Patent Application
20150335316
The present disclosure relates in general to magnetic resonance imaging (MRI) assisted methods and systems, and more particularly relates to improved methods and apparatus for performing needle biopsy of a patient's breast using MRI assisted methods.
When a substance such as human tissue is subjected to a uniform magnetic field (polarizing field B0), the individual magnetic moments of the spins in the tissue attempt to align with this polarizing field, but precess about it in random order at their characteristic Larmor frequency. If the substance, or tissue, is subjected to a magnetic field (excitation field B1) which is in the x-y plane and which is near the Larmor frequency, the net aligned moment, Mz, may be rotated, or “tipped”, into the x-y plane to produce a net transverse magnetic moment M. A signal is emitted by the excited spins after the excitation signal B1 is terminated, this signal may be received and processed to form an image.
When utilizing these signals to produce images, magnetic field gradients (Gx, Gy and Gz) are employed. Typically, the region to be imaged is scanned by a sequence of measurement cycles, or “views”, in which these gradients vary according to the particular localization method being used. The resulting set of received MRI signals are digitized and processed to reconstruct the image using one of many well-known reconstruction techniques.
Intra-operative MR imaging is employed during a medical procedure to assist the doctor in guiding an instrument. For example, during a medical procedure the MRI system is operated in a real-time mode in which image frames are produced at a high rate so that the doctor can monitor the location of the needle during insertion and throughout the procedure. A locator device such as that described in U.S. Pat. Nos. 5,622,170 and 5,617,857 may be used to track the location of the instrument and provide coordinate values to the MRI system which enable it to mark the location of the instrument in each reconstructed image. The position of the medical instrument is detected by surrounding sensors. For example, the handpiece may emit light from two or more light emitting diodes which is sensed by three stationary cameras.
Tracking devices which employ the MRI system to locate markers in the medical device have also been developed. As described in U.S. Pat. Nos. 5,271,400; 5,307,808; 5,318,025; 5,353,795 and 5,715,822, such tracking systems employ a small coil attached to a catheter or other medical device to be tracked. An MR pulse sequence is performed using the tracking coil to acquire a signal which indicates the location of the tracked device. The location of the tracking coil is determined and is superimposed at the corresponding location in a medical image acquired with the same MRI system.
To accurately locate the tracking coil, position information is obtained in three orthogonal directions that require at least three separate measurement acquisitions. To correct for errors arising from resonance offset conditions, such as transmitter maladjustment and susceptibility effects, two measurements may be made in each direction with the polarity of the readout gradient reversed in one measurement. This tracking method requires that six separate measurement pulse sequences be performed to acquire the tracking coil location. As disclosed in U.S. Pat. No. 5,353,795, these separate measurements can be reduced to four in number by altering the readout gradients in a Hadamard magnetic resonance tracking sequence.
One of the primary interventional medical procedures which employ MR imaging is MRI-guided breast biopsies. Typically, these procedures are conducted without real-time MRI imaging guidance and are lengthy (45-60 minutes) complicated procedures, in part due to physical space limitation within cylindrical magnet MRI systems and the need of positioning of the breast at magnet isocenter for imaging. In the majority of these types of systems, a patient is first imaged in the MRI scanner, and images are reviewed to determine lesions/problem areas. For the biopsy, the subject breast is compressed, with a plate on one side of the breast and a coarse, MRI compatible grid on the other, and the breast/grid combination is imaged. The grid is visible in the images, and may be seen relative to the lesion, thus providing a reference to lesion position. Then, with the patient at the home position (i.e. the MRI table completely outside the bore of the magnet), and with the breast still enclosed in the grid, a biopsy is performed manually with the grid providing guidance for the biopsy device. The grid is of relatively coarse resolution, and also does not provide guidance on the angulation or depth of the needle being used in the biopsy. Due to the lack of precise 3D localization of the lesion, it is necessary that a large sample be extracted from the patient, likely more than would be required if the biopsy needle was well localized relative to the lesion. Biopsy procedures that utilize the above-described methods can also be a lengthy procedure, with the patient in and out of the magnet several times, to insure the needle is positioned right next to the lesion.
Accordingly, an improved system is needed to perform MRI assisted breast biopsies. More particularly, an improved system for performing MRI assisted breast biopsies is needed that provides a faster, more accurate, less invasive procedure in an attempt to provide greater patient comfort at a reduced cost.
In accordance with one exemplary embodiment of the present disclosure a breast biopsy system is disclosed. The biopsy system includes a needle biopsy device, a MRI compatible device localization system and a Magnetic Resonance Imaging (MRI) system. The needle biopsy device includes an operating end including a biopsy needle having a needle tip. The needle biopsy device is configured for guidance by a robotic guidance device into a treatment position wherein the needle tip is positioned adjacent target tissue in patient. The MRI compatible device localization system is adapted to track one or more points on the needle biopsy device and generate real-time device localization data. The MRI system is adapted for applying a static magnetic field having substantially uniform amplitude over a target tissue in a patient and acquiring multi-planar reference image data from the patient being treated. The MRI system is connected to the MRI compatible device localization system and operable to display an overlay image reconstructed from the real-time device localization data on the multi-planar reference image data which depicts the location of the needle biopsy device relative to the target tissue in the patient.
In accordance with another exemplary embodiment of the present disclosure a breast biopsy system is disclosed. The biopsy system includes a needle biopsy device including an operating end including a biopsy needle with a needle tip. The needle biopsy device is configured for guidance by an operator into a treatment position wherein the needle tip is positioned adjacent target tissues in patient. The needle biopsy device further includes a tracking coil mounted proximate the needle tip and operable to acquire tracking data and a robotic guidance device adapted for guiding the needle biopsy device into the treatment position. The breast biopsy system further includes a Magnetic Resonance Imaging (MRI) system for acquiring multi-planar reference image data from the patient being treated. The MRI system is connected to the tracking coil for acquiring tracking data from the tracking coil as the needle biopsy device is guided into the treatment position by the robotic guidance device. The MRI system is operable to display an overlay image reconstructed from the acquired tracking data on the multi-planar reference image data which depicts the location of the needle biopsy device in the patient.
In accordance with another exemplary embodiment of the present disclosure a method of performing a robotically assisted MRI breast biopsy is disclosed. The method includes preparing a patient for the intervention by positioning the patient at a home position relative to a Magnetic Resonance Imaging (MRI) system and a robotic guidance device adapted for guiding a needle biopsy device into target tissue relative to the patient. Utilizing algorithms an optimal needle approach for the needle biopsy device and placement of the robotic guidance device relative to a treatment position are determined. The robotic guidance device is next positioned at an approximate position relative to the target tissue and the patient is advanced to a scan position in the MRI system. Multi-planar reference images of the patient are acquired to identify a lesion position on the reference images. Next, an MRI compatible device localization system is enabled to provide real-time device localization of the needle biopsy device. A real-time representation of the needle biopsy device is next displayed as an overlay on the multi-planar reference images. The robotic guidance device is next guided, based on the real-time representation of the needle biopsy device, to advance the needle biopsy device toward the targeted lesion for biopsy.
These and other features and aspects of embodiments of the present invention will become better understood when the following detailed description is read with reference to the accompanying drawings in which like characters represent like parts throughout the drawings, wherein:
The present disclosure is directed to a system and method for performing a breast biopsy utilizing MRI imaging systems that employ guidance and tracking means of a biopsy needle device. In particular, embodiments of the present disclosure provide a breast biopsy system including a needle biopsy device configured for guidance by a robotic guidance device into a treatment position wherein a needle tip is positioned adjacent to the target tissues in a patient. A MRI compatible device localization system is provided to track one or more points on the needle biopsy device and generate real-time device localization data. During operation, the Magnetic Resonance Imaging (MRI) system acquires multi-planar reference image data from the patient being treated. An overlay image is reconstructed from the generated real-time device localization data onto the multi-planar reference image data, thereby depicting the location of the needle biopsy device relative to the target tissue in the patient.
One or more specific embodiments of the present disclosure will be described below. In an effort to provide a concise description of these embodiments, all features of an actual implementation may not be described in the specification. It should be appreciated that in the development of any such actual implementation, as in any engineering or design project, numerous implementation-specific decisions must be made to achieve the developers' specific goals, such as compliance with system-related and business-related constraints, which may vary from one implementation to another. Moreover, it should be appreciated that such a development effort might be complex and time consuming, but would nevertheless be a routine undertaking of design, fabrication, and manufacture for those of ordinary skill having the benefit of this disclosure.
When introducing elements of various embodiments of the present invention, the articles “a,” “an,” “the,” and “said” are intended to mean that there are one or more of the elements. The terms “comprising,” “including,” and “having” are intended to be inclusive and mean that there may be additional elements other than the listed elements.
Referring first to
As illustrated in
Referring still to
Referring now to
The breast biopsy system 10 of
Referring again to
As disclosed, the MRI compatible device localization system 70 is capable of providing precise and accurate real-time device localization data 72. There are multiple technologies available for device localization, but the disclosed localization system 70 is required to track multiple points on the invasive device 40, such that device orientation can be established. More particularly, in an embodiment, a method of use includes interleaving the tracking coil measurement acquisitions with the acquisition of image data. MRI tracking data is then acquired and Fourier transformed by an array processor. The transformed MRI tracking data is used by the imaging and tracking unit 34 as the real-time device localization data 72 to produce an icon representing the invasive device 40 for display on the display 16. The icon is overlaid on the MRI image of the patient anatomy at the location indicated by the tracking coil 60. As described in U.S. Pat. No. 5,353,795 issued on Oct. 11, 1994 and entitled “Tracking System To Monitor The Position Of A Device Using Multiplexed Magnetic Resonance Detection”, which is incorporated herein by reference, errors arising from resonance offset conditions make it necessary to acquire more than three tracking coil measurements.
A breast biopsy utilizing the breast biopsy system according to the preferred embodiment of the disclosure is carried out by a series of steps depicted in
Referring particularly to
The disclosed breast biopsy system is a closed loop feedback system utilizing real-time device position/orientation that provides guidance of the invasive device 40 via the robotic guidance device 44, thereby providing automatic guidance of the needle biopsy device 42 to each targeted lesion. The robotic guidance device 44, in response to operator input or automated signals, based on the feedback from the real-time representation of the invasive device 40 on multi-planar images, advances the biopsy needle 48 toward the targeted lesion. Simultaneously, the operator 20 may be viewing the real-time images of the imaging plane at the tip 52 of the biopsy needle 48, allowing the needle's stopping position to be precisely positioned relative to the lesion. As the system advances the biopsy needle 48 in an automated, semi-automated or manual state of operation, the operator 20 observes the procedure, verifying the correct operation of the system 10, and retains the ability to stop the procedure or assume the control of the invasive device 40, and more particularly the needle biopsy device 42, using a joystick or other control, such as control panel 14. Subsequent to completion of the biopsy procedure, the patient 22 is advanced back to the home position in the magnet system 26, in a step 96.
Many variations are possible from the preferred embodiment described above. For example, the invasive device 40, and more particularly the biopsy needle 48 could be tracked using methods other than MR tracking in conjunction with a robotic guidance device. Also, the invasive device 40 could incorporate additional diagnostic components such as endoscopes, or the like. Alternatively, the invasive device 40 could incorporate therapeutic components such as a cryo-therapy channel or access for a cutting tool.
Accordingly, disclosed herein is breast biopsy system for robotically assisted breast biopsies and method of preforming a biopsy using the breast biopsy system. The disclosed breast biopsy system provides a high precision localization system in conjunction with an operator guided robotic guidance device enabling the ability to perform the entire biopsy procedure in situ with less tissue removal, reduced procedure time, increased patient comfort and reduced cost (reduced time from operator, such as interventional radiologist). While several presently preferred embodiments of the breast biopsy system have been described in detail herein, many modifications and variations will now become apparent to those skilled in the art. It is, therefore, to be understood that the appended claims are intended to cover all such modifications and variations as fall within the true spirit of the disclosure.
It is to be understood that not necessarily all such objects or advantages described above may be achieved in accordance with any particular embodiment. Thus, for example, those skilled in the art will recognize that the systems and techniques described herein may be embodied or carried out in a manner that achieves or improves one advantage or group of advantages as taught herein without necessarily achieving other objects or advantages as may be taught or suggested herein.
While the technology has been described in detail in connection with only a limited number of embodiments, it should be readily understood that the specification is not limited to such disclosed embodiments. Rather, the technology can be modified to incorporate any number of variations, alterations, substitutions or equivalent arrangements not heretofore described, but which are commensurate with the spirit and scope of the claims. Additionally, while various embodiments of the technology have been described, it is to be understood that aspects of the specification may include only some of the described embodiments. Accordingly, the specification is not to be seen as limited by the foregoing description, but is only limited by the scope of the appended claims.
