through the lumen defined by the dilator (e.g., outer sheath), over the anchor member, and to the tissue such that step  1148  can be completed by applying a proximally-directed force on the anchor member such that it is withdrawn from the lumen defined by the dilator (e.g., outer sheath). In an alternative embodiment, step  1136 , step  1138 , step  1146 , and step  1148  can be omitted from method  1100  and similar steps can be omitted from other methods described herein. 
     Step  1150  can be accomplished by applying a proximally-directed force on the medical device until it is withdrawn from the bodily passage. 
     In an alternative embodiment, step  1140  can comprise withdrawing the medical device from the bodily passage, step  1142  can comprise advancing a dilator over the anchor member and toward the tissue to dilate the bodily passage, step  1144  can comprise removing the anchor member from the tissue, and step  1146  can comprise withdrawing the anchor member from the bodily passage. In this alternative embodiment, dilation is accomplished over the anchor member. Sequential dilation can also be accomplished over the anchor member and be completed as described herein utilizing original step  1140 , step  1142 , and step  1144 . 
     Step  1152  can be accomplished by applying a proximally-directed force on the first inner sheath until it is withdrawn from the bodily passage. 
     Step  1154  can be accomplished by applying a proximally-directed force on the second inner sheath until it is withdrawn from the bodily passage. 
     Step  1156  can be accomplished by applying a distally-directed force on the treatment device such that a distal end of the treatment device is advanced into a lumen defined by the outer sheath, or dilator, through the lumen defined by the outer sheath, or dilator, and to the tissue. Any suitable treatment device can be utilized in method  1100  and selection of a suitable treatment device can be based on various considerations, such as the intended use of the treatment device. Examples of treatment devices considered suitable to treat tissue for which a tissue sample meets a predefined criterion include dissection tools, optical fibers, optical fibers formed of a material selected from the group consisting of argon, dye, erbium, excimer, Nd:YAG, and CO 2 , optical fibers that include control cables (e.g., ultra-high molecular weight polyethylene, Dyneema) to direct the fibers toward tissue intended to be treated, needles, cannulas, such as those described herein or incorporated by reference, and any other treatment device considered suitable for a particular embodiment.  FIG. 23  illustrates a tenth example medical device  1139 . In the illustrated embodiment, the medical device comprises an optical fiber  1141  that can be utilized to treat tissue disposed within a cannula  1143 . The cannula  1143  has a beveled end  1145  that is curved allowing the optical fiber  1141  to exit the cannula  1143  at a 90 degree angle relative to a lengthwise axis of the cannula  1143 . Torque can be applied to the optical fiber  1141  and/or cannula  1143  to treat tissue various portions of the tissue. The optical fiber  1141  illustrated in  FIG. 23  is configured to transmit a wide range of frequencies or laser light. Optionally, step  1156  can be completed while scanning an eleventh portion of the patient that includes the treatment device using the magnetic resonance scanner and additional steps that can be completed subsequent to this optional step include obtaining a magnetic resonance image of the eleventh portion of the patient that includes the treatment device, and confirming the position of the treatment device. 
     Step  1158  can be accomplished by physically manipulating the tissue using the treatment device, which can include removing of all or a portion of the tissue, introducing a material into the tissue, applying a treatment to the tissue, and performing any other suitable treatment on the tissue. Examples of treatments considered suitable include laser direct therapy, photodynamic therapy (PDT), chemotherapy, a focal treatment, a radical prostatectomy, infusion of ablative agents, such as acetic acid, ethanol, sclerosants (e.g., sodium tetradecyl sulfate), chemotherapeutic agents, and any other treatment considered suitable for a particular embodiment. Optionally, step  1158  can be completed while scanning a twelfth portion of the patient that includes the treatment device using the magnetic resonance scanner and additional steps that can be completed subsequent to this optional step include obtaining a magnetic resonance image of the twelfth portion of the patient that includes the treatment device, and confirming the position of the treatment device. For example, a magnetic resonance scanner can be utilized to determine areas of tissue that become devitalized during ablative therapies. In embodiments in which one of the cannulas illustrated in  FIGS. 1, 4, 5, and 6 , or a cannula that includes one or more features of these cannulas, is utilized, treatment can include passing a therapeutic agent (e.g., ablative agent, photosensitizers, and/or nanoparticles) through the lumen defined by the cannula. The first portion and/or the plug(s) included in the cannula provide a mechanism for visualizing the position of these features using a magnetic resonance image such that any infusate can be properly placed within, or adjacent to, the tissue. In addition, this approach improves distribution of any therapeutic agent introduced through the cannula and to a point of treatment. 
     Step  1160  can be accomplished by applying a proximally-directed force on the treatment device until it is withdrawn from the lumen defined by the outer sheath, or dilator. 
     Step  1162  can be accomplished by applying a proximally-directed force on the outer sheath, or dilator, until it is withdrawn from the bodily passage. 
     Method  1100  is considered advantageous at least because each step of method  1100  can be performed during a single patient visit and using the same magnetic resonance scanner, which increases efficiency and reduces the number of patient visits and procedures performed. This results in a set of procedures in which a physician can visualize, diagnose, and treat a patient in a single patient visit. While some steps have been described as being completed while scanning a portion of the patient using a magnetic resonance scanner and other steps have not been described as being performed while scanning a portion of the patient using a magnetic resonance scanner, any step described herein can be completed while scanning a portion of a patient using the magnetic resonance scanner and/or an ultrasound device or without scanning a portion of a patient using a magnetic resonance scanner. In embodiments in which an ultrasound image is obtained, the magnetic resonance image obtained can be electronically fused with a real-time ultrasound image (e.g., transrectal ultrasound image of a prostate). Furthermore, any step which is completed while scanning a portion of the patient using the magnetic resonance scanner can comprise obtaining a single still image and be repeated any desired number of times to obtain multiple magnetic resonance images that can be grouped as a cine to show motion and/or any step which is completed while scanning a portion of the patient using the magnetic resonance scanner can comprise obtaining a live image, such as being completed under live real-time MRI visualization. 
       FIGS. 24A and 24B  illustrate another schematic illustration of an example method  1200  of performing treatment on a prostate under MRI. 
     An initial step  1202  comprises positioning a patient within a magnetic resonance scanner. Another step  1204  comprises scanning a prostate and surrounding tissue of the patient using the magnetic resonance scanner. Another step  1206  comprises obtaining a magnetic resonance image of the prostate and surrounding tissue of the patient. Another step  1208  comprises identifying a tissue within the magnetic resonance image that has predefined characteristics. While the patient remains positioned within the magnetic resonance scanner used to scan the prostate and surrounding tissue, another step  1210  comprises advancing a medical device into a bodily passage and to the tissue while scanning a first portion of the patient that includes the medical device using the magnetic resonance scanner. Another step  1212  comprises obtaining a magnetic resonance image of the second portion of the patient that includes the medical device. Another step  1214  comprises confirming the position of the medical device within the bodily passage. Another step  1216  comprises advancing a biopsy device through the medical device and to the tissue while scanning a third portion of the patient that includes the biopsy device using the magnetic resonance scanner. Another step  1218  comprises obtaining a magnetic resonance image of the third portion of the patient that includes the biopsy device. Another step  1220  comprises confirming the position of the biopsy device. Another step  1222  comprises collecting a tissue sample from the tissue using the biopsy device while scanning a fourth portion of the patient that includes the biopsy device and the tissue using the magnetic resonance scanner. Another step  1224  comprises obtaining a magnetic resonance image of the fourth portion of the patient that includes the biopsy device. Another step  1226  comprises confirming the tissue sample has been collected. Another step  1228  comprises withdrawing the biopsy device and the tissue sample through the medical device. Another step  1230  comprises determining whether the tissue sample meets a predefined criterion. If the tissue sample does not meet the predefined criterion, additional steps comprise  1232  withdrawing the medical device from the bodily passage and  1234  removing the patient from the magnetic resonance scanner. If the tissue sample meets the predefined criterion, another step  1236  comprises advancing an anchor member through the medical device through which the biopsy device was advanced and to the tissue while the patient remains positioned within the magnetic resonance scanner. Another step  1238  comprises securing the anchor member to the tissue to retain the position of the medical device relative to the tissue. Another step  1240  comprises advancing a first inner sheath over the medical device and toward the tissue to dilate the bodily passage. Another step  1242  comprises advancing a second inner sheath over the first inner sheath and toward the tissue to dilate the bodily passage. Another step  1244  comprises advancing an outer sheath over the second inner sheath and toward the tissue to dilate the bodily passage. Another step  1246  comprises removing the anchor member from the tissue. Another step  1248  comprises withdrawing the anchor member from the bodily passage. Another step  1250  comprises withdrawing the medical device from the bodily passage. Another step  1252  comprises withdrawing the first inner sheath from the bodily passage. Another step  1254  comprises withdrawing the second inner sheath from the bodily passage. Another step  1256  comprises advancing a treatment device through the outer sheath and to the tissue. Another step  1260  comprises manipulating the tissue using the treatment device. Another step  1262  comprises withdrawing the treatment device from the outer sheath. Another step  1264  comprises withdrawing the outer sheath from the bodily passage. 
       FIG. 25  illustrates an exemplary kit  1300  comprising a first medical device  1302  according to an embodiment, such as medical device  10  illustrated in  FIG. 1 ; a first inner sheath  1304  according to an embodiment, such as first inner sheath  14  illustrated in  FIG. 2 ; a second inner sheath  1306  according to an embodiment, such as second inner sheath  16  illustrated in  FIG. 2 ; an outer sheath  1308  according to an embodiment, such as outer sheath  18  illustrated in  FIG. 2 ; a second medical device  1310  according to an embodiment, such as medical device  110  illustrated in  FIG. 4 ; a third medical device  1312  according to an embodiment, such as medical device  210  illustrated in  FIG. 5 ; a fourth medical device  1314  according to an embodiment, such as medical device  310  illustrated in  FIG. 6 ; a fifth medical device  1316  according to an embodiment, such as medical device  510  illustrated in  FIG. 7 ; a sixth medical device  1318  according to an embodiment, such as medical device  610  illustrated in  FIG. 8 ; a seventh medical device  1320  according to an embodiment, such as medical device  710  illustrated in  FIGS. 9, 10, 11, 12, 13, and 14 ; an eighth medical device  1322  according to an embodiment, such as medical device  810  illustrated in  FIGS. 15, 16, and 17 ; a ninth medical device  1324  according to an embodiment, such as medical device  910  illustrated in  FIGS. 18, 19, and 20 ; a tenth medical device  1326  according to an embodiment, such as medical device  1139  illustrated in  FIG. 23 ; and instructions for use  1328 . 
     While kit  1300  has been illustrated as including ten medical devices  1302 ,  1310 ,  1312 ,  1314 ,  1316 ,  1318 ,  1320 ,  1322 ,  1324 ,  1326 , two inner sheaths  1304 ,  1306 , and an outer sheath  1308 , any suitable number, and type, of medical devices, inner sheaths, and/or outer sheaths can be included in a kit. Selection of a suitable number of medical devices, inner sheaths, and/or outer sheaths to include in a kit according to a particular embodiment can be based on various considerations, such as the treatment intended to be performed. Examples of numbers of medical devices, inner sheaths, and/or outer sheaths considered suitable to include in a kit include at least one, one, two, a plurality, three, four, five, six, seven, eight, nine, ten, more than ten, and any other number considered suitable for a particular embodiment. 
     Furthermore, while medical device  10 , first inner sheath  14 , second inner sheath  16 , outer sheath  18 , medical device  110 , medical device  210 , medical device  310 , medical device  510 , medical device  610 , medical device  710 , medical device  810 , medical device  910 , and medical device  1139  have been illustrated as included in kit  1300 , any suitable medical device, inner sheath, and/or outer sheath can be included in a kit. Selection of a suitable medical device, inner sheath, and/or outer sheath to include in a kit according to a particular embodiment can be based on various considerations, such as the treatment intended to be performed. Examples of medical devices, inner sheaths, and outer sheaths considered suitable to include in a kit include medical device  10 , first inner sheath  14 , second inner sheath  16 , outer sheath  18 , medical device  110 , medical device  210 , medical device  310 , medical device  510 , medical device  610 , medical device  710 , medical device  810 , medical device  910 , and medical device  1139 , and/or any other medical device, inner sheath, and/or outer sheath considered suitable for a particular embodiment. 
       FIGS. 26A and 26B  illustrate another schematic illustration of an example method  1400  of performing treatment under MRI. 
     An initial step  1402  comprises positioning a patient within a magnetic resonance scanner. Another step  1404  comprises scanning a first portion of the patient using the magnetic resonance scanner. Another step  1406  comprises obtaining a magnetic resonance image of the first portion of the patient. Another step  1408  comprises identifying a tissue that has predefined characteristics using the magnetic resonance image. While the patient remains positioned within the magnetic resonance scanner used to scan a portion of the patient, another step  1410  comprises advancing a medical device into a bodily passage and to, within, or adjacent to, the tissue while scanning a second portion of the patient that includes the medical device using the magnetic resonance scanner. Another step  1412  comprises obtaining a magnetic resonance image of the second portion of the patient that includes the medical device. Another step  1414  comprises confirming the position of the medical device within the bodily passage. Another step  1416  comprises advancing an anchor member through the medical device and to the tissue while the patient remains positioned within the magnetic resonance scanner. Another step  1418  comprises securing the anchor member to the tissue to retain the position of the anchor member relative to the tissue. Another step  1420  comprises withdrawing the medical device from the bodily passage. Another step  1422  comprises advancing a first inner sheath over the anchor member and toward the tissue to dilate the bodily passage. Another step  1424  comprises advancing a second inner sheath over the first inner sheath and toward the tissue to dilate the bodily passage. Another step  1426  comprises advancing an outer sheath over the second inner sheath and toward the tissue to dilate the bodily passage. Another step  1428  comprises withdrawing the first inner sheath from the bodily passage. Another step  1430  comprises withdrawing the second inner sheath from the bodily passage. Another step  1432  comprises removing the anchor member from the tissue. Another step  1434  comprises withdrawing the anchor member from the bodily passage. Another step  1436  comprises advancing a biopsy device through the outer sheath and to the tissue while scanning a third portion of the patient that includes the biopsy device using the magnetic resonance scanner. Another step  1438  comprises obtaining a magnetic resonance image of the third portion of the patient that includes the biopsy device. Another step  1440  comprises confirming the position of the biopsy device. Another step  1442  comprises collecting a tissue sample from the tissue using the biopsy device while scanning a fourth portion of the patient that includes the biopsy device and the tissue using the magnetic resonance scanner. Another step  1444  comprises obtaining a magnetic resonance image of the fourth portion of the patient that includes the biopsy device. Another step  1446  comprises confirming the tissue sample has been collected. Another step  1448  comprises withdrawing the biopsy device and the tissue sample through the outer sheath. Another step  1450  comprises determining whether the tissue sample meets a predefined criterion. If the tissue sample does not meet the predefined criterion, additional steps comprise  1452  withdrawing the outer sheath from the bodily passage and  1454  removing the patient from the magnetic resonance scanner. If the tissue sample meets the predefined criterion, another step  1456  comprises advancing a treatment device through the outer sheath and to the tissue. Another step  1458  comprises manipulating the tissue using the treatment device. Another step  1460  comprises withdrawing the treatment device from the outer sheath. Another step  1462  comprises withdrawing the outer sheath from the bodily passage. Another step  1464  comprises removing the patient from the magnetic resonance scanner. 
     While a number of methods have been described herein, it will be appreciated that the method may be a non-invasive method that does not require an invasive intervention by a medical professional. For example, a method may be carried out within a body lumen or passageway, such as the ear canal or a nasal passage, for example in order to place a device within such a passageway. Equally, methods may be implemented on a cadaver or artificial body parts for example for training purposes. Moreover, the skilled person will appreciate that the methods described herein may not be used on the human or animal body at all, but may be used in order to view other types of devices using MRI imaging techniques, for example in an industrial setting. 
     Those with ordinary skill in the art will appreciate that various modifications and alternatives for the described and illustrated examples can be developed in light of the overall teachings of the disclosure, and that the various elements and features of one example described and illustrated herein can be combined with various elements and features of another example without departing from the scope of the invention. Accordingly, the particular arrangement of elements and steps disclosed herein have been selected by the inventor(s) simply to describe and illustrate examples of the invention and are not intended to limit the scope of the invention or its protection, which is to be given the full breadth of the appended claims and any and all equivalents thereof.