MRI imaging probe

Information

  • Patent Grant
  • 9332926
  • Patent Number
    9,332,926
  • Date Filed
    Friday, November 25, 2011
    12 years ago
  • Date Issued
    Tuesday, May 10, 2016
    8 years ago
Abstract
A magnetic resonance imaging (MRI) probe includes a coil section having an imaging coil, and a handle section connected to the coil section. The handle section has a phase shifter circuit with inductors, capacitors, and coax line electrically connected and is configured to provide appropriate phase shift. The handle section further has a coaxial cable winding electrically connected to the imaging coil, and wound cylindrically, and has a slot therethrough between the ends of the cylindrical winding. The handle section further has a pre-amp circuit mounted on a substrate and electrically connected to the cylindrical coax winding.
Description
FIELD OF INVENTION

This invention relates to the field of medical imaging and more specifically to the field of magnetic resonance imaging (MRI).


SUMMARY OF THE INVENTION

In an aspect of the present invention, there is a MRI imaging probe comprising a coil section having an imaging coil and a handle section connected to the coil section. The handle section having a phase shifter circuit comprising a first set of inductors and capacitors electrically connected, a coaxial cable winding electrically connected to the imaging coil and wound cylindrically, and having a slot therethrough between the ends of the cylindrical winding. The handle section further having a pre-amp circuit mounted on a substrate and electrically connected to the cylindrical winding, wherein at least a portion of the substrate is contained within the slot of the coaxial cable winding.


The imaging coil may have a passive tuning circuit. The probe may further comprise a fiducial marker in the coil section. The coil section and the handle section may be substantially cylindrical. The MRI probe may further comprise a substantially cylindrical neck section connecting the coil section to the handle section. The neck section may have a smaller diameter than that of the coil and handle sections. The coil section, handle section and neck portion may be aligned along a longitudinal axis. The substrate may be substantially planar and may be parallel to the longitudinal axis. The slot may be aligned along the longitudinal axis.


The MRI imaging probe may further comprise a second imaging coil in the coil section. The second imaging coil may have a second passive tuning circuit, and may be electrically connected to the first imaging coil through a decoupling circuit. There may also be a second set of inductors and capacitors electrically connected, a second coaxial cable winding electrically connected to the second imaging coil and wound cylindrically around the slot of the first cylindrical winding. There may also be a second pre-amp circuit mounted on the substrate electrically connected to the second cylindrical winding.


The first and second coaxial cylindrical windings may be wound radially relative to each other. The first and second cylindrical windings may also be wound side-by-side. The decoupling circuit may comprise a decoupling capacitor.


The MRI imaging probe may further comprise a coil shell substantially surrounding the coil section and the neck section. The coil shell may comprises a slot therethrough, the slot permitting passage through the coil section of the probe. The coil section may also have a passage therethrough, the passage being aligned with the slot of the coil shell. The slot may extend from a first surface region of the coil shell at the neck section, to a second surface region of the coil shell at the coil section.


The coil shell may have a smaller diameter around the neck section than around the coil section. The MRI imaging probe may further comprise a handle shell substantially surrounding the handle section, and the handle shell may be connected to the coil shell.





BRIEF DESCRIPTION OF THE FIGURES

For a better understanding of embodiments of the system and methods described herein, and to show more clearly how they may be carried into effect, reference will be made by way of example, to the accompanying drawings in which:



FIG. 1 shows an exploded view of an embodiment of an MRI imaging probe;



FIG. 2 shows a circuit diagram of an embodiment of an MRI imaging probe;



FIG. 3 shows a circuit diagram of an alternative embodiment of an MRI imaging probe;



FIG. 4 shows an embodiment of a two channel MRI coil of an MRI imaging probe;



FIG. 5 shows an alternate view of the MRI coil shown in FIG. 4;



FIG. 6 shows an embodiment of the connection of the MRI coil shown in FIG. 4 with transmission cables;



FIG. 7 shows an alternative embodiment of a MRI coil having a fiducial marker;



FIG. 8 shows an embodiment of a phase shifting and pre-amp circuit for use with an MRI imaging probe;



FIG. 9A to 9D shows an embodiment of an MRI imaging probe in a protective casing; and



FIG. 9E shows an alternate embodiment of a protective casing.





DETAILED DESCRIPTION

It will be appreciated that for simplicity and clarity of illustration, where considered appropriate, reference numerals may be repeated among the figures to indicate corresponding or analogous elements or steps. In addition, numerous specific details are set forth in order to provide a thorough understanding of the embodiments described herein. However, it will be understood by those of ordinary skill in the art that the embodiments described herein may be practiced without these specific details. In other instances, well-known methods, procedures, and components have not been described in detail so as not to obscure the embodiments described herein. Furthermore, this description is not to be considered as limiting the scope of the embodiments described herein in any way, but rather as merely describing the implementation of the various embodiments described herein.


Prostate diseases represent a significant health problem. In the United States, metastatic prostate cancer is currently the third leading cause of death among the American men over fifty years, resulting in approximately 31,000 deaths annually. The definitive diagnostic method of prostate cancer tends to be core needle biopsy. Currently, transrectal ultrasound (TRUS) guided needle biopsy is a technique being utilized for the diagnosis of prostate cancer and contemporary intraprostatic delivery of therapeutics tends to be also primarily performed under TRUS guidance. This technique has been popular due to its specificity, real-time nature, low cost, and apparent simplicity. At the same time, however, TRUS-guided biopsy also tends to fail to correctly detect the presence of prostate cancer in approximately 20% of cases.


Magnetic resonance imaging (MRI) detects faint nuclear magnetic resonance (NMR) signals given off by protons in the presence of a strong magnetic field after excitation by a radio frequency signal. The NMR signals are detected using antennae termed “coils”. NMR signals are extremely faint, and so the ability for a coil to detect these signals tends to decrease with increasing distance between the coil and the tissue being imaged.


In typical operation, coils are be tuned to the Larmor frequency associated with the magnet field strength of the main MRI field (or B0 field) in which it is meant to operate. For example, an MRI magnet having a 1.5 T main field requires a coil tuned to 63.86 MHz, and an MRI magnet having a main field of 3.0 T requires 127.7 MHz. In current commercial coils, the coil elements or antenna are typically inseparable from the patient support structure, or are inseparable from the coil housing.


Coils local to the tissue being imaged, such as the prostate, tend to have a higher signal-to-noise ratio (SNR) than coils positioned further away from the tissue, even if the coils that are positioned close to the tissue of interest are smaller than those positioned further away; however, due to the physical location of a person's prostate many existing MRI coils, such as surface coils, are ineffective at obtaining images of a prostate with a high SNR. However, if a coil can be inserted with a cavity of a patient such that it is closer in proximity to the prostate, or other tissue of interest, this can tend to be advantageous to improve SNR of the resulting MRI image obtained.


Additionally, in current MRI applications, due to the low currents and signals obtained by the coils due to the faint NMR signals, the signal obtained are boosted and/or filtered by a pre-amp circuit. However, in such MRI coil applications, the pre-amp circuits are not located proximate to the MRI coil, due to space constraints, especially for MRI coils intended for insertion inside an orifice of a patient, such as the rectum of a patient. To improve SNR of the resulting image it will tend to be advantageous to position the pre-amp circuit proximate the coils to avoid signal losses through lengthy transmission cables from the coil to the pre-amp circuit.


Another consideration for imaging is varying the position in which the tissue is imaged, for example being able to image a tissue in a patient when the patient is in multiple positions, such as the prone position (lying on their stomach), in the supine position (lying on their back) or when lying on their side.


Therefore, it may be desirable to have an improved MRI coil that having improved SNR capabilities that is portable and is capable of use within a cavity of a patient to image tissue that is otherwise difficult to obtain through traditional external MRI coils.


Referring to FIG. 1, MRI imaging probe 100 is shown in an exploded view. In the embodiment shown, MRI imaging probe has coil section 102 and handle section 104, with coil section 102 having imaging coil 110 and handle section 104 having phase shifting circuit 106 and pre-amp circuit 108.


In the embodiment shown, MRI imaging probe 100 is a two channel MRI imaging probe, having two MRI coils; however, in FIG. 1, only one of the two coils, coil 110, is visible with the other coil being hidden from view. In the embodiment shown in FIG. 1, coil 110 has passive tuning circuit 112 which operates as an impedance choke, and blocks out high induced currents, when activated by a PIN diode switched on by voltages induced by the RF transmit field of the MRI magnet when in use.


As discussed above, while not shown in FIG. 1, MRI imaging probe has two channels, having imaging coil 110 and a second imaging coil that is not visible. The two imaging coils are decoupled physically with a small overlap and through a decoupling capacitor (as discussed further below), configured to decouple the two coils and reduce signals in one coil that are induced from current, such as noise current, flowing in the other coil, which can tend to improve the SNR of MRI imaging probe 100.


With reference to FIGS. 4 and 5 alternative views of coil section 102 is shown, where the two imaging coils 110 and 402 are shown. As shown in FIG. 4, coil 110 has passive tuning circuit 112 and while not visible, coil 402 has a corresponding passive tuning circuit positioned in a similar position in the other side of section 102 (See FIGS. 2 and 3)


Additionally, as shown in FIG. 4, coil section 102 contains passage 410, which can be used to position or allow a medical instrument or instruments to pass through, such as a biopsy needle, to allow a user to take biopsy samples from a tissue of interest in a patient through an orifice that coil section 102 is positioned within. For example, when coil section 102 of MRI imaging probe 100 is positioned within a patient's rectum through their anus, a user can position a biopsy needle through passage 410 to obtain biopsy tissue samples of a patient's prostate.


Referring to FIGS. 4 and 5, coils 110 and 402 decoupled physically with a small physical overlap and connected with a decoupling capacitor 404 which, as discussed above, is configured to decouple the two coils and reduce signals in one coil that are induced from current, such as noise current, flowing in the other coil, which can tend to decrease the SNR of MRI imaging probe 100.


Reference will now be made to various positions on coil section 102 that are visible in the Figures (such as the top, bottom and side relative to the view of the elements shown in the Figures); however, skilled persons will appreciate that the coil is not limited by the specific positional references made, and that the positional references are only referred to for the purpose of describing the elements in the Figures.


As shown in FIG. 4, coil 110 is position on the top of coil section 102 close to and along one side (referred to as the back side for convenience) of passage 410 while coil 402 is positioned close to and along the path of the other side (referred to as the front side for convenience) of passage 410. Decoupling capacitor 404 is positioned close to the tip of coil section 102 which, in the embodiment shown is a curved tip that can tend to provide improved patient comfort when inserted into an orifice of the patient.


Coil 110 and coil 402 are each decoupled physically with a small overlap of the coils and decoupled electrically by decoupling capacitor 404, with coil 110 continuing through decoupling capacitor 404 along the front side of coil section 102 and coil 402 continuing through decoupling capacitor 404 along the back side of coil section 102 (not visible in FIG. 4).


With reference to FIG. 6, coil 110 is electrically connected to transmission line 120 through backplate 602 and coil 402 is electrically connected to transmission line 122 through backplate 602; however, skilled persons will appreciate that in some embodiments, backplate 602 may not be used and transmission lines 120 and 122 may be electrically connected or coupled directly to coil 110 and 402 respectively.


Referring back to FIG. 1, in the embodiment shown, handle portion 104 has substrate 130 on which pre-amp circuit 108 is mounted, and handle portion 104 additionally includes shifting circuit 106. In the embodiment shown, a second pre-amp circuit (not shown) is mounted on the reverse side (or underside, as shown) of substrate 130, each pre-amp circuit being associated with one of the two channels of MRI imaging probe 100; however, in other embodiments the second pre-amp circuit can be mounted on substrate 130 in another position. In the embodiment shown, pre-amp circuit 108 (as well as the second pre-amp circuit 108′ in FIG. 9D) is a low input impedance device that has additional circuitry, to provide pre-amp decoupling which can tend to reduce current in coil 110 or 402 and reduce the coupling between coils 110 and 402.


With additional reference to FIG. 8, phase shifting circuit 106 shifts the phase of the received input signal so that the input to pre-amp circuit 108 has the desired inductance such that it resonates with the capacitance in line with coil 110. This can tend to decouple the pre-amp from the coil to increase SNR and filter any unwanted noise generated by currents, such as noise currents, or other undesired signals. In the embodiment shown, phase shifting circuit 106 consists of an inductor and a capacitor for each input signal received (in the embodiment shown, being two input signals, one for each channel of MRI imaging probe 100) maintains the characteristic 50 ohms impedance which is necessary to proper noise matching for the preamp in the embodiment. It will be appreciated that in other embodiments, alternate circuits may be provided to shift the phase.


In the embodiment shown, phase shifting circuit 106 consists of two coaxial cables 134 and 136 wound cylindrically around cylinder 144 having groves therein to seat coaxial cables 134 and 136 in their desired position, and cylinder 144 further has end-caps 140 and 142, that are comprised of a substrate whereby further electrical components can be applied (in the embodiment shown, the capacitors of phase shifting circuit 106 are mounted on end-caps 140 and 142). In this embodiment, coaxial cables 134 and 136 form an inductance with their coax shields that can be resonated with appropriate capacitance to provide high impedance to surface currents on the coax shield. Additionally, in such embodiments, coaxial cables 134 and 136 can convert the signal generated by coils 110 and 402 from a balanced signal or output to an unbalanced signal or output.


In alternative embodiments, coaxial cables 134 and 136 can be wound cylindrically such as around substrate 104, but may not be mounted or positioned around any additional components (such as cylinder 144). In such embodiments, the stiffness of coaxial cables 134 and 136 may be such that they will not deform under normal operation.


In the embodiment shown in FIG. 8, coaxial cables 134 and 136 are wound side-by-side and held together by solder applied in between them; however, in alternative embodiments, coaxial cables 134 and 136 can be mounted radially, with one coaxial cable being mounted on top of the other in the cylindrical winding. In such alternative embodiments, coaxial cables 134 and 136 may be further soldered together.


In the embodiment shown, end-caps 140 and 142 have slots substantially centered in them and a portion of substrate 130 is inserted into end-caps 140 and 142 with a portion of substrate 130 projecting out of each slot. In such embodiments, the portion of substrate that is positioned between end-caps 140 and 142 can be serpentine shape, which can provide strain relief during thermal expansion.


In other embodiments, for example, in those embodiments having no end-caps 140 and 142, substrate 130 can be positioned in a slot, or cavity, formed within the cylindrical windings of coaxial cables 134 and 136 such that a portion of substrate 130 is positioned with the winding, and may project out of one or both sides of the windings.


Coil 110 is electrically connected to coaxial cable 134 by transmission line 120 and connector 150. In the embodiment shown, transmission line 120 is a coaxial cable and is connected to connector 150 through a threaded engagement; however, skilled persons will appreciate that the other means of electrically connecting transmission line 120 to coaxial cable 134 can be implemented.


Additionally, the second channel of MRI probe 100 comprising coil 402 that is not shown in FIG. 1, is connected to coaxial cable 136 through transmission line 122 and can be connected to coaxial cable 136 through a connector that is similar to connector 150 that, in the embodiment shown in FIG. 1 is positioned on the other side (or underside) of substrate 130 and is not shown.


In the embodiment shown, coaxial cable 134 is electrically connected to transmission line 120 at end-cap 140 and coaxial cable 136 is electrically connected to transmission line 122 at end cap 142. In this embodiment, when a first current (or signal) flows through coaxial cable 134 and a second current (or signal) flows through coaxial cable 136, each will be flowing in the opposite direction when MRI imaging probe 100 is in use.


Pre-amp circuit 108, in the embodiment shown, is electrically connected to signal output component 160 which can be electrically connected to a transmission cable or other signal line (not shown) for transmitting signals to an MRI workstation (not shown) for signal processing in order to generate an image of the tissue being imaged with MRI probe 100. In the embodiment shown, the second pre-amp circuit (not shown) that is positioned on the underside of substrate 130 has an additional signal output component (not shown) for transmitting signals generated by the second channel of MRI probe 100 for processing and generation of an MRI image of the tissue being imaged.


Referring again to FIG. 1, protective shell 160 is shown, having coil shell 170 and handle shell 172. MRI imaging probe 100 can be enclosed within protective shell 160 to protect the tissue of a patient that is being imaged by MRI imaging probe 100 from interfering with electrical components and to provide for the sterility of MRI probe 100. In the embodiment shown, coil shell component 170 is cylindrically shaped for a snug fit over coil section 102. In the embodiment shown, coil shell 170 further includes an integral neck shell 174 having a smaller diameter. In the embodiment shown, transmission lines 120 and 122 are positioned with neck shell 174 and extend out the end of coil shell 170. Skilled persons, however, will appreciate that neck shell 174 can be the same diameter as coil shell component 170, or may not be necessary for certain applications.


Handle shell 172 fits over handle section 104 and covers substrate 130 and phase shifting circuit 106 to protect the electronics and to allow an operator to grip MRI imaging probe 100 when in use. In the embodiment shown, coil shell component 170 is removably connected to handle shell 172, and as shown coil shell component 170 has a fitment flange extending therefrom that is inserted into an end of handle shell 172 to form a frictional engagement; however, skill persons will appreciate that other means of attachment can be used, such as for example, a threaded connection. An embodiment of MRI imaging probe 100 contained in protective shell 160 is shown in FIG. 9A to 9D. In FIG. 9E, an alternate embodiment having a shell casing comprising coil shell 970 and handle shell 972 is shown.


In the embodiment shown, neck portion 174 includes slot 176 that can be used to position medical instruments therethrough, such as biopsy needles, so that when MRI imaging probe is in use, a biopsy needle can be inserted through the orifice that probe is inserted within to obtain a biopsy of a tissue being imaged by MRI imaging probe 100. In some embodiments, slot 176 can be aligned with passage 410 of coil section 102, shown on FIG. 4 and on other embodiments, slot 176 may not be necessary, for example in embodiments that are for imaging only or where alternative biopsy tools may be used.


In use, coil section 102 of the embodiment shown in FIG. 1, once encased in coil shell component 170, can be inserted through an orifice of a patient, such as the anus, and extended into the patient's rectum such that coil 110 is positioned close to the tissue near the patient's prostate or other tissue being imaged. In such uses, the anus may contract around neck portion 174 which can tend to offer additional patient comfort and to assist in preventing slippage of MRI imaging probe 100 when in use.


In such embodiments, at least a portion of neck portion 172 can be inserted past the anus and into the rectum of the patient such that slot 176 may have at least a portion of it (and in some embodiments, the aligned passage 410 of coil section 102) is within the rectum of the patient. When this is the case, medical instruments, such as a biopsy needle, can be inserted through the portion of slot 176 that is outside of the patient and can be positioned along the slot such that they pass through the slot beyond the patient's anus and into the rectum, where such medical instruments can be then manipulated so that the end of such instruments are delivered to the tissue of interest to, in some embodiments, obtain a biopsy sample (such as from the patient's prostate) for later analysis.


With reference to FIG. 2, a circuit drawing representative of circuitry associated with each RF coil of the MRI imaging probe is shown, the circuit comprising coil 202, transmission line 204, phase shifter circuit 206 and pre-amp circuit 208. In the embodiment shown, phase shifter circuit 206 consists of inductor 216 and capacitor 210, that operate such that the phase of the electrical input signal is shifted and a desired impedance is input into the pre-amp circuit that resonates with capacitor 212 and capacitor 214 of coil 202. For example, in some embodiments, such as in MRI applications, an impedance of 50 ohms on either side of phase shifter circuit 206 may be desirable.


In the embodiment shown, capacitor 214 will exhibit a high impedance, or Z, value, which can assist in decoupling in coil 202, and which can tend to increase the SNR of the coil and improve the MRI image generated using the MRI imaging probe.


With reference to FIG. 3, an alternative embodiment of a circuit drawing representative of the circuitry associated with each RF coil of the MRI imaging probe of an MRI imaging probe is shown, the circuit comprising coil 302, transmission line 350 and amplifier 330. In the embodiment shown, coil 302 is an MRI receive coil and comprises passive blocking circuit 304, which, in the embodiment shown, is comprised of an inductor and capacitor operating in parallel with cross diodes electrically connected to each. In the embodiment shown, passive blocking circuit 304 operates to reduce current flow which may be induced into coil 302 during the transmit phase of an MRI acquisition, and which can be activated by the body RF transmit field.


Coil 302, in the embodiment shown, further includes active blocking circuit 306, comprising an inductor, capacitor and diode in series. In the embodiment shown, active blocking circuit 306 additionally operates to reduce current flow within coil 302 during the transmit phase of an MRI acquisition using coil 302, to reduce current, and which can be enabled during the transmit phase of the MRI image acquisition.


Coil 302 further comprises coil decoupling circuit 308, which comprises one or more capacitors, some of which may be variable capacitors, electrically connected in parallel. In the embodiment shown, decoupling circuit 308 is comprised of one variable capacitor and one non-variable capacitor, electrically connected in parallel. Coil decoupling circuit 308 operates to decouple currents, such as noise current, and/or other signals that may be induced from other electronic components positioned proximate to coil 302. In some embodiments, such as applications having two coil channels, coil decoupling circuit 308 can decouple coil 302 from another coil channel to reduce any induced current in coil 302 caused by currents, such as noise current, in the other coil channel.


Coil 302 further comprises coil tuning circuit 310 and coil matching circuit 312. Coil tuning circuit 310 operates to tune the resonance frequency of coil 302 and in combination with coil matching circuit 312 gives coil 302 an output impedance of 50 ohms in the embodiment.


Coil 302 is connected to amplifier 330 by transmission line 350, which, in some embodiments, can be a coaxial cable that electrically connects coil 302 to amplifier 330.


In the embodiment shown, amplifier 330 is comprised of coil tuning circuit 332, decoupling and choke circuit 334, phase shifting circuit 336, pre-amp protection circuit 338, pre-amp 340 and output line 342.


Timing circuit 332 is formed by the inductance of the shield with appropriate capacitance. This combination of the embodiment is a tank circuit that will insert a high impedance on the shield to common mode currents that may be induced. Construction of this circuit, as explained above, will tend to provide the appropriate protection to the circuitry of amplifier 330 from the RF induced voltages and currents. In the embodiment, the configuration as shown tends to be advantageous to permit circuit 332 to dissipate sufficient heat during RF transmit pulses.


Decoupling and choke circuit 334 comprises a capacitor and inductor electrically connected in series and operates as an impedance choke to block out high induced currents in amplifier 340.


In the embodiment shown, phase shifter circuit 336 consists of an inductor and two capacitors, connected in shunt across the inductor, pi configuration, that operate such that the phase of the electrical input signal through the phase shifter circuit 336 is shifted, while maintaining an input and output impedance of 50 ohms. In other embodiments, a T configuration may be used. In either case, the circuit is to adjust the phase lag introduced by the transmission line 350 and circuit 332, to a phase equal to a phase necessary to resonant with matching circuit 312 and circuit 310 of coil 302.


Pre-amp protection circuit 338, as shown in the embodiment, forms a voltage limiter that operates to prevent voltage spikes into pre-amp circuit 340.


In the embodiment shown, amplifier 340 amplifies the received signal and outputs the amplified signal through output line 342, which can be connected to an MR receiver. This signal can then be amplified and converted to digital form so MRI imaging software can interpret the amplified signals output through output line 342, and use such signals to generate an MRI image of the tissue being imaged.


The present invention has been described with regard to specific embodiments. The scope of the claims should not be limited by the preferred embodiments set forth in the examples, but should be given the broadest interpretation consistent with the description as a whole. It will be obvious to persons skilled in the art that a number of variants and modifications can be made without departing from the scope of the invention as described herein.

Claims
  • 1. An endocavity MRI imaging probe for use in a magnetic resonance imager (MRI) which generates a main magnetic field, the probe comprising: a coil section having an imaging coil, the coil section being configured for insertion into an orifice of a patient;a handle section connected to the coil section, the handle section being configured to be grasped manually by a clinician during positioning of the handle section having: a phase shifter circuit comprising a set of inductors and capacitors electrically connected, a coaxial cable winding including a coaxial cable electrically connected to the imaging coil and wound around a cylinder; anda pre-amp circuit mounted on a substrate and electrically connected to the coaxial cable winding, wherein at least a portion of the substrate passes through and is supported by the coaxial cable winding.
  • 2. The probe of claim 1, wherein the imaging coil includes a passive tuning circuit.
  • 3. The probe of claim 2, further comprising a fiducial marker disposed in the coil section.
  • 4. The probe of claim 3, wherein the coil section and the handle section are cylindrical and further including: a cylindrical neck section connecting the coil section to the handle section, the neck section having a smaller diameter than that of the coil and handle sections, the neck section, the coil section, the handle section and the neck section being aligned along a longitudinal axis.
  • 5. The probe of claim 4, wherein the substrate is planar and is parallel to the longitudinal axis.
  • 6. The probe of claim 1, comprising: a second imaging coil in the coil section, the second imaging coil having a second passive tuning circuit and electrically connected to the first imaging coil through a decoupling circuit;a second set of inductors and capacitors electrically connected, a second coaxial cable winding electrically connected to the second imaging coil and wound cylindrically around the slot of the first cylindrical winding; anda second pre-amp circuit mounted on the substrate electrically connected to the second cylindrical winding.
  • 7. The probe of claim 6, wherein the first and second coaxial cylindrical windings, the coaxial cables of the first and second coaxial cylindrical windings being wound on the cylinder radially relative to each other.
  • 8. The probe of claim 6, wherein the first and second coaxial cylindrical windings, the coaxial cables of the first and second coaxial cylindrical windings being wound side-by-side on the cylinder.
  • 9. The probe of claim 8, wherein the second coaxial cable windings are wound in opposite directions around the cylinder.
  • 10. The probe of claim 4, further comprising a coil shell surrounding the coil section and the neck section.
  • 11. The probe of claim 10, wherein the coil section further has a passage therethrough, and the coil shell defines a slot therethrough aligned with the passage, the slot and passage permitting passage of a medical instrument to pass through the coil section of the probe.
  • 12. The probe of claim 11, wherein the slot extends from a first surface region of the coil shell at the neck section, to a second surface region of the coil shell at the coil section.
  • 13. The probe of claim 10, further comprising a handle shell surrounding the handle section, the handle shell being connected to the coil shell.
  • 14. An endorectal MR imaging probe for use in imaging a prostate of a patient disposed in a magnetic resonance imager, the probe comprising: a coil section including: first and second RF coils,a decoupling circuit configured to decouple the first and second RF coils,blocking circuitry configured to block currents in the first and second RF coils during a transmit phase of an MRI acquisition, andtuning and matching circuitry configured to tune a resonance frequency and an output impedance of the first and second RF coils;a neck section connected with the coil section and including a coaxial transmission lines connected with the tuning and matching circuitry;a handle section connected with the neck section, the coil section, the neck section and the handle section being axially aligned, the handle section including: tuning circuitry connected with the coaxial transmission lines,phase shift circuitry connected with the tuning circuitry, andpreamplifier circuits connected with the phase shift circuitry.
  • 15. The probe of claim 14, wherein the phase shift circuitry includes: first and second coaxial cable sections, each connected via the tuning circuitry with one of the transmission lines, the first and second coaxial cables being wound around a cylinder; andwherein the preamplifier circuits are mounted on a substrate, the substrate being supported by the cylinder of the phase shift circuitry.
  • 16. The probe of claim 15, wherein the first and second coaxial cables are wound around the cylinder in opposite directions.
  • 17. An endocavity magnetic resonance imaging probe comprising: a coil section including at least one imaging coil, the coil section being configured for insertion into an orifice of a patient, the imaging coil being configured to receive RF resonance signals induced by a magnetic resonance imager which is configured to receive at least a portion of the patient adjacent the orifice;a neck section connected with the coil section, the neck section including a transmission line configured to convey the resonance signals received by the imaging coil;a handle section connected with the neck section, the handle section being configured to be grasped by a clinician during positioning of the coil section in the orifice, the handle section including: a phase shift circuit including a coaxial cable wound around a cylinder, the coaxial cable which is wound around the cylinder is electrically connected with the transmission lines to phase shift the received resonance signal, anda preamplifier circuit mounted on a substrate, the substrate passing through and being supported by the phase shift circuit cylinder, the preamplifier circuit being connected with the phase shift circuit and configured to amplify the phase shifted received resonance signal.
  • 18. The probe of claim 17, wherein the coil section, the neck section, and the handle section are aligned along a longitudinal axis and the neck section being smaller in cross-section than the coil section and wherein the cylinder of the phase shift circuit and the substrate are aligned along the longitudinal axis.
  • 19. The probe of claim 18, wherein the neck and coil portion define a passage therethrough, the passage being configured to receive a medical instrument inserted in through the neck section and exiting through the coil section.
  • 20. The probe of claim 19, wherein: the coil section further includes a second RF coil and a decoupling circuit for decoupling the first and second RF coils;the neck section includes a pair of transmission lines; andthe phase shift circuit disposed in the handle section includes first and second coaxial cables which are wound in opposite directions around the cylinder.
RELATED APPLICATIONS

This application claims priority from U.S. Provisional Patent Application No. 61/417,270 filed Nov. 25, 2010 and U.S. Provisional Application No. 61/417,271 filed Nov. 25, 2010, the contents of each of which are herein incorporated by reference.

US Referenced Citations (197)
Number Name Date Kind
3115140 Volkman Dec 1963 A
3523251 Halstead Aug 1970 A
4503844 Siczek Mar 1985 A
4552346 Schnelle et al. Nov 1985 A
4572203 Feinstein Feb 1986 A
4733661 Palestrant Mar 1988 A
4825162 Roemer et al. Apr 1989 A
4930516 Alfano et al. Jun 1990 A
4930525 Palestrant Jun 1990 A
4943986 Barbarisi Jul 1990 A
4989608 Ratner Feb 1991 A
5014968 Lammers et al. May 1991 A
5047036 Koutrouvelis Sep 1991 A
5072721 Weiler et al. Dec 1991 A
5096216 McCalla Mar 1992 A
5154179 Ratner Oct 1992 A
5158088 Nelson Oct 1992 A
5196019 Davis et al. Mar 1993 A
5297551 Margosian et al. Mar 1994 A
5308352 Koutrouvelis May 1994 A
5426685 Pellegrino et al. Jun 1995 A
5534869 Harman Jul 1996 A
5548218 Lu Aug 1996 A
5569266 Siczek Oct 1996 A
5575798 Koutrouvelis Nov 1996 A
5590653 Aida et al. Jan 1997 A
5590655 Hussman Jan 1997 A
5594337 Boskamp Jan 1997 A
5678549 Heywang-Koebrunner et al. Oct 1997 A
5682098 Vij Oct 1997 A
5682890 Kormos et al. Nov 1997 A
5706812 Strenk et al. Jan 1998 A
5744958 Werne Apr 1998 A
5782764 Werne Jul 1998 A
5817023 William Daft Oct 1998 A
5855554 Schneider et al. Jan 1999 A
5868673 Vesely Feb 1999 A
5868757 Koutrouvelis Feb 1999 A
5944023 Johnson et al. Aug 1999 A
6051974 Reisker Apr 2000 A
6066102 Townsend et al. May 2000 A
6091985 Alfano et al. Jul 2000 A
6159221 Chakeres Dec 2000 A
6163616 Feldman Dec 2000 A
6163717 Su Dec 2000 A
6174291 McMahon et al. Jan 2001 B1
6201392 Anderson et al. Mar 2001 B1
6229145 Weinberg May 2001 B1
6263229 Atalar et al. Jul 2001 B1
6281681 Cline et al. Aug 2001 B1
6295671 Reesby et al. Oct 2001 B1
6298506 Heinold et al. Oct 2001 B1
6302579 Meyer et al. Oct 2001 B1
6324243 Edic et al. Nov 2001 B1
6334067 Brabrand Dec 2001 B1
6421454 Burke et al. Jul 2002 B1
6421553 Costa et al. Jul 2002 B1
6437567 Schenck et al. Aug 2002 B1
6446286 Karmalawy Sep 2002 B1
6459923 Plewes et al. Oct 2002 B1
6470204 Uzgiris Oct 2002 B1
6498489 Vij Dec 2002 B1
6501980 Carlon Dec 2002 B1
6521209 Meade et al. Feb 2003 B1
6526299 Pickard Feb 2003 B2
6591128 Wu et al. Jul 2003 B1
6593101 Richards-Kortum et al. Jul 2003 B2
6628983 Gagnon Sep 2003 B1
6639406 Boskamp et al. Oct 2003 B1
6640364 Josephson et al. Nov 2003 B1
6675037 Tsekos Jan 2004 B1
6697652 Georgakoudi et al. Feb 2004 B2
6723303 Quay Apr 2004 B1
6806711 Reykowski Oct 2004 B2
6810595 Chan Nov 2004 B2
6822450 Klinge et al. Nov 2004 B2
6867593 Menon et al. Mar 2005 B2
6904305 Tsekos Jun 2005 B2
6922859 Gagnon et al. Aug 2005 B2
6927406 Zyromski Aug 2005 B2
6950492 Besson Sep 2005 B2
7011447 Moyers Mar 2006 B2
7020314 Suri et al. Mar 2006 B1
7023209 Zhang et al. Apr 2006 B2
7024027 Suri et al. Apr 2006 B1
7024711 Stasney et al. Apr 2006 B1
D533278 Luginbuhl et al. Dec 2006 S
7155043 Daw Dec 2006 B2
7166113 Arambula et al. Jan 2007 B2
7176683 Reeder et al. Feb 2007 B2
7245125 Harer et al. Jul 2007 B2
7245694 Jing et al. Jul 2007 B2
D569977 Luginbuhl et al. May 2008 S
7373676 Markovic et al. May 2008 B2
7379769 Piron et al. May 2008 B2
7545966 Lewin et al. Jun 2009 B2
7583786 Jing et al. Sep 2009 B2
7656993 Hoernig Feb 2010 B2
7711407 Hughes et al. May 2010 B2
7809426 Kim et al. Oct 2010 B2
7881428 Jing et al. Feb 2011 B2
7908690 Luginbuhl et al. Mar 2011 B2
7925328 Urquhart et al. Apr 2011 B2
7937132 Piron et al. May 2011 B2
7970452 Piron et al. Jun 2011 B2
8050736 Piron et al. Nov 2011 B2
8155417 Piron et al. Apr 2012 B2
8162847 Wale et al. Apr 2012 B2
8162848 Hibner et al. Apr 2012 B2
8162849 Deshmukh et al. Apr 2012 B2
8241301 Zhang et al. Aug 2012 B2
8290569 Piron et al. Oct 2012 B2
8292824 Okada Oct 2012 B2
8298245 Li et al. Oct 2012 B2
20010011394 Heimbrock et al. Aug 2001 A1
20010039378 Lampman et al. Nov 2001 A1
20020035864 Paltieli et al. Mar 2002 A1
20020056161 Falbo et al. May 2002 A1
20020073717 Dean et al. Jun 2002 A1
20020095730 Al-Kassim et al. Jul 2002 A1
20020099264 Fontenot Jul 2002 A1
20020131551 Johnson et al. Sep 2002 A1
20020156365 Tsekos Oct 2002 A1
20020156370 Desouza Oct 2002 A1
20020164810 Dukor et al. Nov 2002 A1
20020180442 Vij Dec 2002 A1
20020193815 Foerster et al. Dec 2002 A1
20030007598 Wang et al. Jan 2003 A1
20030191397 Webb Oct 2003 A1
20030194050 Eberhard et al. Oct 2003 A1
20030199753 Hibner et al. Oct 2003 A1
20030199754 Hibner et al. Oct 2003 A1
20030206019 Boskamp Nov 2003 A1
20040077972 Tsonton et al. Apr 2004 A1
20040081273 Ning Apr 2004 A1
20040183534 Chan et al. Sep 2004 A1
20040216233 Ludwig et al. Nov 2004 A1
20040220467 Bonutti Nov 2004 A1
20050005356 Zacharopoulos et al. Jan 2005 A1
20050033315 Hankins Feb 2005 A1
20050059877 Falbo Mar 2005 A1
20050080333 Piron et al. Apr 2005 A1
20050104591 Qu et al. May 2005 A1
20050228267 Bulkes et al. Oct 2005 A1
20050267373 Lee Dec 2005 A1
20060024132 Seman Feb 2006 A1
20060026761 Falbo Feb 2006 A1
20060106303 Karmarkar et al. May 2006 A1
20060122630 Daum et al. Jun 2006 A1
20060133580 Vezina Jun 2006 A1
20060221942 Fruth et al. Oct 2006 A1
20060241408 Yakubovsky et al. Oct 2006 A1
20070016003 Piron et al. Jan 2007 A1
20070038144 Hughes et al. Feb 2007 A1
20070039101 Luginbuhl et al. Feb 2007 A1
20070050908 Kogan et al. Mar 2007 A1
20070092059 Wayne Eberhard et al. Apr 2007 A1
20070149878 Hankins Jun 2007 A1
20070161935 Torrie et al. Jul 2007 A1
20070167725 Tropp et al. Jul 2007 A1
20070167769 Ikuma et al. Jul 2007 A1
20070233157 Mark et al. Oct 2007 A1
20070238949 Wang et al. Oct 2007 A1
20070255168 Hibner et al. Nov 2007 A1
20070255170 Hibner et al. Nov 2007 A1
20070276234 Shahidi Nov 2007 A1
20080005838 Wan Fong et al. Jan 2008 A1
20080033454 Lukoschek et al. Feb 2008 A1
20080077005 Piron et al. Mar 2008 A1
20080095421 Sun et al. Apr 2008 A1
20080132785 Piron et al. Jun 2008 A1
20080132912 Shabaz Jun 2008 A1
20080216239 Luginbuhl et al. Sep 2008 A1
20080230074 Zheng et al. Sep 2008 A1
20080234569 Tidhar et al. Sep 2008 A1
20080255443 Piron et al. Oct 2008 A1
20080306377 Piron et al. Dec 2008 A1
20090149738 Piron et al. Jun 2009 A1
20090156961 Tsonton et al. Jun 2009 A1
20090216110 Piron et al. Aug 2009 A1
20090222229 Kakinami Sep 2009 A1
20090247861 Manus et al. Oct 2009 A1
20090270725 Leimbach et al. Oct 2009 A1
20090275830 Falco et al. Nov 2009 A1
20100041990 Schlitt et al. Feb 2010 A1
20100249595 Xu et al. Sep 2010 A1
20100280354 Zhang et al. Nov 2010 A1
20100324445 Mollere et al. Dec 2010 A1
20100324448 Mollere Dec 2010 A1
20110034796 Ma et al. Feb 2011 A1
20110134113 Ma et al. Jun 2011 A1
20110152714 Luginbuhl et al. Jun 2011 A1
20110153254 Hartov et al. Jun 2011 A1
20110173753 Luginbuhl et al. Jul 2011 A1
20120172704 Piron et al. Jul 2012 A1
20130053684 Piron et al. Feb 2013 A1
20130137969 Jones May 2013 A1
Foreign Referenced Citations (17)
Number Date Country
1640139 Jul 2005 CN
101601266 Dec 2009 CN
0396866 Nov 1990 EP
0753758 Jan 1997 EP
2445413 May 2012 EP
2503934 Oct 2012 EP
9608199 Mar 1996 WO
0128412 Apr 2001 WO
0239135 May 2002 WO
2006017172 Feb 2006 WO
2007070285 Jun 2007 WO
2008064271 May 2008 WO
2010078048 Jul 2010 WO
2010148503 Dec 2010 WO
2011014966 Feb 2011 WO
2011134113 Nov 2011 WO
2013001377 Jan 2013 WO
Non-Patent Literature Citations (39)
Entry
Lanz et al., “A High-Throughput Eight-Channel Probe Head for Murine MRI at 9.4 T”, Magnetnic Resonance in Medicine 64:80-87, 2010.
International Search Report for International Application No. PCT/CA2010/001228 mailed Oct. 2, 2011, 5 pages.
European Search Report mailed Mar. 1, 2012 for European Patent Application No. 07800538.6, 8 pages.
European Search Report for European Patent Application No. 07800538.6 mailed Mar. 1, 2012, 8 pages.
Piron, Cameron A., Hybrid Imaging Guidance System for Biopsy of the Breast, Thesis Paper, University of Toronto, 2001.
Palmer, Gregory, et al., “Optimal Methods for Fluorescence and Diffuse Reflectance Measurements of Tissue Biopsy Samples,” Lasers in Surgery and Medicine, 30:191-200 (2002).
Kline, Nicole, et al., “Raman Chemical Imaging of Breast Tissue,” Journal of Raman Spectroscopy, vol. 28, 119-124 (1997).
Manoharan, Ramasamy, et al., “Histochemical Analysis of Biological Tissues Using Raman Spectroscopy,” Spectrochimica Acta Part A.52 (1996) 215-249.
Shafer-Peltier, K.E. et al. “Raman Microspectroscopic Model of Human Breast Tissue: Implications for Breast Cancer Diagnosis in Vivo” Journal of Raman Spectroscopy V.33 (2002).
Ntziachristos V., et al. “Concurrent MRI and Diffuse Optical Tomography of Breast After Indocyanine Green Enhancement,” PNAS, Mar. 14, 2000, vol. 97, No. 6, 2767-2772.
Buadu LD, et al., Breast Lesions: Correlation of Contrast Medium Enhancement Patterns on MR Images with Histopathologic Findings and Tumor Angiogenesis.
Kriege, M., et al., “Efficacy of MRI and Mammography for Breast-Cancer Screening in Women with Familial or Genetic Predisposition,” N Engl J Med 351:427-437 (2004).
Non-Final Office Action mailed Feb. 9, 2007 in U.S. Appl. No. 10/916,738.
Response to Feb. 9, 2007 Office Action in U.S. Appl. No. 10/916,738, Jul. 11, 2007.
Non-Final Office Action mailed Sep. 24, 2007 in U.S. Appl. No. 10/916,738.
Response to Sep. 24, 2007 Office Action in U.S. Appl. No. 10/916,738, Dec. 26, 2007.
Non-Final Office Action mailed Nov. 16, 2009 in U.S. Appl. No. 11/442,944.
Response to Nov. 16, 2009 Office Action in U.S. Appl. No. 11/442,944, May 17, 2010.
Non-Final Office Action mailed May 12, 2009 in U.S. Appl. No. 12/031,271.
Response to May 12, 2009 Office Action in U.S. Appl. No. 12/031,271, Nov. 12, 2009.
Final Office Action mailed Feb. 5, 2010 in U.S. Appl. No. 12/031,271.
Response to Feb. 5, 2010 Office Action in U.S. Appl. No. 12/031,271, Aug. 5, 2010.
Non-Final Office Action mailed Jan. 22, 2010 in U.S. Appl. No. 11/447,053.
Response to Jan. 22, 2010 Office Action in U.S. Appl. No. 11/447,053, Jul. 22, 2010.
International Search Report mailed Dec. 13, 2007 in International Application No. PCT/CA2007/001513.
International Preliminary Report on Patentability issued Mar. 3, 2009 in International Application No. PCT/CA2007/001513.
European Search Report mailed Jul. 30, 2009 in EP Application No. 09007010.3.
European Search Report mailed Oct. 16, 2009 in EP Application No. 09007010.3.
General Electric—Press Release—“GE Healthcare Introduces Ultrasound Fusion; New LOGIQ E9 Merges Real-time Ultrasound with CT, MR and PET,” Sep. 2, 2008, 2 pages.
International Preliminary Report of Patentability for International Application No. PCT/CA2010/001871 dated May 30, 2012, 1 page.
International Search Report and Written Opinion of the International Searching Authority for International Application No. PCT/CA2010/001871 dated Mar. 8, 2011, 9 pages.
M. Berger, “Image Fusion and Needle Guidance in Ultrasound”, General Electric, Power Point Presentation, date unknown, 17 pages.
P. Mullen and C. Owen, “MR, Ultrasound Fusion: Bridging the Gap Between Clinical Benefits, Access and Equipment Utilization,” SignaPULSE—A GE Healthcare MR Publication, Spring 2009, 5 pages.
Update of AAPM Task Group No. 43 Report: A revised AAPM protocol for brachytherapy does calculations; Med. Phys. vol. 31 No. 3, Mar. 2004; pp. 633-674.
Supplement to the 2004 update of the AAPM Task Group No. 43 Report; Med. Phys. vol. 34 No. 6, Jun. 2007; pp. 2187-2206.
Erratum: “Update of AAPM Task Group No. 43 Report: A revised AAPM protocol for brachytherapy dose calculations” [Med. Phys. 31, 633-674 (2004)].
International Preliminary Report on Patentability for PCT/CA10/000973, dated Jan. 4, 2012.
International Search Report for International Application No. PCT/CA2010/000973, mailed Oct. 1, 2010, 3 pages.
Pagoulatos et al., “Interactive 3-D Registration of Ultrasound and Magnetic Resonance Images Based on a Magnetic Position Sensor,” IEEE Transactions on Information Technology in Biomedicine, vol. 3, No. 4, Dec. 1999, 11 pages.
Related Publications (1)
Number Date Country
20120242337 A1 Sep 2012 US
Provisional Applications (2)
Number Date Country
61417270 Nov 2010 US
61417271 Nov 2010 US