Biopsy Systems For Breast Computed Tomography

• US 20080187095A1
• Filed: 05/03/2006
• Published: 08/07/2008
• Est. Priority Date: 05/03/2005
• Status: Active Grant

• Current Assignee: Regents of the University of California (University of California)
• Original Assignee: Regents of the University of California (University of California)
• Inventors: Boone, John M., Nelson, Thomas R.
• Granted Patent: US 10,492,749 B2
• Time in Patent Office: Days
• US Class Current: 378/37
• CPC Class Codes: A61B 10/0041 Detection of breast cancer mammography by transillumination A61B5/0091, by X-rays A61B6/502, by ultrasonic means A61B8/0825
• CPC Class Codes: A61B 6/03 Computed tomography [CT] echo-tomography A61B8/14
• CPC Class Codes: A61B 6/032 Transmission computed tomography [CT]
• CPC Class Codes: A61B 6/037 Emission tomography
• CPC Class Codes: A61B 6/0435 with means for imaging suspended breasts
• CPC Class Codes: A61B 6/06 Diaphragms
• CPC Class Codes: A61B 6/12 Arrangements for detecting or locating foreign bodies
• CPC Class Codes: A61B 6/4028 resulting in acquisition of views from substantially different positions, e.g. EBCT
• CPC Class Codes: A61B 6/405 Source units specially adapted to modify characteristics of the beam during the data acquisition process A61B6/4021, A61B6/4035 take precedence
• CPC Class Codes: A61B 6/4417 related to combined acquisition of different diagnostic modalities
• CPC Class Codes: A61B 6/4423 related to hygiene or sterilisation
• CPC Class Codes: A61B 6/4452 the source unit and the detector unit being able to move relative to each other
• CPC Class Codes: A61B 6/469 for selecting a region of interest [ROI]
• CPC Class Codes: A61B 6/482 involving multiple energy imaging
• CPC Class Codes: A61B 6/488 involving pre-scan acquisition
• CPC Class Codes: A61B 6/502 for diagnosis of breast, i.e. mammography
• CPC Class Codes: A61B 6/5235 combining images from the same or different ionising radiation imaging techniques, e.g. PET and CT
• CPC Class Codes: A61B 6/584 determining position of components of the apparatus or device using images of the phantom
• CPC Class Codes: A61B 8/0825 for diagnosis of the breast, e.g. mammography
• CPC Class Codes: A61B 8/4416 related to combined acquisition of different diagnostic modalities, e.g. combination of ultrasound and X-ray acquisitions
• CPC Class Codes: A61N 2005/1061 : using an x-ray imaging system having a separate imaging source
• CPC Class Codes: G16H 50/70 : for mining of medical data, e.g. analysing previous cases of other patients

Abstract

A device and methods for performing a simulated CT biopsy on a region of interest on a patient. The device comprises a gantry configured to mount an x-ray emitter and CT detector on opposing sides of the gantry, a motor rotatably coupled to the gantry such that the gantry rotates horizontally about the region of interest, and a high resolution x-ray detector positioned adjacent the CT detector in between the CT detector and the x-ray emitter.

Claims

1. A method for breast imaging, comprising the steps of:

(a) generating a three-dimensional volume data set of at least a portion of the breast;

(b) compressing the volume data set in a first direction to simulate compression of the breast in the first direction per compression mammography; and

(c) projecting the compressed volume data along the first direction to produce a simulated compression mammogram image.

2. A method as recited in claim 1, wherein the breast region hangs pendant while the three-dimensional volume dataset is acquired.

3. A method as recited in claim 1, wherein compressing the volume data set comprises a mathematical transformation of locations of data of the volume data set.

4. A method as recited in claim 1, further comprising the steps of:

comparing the simulated compression mammogram image to one or more compression mammogram images; and

changing at least one of the compression and projection to better match the simulated compression mammogram image to the one or more compression mammogram images.

5. A method as recited in claim 4, wherein the changing of at least one of the compression and projection changes at least one of the parameters of the group comprising:

orientation, non-linear warping, scaling, elasticity, rotation, shifting, and shearing.

6. A method as recited in claim 1, further comprising transforming the simulated compression mammography image contrast to simulate a mammogram taken at low x-ray density.

7. A method as recited in claim 6, further comprising co-locating a suspect lesion on both the simulated compression mammography image and at least one of the compression mammogram images.

8. A method as recited in claim 6, further comprising co-locating a suspect lesion on at least one of the compression mammogram images and on slice images derived from the three-dimensional volume data set.

9. A method of measuring breast density, comprising:

(a) generating a three-dimensional volume data set of at least a portion of the breast;

(b) segmenting the volume data into volume elements associated with glandular tissue and non-glandular tissue;

(c) calculating a volume of the portion of the breast associated with each of the glandular tissue and non-glandular tissue; and

(d) outputting a breast density measurement being a function of the volume of the portion of the breast associated with each of the glandular tissue and non-glandular tissue.

10. A method as recited in claim 9, wherein segmenting the volume data generates a histogram of the volume elements;

and selects volume elements according to a threshold value distinguishing glandular tissue and non-glandular tissue.

11. A method as recited in claim 9, further including the step of removing volume elements associated with skin before step (c).

12. A method as recited in claim 11, wherein the step of removing volume elements associated with skin applies an erosion filter to the volume data set.

13. A method as recited in claim 9, further comprising adjusting the breast density measurement according to a patient'"'"'s age.

14. A method as recited in claim 13, further comprising the step of outputting a standard deviation of the breast density measurement with respect to patients in a particular age group.

15. A method as recited in claim 9 further including the steps of comparing the breast density measurement to data of reference patients to output a risk factor indicating a relative risk of breast cancer for an individual patient.

16. The method as recited in claim 15, wherein the comparing entails comparing the breast density measurement with a mean breast density value and a standard deviation of the mean breast density value of breast density measurements obtained from a plurality of individual reference patients grouped according to age.

17. A method of performing a simulated CT breast biopsy comprising the steps of:

(a) acquiring a first CT projection set of the breast at a first spatial resolution;

(b) producing at least one image of the breast from the first CT projection set;

(c) identifying a location of a possible tumor in the image;

(d) acquiring a second CT projection set of only a portion of the breast around the location at a second spatial resolution higher than the first spatial resolution; and

(e) producing a high resolution image of the portion of the breast from the second CT projection set.

18. The method as recited in claim 17, wherein step (e) comprises the steps of combining the second projection set with at least portions of the first projection set and reconstructing the second projection set as combined.

19. The method of claim 17 wherein the first projection set is obtained with a first detector having a first area and first spatial resolution and the second projection set is obtained with a second detector having a second area smaller than the first area and a second spatial resolution greater than the first spatial resolution.

20. The method of claim 17 wherein including the step of illuminating the possible tumor with an x-ray source at a range of angles about the possible tumor and varying the position of the second detector with respect to the x-ray source to remain aligned with the possible tumor.

21. The method of claim 17 wherein including the step of collimating an x-ray source around the possible tumor with a collimator and varying a position of the collimator with respect to the x-ray source to remain aligned with the possible tumor.

22. A method of performing a breast biopsy, comprising the steps of:

(a) generating a 3-D volume CT dataset of a breast;

(b) reconstructing the dataset into at least two images;

(c) identifying at least two spatial coordinates of a region of interest within the breast by location of a cursor on the two images; and

(d) manipulating a robotic assembly according to the coordinates to deliver a biopsy needle to the region of interest.

23. The method, as recited in claim 22, wherein the two images include three orthogonal projection views of the breast.

24. The method, as recited in claim 22, wherein the two images include multiple-slice images through the breast and multiple projection and rendered images.

25. The method as recited in claim 22 wherein the two images include at least one standard compression mammogram and multi-planar images and including the step of co-locating cursors on each of the standard compression mammogram and multiple planar slice images.

26. A method as recited in claim 22, wherein the breast region is pendant during the generating of the 3-D volume dataset.

27. A method as recited in claim 22, wherein the breast region is pendant during the manipulation of the biopsy needle.

28. A method as recited in claim 22 wherein the robotic assembly provides one axis of rotation aligned with a vertical axis of a pendant breast.

29. A method as recited in claim 22 wherein the robotic assembly operates within a volume between an x-ray source and x-ray detector to allow concurrent image acquisition.

30. An apparatus for generating imaging a breast comprising:

(a) a table supporting a patient in a prone position with at least one breast pendant;

(b) an x-ray source and detector positioned to acquire a CT projection set about a horizontal axis around the pendant breast; and

(c) a PET detector positioned to acquire PET data of the breast of interest contemporaneously with the acquisition of the CT projections set.

31. A method of determining abnormal structures in a patient'"'"'s breast, comprising:

(a) generating CT images of a series of reference patients;

(b) identifying normal duct structures in the generated CT images to generate a database of normal duct structures;

(c) generating CT images of a treatment patient; and

(d) comparing the CT images of the treatment patient with the database to identify all abnormal structure in the patient'"'"'s breast.

32. A method for restraining a patient'"'"'s breast during a medical procedure, comprising employing an immobilization device to:

(a) apply a vacuum to a portion of the patient'"'"'s breast; and

(b) apply a tensile force on the patient'"'"'s breast with the vacuum to immobilize the breast.

33. A method as recited in claim 32, further including the step of inserting a biopsy device through the immobilization device into the immobilized breast.

34. A method as recited in claim 32, wherein the breast is immobilized while the breast hangs in a pendant position.

35. A method as recited in claim 33, including the step of imaging the biopsy device during insertion of the device and correcting a trajectory of the biopsy device based on the imaging.

36. A method of delivering radiotherapy treatment with a CT scanner, comprising:

(a) generating a CT volume dataset with a the CT scanner with a first x-ray energy;

(b) identifying a region of interest within the CT volume dataset; and

(c) delivering a focused radiotherapy treatment to the identified region of interest with a second x-ray energy; and

the second x-ray energy having a significantly lower x-ray spectra.

37. A method as recited in claim 36, wherein the second x-ray energy is less than 1 MVp.

38. A method as recited in claim 36, wherein the second x-ray energy is between 160 kVp and 320 kVp.

39. A method of delivering ultrasound treatment with a CT scanner, comprising:

(a) generating a CT volume dataset with a the CT scanner;

(b) identifying a region of interest within the CT volume dataset; and

(c) delivering a focused ultrasonic treatment to the identified region of interest with a high energy focused ultrasound beam.