Patent Description:
The present disclosure is related to medical imaging, such as magnetic resonance imaging (MRI) techniques, for example, and/or various medical interventions, such as biopsy procedures, for example.

MRI or other imaging modalities often use fiducials to demark the location of a patient's anatomy and/or location of an interventional device. However, these devices are often standalone and not incorporated into the magnetic resonance (MR) receive coil (RX coil). In addition, these devices typically are designed for the guidance of particular body parts. For example, current guide systems include stereotactic frames used for cranial interventions.

<CIT> describes a patient supporting apparatus having a tabletop and stretcher system for use in medical imaging technologies. The tabletop has a gap or narrowing of prescribed location and size, for example, more than thirty percent of the width of the tabletop is removed inferior to the patient's pelvis within a region of at least <NUM> meters in length. The stretcher supports the tabletop and includes a gap or narrowing so that the access of the operator's hand, arm, and line of sight is not obstructed from the gap or narrowing of the tabletop.

A paper by <NPL>, reports a remotely actuated manipulator for transrectal prostate imaging and intervention, designed for use in a standard cylindrical, high-field magnetic resonance imaging (MRI) scanner. The device provides three-dimensional MRI guided needle placement with millimeter accuracy under physician control.

A paper by <NPL>, discusses the development of powerful magnetic resonance imaging techniques allowing for advanced possibilities to guide and control minimally invasive interventions.

A paper by <NPL>, describes a registration technique for registration of tracked medical devices to pre-procedural MR images based on magnetic resonance (MR) active microcoils (active markers).

A paper by <NPL> describes the design of small receiver coils and fiducials.

A paper by <NPL>, describes the use of an office-based low-field MR system to acquire images of prostate phantoms with needles inserted through a transperineal template. Coordinates of the estimated sample core locations in the office-based MR system were compared to ground truth needle coordinates identified in a <NUM> T external reference scan. The error was measured as the distance between the planned target and the ground truth core center and as the shortest perpendicular distance between the planned target and the ground truth trajectory of the whole core.

A paper by <NPL>) presents the development, preclinical evaluation, and preliminary clinical study of a robotic system for targeted transperineal prostate biopsy under direct interventional magnetic resonance imaging (MRI) guidance. The clinically integrated robotic system is developed based on a modular design approach, comprised of surgical navigation application, robot control software, MRI robot controller hardware, and robotic needle placement manipulator.

In one general aspect, the present disclosure provides a stereotactic perineum positioning device for magnetic resonance (MR) imaging. The stereotactic perineum positioning device comprises a frame, a patient receive coil rigidly mounted to the frame, and a fiducial array rigidly mounted to the frame. The fiducial array comprises three distinct MR-visible fiducials and a fiducial receive coil wrapped around the three distinct MR-visible fiducials.

In another aspect, the present disclosure provides a method, comprising acquiring, by a processor, a T2 scan acquired by an magnetic resonance imaging (MRI) system, wherein the T2 scan comprises a positioning device and MR-visible fiducials. The method further comprises localizing, by the processor, the MR-visible fiducials in the T2 scan, acquiring, by the processor, a third party MR image, and co-registering the MR-visible fiducials in the T2 scan with the third party MR image.

The novel features of the various aspects are set forth with particularity in the appended claims. The described aspects, however, both as to organization and methods of operation, may be best understood by reference to the following description, taken in conjunction with the accompanying drawings.

The exemplifications set out herein illustrate certain aspects of the invention, in one form, and such exemplifications are not to be construed as limiting the scope of the invention in any manner.

Reference is made to the following international patent applications:.

Before explaining various aspects of an magnetic resonance imaging (MRI) component, system, and method in detail, it should be noted that the illustrative examples are not limited in application or use to the details of construction and arrangement of parts illustrated in the accompanying drawings and description. The illustrative examples may be implemented or incorporated in other aspects, variations, and modifications, and may be practiced or carried out in various ways. Further, unless otherwise indicated, the terms and expressions employed herein have been chosen for the purpose of describing the illustrative examples for the convenience of the reader and are not for the purpose of limitation thereof. Also, it will be appreciated that one or more of the following-described aspects, expressions of aspects, and/or examples, can be combined with any one or more of the other following-described aspects, expressions of aspects, and/or examples.

In accordance with various aspects, an MRI system is provided that can include a unique imaging region that can be offset from the face of a magnet. Such offset and single-sided MRI systems are less restrictive as compared to traditional MRI scanners. In addition, this form factor can have a built-in or inherent magnetic field gradient that creates a range of magnetic field values over the region of interest. In other words, the inherent magnetic field can be inhomogeneous. The inhomogeneity of the magnetic field strength in the region of interest for the single-sided MRI system can be more than <NUM> parts per million (ppm). For example, the inhomogeneity of the magnetic field strength in the region of interest for the single-sided MRI system can between <NUM> ppm and <NUM>,<NUM> ppm. In various aspects of the present disclosure, the inhomogeneity in the region of interest can be greater than <NUM>,<NUM> ppm and can be greater than <NUM>,<NUM> ppm. In one instance, the inhomogeneity in the region of interest can be <NUM>,<NUM> ppm.

The inherent magnetic field gradient can be generated by a permanent magnet within the MRI scanner. The magnetic field strength in the region of interest for the single-sided MRI system can be less than <NUM> Tesla (T), for example. For example, the magnetic field strength in the region of interest for the single-sided MRI system can be less than <NUM> T. In other instances, the magnetic field strength can be greater than <NUM> T and may be <NUM> T, for example. This system can operate at a lower magnetic field strength as compared to typical MRI systems allowing for a relaxation on the RX coil design constraints and/or allowing for additional mechanisms, like robotics, for example, to be used with the MRI scanner. Exemplary MRI-guided robotic systems are further described in International Application No. <CIT>, for example.

<FIG> depict an MRI scanner <NUM> and components thereof. As shown in <FIG>, the MRI scanner <NUM> includes a housing <NUM> having a face or front surface <NUM>, which is concave and recessed. In other aspects, the face of the housing <NUM> can be flat and planar. The front surface <NUM> can face the object being imaged by the MRI scanner. As shown in <FIG>, the housing <NUM> includes a permanent magnet assembly <NUM>, an RF transmission coil (TX) <NUM>, a gradient coil set <NUM>, an electromagnet <NUM>, and a RF reception coil (RX) <NUM>. In other instances, the housing <NUM> may not include the electromagnet <NUM>. Moreover, in certain instances, the RF reception coil <NUM> and the RF transmission coil <NUM> can be incorporated into a combined Tx/Rx coil array.

Referring primarily to <FIG>, the permanent magnet assembly <NUM> includes an array of magnets. The array of magnets forming the permanent magnet assembly <NUM> are configured to cover the front surface <NUM>, or patient-facing surface, of the MRI scanner <NUM> (see <FIG>) and are shown as horizontal bars in <FIG>. The permanent magnet assembly <NUM> includes a plurality of cylindrical permanent magnets in a parallel configuration. Referring primarily to <FIG>, the permanent magnet assembly <NUM> comprises parallel plates <NUM> that are held together by brackets <NUM>. The system can be attached to the housing <NUM> of the MRI scanner <NUM> at a bracket <NUM>. There can be a plurality of holes <NUM> in the parallel plates <NUM>. The permanent magnet assembly <NUM> can include any suitable magnetic materials, including but not limited to rare-earth based magnetic materials, such as for example, Neodymium-based magnetic materials, for example.

The permanent magnet assembly <NUM> defines an access aperture or bore <NUM>, which can provide access to the patient through the housing <NUM> from the opposite side of the housing <NUM>. In other aspects of the present disclosure, the array of permanent magnets forming a permanent magnet assembly in the housing <NUM> may be bore-less and define an uninterrupted or contiguous arrangement of permanent magnets without a bore defined therethrough. In still other instances, the array of permanent magnets in the housing <NUM> may form more than one bore/access aperture therethrough.

In accordance with various aspects of the present disclosure, the permanent magnet assembly <NUM> provides a magnetic field B0 in a region of interest <NUM> that is along the Z axis, shown in <FIG>. The Z axis is perpendicular to the permanent magnet assembly <NUM>. Stated differently, the Z axis extends from a center of the permanent magnet assembly <NUM> and defines a direction of the magnetic field B0 away from the face of the permanent magnet assembly <NUM>. The Z axis can define the primary magnetic field B0 direction. The primary magnetic field B0 can decrease along the Z axis, i.e. an inherent gradient, farther from the face of the permanent magnet assembly <NUM> and in the direction indicated with the arrow in <FIG>.

In one aspect, the inhomogeneity of the magnetic field in the region of interest <NUM> for the permanent magnet assembly <NUM> can be approximately <NUM>,<NUM> ppm. In another aspect, the inhomogeneity of the magnetic field strength in the region of interest <NUM> for the permanent magnet assembly <NUM> can be between <NUM> ppm to <NUM>,<NUM> ppm and can be greater than <NUM>,<NUM> ppm in certain instances, and greater than <NUM>,<NUM> ppm in various instances.

In one aspect, the magnetic field strength of the permanent magnet assembly <NUM> can be less than <NUM> T. In another aspect, the magnetic field strength of the permanent magnet assembly <NUM> can be less than <NUM> T. In other instances, the magnetic field strength of the permanent magnet assembly <NUM> can be greater than <NUM> T and may be <NUM> T, for example. Referring primarily to <FIG>. , the Y axis extends up and down from the Z axis and the X axis extends to the left and right from the Z axis. The X axis, the Y axis, and the Z axis are all orthogonal to one another and the positive direction of each axis is indicated by the corresponding arrow in <FIG>.

The RF transmission coils <NUM> are configured to transmit RF waveforms and associated electromagnetic fields. The RF pulses from the RF transmission coils <NUM> are configured to rotate the magnetization produced by the permanent magnet <NUM> by generating an effective magnetic field, referred to as B1, that is orthogonal to the direction of the permanent magnetic field (e.g. an orthogonal plane).

Referring primarily to <FIG>, the gradient coil set <NUM> includes two sets of gradient coils <NUM>, <NUM>. The sets of gradient coils <NUM>, <NUM> are positioned on the face or front surface <NUM> of the permanent magnet assembly <NUM> intermediate the permanent magnet assembly <NUM> and the region of interest <NUM>. Each set of gradient coils <NUM>, <NUM> includes a coil portion on opposing sides of the bore <NUM>. Referring to the axes in <FIG>, the gradient coil set <NUM> may be the gradient coil set corresponding to the X axis, for example, and the gradient coil set <NUM> may be the gradient coil set corresponding to the Y axis, for example. The gradient coils <NUM>, <NUM> enable encoding along the X axis and Y axis, as further described herein.

In accordance with various aspects, using the MRI scanner <NUM> illustrated in <FIG>, a patient can be positioned in any number of different positions depending on the type of anatomical scan. <FIG> shows an example where the pelvis is scanned with the MRI scanner <NUM>. To perform the scan, a patient <NUM> can be laid on a surface in a lithotomy position. As illustrated in <FIG>, for the pelvic scan, the patient <NUM> can be positioned to have their back resting on a table and legs raised up to be resting against the top of the scanner <NUM>. The pelvic region can be positioned directly in front of the permanent magnet assembly <NUM> and the bore <NUM> and the region of interest <NUM> is in the pelvic region of the patient <NUM>.

Referring now to <FIG>, a control schematic for a single-sided MRI system <NUM> is shown. The single-sided MRI scanner <NUM> and/or components thereof (<FIG>) can be incorporated into the MRI system <NUM> in various aspects of the present disclosure. For example, the imaging system <NUM> includes a permanent magnet assembly <NUM>, which can be similar to the permanent magnet assembly <NUM> (see <FIG>) in various instances. The imaging system <NUM> also includes RF transmission coils <NUM>, which can be similar to the RF transmission coil <NUM> (see <FIG>), for example. Moreover, the imaging system <NUM> includes RF reception coils <NUM>, which can be similar to the RF reception coils <NUM> (see <FIG>), for example. In various aspects, the RF transmission coils <NUM> and/or the RF reception coils can also be positioned in the housing of an MRI scanner and, in certain instances, the RF transmission coils <NUM> and the RF reception coils <NUM> can be combined into integrated Tx/Rx coils. The system <NUM> also includes gradient coils <NUM>, which are configured to generate gradient fields to facilitate imaging of the object in the field of view <NUM>.

The single-sided MRI system <NUM> also includes a computer <NUM>, which is in signal communication with a spectrometer <NUM>, and is configured to send and receive signals between the computer <NUM> and the spectrometer <NUM>.

The main magnetic field B0 generated by the permanent magnet <NUM> extends away from the permanent magnet <NUM> and away from the RF transmission coils <NUM> into the field of view <NUM>. The field of view <NUM> contains an object that is being imaged by the MRI system <NUM>.

During the imaging process, the main magnetic field B0 extends into the field of view <NUM>. The direction of the effective magnetic field B1 changes in response to the RF pulses and associated electromagnetic fields from the RF transmission coils <NUM>. For example, the RF transmission coils <NUM> are configured to selectively transmit RF signals or pulses to an object in the field of view, e.g. tissue. These RF pulses alter the effective magnetic field experienced by the spins in the sample (e.g. patient tissue). When the RF pulses are on, the effective field experienced by spins on resonance is solely the RF pulse, effectively canceling the static B0 field. The RF pulses can be chirp or frequency sweep pulses, for example, as further described herein.

Moreover, when the object in the field of view <NUM> is excited with RF pulses from the RF transmission coils <NUM>, the precession of the object results in an induced electric current, or MR current, which is detected by the RF reception coils <NUM>. The RF reception coils <NUM> can send the excitation data to an RF preamplifier <NUM>. The RF preamplifier <NUM> can boost or amplify the excitation data signals and send them to the spectrometer <NUM>. The spectrometer <NUM> can send the excitation data to the computer <NUM> for storage, analysis, and image construction. The computer <NUM> can combine multiple stored excitation data signals to create an image, for example.

From the spectrometer <NUM>, signals can also be relayed to the RF transmission coils <NUM> via an RF power amplifier <NUM>, and to the gradient coils <NUM> via a gradient power amplifier <NUM>. The RF power amplifier <NUM> amplifies the signal and sends it to RF transmission coils <NUM>. The gradient power amplifier <NUM> amplifies the gradient coil signal and sends it to the gradient coils <NUM>.

An interventional localization guide or device can allow for the integration of a fiducial tracker, i.e. fiducial arrangement <NUM> (<FIG>), on top of or in combination with an interventional device (e.g. a template for biopsy guidance) and can also be integrated with a MR receive coil <NUM> (<FIG>), for example. The MR receive coil <NUM> (<FIG>) and fiducial tracker <NUM> (<FIG>) can be used with a single-sided MRI scanner <NUM> for prostate interventions in certain instances. A single-sided, low-field MRI system <NUM> is shown in <FIG>, in which an auxiliary cart <NUM> can house the electrical and electronic components, such as a computer, display <NUM>, user interface <NUM>, programmable logic controller, power distribution unit, and amplifiers, for example. A magnet cart, i.e. single-sided MRI scanner <NUM>, can house a magnet, gradient coils, and a transmission coil and can attach to the receive coil. The single-sided, low-field MRI scanner <NUM> can be utilized with a lithotomy scanning position <NUM> in which the patient's legs are positioned around the MRI scanner <NUM>, as depicted in <FIG>.

The region of interest can be offset from the face of the magnet cart along a Z axis defined by the permanent magnet housed therein. The magnetic field strength in the region of interest for the single-sided MRI system can be less than <NUM> Tesla (T), for example. For example, the magnetic field strength in the region of interest for the single-sided MRI system can be less than <NUM> T. In other instances, the magnetic field strength can be greater than <NUM> T and may be <NUM> T, for example.

Various single-sided MRI systems are further described in <CIT>, and various additional references herein.

The integrated MR receive coil <NUM> and fiducial tracker <NUM> can act like a stereotactic perineum positioning device, i.e. interventional localization guide <NUM>, for imaging of the pelvis, for example. The device creates a common coordinate system for registering MR-acquired images to a physical template <NUM> (<FIG>) or structure adjacent to the patient's anatomy allowing for guidance of interventional devices, including but not limited to prostate biopsy guns, cryotherapy needles, or brachytherapy needles relative to the patient's anatomy and, in certain instances, with the benefit of intraoperative MR imaging. Stated differently, the stereotactic perineum positioning device including the MR receive coil <NUM> and fiducial tracker system <NUM> with fiducials <NUM> and a physical template <NUM> (<FIG>) can form an intraoperative interventional localization guide <NUM> for synchronous prostrate imaging and biopsy.

The stereotactic structure can include two coil arrangements: (A) a fiducial coil <NUM>, i.e. fiducial receive coil / fiducial RF coil / fiducial solenoid, which incorporates multiple separate fiducials <NUM> and (B) an MR receive coil <NUM>, i.e. main radio frequency (RF) receive coil / patient coil / patient-wearable receive coil, that surrounds at least a portion of the patient's pelvis. With respect to the fiducial receive coil <NUM>, three separate fiducials <NUM> are each wound with a connected solenoid surrounding a rectangular space into which a biopsy template or guidance structure can be rigidly attached. The fiducials <NUM> can be made from mineral oil or constructed from any MR-visible substance.

The MR receive coil <NUM> is positioned within a housing or enclosure <NUM>, which houses the different coils <NUM>, <NUM>, <NUM>, <NUM>, and <NUM> that make up the MR receive coil <NUM>. In the example embodiment shown in <FIG> and <FIG>, the MR receive coil <NUM> comprises five coils <NUM>, <NUM>, <NUM>, <NUM>, and <NUM>. The coils <NUM>, <NUM>, <NUM>, <NUM>, and <NUM> are butterfly coils comprising a pair of lobes. The first coil <NUM> forms a first lobe or loop at an upper portion of the array and a second lobe or loop in a middle portion of the array. The first loop of the first coil <NUM> surrounds the second coil <NUM>. The second loop of the first coil <NUM> surrounds a through hole <NUM> in the enclosure <NUM>. The second coil <NUM> is located above the through hole <NUM>. The third coil <NUM> extends around the upper half of the through hole <NUM>. The fourth coil <NUM> extends around the lower half of the through hole <NUM>. Ends of the loops of the third and fourth coil <NUM>, <NUM> overlap at a vertical centerline through the through hole <NUM>. The first coil <NUM> also overlaps/underlaps a portion of the second coil <NUM>, the third coil <NUM>, and the fourth coil <NUM>. The fifth coil <NUM> is positioned along a lower portion of the enclosure <NUM> below the through hole <NUM>. All of the coils <NUM>, <NUM><NUM>, <NUM>, and <NUM> overlap each other in areas so that at least a portion of each coil sits on top of a portion of one other coil in order to form an overlapping array.

The enclosure <NUM> also defines a curve. In other embodiments, the enclosure <NUM> and coils therein can define a different radius of curvature or multiple different radii of curvature. A different number of coils could be included in alternative MR receive coil and/or the coils could comprise different geometries and/or sizes, for example.

The fiducial RF coil <NUM> wrapped around the fiducials <NUM> can be one large solenoid. In other instances, it can be of any RF design created in such a way to pick up a signal from the fiducials <NUM>. The fiducial RF coil <NUM> could also be incorporated into the main RF receive coil <NUM> in certain instances. The fiducial RF coil <NUM> is mounted to a support structure that can be designed with a crossbar <NUM> and generally horizontal supports <NUM> configured to be inserted below the patient's back when in a supine/lithotomy position, for example, so that it is rigidly registered to the patient's perineum. The fiducial RF coil <NUM> can be translated in the y-direction (up and down) and can be positioned in such a way that it is centered at the perineum above the rectum and encompassing the y-direction expanse of the prostate.

The main RF receive coil <NUM> surrounds the patient's pelvis to optimize the signal acquisition from the prostate region. This coil <NUM> also contains a large access port <NUM> designed so that the fiducial RF coil <NUM> can be mated to the main RF receive coil <NUM>. This allows for the two coils <NUM>, <NUM> to be co-located and rigidly attached to the patient during the image acquisition. In various instances, the components can be mated by simply placing one on top of and/or adjacent to the other (see, e.g., <FIG>). For example, the two coils <NUM>, <NUM> can be sandwiched with each other and pressed against the anatomy. In other instances, geometrical features such as a ridge/groove is configured to lock them into place while allowing for a single degree of freedom of movement (e.g., up and down in the vertical direction).

Referring to <FIG>, an interventional localization guide <NUM> including a frame <NUM>, an arrangement of MR-visible fiducials <NUM> and a fiducial receive coil <NUM>, and a main RF receive coil <NUM> are shown. The interventional localization guide <NUM> is designed to have a through hole <NUM> that can allow a clinician access through the interventional localization guide <NUM>. The main RF receive coil <NUM> is comprised of multiple receive coil elements <NUM>, <NUM><NUM>, <NUM>, and <NUM> that are mounted to the frame. The MR-visible fiducials <NUM> can be seen on an MRI, see <FIG>. The fiducial receive coil <NUM> is wrapped around the MR-visible fiducials <NUM>. A goalpost-style holder <NUM> is configured to position the two coils (MR receive coil <NUM> and fiducial receive coil <NUM>) relative to each other. For example, MR-invisible material (e.g. ceramics) can allow the two structures <NUM>, <NUM> (<FIG>) to be attached together. In certain instances, ceramic rods <NUM> can be received within cylindrical bores <NUM> in the two structures <NUM>, <NUM>. For example, the fiducial coil frame <NUM> can include cylindrical bores <NUM> extending along a vertical direction, and the ceramic rods <NUM> can be inserted within these bores <NUM>. The height of the fiducial coil frame <NUM> along the ceramic rods <NUM> can be adjusted by the application of a small plastic set screw that extends into the fiducial coil frame <NUM> and applies pressure to the ceramic rod <NUM>. In various instances, the ceramic rods <NUM> can also be adjustably positioned in cylindrical bores <NUM> in the goalpost-style holder <NUM>. The goalpost-style holder <NUM> can utilize ceramic rods <NUM>, which can allow for rotation about the rods <NUM> (e.g. a rotation about the x-axis). Set screws can similarly secure the ceramic rods <NUM> relative to the goalpost-style holder <NUM>. In such instances, the two structures <NUM>, <NUM> can be secured together in different geometries/shapes to accommodate patients of different sizes and shapes.

The placement of a main RF receive coil <NUM> (i.e. patient coil) and the fiducial receive coils <NUM> relative to a patient <NUM> and an MRI system <NUM> are shown in <FIG>. <FIG> shows a patient <NUM> positioned in a lithotomy position on a table <NUM> with each leg <NUM> in a brace <NUM> attached to the table <NUM>. The horizontal supports <NUM> of the interventional localization guide <NUM> can be slid under the patient's <NUM> back holding the interventional localization guide <NUM> close to the patient's <NUM> prostate. <FIG> and <FIG> show different close up views of the interventional localization guide <NUM> being positioned against the patient <NUM>. The region of interest <NUM> represents the patient's <NUM> prostate in <FIG>. <FIG> provides a view showing a through hole <NUM> in the interventional localization guide <NUM>, which allows a clinician access through the interventional localization guide <NUM> to the region of interest <NUM>. <FIG> shows the positioning of the interventional localization guide <NUM> relative to MRI scanner <NUM>. The access bore <NUM> of the MRI system is aligned with the through hole <NUM> of the interventional localization guide <NUM>. This alignment provides access for a clinician to the region of interest <NUM>. For example, the clinician can access the region of interest <NUM> by going through the access bore <NUM> of the MRI scanner <NUM> and then through the through hole <NUM> of the interventional localization guide <NUM> to reach the region of interest <NUM>. <FIG> shows how the patient <NUM>, interventional localization guide <NUM>, and the MRI scanner <NUM> are positioned. The patient <NUM> is in the lithotomy position and the braces <NUM> position the patient's legs <NUM> around the MRI scanner <NUM> of the MRI system <NUM>. <FIG> shows the access for a clinician to the region of interest <NUM> through the access bore <NUM> and through hole <NUM>. For example, a clinician could use a surgical device to extend through the access bore <NUM> to the region of interest. It is also noted that a clinician could use a surgical device to reach around the MRI scanner <NUM> (not using the access bore <NUM>) to reach the region of interest.

In at least one aspect of the present disclosure, the MRI biopsy localization system includes two coils <NUM>, <NUM> designed to surround a patient's lower abdomen and provide guidance using MR-visible fiducials <NUM> for the purpose of a prostate biopsy. The patient receive coil network is positioned as close as possible to the patient's prostate to maximize signal acquisition from the region. As described in various additional references described herein, see, e.g. International Application No. <CIT>, due to the direction of the main magnetic field used to align the spin of the protons, the main RF receive coil <NUM> (RX coil) needs to be sensitive to a direction perpendicular to the main field direction. Referring still to <FIG>, that direction is perpendicular to the access bore <NUM> of the magnet. The fiducial receive coil <NUM> has the same requirement. However, since the sample can be fully enclosed by a coil, a solenoid can be wrapped around each MR visible fiducial element <NUM>. Referring primarily again to <FIG> and <FIG>, the fiducial arrangement <NUM> includes a fiducial receive coil <NUM> wrapped around four fiducials <NUM> (three fiducials seen in the front view (<FIG>) and a small additional fiducial <NUM> is positioned near the bottom, backside of the structure <NUM> (<FIG>)). In other instances, the fiducial arrangement <NUM> includes three fiducials <NUM>. In various instances, three separate fiducials <NUM> are needed to localize the template to a plane within the MR imaging space. Fewer or more fiducials <NUM> are possible in certain instances provided there are at least three points to register. Therefore, in many instances, three separate fiducials <NUM> are preferred. The fiducial arrangement <NUM> also has a space for the insertion of a biopsy template <NUM> (<FIG>) showing access ports <NUM>. The biopsy template <NUM> can be registered into the MR frame of reference, shown as a virtual template <NUM> showing the access ports <NUM> (<FIG>), and used to identify locations from which to acquire a biopsy. <FIG> shows the biopsy template <NUM> and access ports <NUM> shown in the MR frame of reference as the virtual template <NUM> and access ports <NUM>. The patient <NUM> and fiducial coil <NUM> are co-located in such a way to position the fiducials <NUM> orthogonal to the MR access aperture <NUM> while the patient receive coil <NUM> interlocks with the fiducial receive coil <NUM>.

In various instances, the interventional localization guide <NUM> can be utilized with a robotic system and a robotic arm can extend through an access bore <NUM> and/or around the perimeter of the magnet cart <NUM> to the patient <NUM> and/or region of interest <NUM>, as further described in International Application No. <CIT>.

In other instances not covered by the claims, the fiducial arrangement <NUM> does not need to have separate receive coils and instead the fiducials <NUM> can be imaged using the patient wearable receive coil.

In certain instances, there could be more than three fiducials <NUM> as long as three distinct regions can be identified. In other instances not covered by the claims, there could be less than three fiducials <NUM> as long as three distinct regions can be identified.

In various instances, both receive coils <NUM>, <NUM> can be combined into one structure as long as the resultant structure is rigidly attached and located to the patient to ensure a static patient frame of reference.

In one or more instances, an endorectal coil could be used.

In certain instances, the fiducials <NUM> can be constructed of MR-visible materials that are not at the hydrogen resonant frequency potentially necessitating a differently tuned receive coil array for localizing the fiducials <NUM>.

The template might be sized differently (e.g. larger or smaller) for different interventional therapies.

In various instances, there may not be a template and the coordinate system might be shared with a robotic interventional device to perform the interventions.

In certain instances, MR-visible fiducials <NUM> may not be needed and instead a small receive coil can be used in conjunction with an applied gradient or RF signal produced by the system to localize the small pickup coils in three-dimensional space. By utilizing a spatially varying electromagnetic or RF transmission field, the voltage induced into the small receive coil will be dependent upon the signal strength sent through the gradient or RF coils as well as the position in three-dimensional space. By mapping the field a priori, the spatial location of the pick-up loop and therefore the template can be localized in space.

In various instances, an acquisition method for an MRI image can allow for the acquisition of an MRI image of a rigidly attached fiducial <NUM> to extract the patient's frame of reference. This frame of reference can then allow a clinician to select and target desired foci within the body. The following methodology for a clinical workflow allows for the co-registration of externally-acquired MR images, recently-acquired MR images, and an attached physical template <NUM> to a common frame of reference. In various instances, the attached physical template <NUM> can be the stereotactic perineum positioning device shown in <FIG>.

In one aspect of the present disclosure, referring now to <FIG>, a T2 scan is acquired (<NUM>) with the physical template <NUM>, e.g. a stereotactic perineum positioning device having an RF receive coil and fiducial receive coil array/registration, as further described herein. The MR fiducials <NUM> are localized within the scan and registered in a frame of reference (<NUM>). The T2 scan is then registered to a third party MRI scan using anatomical landmarks (<NUM>). These registrations create a common frame of reference between all images and the physical world. From the third party scan or from the acquired T2 scan, a region of interest <NUM> is selected and the three-dimensional coordinate of the interventional site is calculated. From this coordinate, a depth and desired access port <NUM> on the physical template <NUM> is determined. In the embodiment of <FIG>, a biopsy needle is inserted into the physical template <NUM> and guided to the appropriate depth (<NUM>).

The interventional procedure can be any number of prostate or pelvic interventional procedures, such as cryotherapy, brachytherapy, etc..

In various instances, multiple third party images can be co-registered to the acquired scans.

In certain instances, an image can also be acquired during or after the intervention to confirm the location of the targeted intervention.

In at least one aspect of the current disclosure, an endorectal coil could be used.

In various instances, the template might be larger or smaller for different interventional therapies. In still other instances, there may not be a template as the coordinate system might be shared with a robotic interventional device to perform the interventions.

In certain instances, MR-visible fiducials may not be needed. Instead a small receive coil can be used in conjunction with an applied gradient or RF signal produced by the system to localize the small pickup coils in three-dimensional space.

While several forms have been illustrated and described, it is not the intention of Applicant to restrict or limit the scope of the appended claims to such detail. Numerous modifications, variations, changes, substitutions, and combinations of those forms may be implemented and will occur to those skilled in the art without departing from the scope of the present disclosure. Moreover, the structure of each element associated with the described forms can be alternatively described as a means for providing the function performed by the element. Also, where materials are disclosed for certain components, other materials may be used.

The foregoing detailed description has set forth various forms of the devices and/or processes via the use of block diagrams, flowcharts, and/or examples. Insofar as such block diagrams, flowcharts, and/or examples contain one or more functions and/or operations, it will be understood by those within the art that each function and/or operation within such block diagrams, flowcharts, and/or examples can be implemented, individually and/or collectively, by a wide range of hardware, software, firmware, or virtually any combination thereof. Those skilled in the art will recognize that some aspects of the forms disclosed herein, in whole or in part, can be equivalently implemented in integrated circuits, as one or more computer programs running on one or more computers (e.g., as one or more programs running on one or more computer systems), as one or more programs running on one or more processors (e.g., as one or more programs running on one or more microprocessors), as firmware, or as virtually any combination thereof, and that designing the circuitry and/or writing the code for the software and or firmware would be well within the skill of one of skill in the art in light of this disclosure. In addition, those skilled in the art will appreciate that the mechanisms of the subject matter described herein are capable of being distributed as one or more program products in a variety of forms, and that an illustrative form of the subject matter described herein applies regardless of the particular type of signal bearing medium used to actually carry out the distribution.

Instructions used to program logic to perform various disclosed aspects can be stored within a memory in the system, such as dynamic random access memory (DRAM), cache, flash memory, or other storage. Furthermore, the instructions can be distributed via a network or by way of other computer readable media. Thus a machine-readable medium may include any mechanism for storing or transmitting information in a form readable by a machine (e.g., a computer), but is not limited to, floppy diskettes, optical disks, compact disc, read-only memory (CD-ROMs), and magneto-optical disks, read-only memory (ROMs), random access memory (RAM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), magnetic or optical cards, flash memory, or a tangible, machine-readable storage used in the transmission of information over the Internet via electrical, optical, acoustical or other forms of propagated signals (e.g., carrier waves, infrared signals, digital signals, etc.). Accordingly, the non-transitory computer-readable medium includes any type of tangible machine-readable medium suitable for storing or transmitting electronic instructions or information in a form readable by a machine (e.g., a computer).

As used in any aspect herein, the term "control circuit" may refer to, for example, hardwired circuitry, programmable circuitry (e.g., a computer processor including one or more individual instruction processing cores, processing unit, processor, microcontroller, microcontroller unit, controller, digital signal processor (DSP), programmable logic device (PLD), programmable logic array (PLA), or field programmable gate array (FPGA)), state machine circuitry, firmware that stores instructions executed by programmable circuitry, and any combination thereof. The control circuit may, collectively or individually, be embodied as circuitry that forms part of a larger system, for example, an integrated circuit (IC), an application-specific integrated circuit (ASIC), a system on-chip (SoC), desktop computers, laptop computers, tablet computers, servers, smart phones, etc. Accordingly, as used herein "control circuit" includes, but is not limited to, electrical circuitry having at least one discrete electrical circuit, electrical circuitry having at least one integrated circuit, electrical circuitry having at least one application specific integrated circuit, electrical circuitry forming a general purpose computing device configured by a computer program (e.g., a general purpose computer configured by a computer program which at least partially carries out processes and/or devices described herein, or a microprocessor configured by a computer program which at least partially carries out processes and/or devices described herein), electrical circuitry forming a memory device (e.g., forms of random access memory), and/or electrical circuitry forming a communications device (e.g., a modem, communications switch, or optical-electrical equipment). Those having skill in the art will recognize that the subject matter described herein may be implemented in an analog or digital fashion or some combination thereof.

As used in any aspect herein, the term "logic" may refer to an app, software, firmware and/or circuitry configured to perform any of the aforementioned operations. Software may be embodied as a software package, code, instructions, instruction sets and/or data recorded on non-transitory computer readable storage medium. Firmware may be embodied as code, instructions or instruction sets and/or data that are hard-coded (e.g., nonvolatile) in memory devices.

As used in any aspect herein, the terms "component," "system," "module" and the like can refer to a computer-related entity, either hardware, a combination of hardware and software, software, or software in execution.

As used in any aspect herein, an "algorithm" refers to a self-consistent sequence of steps leading to a desired result, where a "step" refers to a manipulation of physical quantities and/or logic states which may, though need not necessarily, take the form of electrical or magnetic signals capable of being stored, transferred, combined, compared, and otherwise manipulated. It is common usage to refer to these signals as bits, values, elements, symbols, characters, terms, numbers, or the like. These and similar terms may be associated with the appropriate physical quantities and are merely convenient labels applied to these quantities and/or states.

Unless specifically stated otherwise as apparent from the foregoing disclosure, it is appreciated that, throughout the foregoing disclosure, discussions using terms such as "processing," "computing," "calculating," "determining," "displaying," or the like, refer to the action and processes of a computer system, or similar electronic computing device, that manipulates and transforms data represented as physical (electronic) quantities within the computer system's registers and memories into other data similarly represented as physical quantities within the computer system memories or registers or other such information storage, transmission or display devices.

One or more components may be referred to herein as "configured to," "configurable to," "operable/operative to," "adapted/adaptable," "able to," "conformable/conformed to," etc. Those skilled in the art will recognize that "configured to" can generally encompass active-state components and/or inactive-state components and/or standby-state components, unless context requires otherwise.

The terms "proximal" and "distal" are used herein with reference to a clinician manipulating the handle portion, or housing, of a surgical instrument. The term "proximal" refers to the portion closest to the clinician and/or to the robotic arm and the term "distal" refers to the portion located away from the clinician and/or from the robotic arm. It will be further appreciated that, for convenience and clarity, spatial terms such as "vertical", "horizontal", "up", and "down" may be used herein with respect to the drawings. However, robotic surgical tools are used in many orientations and positions, and these terms are not intended to be limiting and/or absolute.

Those skilled in the art will recognize that, in general, terms used herein, and especially in the appended claims (e.g., bodies of the appended claims) are generally intended as "open" terms (e.g., the term "including" should be interpreted as "including but not limited to," the term "having" should be interpreted as "having at least," the term "includes" should be interpreted as "includes but is not limited to," etc.). It will be further understood by those within the art that if a specific number of an introduced claim recitation is intended, such an intent will be explicitly recited in the claim, and in the absence of such recitation no such intent is present. However, the use of such phrases should not be construed to imply that the introduction of a claim recitation by the indefinite articles "a" or "an" limits any particular claim containing such introduced claim recitation to claims containing only one such recitation, even when the same claim includes the introductory phrases "one or more" or "at least one" and indefinite articles such as "a" or "an" (e.g., "a" and/or "an" should typically be interpreted to mean "at least one" or "one or more"); the same holds true for the use of definite articles used to introduce claim recitations.

In addition, even if a specific number of an introduced claim recitation is explicitly recited, those skilled in the art will recognize that such recitation should typically be interpreted to mean at least the recited number (e.g., the bare recitation of "two recitations," without other modifiers, typically means at least two recitations, or two or more recitations). Furthermore, in those instances where a convention analogous to "at least one of A, B, and C, etc." is used, in general such a construction is intended in the sense one having skill in the art would understand the convention (e.g., "a system having at least one of A, B, and C" would include but not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and/or A, B, and C together, etc.). In those instances where a convention analogous to "at least one of A, B, or C, etc." is used, in general such a construction is intended in the sense one having skill in the art would understand the convention (e.g., "a system having at least one of A, B, or C" would include but not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and/or A, B, and C together, etc.). It will be further understood by those within the art that typically a disjunctive word and/or phrase presenting two or more alternative terms, whether in the description, claims, or drawings, should be understood to contemplate the possibilities of including one of the terms, either of the terms, or both terms unless context dictates otherwise. For example, the phrase "A or B" will be typically understood to include the possibilities of "A" or "B" or "A and B.

With respect to the appended claims, those skilled in the art will appreciate that recited operations therein may generally be performed in any order. Also, although various operational flow diagrams are presented in a sequence(s), it should be understood that the various operations may be performed in other orders than those which are illustrated, or may be performed concurrently. Examples of such alternate orderings may include overlapping, interleaved, interrupted, reordered, incremental, preparatory, supplemental, simultaneous, reverse, or other variant orderings, unless context dictates otherwise. Furthermore, terms like "responsive to," "related to," or other past-tense adjectives are generally not intended to exclude such variants, unless context dictates otherwise.

It is worthy to note that any reference to "one aspect," "an aspect," "an exemplification," "one exemplification," and the like means that a particular feature, structure, or characteristic described in connection with the aspect is included in at least one aspect. Thus, appearances of the phrases "in one aspect," "in an aspect," "in an exemplification," and "in one exemplification" in various places throughout the specification are not necessarily all referring to the same aspect. Furthermore, the particular features, structures or characteristics may be combined in any suitable manner in one or more aspects.

Claim 1:
A stereotactic perineum positioning device for magnetic resonance, MR, imaging, the stereotactic perineum positioning device comprising: a frame (<NUM>); a patient receive coil (<NUM>) rigidly mounted to the frame; and a fiducial array rigidly mounted to the frame, characterized in that the fiducial array comprises three distinct MR-visible fiducials (<NUM>) and a fiducial receive coil (<NUM>) wrapped around the three distinct MR-visible fiducials.