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Description  |
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FIELD OF THE INVENTION
The present invention relates generally to mammography and analysis or
treatment of suspicious breast lesions and, more particularly, to an
apparatus for use in mammographic screening and diagnosis as well as in
medical procedures involving insertion of a medical instrument into a
suspicious breast lesion, the apparatus having an improved flexibility of
movement so as to simplify and enhance the efficacy of such procedures.
BACKGROUND OF THE INVENTION
A number of medical procedures involve identification of, localization of,
and/or insertion of a medical instrument into a suspicious breast lesion.
For example, such procedures may be utilized to detect or diagnose the
nature of a lesion, to ablate or remove a lesion, to deliver a drug or
other treatment to the lesion, or to mark a pathway to the lesion for use
in subsequent open surgery.
One application of such procedures relates to the detection of breast
cancer. Breast cancer is a leading cause of death of women in the United
States. Early detection and analysis of breast lesions suspected of being
cancerous is therefore of great importance. Accordingly, women
increasingly undergo routine mammography to detect suspicious lesions
which may not be palpable and which can therefore escape detection through
self-examination. In many cases, an initial screening or diagnostic
mammography procedure identifies a suspicious lesion which can then be
analyzed through a biopsy procedure.
Detection of non-palpable lesions can be accomplished through x-ray
imaging. In order to obtain a complete image of a breast, two x-ray images
per breast, e.g., a top or cranial-caudal view and a side or
medial-lateral view, are commonly utilized although some believe that a
single, oblique view, commonly called a "Cleopatra" view, may be
sufficient for this purpose. As used herein, the phrase "oblique views"
refers to views of a breast from directions transverse to the plane in
which conventional top and side views are taken. Current mammographic
systems generally do not provide positioning flexibility to easily obtain
a Cleopatra view. Thus, a complete imaging procedure normally involves
obtaining four x-ray views, two views per breast. This can be time
consuming and exposes the patient to four intervals of x-ray radiation.
Similarly, due to the lack of flexibility in positioning current
mammographic systems to the patient's breasts, the patient is ordinarily
positioned to the equipment, e.g., the patient is ordinarily moved in
order to sequentially examine the left and right breasts, and the
patient's breast and arms are moved with the assistance of an operator in
order to achieve a high quality mammographic image, thereby further
complicating the procedure.
If a suspicious lesion is identified through screening or diagnostic
mammography, further definition of the nature of the lesion, i.e.,
malignant or benign, normally involves surgical biopsy of the suspicious
area following a needle localization procedure to mark the non-palpable
lesion for the surgeon. Needle biopsy procedures of either fine needle
aspiration (i.e., to obtain cell samples for cytological analysis) or core
biopsy (i.e., to obtain a tissue sample for histological analysis) are
gaining acceptance as a minimally invasive alternative to surgical
excisional biopsy. In this regard, it will be appreciated that tissue
samples from core biopsy are preferred over cell samples because such
samples permit histological examination of the lesion, not merely
cytological examination, thereby providing a definitive diagnosis and
reducing or eliminating the need for a specialized cytologist.
The screening and diagnostic mammography and certain stereotaxic needle
biopsy procedures have generally been performed with the patient either in
a vertical sitting or standing position or in a face down, horizontal
position, wherein one of the patient's breasts protrudes through an
opening in the examination table. The sitting or standing position is
advantageous for certain procedures as easy access to the breast is
provided for the technologist and equipment. In addition, the sitting or
standing procedures do not require an examination table mounting and
dismounting process which can be difficult for some patients. On the other
hand, the horizontal position has been found advantageous in that the
breast is pendulantly disposed thereby facilitating positioning of the
breast for mammographic procedures and access to lesions near the chest
wall. In addition, the horizontal position allows small breasts to be
compressed more efficiently. Such breast compression is desired during
mammographic procedures. The horizontal position also enhances patient
comfort and reduces the likelihood of movement of the breast during a
mammographic and particularly a needle biopsy procedure. Further, a safety
advantage is obtained when the patient is in a horizontal position as
there is always a risk of fainting during the procedure.
SUMMARY OF THE INVENTION
Accordingly, objects of the present invention include the following.
The provision of an apparatus for use in mammographic procedures which
permits improved efficacy of screening and diagnostic mammography as well
as medical procedures involving insertion of a medical instrument into the
patient's breast.
The provision of an apparatus for use in mammographic procedures wherein
the patient can be reclined enough from a vertical position so that her
breasts project pendulantly, and wherein the patient can be inclined from
a horizontal position for convenient breast access.
The provision of an apparatus for use in mammographic procedures wherein
the patient is supported on a frame which is tiltable so that the patient
can be inclined at angles selected to facilitate particular screening and
diagnostic mammography as well as needle biopsy procedures.
The provision of an apparatus for use in mammographic procedures which is
positionable relative to the patient's breasts and, more specifically,
moveable across the patient's chest from one breast to the other.
The provision of an apparatus for use in mammographic procedures wherein
the apparatus provides an additional degree of freedom in positioning
relative to the patient so as to enhance single view screening of a
breast, to allow more breast tissue to be viewed on one mammographic
image, and to provide increased flexibility of biopsy instrument
positioning.
The provision of an improved apparatus for use in mammographic needle
biopsy procedures wherein a tissue sample suitable for histological
examination or a cell sample can be reliably obtained through a minimally
invasive needle biopsy technique.
Additional objectives and corresponding advantages of the present invention
will be apparent to those skilled in the art upon consideration of the
present specification.
The present invention discloses a mammographic apparatus suitable for use
in both screening and diagnostic mammography, as well as in medical
procedures such as needle biopsy which involve insertion of a medical
instrument to a point of interest within the patient's breast, which
apparatus enhances the efficacy of such procedures. The apparatus has an
improved flexibility of movement which permits improved imaging for a
single view of a breast and sequential examination of both of a patient's
breasts substantially without moving the patient. In addition, the
invention also allows for realization of the advantages associated with
vertical and horizontal patient positioning. The apparatus also enhances
accurate and reliable placement of a biopsy needle so that tissue or cell
samples suitable for histological or cytological examination can be
obtained without surgery.
According to one aspect of the present invention, an apparatus is provided
which comprises a tiltable frame for supporting the patient including an
opening to allow passage of at least one of the patient's breasts
therethrough, an instrument mounted on the frame means for use in
performing medical procedures on the patient's breast, and a mechanism for
selectively moving the frame and instrument across a range of orientations
relative to vertical so as to allow the patient and frame to be positioned
at orientations selected to facilitate performance of medical procedures
using the instrument. In this regard, it will be appreciated that
positions reclined even slightly from vertical will allow the patient's
breast to be projected outward due to gravity so that advantages
associated with conventional horizontal positioning can be obtained.
Similarly, positions inclined even slightly from horizontal provide
improved access to the patient's breast such that advantages associated
with conventional vertical positioning can be obtained. The positioning of
the patient for particular procedures can be selected based on
considerations of patient comfort and safety, the size of the patient, the
location of a lesion, ease of access for the physician and equipment and
other factors. Accordingly, the frame may be moveable across a range of
positions from a substantially vertical position to a substantially
horizontal position. The frame can be moveable to positions past vertical
or horizontal if desired. The movement of the frame can be accomplished
manually or may be automated, e.g., directed by a computer controlled
motor.
According to another aspect of the present invention, an imaging system is
provided which improves breast imaging and allows oblique views of a
breast to be obtained. The imaging system, which can be interconnected to
a frame for supporting the patient in a sitting or standing position,
comprises a transmitter for transmitting an imaging beam, such as a
radiographic or other radiation beam, through the patient's breast and a
receiver for receiving at least a portion of the beam transmitted through
the patient's breast. The transmitter can include a conventional x-ray
source or a laser and the receiver can include an x-ray film tray or a
charge-coupled imaging device or the like for substantially instantaneous
electronic imaging. At least one of the transmitter and receiver can be
rotatable about an axis extending forwardly from the patient's breast to
permit various views of the breast to be obtained. Additionally, at least
one of the transmitter and receiver can be rotatable about an axis
substantially parallel to the patient's cranial-caudal axis to obtain
oblique views. Alternatively, the frame can be moveable in a cradle motion
to obtain oblique views. It will thus be appreciated that an imaging
system constructed in accordance with the present invention provides a
flexibility of movement sufficient to obtain a wide variety of views
including Cleopatra views.
According to a further aspect of the present invention, an apparatus for
use in performing medical procedures on a patient's breasts is provided
which reduces or eliminates the need to reposition the patient during such
procedures. The apparatus comprises a frame for supporting the patient and
an imaging system for imaging a breast. A mechanism for providing relative
movement between the frame and the imaging system is provided such that
the imaging system is moveable across the patient's chest from one breast
to the other. This can be accomplished by moving the frame and/or the
imaging system. The frame is provided with at least one opening to allow
passage of the patient's breasts therethrough. In this regard, a single
opening dimensioned to allow passage of both breasts or separate openings
for each breast may be provided.
According to a still further aspect of the present invention, an apparatus
for performing medical procedures on a breast includes a frame for
supporting a patient and a puncture instrument for use in performing a
breast biopsy. The puncture instrument may include a biopsy needle for
obtaining cell or tissue samples from the patient's breast. For example,
the puncture instrument may comprise a spring-loaded biopsy gun. The
puncture instrument and frame can be movably interconnected such that the
puncture instrument is moveable across the patient's chest from one breast
to the other. In addition, the puncture instrument can be rotatable about
a first axis extending forwardly from the patient's breast and about a
second axis substantially parallel to the patient's cranial-caudal axis.
BRIEF DESCRIPTION OF THE DRAWINGS
For a more complete understanding of the present invention and for further
advantages thereof, reference is now made to the following detailed
description taken in conjunction with the drawings in which:
FIG. 1 is a side view of an apparatus constructed in accordance with the
present invention in a substantially vertical position;
FIG. 2 is a side view of the apparatus of FIG. 1 in a non-vertical
position;
FIG. 3 is a top view of the apparatus of FIG. 1; and
FIG. 4 is a front view of the apparatus of FIG. 1 in a substantially
horizontal position.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to FIGS. 1-4, an apparatus constructed in accordance with the
present invention is generally identified by the reference numeral 10.
Generally, the apparatus 10 comprises a frame assembly 12 for supporting a
patient 14 in a prone position pivotally mounted on a pedestal 16 or other
support member, a mammography imaging system 18 comprising an imaging beam
source 19 and receiver including film tray 36 for imaging the patient's
breasts so as to identify any suspicious lesion therein, and a detachable
needle biopsy assembly 20 for extracting a cell or tissue sample from any
identified lesion.
The frame assembly 12 supports the patient 14 in a prone position wherein
the patient's breasts are permitted to protrude through an opening 22 in
the frame assembly 12. Although in the illustrated embodiment both of the
patient's breasts protrude through a single opening 22, it will be
appreciated that separate openings for each breast could be provided or a
moveable window, door or diaphragm could be provided to permit exposure of
only a single breast or portion thereof. The frame assembly 12 comprises
an elongated patient support member 24 interconnected to the top end of a
central structural member 26 and a platform 28 interconnected to the
bottom end of and extending rearwardly away from the central structural
member 26. A handle 30 is provided across the top of patient support
member 24 for gripping and an optional restraining belt 32 is centrally
disposed across the patient support member 24 for enhanced patient
stabilization.
The patient 14 can stand on platform 28 and grip handle 30 as shown such
that the patient's breast received between compression paddle 34 and film
tray 36 during a medical procedure such as a mammographic biopsy
procedure. Alternatively, a second paddle juxtaposed between the breast
and film tray 36 in opposed relation to first paddle 34 could be utilized
to stabilize the breast if direct contact between the breast and film tray
36 is not desired. In place of or in addition to the illustrated grip
handle 30, individual handles (not shown) may be provided underneath the
frame assembly 12 so that the patient can grip such handles with her
pectoral muscles relaxed. The patient 14 is thus supported by the support
member 24 in combination with the platform 28 and handle 30. As will be
explained in greater detail below, the patient 14 is further supported by
compression paddle 34 which also serves to hold the patient's breast
stationary during the course of the mammographic biopsy procedure. Further
support may be provided, for example, by way of a fabric strip attached to
the frame assembly 12 and extending across the patient's upper body if
desired.
The frame assembly 12 is mounted on pedestal 38, which in turn is mounted
on the floor, in a manner which allows the frame assembly 12 to be tilted
(as shown by arrow A) and raised or lowered (arrow B). It will be
appreciated that the frame assembly 12 could alternatively be supported by
an arm extending from a wall or ceiling or other support member. In this
manner, the patient 14 can be supported by the frame assembly 12 at a tilt
angle suitable for the procedure being performed as described above. For
example, a biopsy procedure may be performed with the frame assembly 12
inclined slightly relative to horizontal such that the patient's breast
protrudes pendulantly through the opening 22 and is readily accessible to
the physician. Access to the patient's breast can be further enhanced by
raising frame assembly 12.
In the illustrated embodiment, the frame assembly 12 can be raised or
lowered by operation of a first actuator (not shown) housed in pedestal
16. The actuator, which is interconnected to frame assembly 12 by arm 38
and 40, can comprise, for example, a pneumatic or hydraulic cylinder or a
linear screw actuator. In this manner, the frame assembly 12 and patient
14 can be raised as shown by arrow B to provide easier access to the
patient's breast for the physician. A vertical adjustment range of about
ten inches at a rate of about one inch per second has been found to be
adequate for this purpose.
Access to the patient's breast can be further enhanced by tilting the frame
assembly 12. In this regard, it will be appreciated that improved access
to the breast, as compared with horizontal patient positioning, is
provided by tilting the patient 14 slightly from horizontal as shown in
FIG. 2. In the illustrated embodiment, arms 38 and 40 are pivotably
interconnected at pin 42 such that the frame assembly 12 can be pivoted by
extension or retraction of actuator 17 which is interconnected to lever
arm 19 (FIG. 2). The frame assembly 12 and patient 14 can thus be tilted
by pivoting arm 38 relative to arm 40. It should be noted that the patient
14 is simultaneously raised and tilted by this pivotal motion. This
pivotal motion is preferably controlled by a computer driven motor which
can be programmed to accurately repeat selected positions. The illustrated
frame assembly 12 is tiltable across an approximately 90.degree. range,
from a substantially vertical position to a substantially horizontal
position, at a rate of about 4.5.degree. per second. It will be
appreciated that this tilting motion, in addition to providing flexibility
in adjusting patient positioning for improved access and physician
convenience, allows the patient 14 to mount and dismount the apparatus 10
in a standing position, thereby eliminating side mounting and dismounting
procedures associated with known mammographic tables which procedures are
difficult for some patients.
The frame assembly 12 is interconnected to imaging system 18 and biopsy
assembly 20 by a generally "L" shaped support member 44. The support
member 44 is engaged with member 26 in a telescopic sliding arrangement
such that the imaging system 18, biopsy assembly 20, compression paddle 34
and associated components can be longitudinally moved relative to the
frame assembly 12 to allow adjustment for patients of various heights.
That is, the frame assembly 12 can be raised or lowered so that the
patient's breast is properly positioned on the film tray 36. As will be
described below, the film tray 36 can also be raised and lowered (as shown
by arrow C) as needed. A sliding adjustment range of about eight inches is
believed to be sufficient to accommodate most patients. This adjustment is
preferably motorized such that the physician can easily make fine
adjustments during the course of medical procedures.
A carriage arm 46 is slidably mounted on support member 44 such that the
imaging system 18, biopsy assembly 20, compression paddle 34 and
associated components can be moved forwardly and rearwardly, i.e., towards
and away from the patient 14 (arrow D). In this manner, the film tray 36
and compression paddle 34 can be properly positioned to the patient's
breast. In the illustrated embodiment, the carriage arm movement is
motorized to move across an eight inch range at a rate of about 0.4 inches
per second. Although this range is greater than patient anatomy requires,
such movement permits changing of the tray during medical procedures.
A generally "L" shaped support member 48 is mounted on the carriage arm 46
in a manner which permits the following movements of member 48 with
respect to arm 46. First, the member 48 is slidably mounted on arm 46 such
that the member 48 and components supported thereon can be moved across
the patient's chest (arrow E of FIG. 3). It will be appreciated that
medical procedures can therefore be performed sequentially on the
patient's left and right breasts substantially without moving the patient
14. In addition, the member 48 is pivotably mounted on arm 46 such that
the member 48 and components mounted thereon can be rotated about axis 50
(arrow F). It will be appreciated upon consideration of the description
below that this latter movement allows the imaging system 18 including
film tray 36 to be positioned such that an oblique, Cleopatra view of the
breast can be obtained. A single Cleopatra view is believed by some to be
sufficient for screening, thereby reducing or eliminating the need for
conventional top and side views of the breast. Additionally, this motion
allows the biopsy gun to approach the breast from oblique angles. It is
believed that a rotational motion of about 15.degree. is sufficient for
this purpose, although a greater range rotational motion may be provided
if desired. This rotational motion can be motorized so that tilting at a
rate of about 2.degree. per second can be achieved.
Transmitter arm 52 and receiver arm 54 are pivotably mounted on support
member 48 via pin 49 such that the arms 52 and 54 can be rotated, in
unison or separately, about axis 56 as shown by arrow F. Preferably, axis
56 is arranged to be substantially coincident with an axis extending
forwardly from a point of interest within the patient's breast so that the
components mounted thereon can be rotated about the breast, i.e., moved
circumferentially relative to the base of the breast. In this regard, it
will be appreciated that it is desirable to rotate the imaging system 18
and biopsy assembly 20 relative to the patient's breast to facilitate
particular mammographic biopsy procedures. In this illustrated embodiment,
the receiver arm is manually rotatable around the patient's breast across
a 105.degree. range. The transmitter arm 54 is rotatable across a
120.degree. range, such movement being motorized at a rate of about
10.degree. per second.
Imaging beam source 19 is slidably carried by arcuate arm 58 mounted on
transmitter arm 52. The source 19 can thus be manually moved along arcuate
arm 58 as shown by arrow G over a range of approximately 15.degree. to
provide a desired beam angle, for example, based on the location of a
lesion with respect to the patient's chest wall, and to avoid the heads of
patients who are unable to straighten their backs. The beam source 19
provides a beam which can be transmitted through the patient's breast for
imaging thereof. In this regard, X-ray, laser imaging or other suitable
imaging equipment may be utilized. The illustrated beam source 19
comprises a conventional x-ray beam source.
The receiver arm 54 carries film tray 36, compression paddle 34, and
detachable biopsy assembly 20. It will be appreciated that any suitable
receiver for receiving a portion of the beam transmitted through the
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