Patent Publication Number: US-11648033-B2

Title: Methods and devices for sonographic imaging

Description:
This application is a continuation of U.S. patent application Ser. No. 16/283,091, filed Feb. 22, 2019, which is a continuation of U.S. patent application Ser. No. 16/043,996, filed Jul. 24, 2018, now U.S. Pat. No. 10,258,375, which is a continuation of U.S. patent application Ser. No. 12/245,265, filed Oct. 3, 2008, now U.S. patent Ser. No. 10/070,888, each of which is herein incorporated by reference in its entirety. 
    
    
     TECHNICAL FIELD 
     The present invention relates to methods and devices for sonographic imaging of organs, ducts and cavities. In particular, methods and devices of the present invention use detectable acoustic variations of alternating patterns of a gas phase and a liquid phase traversing a passage. 
     BACKGROUND OF THE INVENTION 
     Non-surgical diagnostic procedures for examining body ducts and cavities, in particular the uterus and Fallopian tubes, are well known. One procedure, known as hysterosalpingography, employs contrast agents and diagnostic fluoroscopic imaging techniques for viewing the uterus and Fallopian tubes. A safer, cheaper and easier method is hysterosonosalpingography, where ultrasound is utilized as the imaging modality. Ultrasound imaging also allows for evaluation of the uterine cavity using saline as a method of choice without assessment of Fallopian tube patency. Tubal patency and tubal occlusion can be assessed only under ideal sonographic conditions, limiting its usefulness clinically. Currently, no contrast agent indicated for contrast enhancement during ultrasound evaluation of the uterine cavity and Fallopian tubes is available in the U.S. Other ultrasound contrast agents are available for widespread use but are limited to use in cardiac and vascular applications. Most of the currently available vascular contrast agents are stabilized against dissolution and coalescence by the presence of additional materials, such as an elastic solid shell that enhances stability, or a surfactant or a combination of two or more surfactants. Contrast agents can improve the image quality of sonography either by decreasing the reflectivity of the undesired interfaces or by increasing the backscattered echoes from the desired regions. In the former approach, the contrast agents are taken orally, and for the latter effect, the agent is introduced vascularly. To pass through the lung capillaries and enter into the systemic circulation, microbubbles within a vascular contrast agent should be less than 10 microns in diameter (2 to 5 microns on average for most of the newer agents). Stability and persistence become major issues for such small microbubbles and air bubbles in this size range persist in solution for only a short time. Hence the gas bubbles have to be stabilized for the agent to persist long enough and survive pressure changes in the heart for systemic vascular use. Therefore, availability of contrast agents, procedural challenges, particularly during preparation of the patient and the contrast materials, and cost are disadvantages associated with known contrast media used sonographically. 
     Although conventional contrast agents function adequately, the disadvantages inherent in the conventional agents create a need for better contrast agents. One disadvantage with currently used contrast agents is that they are very expensive and difficult for some physicians to obtain. Another disadvantage is that conventional contrast agents must be shaken prior to injection to either mix the components or to generate bubbles, thus making the entire diagnostic procedure cumbersome and possibly somewhat subjective. A third disadvantage is that the contrast agent composition has a very short shelf life due to its unstable nature once it is prepared for use in a patient. 
     In view of these disadvantages, other solutions have been tried. One attempt to overcome these disadvantages is a contrast medium that is made from air mixed with sterile solutions of saline. Air and saline can be used in place of conventional contrast agents in sonographic investigations, due to the ultrasound reflective properties of low density phases, i.e., gas, in liquids. Generally, microbubbles of a gas are formed in the liquid carrier. 
     Microbubbles in liquids have been used as contrast media previously. Microbubbles may be generated by such methods as syringe motions in a back and forth manner in combinations of air and dispersants, or ultrasonic cavitation means. It is known that such microbubbles are only stable for a short amount of time. Pre-formed microparticles using temporary or permanent polymeric films have been used to address the short stability lifespan. Pressurized systems have been used to create microbubbles in solutions. The technique involves a means of generating a focused jet of gas in order to aerate the fluids with microbubbles. Such microbubbules may coalesce if there is a lag time between generation and application into the structure to be visualized, thus these methods have used a high velocity flow of liquid. Thus, limitations to this method are that the microbubbles introduced into a fluid may coalesce into a few large bubbles or one large air pocket, the microbubbles formed must be stable long enough for visualization to occur, and due to the instability of the microbubbles, it is difficult to create reproducible conditions for comparative visualizations. 
     Accordingly, devices and methods are needed for creating contrast agents that resolve the issues currently encountered. Particularly, methods and devices are needed for visualization of organ structure and function, such as visualization of the uterus and Fallopian tubes. 
     SUMMARY 
     The present invention comprises methods and devices for making and using contrast agents. Methods of the present invention comprise use of a device for generating a contrast agent that is used for sonographically observing organs or bodily structures, for example, the uterus and Fallopian tubes. The contrast agent device may comprise a container assembly and optionally, a catheter assembly fluidly coupled to the container assembly. A container assembly may comprise a first container for providing a solution of a liquid, such as saline, and a second container for providing a gas, such as air, and elements for creating an alternating pattern of gas and fluid, which is delivered directly to the organ or structure by the catheter assembly. A container assembly may comprise one or more containers. A container assembly may comprise elements for providing the contained substance from a container to the catheter. 
     Methods of the present invention comprise sonographically observing a location of a body, such as a uterus and its associated Fallopian tubes, using the devices disclosed herein. Methods comprise placement of a catheter delivery end in close approximation to the structure to be observed, and providing the fluid/gas mixture to the structure. For example, in a method of viewing a Fallopian tube, a delivery device comprising at least one catheter is placed within the uterus, and the at least one catheter is provided through the delivery device and is extended to the cornua of the uterus and the delivery end of the catheter is held in place, for example, by an end structure such as a balloon. Once the catheter(s) is in place, the liquid/gas mixture, the contrast medium, is provided from the contrast agent device to the catheter, and to the Fallopian tube(s). Sonographic visualization is begun, and one or both of the Fallopian tubes is examined. Depending on the delivery device used to provide the contrast agent, the Fallopian tubes may be examined simultaneously or sequentially. If visualization of the entire uterus is desired, for example, after visualization of the Fallopian tubes, the catheter(s) is withdrawn from the cornua, and retracted until the end structure of a single catheter is in place at the entrance to the uterus. The end structure, such as a balloon, is enlarged to provide a liquid seal of the uterus and the liquid/gas contrast agent is introduced into the uterus. Sonographic visualization is begun and may be continued until a sufficient amount of the liquid/gas contrast agent is within the uterus. 
     Bodily structures of humans or animals, or inanimate objects can be easily observed with the contrast agents of the present invention. Providing the contrast agent directly to the structure to be observed with a catheter assembly aids in maintaining the structure of the gas within the liquid of the liquid/gas mixture. The methods of the present invention aid in the reproducibility of the methods of visualization and comparative results therefrom. 
    
    
     
       DESCRIPTION OF FIGURES 
         FIG.  1    is a schematic of an exemplary embodiment of the present invention. 
         FIG.  2    is a schematic of an exemplary embodiment of the present invention. 
         FIG.  3    is a schematic of an exemplary embodiment of the present invention 
         FIG.  4    is a schematic of an exemplary embodiment of the present invention. 
         FIG.  5    is a schematic of a pattern of a contrast material in a Fallopian duct. 
     
    
    
     DETAILED DESCRIPTION 
     The present invention comprises methods and devices for making and using contrast agents for ultrasound or sonography visualization of structures. Such structures may be present in the bodies of humans or animals, or may be inanimate structures. As discussed herein, the methods and devices are used for ultrasound visualization of a uterus and one or more Fallopian tubes of a mammal. It is to be understood that the methods and devices are not limited to this application, but can be used in visualization of ducts or structures, whether in living beings or inanimate structures. 
     The present invention comprises devices for making a contrast medium composition. As used herein, contrast agent and contrast medium mean a composition that is visible by ultrasound methods, referred to as sonography, and the terms may be used interchangeably. Methods of the present invention comprise use of a contrast agent device for generating a contrast agent that is useful for sonographically observing organs or bodily structures, for example, the uterus and Fallopian tubes. 
     A contrast agent device comprises a container assembly and optionally, a catheter assembly fluidly coupled to the container assembly. A container assembly may comprise at least one container for a fluid. A fluid comprises a liquid or a gas. A container assembly may comprise a first container for a liquid, such as saline, and a second container for a gas, such as air, and elements for creating an alternating pattern of gas and fluid. A container assembly may comprise elements for providing the contained fluid from a container to the catheter assembly. The container may comprise one or more outlets through which the fluid, such as gas or liquid, exits the container, or the outlet may be used to provide a fluid, either liquid or gas into the container. The container assembly may comprise a component for providing force upon the fluid contained within the container. For example, a container may be a syringe, and the component for providing force upon the fluid is a syringe plunger. The container assembly may comprise a component for activating the component for providing force. For example, the container may be a syringe, the component for providing force upon the contained fluid is a syringe plunger, and the component for activating the plunger may be a pump, or the hand of an operator. 
     The container assembly may further comprise fluid connections between one or more containers and a contrast pattern generating chamber. Such fluid connections include, but are not limited to, tubing or needles. The container assembly may comprise a contrast pattern generating chamber wherein the gas phase is introduced into the liquid phase and the composition exiting the contrast pattern generating chamber is characterized by alternating phases of gas and liquid which form the pattern of the contrast medium composition. The container assembly may provide the contrast medium composition to a catheter assembly or directly to a structure to be visualized. 
     The container assembly may be in fluid connection with the catheter assembly. The catheter assembly may be a single or double lumen catheter. The catheter may comprise end structures, such as a balloon on the delivery end of the catheter. The opposite end of the catheter, the attachment end, may have attachment elements for attaching the catheter to other elements, such as elements, such as a luer lock, to attach the catheter to a container assembly. The catheter may comprise other components such as a wire, sensors, cutting elements, retrieval elements such as clamps or pincers. 
     The present invention comprises devices for delivery of a contrast medium to a structure. It is contemplated by an embodiment of the present invention that the contrast medium is provided by the catheter assembly substantially directly to a structure to be visualized. In an aspect of the invention, for example, in direct delivery to a fallopian tube, the amount of contrast medium used per each fallopian tube evaluation may be small, such as less than 20 mL, less than 15 mL, less 10 mL, less than 8 mL, less than 5 mL, less than 4 mL, less than 3 mL, less than 2 mL, less than 1 mL, less than 0.5 mL. The amount of contrast fluid used may be any amount that is sufficient to provide an accurate visualization of the structure. The contrast fluid may substantially fill the structure visualized, or may only be present in particular locations within the structure. 
     When the structure to be visualized is a Fallopian tube, any device that provides a catheter to the Fallopian tube may be used. A catheter may be connected to the contrast media device comprising a container assembly described herein. A particular device for providing a catheter to a body structure, such as a Fallopian tube, and that is useful in methods of visualizing a Fallopian tube is the device taught in U.S. patent application Ser. Nos. 11/065,886, 12/240,738, and 12/240,791, each of which is herein incorporated in its entirety. In general these applications disclose a device comprising a housing and an introducer shaft that is used to enter and traverse the uterus until the tip of the shaft approaches or touches the fundus of a uterus. Once the tip of the introducer shaft is at the fundus of the uterus, the device may be stabilized. One or more catheters, such as two, are fed through the introducer shaft and out into the uterine cavity. The placement of the introducer shaft allows for the three dimensional alignment of the catheter(s) with the cornua of the uterus. The catheter(s) is advanced until the delivery end(s) of the catheter(s) are in place in the cornua. An end structure, such as a balloon, is inflated or engaged, to stabilize the catheter(s) in place, and the end structure may prevent or minimize back-flow of materials exiting the catheter delivery end. Once the end structure is engaged, the catheter(s) is ready for delivery of materials or other activities. 
     In a method of the present invention, the catheter placed by the introducer shaft comprises the catheter assembly. The end of the catheter opposite the delivery end, referred to herein as the proximal end or the attachment end, is attached to a container assembly of a contrast medium device of the present invention. The contrast medium is generated by the actions of the container assembly and the contrast medium is provided into and through the catheter(s) and out into the cornua of the uterus and into to a Fallopian tube(s). Visualization techniques are initiated as the contrast medium enters the Fallopian tube(s) and if possible, flows through the tube(s) and out into the peritoneal cavity. If a tube is blocked, the medium will not flow. The pressure built up by the blockage may or may not unseat the balloon to relieve pressure and the flow would then be directed into the uterus. 
     If the device providing the catheter uses only one catheter, then visualization of one Fallopian tube occurs, followed by readjustment of the device, such as rotation of the introducer shaft, as taught in the cited patent applications, and the steps are repeated to provide a contrast medium to the other Fallopian tube. The contrast medium provided may be any currently known contrast medium that may be provided through a catheter to a location. 
     Methods of the present invention comprise making a contrast medium. A contrast medium device of the present invention is used to make a contrast medium. For example, a contrast medium device comprising one container for fluid may comprise a container comprising a flexible porous material contained within the container. An example wherein the container is a syringe body is described, such as one shown in  FIG.  4   . The present invention is not limited to this design, but contemplates other containers that would function in similar ways. The syringe is substantially filled with a flexible porous material. The flexible porous material includes, but is not limited to, strips or pieces of woven or nonwoven material, an open-celled material, such as a sponge, or fragments of a sponge, or any material that would contain a gas and release the gas when acted upon, such as by compression forces. For example, the flexible, porous material is an open-celled sponge. The sponge is placed in the container and a liquid is added, but the liquid does not displace all of the air in the sponge. The syringe plunger is applied to the large open end of the syringe and the other end of the syringe is in fluid connection with the catheter assembly. As the plunger is depressed into the syringe, the sponge is compressed and the air is forced out into the liquid, creating bubbles. The bubbles and fluid enter the catheter and transit the catheter to the structure. Visualization of the structure is then possible. See  FIG.  5    for an illustration of visualization of a Fallopian tube. 
     The present invention comprises contrast medium devices comprising more than one container. For example, the contrast medium device may comprise two containers, such as one shown in  FIG.  1   , an example wherein the containers comprise a syringe body. The present invention is not limited to this design, but contemplates other containers that would function in similar ways. One of the containers, which may be a pre-filled syringe, contains a liquid. The liquid may be any of those disclosed herein, such as saline or water, or known contrast agent fluids. A second container, which may be a pre-filled syringe, contains a gas. The gas may be any of those disclosed herein, such as air, carbon dioxide, oxygen, nitrogen or halocarbon compound gases, other gases, or known contrast agent gases. The plungers of the two syringes are depressed simultaneously either manually or mechanically and the mixture of the gas and liquid form an alternating pattern of gas phase and liquid phase, which is a contrast medium. The contrast medium then enters and transits the attached catheter and exits into the structure, such as the Fallopian tube. Visualization of the structure is possible by ultrasound techniques. 
     Compositions of the present invention comprise a contrast medium made using the methods taught herein. A contrast medium of the present invention comprises a gas phase within a liquid carrier. The gas phase may be a bubble or may be a liquid-free, gas-filled area adjacent to a liquid phase area, and the alternating gas-filled area and liquid area may repeat multiple times. The sizes of the gas-filled areas or the liquid filled areas may be uniform in size or not. The present invention contemplates providing a contrast medium in reduced volumes, compared to amounts currently used which may be 20 mL or more, and providing the contrast medium substantially in or very near the structure to be visualized (i.e. Fallopian tube). The present invention controls the amount of gas and liquid used in combination to form the mixed gas/liquid composition, which enters the structure. The pattern of the contrast medium composition can range from predominantly a gas (air or other gas) phase to predominantly a liquid (saline or other liquid) phase and can be provided in a regular pattern or in an irregular pattern. The ratios of the gas to liquid may be determined by the size of the respective syringe. The larger the air syringe the greater the air segment in the pattern of the composition. The use of a porous structure may create a more random or irregular pattern. The amount of contrast medium delivered may be controlled by the amount of syringe plunger displacement. 
     A composition of the present invention may comprise a liquid and a gas, and optionally, surfactants, emulsifiers, or other stabilizing agents. The liquid, which may be seen as a carrier of the gas phase, may be any liquid that is substantially free of solids and flows at normal or bodily temperatures. For example, the liquid may be water or physiologically acceptable aqueous solutions including, but not limited to, physiological electrolyte solutions, physiological saline solutions, Ringer&#39;s solution or aqueous solutions of sodium chloride, calcium chloride, sodium bicarbonate, sodium citrate, sodium acetate, or sodium tartrate, glucose solutions, or solutions or mono- or polyhydric alcohol, e.g., ethanol, n-butanol, ethylene glycol, polyvinylpyrrolidone, or mixtures or combinations of these. Further, the liquid carrier may comprise physiologically acceptable non-aqueous solutions, including, but not limited to, anhydrous or substantially anhydrous carrier liquids, alcohols, glycols, polyglycols, synthetic perfluoranated hydrocarbons, or in mixtures or combination with other non-aqueous or aqueous liquids. 
     The contrast media compositions of the present invention may comprise surfactants or compounds that stabilize the gas-liquid interface. Surfactant composition may be useful when the contrast medium is provided to a structure that is larger than the catheter size used to transmit the contrast medium. Surfactants include tensides, such as lecithins; esters and ethers of fatty acids and fatty alcohols with polyoxyethylene and polyoxyethylated polyols like sorbitol, glycols and glycerol, cholesterol; and polyoxy-ethylene-polyoxypropylene polymers, viscosity raising and stabilizing compounds, mono- and polysaccharides (glucose, lactose, sucrose, dextran, sorbitol); polyols, e.g., glycerol, polyglycols; and polypeptides like proteins, gelatin, oxypolygelatin, plasma protein, amphipathic compounds capable of forming stable films in the presence of water and gases, such as the lecithins (phosphatidyl-choline) and other phospholipids, inter alia phosphatidic acid (PA), phosphatidylinositol, phosphatidylethanolamine (PE), phosphatidylserine (PS), phosphatidylglycerol (PG), cardiolipin (CL), sphingomyelins, the plasmogens, the cerebrosides, natural lecithins, such as egg lecithin or soya bean lecithin, or synthetic lecithins such as saturated synthetic lecithins, for example, dimyristoylphosphatidylcholine, dipalmitoylphosphatidylcholine or distearoylphosphatidylcholine or unsaturated synthetic lecithins, such as dioleylphosphatidylcholine or dilinoleylphosphatidylcholine, free fatty acids, esters of fatty acids with polyoxyalkylene compounds like polyoxypropylene glycol and polyoxyalkylene glycol; ethers of fatty alcohols with polyoxyalkylene glycols; esters of fatty acids with polyoxyalklated sorbitan; soaps; glycerol-polyalkylene stearate; glycerol-polyoxyethylene ricinoleate; homo- and copolymers of polyalkylene glycols; polyethoxylated soya-oil and castor oil as well as hydrogenated derivatives; ethers and esters of sucrose or other carbohydrates with fatty acids, fatty alcohols, these being optionally polyoxyalkylated; mono-di and triglycerides of saturated or unsaturated fatty acids; glycerides of soya-oil and sucrose, block copolymers of polyoxypropylene and polyoxyethylene (poloxamers), polyoxyethylenesorbitans, sorbitol, glycerol-polyalkylene stearate, glycerolpolyoxyethylene ricinoleate, homo- and copolymers of polyalkylene glycols, soybean-oil as well as hydrogenated derivatives, ethers and esters of sucrose or other carbohydrates with fatty acids, fatty alcohols, glycerides of soya-oil, dextran, sucrose and carbohydrates. Surfactants may be film forming and non-film forming and may include polymerizable amphiphilic compounds of the type of linoleyl-lecithins or polyethylene dodecanoate, phosphatidic acid, phosphatidylcholine, phosphatidylethanolamine, phosphatidylserine, phosphatidylglycerol, phosphatidylinositol, cardiolipin, sphingomyelin and biocompatible and amphipathic compound capable of forming stable films in the presence of an aqueous phase and a gas, phospholipids including phosphatidylcholine (PC) with both saturated and unsaturated lipids; including phosphatidylcholine such as dioleylphosphatidylcholine; dimyristoylphosphatidylcholine (DMPC), dipentadecanoylphosphatidylcholine-, dilauroylphosphatidylcholine (DLPC); dipalmitoylphosphatidylcholine (DPPC); disteraoylphosphatidylcholine (DSPC); and diarachidonylphosphatid-ylcholine (DAPC); phosphatidylethanolamines (PE), such as dioleylphosphatidylethanolamine, dipaimitoylphosphatidylethanolamine (DPPE) and distearoylphosphatidylethanolamine (DSPE); phosphatidylserine (PS) such as dipalmitoyl phosphatidylserine (DPPS), disteraoylphosphatidylserine (DSPS); phosphatidylglycerols (PG), such as dipalmitoylphosphatidylglycerol (DPPG), distearoylphosphatidylglycerol (DSPG); and phosphatidylinositol. 
     The contrast medium compositions comprise gases, and any physiologically acceptable gas may be present in the compositions of the present invention. The term “gas” as used herein includes any substances (including mixtures) substantially in gaseous form at the normal human body (37° C.). Close to 200 different gases have been identified as potentially useful for making ultrasound contrast agents, and include oxygen, air, nitrogen, carbon dioxide or mixtures thereof, helium, argon, xenon, krypton, CHClF 2  or nitrous oxide, sulfur hexafluoride, tetrafluoromethane, chlorotrifluoromethane, dichlorodifluoro-methane, bromotrifluoromethane, bromochlorodifluoromethane, dibromodifluoromethane dichlorotetrafluoroethane, chloropentafluoroethane, hexafluoroethane, hexafluoropropylene, octafluoropropane, hexafluoro-butadiene, octafluoro-2-butene, octafluorocyclobutane, decafluorobutane, perfluorocyclopentane, dodecafluoropentane, fluorinated gases including materials which contain at least one fluorine atom such as SF 6 , freons (organic compounds containing one or more carbon atoms and fluorine, i.e. CF 4 , C 2 F 6 , C 3 F 8 , C 4 F 8 , C 4 F 10 , CBrF 3 , CCl 2 F 2 , C 2 ClF 5  and CBrClF 2  and perfluorocarbons. The term perfluorocarbon refers to compounds containing only carbon and fluorine atoms and includes saturated, unsaturated, and cyclic perfluorocarbons such as perfluoroalkanes such as perfluoromethane, perfluoroethane, perfluoropropanes, perfluorobutanes (e.g. perfluoro-n-butane, optionally in admixture with other isomers such as perfluoro-isobutane), perfluoropentanes, perfluorohexanes and perfluoroheptanes; perfluoroalkenes such as perfluoropropene, perfluorobutenes (e.g. perfluorobut-2ene) and perfluorobutadiene; perfluoroalkynes such as perfluorobut-2-yne; and perfluorocycloalkanes such as perfluorocyclobutane, perfluoromethylcyclobutane, perfluorodimethylcyclobutanes, perfluorotrimethylcyclobutanes, perfluorocyclopentane, perfluoromethylcyclopentane, perfluorodimethylcyclopentanes, perfluorocyclohexane, perfluoromethylcyclohexane and perfluorocycloheptane). The saturated perfluorocarbons, which are usually preferred, have the formula C n F n+2 , where n is from 1 to 12, preferably from 2 to 10, most preferably from 3 to 8 and even more preferably from 3 to 6. Suitable perfluorocarbons include, for example, CF 4 , C 2 F 6 , C 3 F 8  C 4 F 8 , C 4 F 10 , C 5 F 12 , C 6 F 12 , C 7 F 14 , C 8 F 18 , and C 9 F 20 . 
     The present invention comprises embodiments of a contrast medium device. A device may be two separable components; a container assembly and a catheter assembly that locates the fluid output of the catheter assembly near or in the targeted duct or cavity. Alternatively, a contrast medium device may be of a single, one-piece construction with a container assembly adjoined to a catheter assembly. A contrast medium device may comprise a container assembly, and optionally, a catheter assembly. A contrast medium device may comprise a container assembly that provides a contrast medium comprising a gas phase and a liquid phase. The contrast medium device may comprise a container assembly comprising a modified conventional multiple syringe pump, either a mechanical or a manual handheld device capable of accepting variously sized syringes. The syringe outputs are directed into a mixing chamber or conduit where the appropriately created train of gas (i.e. air) and liquid (i.e. saline) are then driven into the input of a catheter assembly. Directed delivery of the injected contrast media in the proximity or within the duct (i.e. Fallopian tube) will allow for sonography of the structure. The contrast medium composition is provided directly to the fallopian tube, by which is meant that the contrast medium composition is delivered only to the fallopian tube, or only to the fallopian tube first, and not by a filling of the uterus with a fluid and having that fluid overflow into the fallopian tubes. Providing a composition directly to a structure is meant herein to mean that the composition is provided at or near an opening of the structure to be assessed, so that the composition enters the structure and does not flow into the structure from a remote site of delivery of a composition. 
     An aspect of the present invention comprises a contrast medium device comprising a container assembly comprising a contrast pattern generating chamber having a diameter in a range of 0.3 to 1.8 ratio to the diameter of the structure to be visualized. The diameter of the contrast pattern generating chamber may be in a ratio of 0.1 to 100 the diameter of the structure to be visualized. The contrast pattern generating chamber may have a diameter ratio of 0.5 to 1 of the structure to be visualized, a diameter ratio of 1 to 1 of the structure to be visualized, a diameter ratio of 1 to 1.5 of the structure to be visualized, a diameter ratio of 1 to 2 of the structure to be visualized. An aspect of a contrast medium device comprises a container assembly comprising a contrast pattern generating chamber that has a diameter substantially equal to the diameter of the structure to be visualized, wherein the ratio of the diameters is 1. 
     The interfaces of the alternating gas and liquid phases must be present in sufficient numbers if a duct, tube or structure is to be visualized by this contrast medium, and both phases must be present in the viewing region during the time of viewing. It is the presence of both phases traversing the viewing region that provide the visualization contrast. For example, if only one phase (either liquid or gas) is visible in the viewing region at a given time, assessment difficult or impossible. By the creation of multiple interfaces between the two phases in the contrast medium, observation of structure is possible due to the flow of the contrast medium comprising the interfaces of the phases. 
     An aspect of the present invention comprises contrast medium devices comprising contrast pattern generating chambers having diameters similar in diameter to the structure being observed. For example, if gas phase is created that is smaller than the diameter of the structure to be observed, the gas will rise to the upper portion of the duct and coalesce with another gas phase and fill the diameter of the structure. An aspect of the present invention comprises contrast medium devices comprising contrast pattern generating chambers having diameters that are either larger or smaller in diameter to the structure being observed. For example, if very small gas phases are created in the contrast pattern generating chamber, the small gas phases can be maintained in a larger diameter structure using dispersing agents, surfactants, or other similar acting components in the liquid or gas phase. Such small gas phases may be achieved by vibratory manipulation of the container assembly. The higher the frequency of the oscillations, the smaller the released gas phase bubbles. 
     A manual means of creating a contrast medium can be achieved by the use of a contrast medium device comprising a container assembly comprising a single syringe and a porous substance, such as open cell foams, sponges, or woven or non-woven fabrics or fibers or combinations thereof. The syringe is charged with one or more of these substances in a loosely fitted fashion and the plunger is then replaced in the fully retracted position. The contrast medium is then injected or otherwise fed or drawn into the syringe chamber containing the porous substance(s). Upon controlled depression of the syringe plunger, the fluid and air or other gas egresses in a manner similar to the dual syringe system described above. The catheter assembly delivers the contrast medium into the structure being assessed. 
     A use of the devices disclosed herein is to deliver compositions to a structure to be visualized. Diagnostic or therapeutic treatments may be provided to humans or animals by delivering diagnostic compositions, such as contrast medium compositions, or therapeutic compositions comprising therapeutic agents to a structure by using the contrast medium device and a catheter assembly as described herein. For example, therapeutic compositions may be provided to a Fallopian tube in combination with alternating phase interfaces provided by the introduction of a gas to the composition, and for treatment of the Fallopian tube may comprise methotrexate, hormones, fertility enhancing compounds, fertility interfering compounds, motility enhancing compounds, motility interfering compounds, compounds affecting the cilia/deciliation cycle, cilia growth enhancing or interfering compounds, ovarian follicle treatment compounds, antibacterial, antimicrobial, antifungal, antiviral, antimycoplasmal, or antiparisital compounds, compounds that reduce inflammation or scar tissue formation, composition comprising one or more antibiotics, antimycoplasma agents, or antiviral compounds; compositions comprising mucoproteins, electrolytes or enzymes to enhance or inhibit fertility, progesterone, estrogen, adrenergic active compounds, noradrenergic active compounds, nonsteroidal anti-inflammatory drug, prostaglandins, other compounds that may treat or prevent conditions related to the fallopian tube, uterus, ovaries, or other organs or coverings reached by a composition flowing from the cornua or ostia of a fallopian tube or combinations thereof. Therapeutic compositions comprise hormones for fertility, fertility enhancing compounds, gametes, sperm, ova, combinations of sperm and ova, one or more zygotes, or one or more embryos, or combinations thereof. In methods where delivery of such diagnostic or therapeutic compositions are provided by directly providing such compositions to structures, the compositions may further comprise the intermingling of a gas with the diagnostic or therapeutic composition, and the delivery of the diagnostic or therapeutic compositions may be monitored by techniques such as ultrasound. A composition comprising therapeutic agents combined with the interfaces created by combining a gas with the therapeutic composition using a contrast medium device of the present invention may provide both treatment and diagnosis of the condition of a structure in one step of delivering the composition. Alternatively, the combined therapeutic agent composition with interfaces from gas/liquid phases may be employed to limit or locate the medicament in the targeted structure with the support of sonographic imaging allowing for diagnosis and treatment to occur simultaneously or in sequence. 
       FIG.  1    presents a schematic of an embodiment of contrast medium device  100  comprising container assembly  101 , and shows a portion of a catheter assembly  102  in fluid connection with container assembly  101 , for creating alternating and repetitive interfaces of gas and liquid phases. The container assembly  100  may be coupled to a catheter assembly comprising a catheter  1 . The dimensions of a contrast pattern generating chamber  3  and/or a catheter may have diameters so as to maintain the distinct gas/liquid phases and thereby minimize coalescing of like phases. In some embodiments, diameters of the contrast generating chamber and the catheter may range from about 0.5 mm to about 5.0 mm. A pressure relief valve  2  may minimize undue pressure build up in a structure, such as in a Fallopian tube, if the structure is blocked, such as if a Fallopian tube is not patent. Such valves may be used in line in other locations in the device (not shown) or embodiments may have no valves. It may also function as a secondary relief to an end structure on a catheter, such as a balloon, when the catheter is positioned in the entryway to the Fallopian tube, the cornua, and the end structure acts to hold the catheter in place. 
     The contrast pattern generating chamber  3  creates the phases with interfaces between a liquid (e.g., saline) phase  14  and the gas (e.g., air) phase  13 . Formation of interfaces between gas and liquid phases occurs as the two media enter the contrast pattern generating chamber upon being advanced by dual syringe pump  7 . A rubber septum  4  permits a needle  9  to be inserted into contrast pattern generating chamber  3  with air tight sealing. A liquid phase is introduced into contrast pattern generating chamber  3  through a connection  10 , which may be tubing. The gas or liquid may be provided from either container. Valves may be added in line, such as inn order to prevent possible flow along the path of least resistance, a one-way check valve  12  may be positioned posterior to needle  9 . Preceding the check valve is an in-line aseptic filtration device  5  of 0.2 or so micron porosity, such filters may be used in line for either or both media. Embodiments of the present invention may comprise devices that do not include such valves or filters. Syringe  11   a  as well as syringe  11   b  may be pre-loaded with their respective medium, either liquid or gas, and placed and locked into dual syringe pump  7 . The syringe pump drive block  8  advances the respective gas and liquid syringe plungers  6   a  and  6   b  in a simultaneous fashion. Junction  15  is formed between the contrast generating chamber and a catheter. Vibrator  16  is an optional element that is used to create vibrations through needle  9  to create smaller phases, such as bubbles, of the phase exiting needle  9 , either gas or liquid. 
     An alternative embodiment comprises a dual pump where the drive block comprises two separate drivers for the two individual syringes. This permits the modification of the interface pattern, or the gas/liquid phases, to provide one phase in shorter or longer segments over the other. This could be accomplished by a slower (or faster) rate of delivery by one plunger over the other. 
     Needle  9  diameter may be somewhat smaller or slightly smaller than the diameter of the contrast pattern generating chamber to allow the phase delivered through needle  9  to be affected by the other phase in the contrast pattern generating chamber  3 , so that the phase delivered by needle  9  is dispersed in discrete amounts. For example, surface tension of a liquid, delivered through needle  9 , may cause a definite amount of liquid to detach from the needle end and form a liquid phase within the gas in the contrast pattern generating chamber. For example, the needle gauge can range from about 10 to 30. 
       FIG.  2    is similar to  FIG.  1    except that contrast medium device  200  has a contrast pattern generating chamber having a diameter larger than a delivery catheter.  FIG.  2    is numbered similarly to  FIG.  1   , showing container assembly  201  in fluid connection with catheter assembly  202 . 
       FIG.  3    is similar to  FIG.  1    except that contrast medium device  300  has a contrast pattern generating chamber having a diameter larger than a delivery catheter, and no needle  9  is present.  FIG.  3    is numbered similarly to  FIG.  1   , showing container assembly  301  in fluid connection with catheter assembly  302 . 
       FIG.  4    is a schematic of an embodiment of a container assembly  200  used for creating and delivering an alternating gas/liquid contrast medium to a catheter assembly or similar device. The syringe  10  is packed with a porous substance  20 . The porous substance  20  is partially saturated with a liquid  30 . This may be achieved by withdrawal of the plunger  40 , and submersing the syringe in a liquid, injection of liquid via the syringe opening  50  or other suitable means of placement of the liquid in the interstices of the porous substance  20 . For example, the porous substance may be provided in a wetted state, with the liquid already associated with the porous substance, prior to placement in the container. The syringe opening  50  is properly coupled with or without an aseptic filtration component, to a catheter assembly or similar delivery component to transfer the contrast medium to the desired site. The plunger  40  is gradually advanced so that the liquid and gas phases alternatively exit the syringe opening  50  to the catheter assembly and is delivered to the intended site to be imaged. 
       FIG.  5    is a schematic of visualization of a Fallopian tube using a contrast medium composition of the present invention, and a delivery device of U.S. patent application Ser. Nos. 12/240,738 and 12/240,791. Introducer shaft  60  is shown positioned in the uterus  120 . The catheter assembly  70  is extended from introducer shaft  60  and delivery end of the catheter  80  is in place in the cornua of the uterus. Contrast medium  130  is present in Fallopian tube  90 , and comprises contrast medium  130  with a fluid phase  100  and a gas phase  110 . 
     Methods of the present invention comprise using a contrast medium to observe structures via ultrasound techniques. The present invention comprises making a contrast medium using liquid and gas phases in a pattern using a contrast medium device as described herein. The contrast medium is delivered directly to or in the structure to be visualized by sonography. For example, if Fallopian tubes are to be examined, the contrast medium is delivered to the uterine cornua or at the opening of the Fallopian tube by a catheter. In contrast, other known systems require filling the entire uterus with a liquid, such as saline, and then adding mixed gas/liquid composition to the saline-filled uterus and waiting until the gas/liquid mixture reaches the Fallopian tubes. Procedural limitations exist with such a method in that it requires charging the uterus with enough saline for distension before the introduction of the air and saline to visualize the Fallopian passages, the air present in the uterus or tubes may create air pockets that change fluid flow, and the patient may need to be maneuvered to odd positions for gas flow in a useful direction. The physician must perform multiple switching steps of a complex nature. The present invention may comprise a single step process which uses a simple automated contrast medium device or a handheld contrast medium devices. 
     With the present invention, the direct delivery of the contrast medium comprising a gas/liquid interface pattern from the contrast medium device to the Fallopian tubes will confirm patency of the tubes by the unobstructed flow during visualization and does not result in an unnecessary buildup of material in the cul-de-sac. The delivery volume may be confined to the potential volume of the Fallopian duct, approximately about 2 milliliters, for a single evaluation and may comprise a greater amount to confirm the initial observations. Imaging a Fallopian tube may comprise use of a combined fluid/gas phase composition of from about 0.5 mL to about 20 mL, from about 1 mL to about 15 mL, from about 1 mL to about 5 mL, from about 1 mL to about 10 mL, from about 10 mL to about 20 mL, from about 1 mL to about 3 mL, from about 15 mL to about 20 mL. 
     Tubal blockage may be evident by the lack of contrast medium mobility along the Fallopian tube into the peritoneal cavity. Ensuing pressure relief may be provided by a relief valve in the device or by movement of an end structure on the delivery catheter from its position in the cornua. A device of the present invention lends itself to being automated once the syringes have been inserted into the pumping system or activation by manual delivery once syringes are inserted into or attached to a handheld device. 
     An embodiment of the present invention contemplates a contrast medium delivery device that does not require supplemental systems, such as a liquid reservoirs or valve control of the fluid flow on or attached to the device. A simplified device and methods leads to a higher likelihood of a successful procedure and outcome. Further, the present device is able to maintain the pattern of alternating phases for periods of time that are useful for sonography. This permits the user the freedom to properly locate structures and reposition the patient or structure, or catheter during the procedure. Generally, there is no coalescing of individual phases. The pattern of gas/liquid phases or interfaces created by the contrast medium device is visually observed at the onset and each segment of media and rate of delivery can be controlled to suit the needs of the user. 
     In passageways of structures where the volumes and diameters are large, such those with diameters greater than the dimensions found in Fallopian tubes, the two phases of gas and liquid may be maintained by additives or surfactants, such as those disclosed herein. The contrast medium device may comprise larger containers than the syringes shown herein. For example, one container may be used, and the container may contain a liquid that is foamed. The foam may be created by shaking, adding foaming agents, by sonication or stirring. The foam may be transferred to the cavity to be imaged by transporting the foam from the container assembly through a catheter assembly to the structure to be assessed. It is apparent that other methods of creating the dispersion are possible and can include mechanized means to do so. The phase created by these methods permits one to regulate the sizes of the resultant foam by control of shaking or agitation as well as the types and concentrations of the dispersants. 
     The methods of the present invention allow for assessment of passageways, such as the Fallopian tube and uterine cavity, by ultrasound and provide a simple, safe and inexpensive outpatient method. Methods of the present invention comprise sonigraphically observing a location of a body, such as a uterus and its associated Fallopian tubes, using the devices and compositions disclosed herein. 
     In general, the present invention comprises methods and devices for visualizing structures, by providing contrast medium compositions to the structure and visualization techniques such as ultrasound. Visualization of the contrast medium in or around the structure provides information to the viewer and such methods and devices can be used for diagnosis and treatment of conditions related to the structure viewed. The methods and devices of the present invention are useful for diagnosis and treatment of conditions related to Fallopian tubes of humans and animals. 
     A contrast medium device of the present invention comprises a container assembly comprising at least one container for containing a fluid, a component for moving a fluid from the container, components for connecting the at least one container to the container assembly, and optionally comprising a catheter assembly in fluid connection with the container assembly. In embodiments of the invention, the container is a syringe and the component for moving a fluid from the container is a syringe plunger. Embodiments may further comprise a component for activating the syringe plunger, and the component is a mechanical pump or hand action. The devices may further comprise connecting elements to fluidly connect parts of the devices, valves, needles, filters, vibrators, pumps and other components. 
     Embodiments comprise devices where at least one container further comprises a porous substance and a gas. A porous substance may be any substance that can contain gas and liquid and release the gas and liquid easily upon compression or physical force upon the porous substance. For example, a porous substance may be a sponge, such as open cell polyurethane sponge, that may be compressible. For example, a porous substance may be material that contains a gas and a liquid is rigid, but collapses upon compression, to release the gas and liquid. A porous substance may be provided to a container in a dry state, wherein the porous substance contains gas, and a liquid may be added to the container so that the porous substance contains both a gas and a liquid. Alternatively, the porous substance may be wet, containing both liquid and gas, and thus be provided to a container. More liquid may be added to the container or not after insertion of the wetted porous substance. It is theorized that the porous substance comprises a gas within its pores and a liquid associated therewith the porous substance. The liquid and gas may be found within the pores or associated with the porous material in an easily releasable fashion, such as by surface tension, hydrogen bonding or other weak bonding associations. 
     The liquids provided to containers or porous substances may further comprise a surfactant, emulsifier, other stabilizing agents, or other dispersing agents. The liquids provided to containers or porous substances may further comprise liquids that are foamed. Liquids may be foamed by methods known in the art. 
     Embodiments of the present invention comprise contrast medium devices comprise a container assembly comprising two containers and a pattern contrast generating chamber in fluid connection with the containers. For example, the containers may be syringes, each comprising a component for moving fluid from the container that is a syringe plunger. Such embodiments may further comprising a component for activating the syringe plungers and the component is a mechanical pump or hand action. In two container devices, one container contains a gas and the other container contains a liquid. For example, where the containers are syringes, one contains a gas and the other syringe contains a liquid. In the present invention, where two or more containers are used in a device, the containers may be of the same or different size, volume, diameter, length or made from the same or different materials. 
     A method of the present invention comprising viewing structures using ultrasound techniques known to those skilled in the art. A method of sonographic visualization of a structure comprises, creating a contrast medium comprising alternating phases of a gas and a liquid in a contrast medium device comprising at least one container; providing the contrast medium to a catheter assembly, wherein the catheter assembly comprises a catheter delivery end positioned at or near a structure to be visualized; delivering the contrast medium directly to the structure to be visualized; and viewing the contrast medium in the structure by ultrasound. A method of sonographic visualization of a structure comprises observing a structure having a contrast medium of the present invention contained within it, or flowing through the structure. Methods of the present invention comprise making a contrast medium comprising admixing a gas and liquid in a contrast medium device such that alternating phases of gas and liquid, with visible interfaces between the phases that form a visible pattern by ultrasound, are created to form a contrast medium composition. 
     Any structure that is viewable using ultrasound may be viewed using the contrast medium compositions of the present invention, and contrast medium compositions made by the contrast medium devices taught herein. For example, a structure to be visualized is at least one Fallopian tube of a human or animal. 
     The contrast medium compositions of the present invention may be made with a liquid that is flowable and forms a discrete liquid phase when in contact with a gas. The contrast medium liquid may comprise visualizable liquids or not. The contrast medium composition may further comprise a therapeutic composition. Therapeutic compositions comprise therapeutic agents including, but not limited to, methotrexate, hormones, fertility enhancing compounds, fertility interfering compounds, motility enhancing compounds, motility interfering compounds, compounds affecting the cilia/deciliation cycle, cilia growth enhancing or interfering compounds, ovarian follicle treatment compounds, antibacterial, antimicrobial, antifungal, antiviral, antimycoplasmal, or antiparisital compounds, compounds that reduce inflammation or scar tissue formation, composition comprising one or more antibiotics, antimycoplasma agents, or antiviral compounds; compositions comprising mucoproteins, electrolytes or enzymes to enhance or inhibit fertility, progesterone, estrogen, adrenergic active compounds, noradrenergic active compounds, nonsteroidal anti-inflammatory drug, prostaglandins, other compounds that may treat or prevent conditions related to the fallopian tube, uterus, ovaries, or other organs or coverings reached by a composition flowing from the cornua or ostia of a fallopian tube or any combination thereof, or combinations thereof. Treatment compositions comprise hormones for fertility, fertility enhancing compounds, gametes, sperm, ova, combinations of sperm and ova, one or more zygotes, or one or more embryos, or combinations thereof. 
     Methods of visualization of structures may comprise use of compositions made by a contrast medium device of the present invention. In embodiments, the contrast medium device comprises a container containing a porous substance and a fluid. The porous substance further comprises a gas, and the liquid may comprise a surfactant, emulsifier, other stabilizing agents, or other dispersing agents. The liquid may be foamed. 
     Methods of the present invention comprise delivery of a contrast medium composition of the present invention directly to the structure. For example, a contrast medium composition may be delivered directly to a Fallopian tube. The composition may be delivered by a catheter and the catheter may be provided to the location by devices known in the art and by those taught herein. For example, the catheter may be provided so that the catheter delivery end is positioned in the cornua of a uterus. The contrast medium composition is provided through the catheter and out into the opening of the Fallopian tube, and the composition flows through the Fallopian tube, if possible. The contrast medium composition is visible by ultrasound and the condition of the Fallopian tube can be determined by the visualization, diagnoses may be provided or treatment to the Fallopian tube or other structures may be provided. For example, the patency or occlusion of at least one Fallopian tube is determined when viewing the at least one Fallopian tube by ultrasound. Methods of the present invention comprise using small amounts of contrast medium composition to assess or treat structures, such as a Fallopian tube, and the amount of contrast medium to be provided to the structure is less than 20 mL for a single evaluation. 
     It must be noted that, as used in this specification and the appended claims, the singular forms “a,” “an,” and “the” include plural referents unless the context clearly dictates otherwise. 
     All patents, patent applications and references included herein are specifically incorporated by reference in their entireties. 
     It should be understood, of course, that the foregoing relates only to preferred embodiments of the present invention and that numerous modifications or alterations may be made therein without departing from the spirit and the scope of the invention as set forth in this disclosure. 
     The present invention is further illustrated by the following examples, which are not to be construed in any way as imposing limitations upon the scope thereof. On the contrary, it is to be clearly understood that resort may be had to various other embodiments, modifications, and equivalents thereof which, after reading the description herein, may suggest themselves to those skilled in the art without departing from the spirit of the present invention and/or the scope of the appended claims. 
     EXAMPLES 
     Example 1 
     Preparation of Contrast Medium with Dual Syringe Pump 
     A container assembly comprising a dual pump was made, as generally depicted in  FIG.  1   , with two syringes, one 6 cc and the other 20 cc in volume. The 6 cc syringe was completely filled with saline and the 20 cc was filled with air. Sterile 0.2 μm filters (Sartorius Minisart or Whatman Syrfil-MF) were attached to the syringes, as sterile technique was desired. A 27 gauge, 3.5″ length spinal needle was used to inject a gas phase into a fluid phase in the contrast pattern generating chamber to create the alternating air and liquid phase interfaces. A PICC-Nate catheter T-port extension and two lengths of extension tubing were utilized in the set-up. 
     Variations of syringe ID, pump volume, pump rate and pump delay settings were evaluated and yielded an acceptable contrast medium, as visualized in a catheter assembly forward of the container assembly. The contrast medium was delivered into clear PVC tubing that simulated the dimensions of a Fallopian tube. The user could alter the pattern created with the gas and liquid phases by allowing for increased volumes of gas or liquid and the speed by which the contrast medium was delivered by adjusting the settings on the pump. A fairly regular pattern of gas/liquid phase interfaces was created by the contrast medium device. 
     Example 2 
     Preparation of Contrast Medium with Handheld Dual Syringes 
     The assembly of Example 1 was followed using a housing to support the dual syringes. A block was placed behind the plunger of the 6 cc syringe containing saline to align with the plunger distance of the 20 cc syringe containing air. The creation of the contrast medium and its delivery to a catheter were controlled and manipulated by hand force on the plungers of the dual syringes as necessary to deliver the contrast medium into the catheter. When the two plungers of the syringes were pushed simultaneously, the pattern of the contrast medium was uniform, with substantially equal amounts of air and saline phases, alternating in the catheter. When one plunger was pushed, followed by pushing of the plunger of the other syringe, the pattern was sometimes regular and sometimes irregular, depending on the activation of the individual plungers. Although the sizes of the individual segments of air and saline phases were not uniform, the phases of liquid/air were repeated sufficiently to view easily. The contrast medium was delivered into clear PVC tubing that simulated the dimensions of the Fallopian tube. 
     Example 3 
     Preparation of Contrast Medium with Syringe Containing Porous Substance 
     A sterile Optipore scrubbing sponge was cut lengthwise in two equal parts. The plunger from a 60 cc syringe was removed and the sponge halves were inserted, one behind the other. The plunger was reinserted in the syringe and depressed to the 15 cc mark. The syringe tip was submerged into a sterile container of saline and the plunger was withdrawn to the 30 cc mark. The container assembly was now assembled and loaded. The container assembly was attached to a catheter assembly and the plunger was depressed to create an air and saline composition, a contrast medium composition, for sonographic visualization. The contrast medium was delivered into clear PVC tubing that simulated the dimensions of the Fallopian tube. An irregular pattern or random pattern was visualized as the user controlled the delivery of the contrast medium. Although the sizes of the individual segments of air and saline phases were not uniform, the phases of liquid/air were repeated sufficiently to view easily. 
     Example 4 
     Study of Contrast Medium Created by Dual Syringe Pump in Simulated Model 
     A contrast medium device of  FIG.  1    and Example 1 was used to deliver contrast medium created by the device, made with saline as the liquid phase and air as the gas phase, to a channel sized to mimic the human Fallopian tubes in an ultrasound phantom model (purchased from Blue Phantom, a division of Advanced Medical Technologies, LLC, Kirkland, Wash.). The delivery end of a catheter assembly was positioned in the simulated Fallopian tube. The contrast medium device pump was activated, creating the contrast medium, and the contrast medium was delivered to the model Fallopian tube and resembled the pattern shown in  FIG.  5   . An ultrasound machine (manufactured by GE Medical Systems, model: Voluson 730Pro) was used to visualize the contrast medium created, which traveled in real-time down the channel or simulated Fallopian tube and the gas/liquid phase contrast was visualized with the ultrasound probe. 
     Example 5 
     Study of Contrast Medium Created by Dual Syringe Pump in Human Subjects 
     A contrast medium device of  FIG.  1    and Example 1 was used to deliver contrast medium to human subjects&#39; fallopian tubes. The contrast medium composition was created by the device using saline as the liquid phase and air as the gas phase, each traveling through an aseptic filter of approximately 0.2 microns in size to ensure sterility. The catheter assembly was provided to the human patients using a delivery system, described in U.S. patent application Ser. No. 11/065,886 placed at the cornua of each subject. The contrast medium was delivered through the catheter of the delivery system and was visualized using an ultrasound instrument (manufacturer: GE Medical Systems, Model: Logic 500). Tubal patency was evidenced by contrast medium traversing the Fallopian tubes and exiting into the peritoneal cavity. This evaluation was conducted in real-time with assessment of contrast medium flow evident upon proper positioning of the delivery system. 
     Example 6 
     Study of Contrast Medium Created by Syringe Containing Porous Substance in Simulated Model 
     A contrast medium device like that shown in  FIG.  4    and Example 3 was used to deliver contrast medium created by the device, wherein saline was the liquid phase and air was the gas phase, to a channel sized to mimic the human Fallopian tubes in an ultrasound phantom model (purchased from Blue Phantom, a division of Advanced Medical Technologies, LLC, Kirkland, Wash.). The porous substance used was a highly porous polyurethane open cell foam designed for protective packaging material. A delivery end of a catheter assembly was positioned in the simulated Fallopian tube and the contrast medium device was activated by hand, creating a contrast medium that was more irregular in pattern than that shown in  FIG.  5   . An ultrasound machine (manufactured by GE Medical Systems, model: Voluson 730Pro) was used to visualize the contrast medium created, which traveled in real-time down the channel or simulated Fallopian tube and the gas/liquid phase contrast medium composition was visualized with the ultrasound probe. 
     Example 7 
     Study of Contrast Medium Created by Syringe Containing Porous Substance in Human Subjects 
     A contrast medium device like that shown in  FIG.  4    and Example 3 was used to deliver contrast medium created by the device wherein saline was the liquid phase and air was the gas phase, to human subjects&#39; Fallopian tubes by way of a catheter assembly incorporated in a delivery system as described in U.S. patent application Ser. No. 11/065,886. The delivery device was placed in the uterus of a human subject and the delivery end of one or both catheters were in place in the cornua of the uterus. A 60 cc sterile syringe was packed with a 3×2″ sterile Optipore wound cleansing sponge (manufactured for ConvaTec, division of E. R. Squibb &amp; Sons, LLC, Princeton, N.J.). The sponge was constructed of polyurethane and was highly porous in nature. Saline was drawn into the syringe so as to fill the syringe, but not to remove the air trapped in the sponge. The syringe was attached to the attachment end of one or both catheters of the delivery device. When the plunger of the syringe was depressed, the contrast medium was formed and was delivered through the catheter assembly, and out into the Fallopian tube(s). The contrast medium was visible under ultrasound (manufacturer: Philips, Model: HD3) This evaluation was conducted in real-time with assessment of contrast medium flow evident upon proper positioning of the delivery system.