Title: Breast biopsy and therapy system for magnetic resonance imagers
Abstract: The present invention describes a device for performing breast biopsies and/or therapy within magnetic resonance imaging (MRI) systems. The apparatus includes a RF receiver antenna for magnetic resonance imaging of the breast. The RF coil includes openings in the front and side to provide access to the breast during the procedure. Compression plates are integrated into the breast coil which compress the breast either laterally or in the head/feet direction as required for optimal access to the breast. The apparatus includes a mechanical device for positioning interventional instruments in the breast such as biopsy or therapy instruments. The mechanical positioning devices position the instrument along the desired trajectory to the target site and insert the instrument into the breast while the patient remains inside the MRI scanner. Real time MR images may be acquired during instrument alignment and insertion to verify the trajectory. The mechanical positioning devices allow manipulation of instruments in any type of MRI scanner, including high field MRI systems with cylindrical magnets. The positioning devices provide a means to overcome limited access to the patient in MRI scanners. The positioning devices may be manually operated by means of gears, drive shafts, cables or other mechanical means. Or they may be electronically controlled by means of MR compatible motorized drive systems. The devices may be remotely controlled from outside the magnet for MRI systems that have limited access to the patient in the magnet. An interface between the electronically controlled drivers and the MRI scanner computer can provide robotic control of the instrument.
Patent Number: 6,889,073 Issued on 05/03/2005 to Lampman, et al.
| Inventors:
|
Lampman; David A. (1413 Golden Gate Blvd., Mayfield Hts, OH 44124);
Mastandrea; Nick (1413 Golden Gate Blvd., Mayfield Hts, OH 44124);
Thomason; Scott (1413 Golden Gate Blvd., Mayfield Hts, OH 44124)
|
| Appl. No.:
|
847641 |
| Filed:
|
May 2, 2001 |
| Current U.S. Class: |
600/422; 600/424 |
| Intern'l Class: |
A61B 005/05 |
| Field of Search: |
600/422,417,410,415,423,424,426
|
References Cited [Referenced By]
U.S. Patent Documents
| 5078140 | Jan., 1992 | Kwoh.
| |
| 5363845 | Nov., 1994 | Chowdhury.
| |
| 5437280 | Aug., 1995 | Hussman.
| |
| 5569266 | Oct., 1996 | Siczek.
| |
| 5602557 | Feb., 1997 | Duerr.
| |
| 5664569 | Sep., 1997 | Damadian.
| |
| 5678549 | Oct., 1997 | Heywang-Koebrunner.
| |
| 5682890 | Nov., 1997 | Kormos.
| |
| 5690108 | Nov., 1997 | Chakeres.
| |
| 5699802 | Dec., 1997 | Duerr.
| |
| 5706812 | Jan., 1998 | Strenk.
| |
| 5755667 | May., 1998 | Friedrich.
| |
| 6023166 | Feb., 2000 | Eydelman.
| |
| 6163717 | Dec., 2000 | Su et al.
| |
| 6580938 | Jun., 2003 | Acker.
| |
| 6589163 | Jul., 2003 | Aizawa et al.
| |
| 6591130 | Jul., 2003 | Shahidi.
| |
| 6654629 | Nov., 2003 | Montegrande.
| |
| 6731966 | May., 2004 | Spigelman et al.
| |
| 6773393 | Aug., 2004 | Taniguchi et al.
| |
Other References
Katharina, C., et al., "Interventional Breast MR Imaging: Clinical Use of a Stereotactic
Locialization and Biopsy Device", Radiology, 204: 669-675, 1997.
|
Primary Examiner: Robinson; Daniel I.
Parent Case Text
CROSS-REFERENCE TO RELATED APPLICATIONS
The enclosed patent application is based upon Provisonal Application for Patent
60/202,821, filed on May 8, 2000.
Claims
1. A MR compatible mechanical device for positioning an interventional instrument
such as a biopsy needle or therapy probe inside a MRI scanner, said positioning
device comprising;
an instrument platform in which a biopsy or therapy instrument is secured to
a mechanical positioning device, said platform being movable to align the instrument
trajectory, insert the instrument to the patient and remove the instrument from
the patient.
a mounting block to control the vertical and horizontal motion of the instrument
platform, said mounting block including or attached to a mechanical means for horizontal
motion of the instrument platform and another mechanical means for vertical motion
of the instrument platform.
a base-plate that is attached to a mechanical means that moves said base-plate
in a horizontal or vertical direction,
a single post or a plurality of posts that support the aforementioned mounting
block and physically link said mounting block to the aforementioned base-plate,
said support post(s) attached to a mechanical means for moving said mounting block,
a plurality of mechanical means for adjusting the position of the aforementioned
instrument platform, mounting block and base-plate.
2. The apparatus of claim 1, further comprising a means of mounting the positioning
device to said imaging coil.
3. The apparatus of claim 1, whereby the positioning device is located in front
of the coil, providing a means to insert instruments into the patient from the
direction of the patient's head.
4. The apparatus of claim 1, whereby the positioning device is located on the
side of the coil, providing a means to insert intents into the patient from the
lateral direction.
5. The apparatus of claim 1, further comprising a plurality of positioning devices
that can be used to position a plurality of instruments in one or both breasts.
6. The apparatus of claim 1, further comprising an acme screw for moving the
base-plate along a horizontal or vertical axis.
7. The apparatus of claim 1, further comprising an inchworm gear for moving the
instrument platform along a horizontal or vertical axis.
8. The apparatus of claim 1, further comprising a rack and pinion mechanism for
moving the instrument platform along a horizontal or vertical axis.
9. The apparatus of claim 1, further comprising a mechanical means of rotating
the support post about an axis.
10. The apparatus of claim 9, further comprising a plurality of gears for rotating
the support post about an axis.
11. The apparatus of claim 1, further comprising manually operated drive shafts
and gears to adjust the position of the instrument platform inside the MRI scanner.
12. The apparatus of claim 1, further comprising cables to adjust the position
of the instrument platform.
13. The apparatus of claim 1, further comprising an instrument platform with
side rails for guiding an instrument along a predetermined trajectory.
14. The apparatus of claim 1, further comprising an instrument platform with
indentations or clamps to secure the instrument into a locked position in the instrument platform.
15. The apparatus of claim 1, further comprising a needle guide for guiding the
needle along a predetermined trajectory.
16. The apparatus of claim 1, further comprising a needle guide containing MR
visible material for trajectory alignment of an instrument by means of MR imaging.
17. The apparatus of claim 16, further comprising a method for aligning the trajectory
of an instrument and verifying the insertion trajectory of an instrument in a MRI
scanner using real time MR imaging, said trajectory imaging method comprising;
selecting a desired trajectory to a lesion from a set of MR images,
acquiring a time series of real time MR images in the plane of the desired trajectory
to the target,
adjusting the position of the MR visible needle guide until it appears in the
images aligned with the desired trajectory to the target,
inserting the instrument into the patient along the trajectory indicated by said
needle guide,
acquiring real time MR images in the plane of the instrument as it is inserted
to verify that the trajectory conforms to the desired trajectory,
interactively adjusting the insertion trajectory of the instrument to maintain
a correct course using real time MR images for feedback.
18. The apparatus of claim 16, further comprising a method for aligning the trajectory
of an instrument and verifying the insertion trajectory of an instrument in a MRI
scanner using real time MR imaging, said trajectory imaging method comprising;
selecting a desired trajectory to a lesion from a set of MR images,
acquiring a series of real time MR images perpendicular to the plane of the desired
trajectory, said imaging plane centered on the desired trajectory to the target
and offset to include a cross-section of the MR visible needle guide,
adjusting the position of the MR visible needle guide until the cross sectional
image of the needle guide indicates that said needle guide is aligned with the
desired trajectory to the target,
inserting the instrument into the patient along the trajectory indicated by said
needle guide,
acquiring real time MR images in the plane of the instrument as it is inserted
into the patient to verify that the trajectory conforms to the desired trajectory,
interactively adjusting the insertion trajectory of the instrument to maintain
a correct course using real time MR images for feedback.
19. The apparatus of claim 16, further comprising a means to manually insert
the instrument along the trajectory indicated by said needle guide.
20. The apparatus of claim 1, further comprising an instrument platform for positioning
therapy instruments, such as RF, laser, cryogenic or drug delivery probes, inside
a patient in a MRI system using real time imaging for guidance and monitoring of
the therapy.
21. The apparatus of claim 1, further comprising a remotely controlled means
for adjusting the position of the instrument inside the MRI scanner.
22. The apparatus of claim 1, further comprising an electronically controlled
means for adjusting the position of the instrument inside the MRI scanner.
23. The apparatus of claim 22, further comprising a robotically controlled means
for adjusting the position of the instrument inside the MRI scanner.
Description
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
Not applicable.
REFERENCE TO A MICROFICHE APPENDIX
Not applicable.
FIELD OF THE INVENTION
This invention relates to MRI-guided breast biopsies and therapy. It describes
an apparatus for performing breast biopsies and/or therapy inside any type of MRI
scanner, including high field "closed" MRI systems. It includes a RF receive coil
for magnetic resonance imaging (MR) of the breast and a mechanical device for positioning
interventional instruments inside the MRI scanner. Real time MR imaging is used
to guide and monitor the interventional procedure.
BACKGROUND OF THE INVENTION
Magnetic resonance imaging (MRI) is an important clinical modality for the
detection and delineation of breast carcinoma. Its high sensitivity allows detection
and characterization of breast lesions not seen by other imaging technologies.
However, current MRI systems are not optimized for breast biopsy. Low field open
MRI systems provide access to the patient but have limited imaging performance
for detecting and characterizing breast carcinoma. High field "closed" systems
provide superior imaging performance but have limited access to the patient, preventing
the use of real time imaging to guide the biopsy.
Existing breast biopsy systems for high field closed MRI systems require
that the patient be removed from the scanner in order to perform the biopsy. This
prevents the use of real time imaging to guide the biopsy. Errors in the instrument
trajectory cannot be detected which can reduce the diagnostic quality of the tissue sample.
U.S. Pat. No. 6,163,717 issued in the name of Su, discloses an open breast coil
for interventional MRI. Su does not disclose methods for incorporating breast compression
plates into the coil or a means to position breast biopsy or therapy instruments
inside the MRI scanner. Su's design is most useful for a lateral access to the
breast. Access from the front is more limited than the present invention. Also,
Su's design does not teach a robust means of supporting the patient weight while
maintaining adequate access to the breast for performing interventional procedures.
U.S. Pat. No. 5,706,812, granted to Strenk, teaches a MRI breast biopsy coil
with a transverse access portal and a stereotactic flame for guiding a biopsy needle.
The coil is a linear coil that has reduced sensitivity compared to quadrature or
phased array imaging coils. The design does not allow breast compression laterally
or in the head/feet direction. Also, the design does not teach means for positioning
instruments in the MRI scanner or methods of performing breast biopsies inside
high field MRI scanners with limited access to the patient.
U.S. Pat. No. 5,755,667, issued in the name of Friedrich, discloses a MRI breast
coil with compression plates. The coil is not open and does not allow performance
of breast biopsies while the patient remains inside the MRI scanner.
U.S. Pat. No. 5,437,280, issued to Hussman, teaches a localizer apparatus suitable
for guidance of medical instruments to lesions in the breast using a MR visible
coordinate system. The patent does not teach design of open breast imaging coils
or methods of performing breast biopsies while the patient remains inside the MRI scanner.
U.S. Pat. No. 5,678,549, granted to Heywang-Koebrunner, discloses a stereotactic
compression device and imaging coil for performing MRI guided breast biopsies.
The patent does not disclose breast coil designs that are open in the front, or
a means of performing breast biopsies inside high field MRI systems. The device
requires that the patient be removed from the scanner to perform the biopsy.
U.S. Pat. No. 5,690,108, issued to Chakeres, teaches an apparatus for aligning
an instrument along a desired trajectory to a target using MR imaging. It does
not teach open access imaging coils for breast biopsy or a method to insert a variety
of instruments into the patient inside the MRI scanner.
U.S. Pat. No. 5,569,266, granted to Siczek, discloses a MRI guided breast biopsy
device, including an imaging coil and a device for positioning a biopsy instrument
in the breast. The patent does not disclose means to insert instruments into the
patient while they remain inside the scanner. The device requires that the patient
be removed from the scanner to insert the biopsy instrument.
SUMMARY OF THE INVENTION
To overcome the limitations of the known apparatus and medical procedures we
have
discovered a novel apparatus that provides important advantages over the prior
art. The subsequently disclosed and claimed invention discloses a device for performing
MRI guided breast biopsies and/or therapy without having to remove the patient
from the scanner. The device can be used in any type of MRI system, including both
low field open MRI systems and high field "closed" systems. The device allows a
variety of interventional procedures to be performed on the breast using real time
MR for guidance and monitoring.
According to one aspect of the present invention, the MRI biopsy device
includes a RF receiver coil for imaging both breasts, said coil being open in the
front and the side in order to provide access to the breast while the patient remains
inside the scanner. The patient lies prone on top of the coil and the breasts extend
down into the coils. In high field closed scanners the patient is put feet first
into the cylindrical magnet and the procedure is performed from the front of the
magnet through the opening in the front of the coil. Alternatively, the patient
may be put into the scanner head first and the procedure is performed from the
rear of the magnet through the opening in the front of the coil.
According to another aspect of the invention, the breast coil includes
compression plates for compressing the breast during imaging and holding it rigidly
in place during the biopsy or therapy. The compression plates are designed such
that they may compress the breast in either the head/feet direction or laterally.
The compression plates include holes through which the interventional instrument
is inserted into the breast. In one embodiment the compression plate includes a
grid of finely-spaced holes through which the instrument is inserted. In another
embodiment the compression plate includes large rectangular access windows through
which the instrument is inserted.
According to a further aspect of the present invention, the device includes
a mechanical apparatus for positioning an instrument inside the MRI system. In
the preferred embodiment an instrument is attached to the mechanical positioning
apparatus and the position of the instrument is manipulated by a plurality of mechanical
means. The controls for the mechanical instrument positioning device may be substantially
removed from the instrument positioning assembly, providing remote control of the
instrument position. Remote control operation is especially advantageous in the
cylindrical magnets of high field "closed" MRI systems. Mechanical means for positioning
the instrument inside the MRI scanner allows the use of real time imaging to guide
the alignment of the trajectory and the insertion of the instrument into the lesion.
Alternate embodiments include positioning thermal therapy or drug delivery
probes inside the MRI system, using real-time imaging to guide and/or monitor the
procedure. Another embodiment includes remote control operation of interventional
instruments inside the MRI scanner and robotic control of the instrument position.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a view of the bilateral breast receiver coil with open access from
the front and lateral directions. FIG. 1 also shows the compression plates used
to secure the breast in the coil.
FIG. 2 shows the conductor geometry for the RF antennae in the bilateral breast
receiver coil.
FIG. 3 shows the mechanical positioning device that is used to position an interventional
instrument such as a biopsy needle or therapy probe in the MRI scanner.
FIG. 4 shows the mechanical positioning device integrated into the breast coil assembly.
FIG. 5 shows a mechanical positioning device with a regional degree of freedom
about the Y-axis.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 shows the breast imaging coil assembly. The patient lies prone on top
of the coil with the sternum resting on the central support beam
190. The
patient's head is supported by head support
140. The patient's shoulders
are supported by shoulder supports
130. The patient's breasts extend down
into the RF coil assemblies
120. In a high field closed MRI scanner the
patient may be inserted feet first into the cylindrical magnet and the procedure
performed from the front of the magnet through the opening in the front of the
coil. Alternatively, the patient may be put into the scanner head first and the
procedure performed from the rear of the magnet through the open in the front of
the coil.
The breasts are compressed by compression plates
110 or
150. Said
compression plates may compress the breast either in the head/feet direction (z
axis) or the lateral direction (x axis). The compression plates may be one of two
types; compression plate
110 consists of a plastic plate with a grid of
finely-spaced needle guide holes. In FIG. 1 the compression plate
110 is
shown oriented along the lateral direction but it may also compress the breast
in the head/feet direction. Compression plate
150 consists of a plastic
plate with large rectangular access windows, which is advantageous when a mechanical
device is used for positioning the interventional instrument, as is described below.
Compression plate
150 can be made MR visible by embedding or attaching MR
visible material such as tubes filled with water to said compression plate. FIG.
1 shows compression plate
150 compressing the breast in the head/feet direction
but it may also be used in the lateral direction.
Referring to FIG. 1
b, the compression plates are secured to the
breast coil housing by means of clamps or latching mechanism
160 which slide
in and out of the coil housing by means of side rails
170 embedded in the
coil housing. The compression plates may also be secured to the coil cross-members
120 by means of clamps or latch mechanism
180. Compression plate
110 includes MR visible markers
112. The position of the markers
112 relative to the tumor is measured on the MR images. The proper needle
entry hole is then determined by determining which hole in the compression plate
is closest to the desired entry point, as is known in the art (see for example
U.S. Pat. Nos. 5,678,549 and 5,437,280).
Compression plates
110 and
150 may also be used for laterally
directed biopsies performed outside the magnet as is known in the art (see for
example Katharina, et al., Radiology, 1997; 204: 667-675).
The housing for the coil also includes an abdominal support (
100), and
head and shoulder supports (
130,
140). The head support
140
and shoulder supports
130 may be elevated at an angle in order to provide
additional access to the breast from the front.
FIG. 2 shows a schematic view of the RF antennas that are enclosed in the breast
receiver coils
120. The RF antenna conductor elements
10 are configured
to form four loop antennae spaced apart vertically and horizontally sufficiently
to accommodate the patient's breast
50. The RF antenna housings are open
in both the lateral and front (head) directions, as shown in FIG.
1. This
provides access to the breast either from the front or the side. The patient's
breasts are inserted through the top opening in the coils. The RF signals from
each of the coils are conducted into an electronic interface
40 by means
of cables
30. The coils may be electrically combined as a quadrature coil
or as a 4-channel phased array coil. The RF signals from each of the coils are
pre-amplified and combined as required in the electronic interface(s)
40,
as is known in the art. The capacitors
20 are used to time the coil to the
proper operating frequency of the MRI scanner and to suppress unwanted eddy currents
in the RF coils. Additional capacitors not shown in the electronic interfaces
40
are also used for tuning the coil to the proper operating frequency and impedance matching.
FIG. 2 shows the embodiment of the coil geometry for a high field MRI system
with the magnetic field oriented along the z-axis. In low field "open" MRI systems
the magnetic field is oriented along the y-axis. For this case, the coil assembly
shown in FIG. 2 is rotated 90 degrees about the x-axis in order to maintain the
proper orientation of the coil with respect to the direction of the magnetic field.
The coil housing and compression plates require no modifications for this embodiment.
In an alternate embodiment the coil may consist of only 2 antennae, spaced apart
either vertically or horizontally. This embodiment could provide improved access
to the patient at the expense of imaging sensitivity.
FIG. 3 shows a manually operated mechanical apparatus for positioning instruments
within the MRI scanner. The instrument
200 can be any one of a number of
commercially available biopsy instruments. Alternatively, the instrument could
be a therapy probe such as a RF, laser or cryogenic probe for thermal ablation
of tumors or a drug delivery probe for localized delivery of drugs. In the embodiment
shown in FIG. 3 the interventional instrument
200 is mounted to the instrument
platform
220 by means of side rails
211 on said instrument
200
that slide into corresponding slots
212 on instrument platform
220
(see FIG. 3
b). The instrument
200 may be rigidly secured to the instrument
platform
220 by means of snaps
210 on said instrument. Said snaps
mate with corresponding indentations in the instrument platform
220. An
alternate embodiment uses clamps to secure the instrument
200 to the instrument
platform
220. The instrument platform
220 includes a MR-visible needle
guide
230 that is visible in the MR images, providing a means to align the
instrument trajectory using real time MR imaging, as described below. The MR visible
needle guide
230 consists of a cylinder with an inner cavity filled with
MR visible material such as water, Gd-DPTA, or vegetable oil. Instrument platform
220 is attached to mounting block
240 by means of an inchworm gear
221. By rotating drive shaft
270 the inchworm gear
221 advances
the instrument platform
220 such that the instrument
200 is advanced
into the patient. In an alternate embodiment, the instrument may be manually inserted
through the needle guide into the patient. Mounting block
240 is also used
to control the vertical motion of the instrument platform. A rack
255 is
attached to vertical support post
250 (FIG. 3
b). A corresponding
pinion gear in mounting block
240 (not shown) is used to drive the mounting
block up and down the vertical support post
250. Drive shaft
260
on mounting block
240 is used to drive the pinion gear in said mounting
block. The base-plate
280 of the instrument positioning device includes
guide rails
295 and a threaded borehole
290.
With reference to FIG. 4, the mechanical positioning device is mounted to the
base of the breast-imaging coil. Base-plate
280 is attached to an acme screw
300 in the base of the imaging coil by means of threaded bore hole
290
through said base-plate. Acme screw
300 is used to move the base-plate
280
of the instrument positioning device in the left/right direction. In this manner
rotational motion of said acme screw translates into linear motion of said base-plate.
Drive shaft
310 is used to rotate the acme screw. Rails
295 in baseplate
280 travel along guide slots
320 in the base of the breast coil.
Said rails and slots serve to guide base-plate
280 along the guide slots
320 and prevent twisting or rotation of the base-plate assembly.
FIG. 5 shows a mechanical positioning device with a rotational degree of freedom
about the y-axis. This device enables the use of oblique trajectories to the target.
Support post
250 is mounted on a rotatable gear
300. Gear
300
is rotated by a second gear
310. Gear
310 is rotated by means of
drive shaft
320.
The desired trajectory to the target is determined from a preliminary set of
MR images. There are a number of methods that can be used to align the trajectory
of the instrument. In the simplest embodiment the needle guide
230 is aligned
with the desired trajectory by acquiring real time MR images in the plane of said
trajectory and adjusting the position of said needle guide so that it is aligned
with the desired trajectory in the MR images. In an alternate embodiment, real
time MR images may be acquired in a plane perpendicular to the desired trajectory
with the center of the imaging plane centered on the line defining the trajectory.
The imaging plane is offset so that a cross sectional image of needle guide
230
is visible in the images. The position of the needle guide is then adjusted until
the cross section of the needle guide is aligned with the desired trajectory in
the images. Following trajectory alignment the instrument is inserted into the
patient through said needle guide. Real time images are acquired in the plane of
the instrument to verify that the instrument insertion trajectory is correct. Realignment
of the instrument trajectory may be performed in real time based on feedback from
the MR images. In this manner, misalignment in the trajectory or any other sources
of error in the instrument position may be detected and compensated for in real time.
In high-field "closed" MRI systems the preferred embodiment is to locate the
instrument
positioning device in the front of the coil, thereby providing a means to insert
the instrument from the direction of the patient's head. A lateral approach in
a high field system is limited by the diameter of the magnet bore. In a low field
"open" ME system the instrument positioning device may be located either in the
front or the side of the coil, providing a means to insert the instrument either
from the front or lateral directions.
A plurality of positioning devices may be used to insert a plurality of instruments
into one or both breasts in a single session. For example, two positioning devices
could be used to insert instruments into both breasts, either from the front or
the side. In another embodiment, a positioning device could be located in front
of the coil and a separate positioning device could be located on the side of the
coil, providing a means to insert instruments both from the head and lateral directions.
In a low field open MRI system up to four positioning devices could be used in
a particular session, two in the front and one on each side of the patient.
The mechanical positioning device must not distort the magnetic field of the
MRI scanner so all of its components must be non-ferrous. Also, the positioning
device must not interfere with the RF and pulsed magnetic field gradients of the
MRI system so the use of conductive components must be avoided. Preferred materials
for construction of the positioning device include thermo-plastics and thermo-sets.
In an alternate embodiment, an inchworm gear may be used for vertical motion
of
the instrument platform. A rack and pinion drive mechanism may also be used for
horizontal motion of the instrument platform.
Another alternate embodiment uses cables instead of drive shafts to move
the positioning device. The cables may be used to rotate the gears which move the
instrument platform, mounting block, base-plate and/or support post. Alternatively,
the cables may be directly connected to the instrument platform, mounting block
and/or base-plate. The cables would then apply a push/pull to these components,
causing them to move along guide rails, guide slots and/or guide rods.
In another alternate embodiment the positioning device may be used to position
other types of instruments, such as spring-loaded biopsy guns, thermal therapy
probes, or drug delivery probes. The instrument platform
220 may be modified
as required to accommodate instruments of a variety of shapes and sizes. Alternatively,
a variety of adaptors could be designed to mate a variety of instruments to the
instrument platform
220 shown in FIG.
3.
Another alternate embodiment is to electronically control the position device
by means of MR compatible motors. Examples of MR compatible motors include piezoelectric
motors, vacuum-actuated drivers or hydraulic drivers. Electronic control of the
mechanical positioning device allows remote control operation of the instrument
inside the MRI scanner. Robotic control of the instrument is accomplished by means
of an interface such that the MRI scanner computer controls the motors that drive
the instrument positioning device.
The invention has been described with reference to the preferred embodiment.
Obviously, modifications and alterations will occur to others upon reading and
understanding the preceding detailed description. It is intended that the invention
be construed as including all such modifications and alterations insofar as they
come within the scope of the appended claims or the equivalents thereof.
*
