US-20260123901-A1 - SYSTEMS AND METHODS FOR MEASURING THICKNESS OF FOAM COMPRESSIVE ELEMENTS

US20260123901A1US 20260123901 A1US20260123901 A1US 20260123901A1US-20260123901-A1

Abstract

A method of imaging a breast of a patient with a breast imaging system includes supporting the breast on a breast support platform. A compressive force is applied to the breast with a breast immobilization element including a rigid substrate, a foam compressive element secured below the rigid substrate, and a force sensor. The foam compressive element is in contact with the breast during application of the compressive force. A force signal is detected at the force sensor based on the applied compressive force. A compressed thickness of the breast proximate the force sensor is determined based at least in part on the detected force signal at the force sensor. An automatic exposure control is set based at least in part on the determined thickness of the breast proximate the force sensor.

Inventors

Kenneth F. Defreitas
Baorui Ren

Assignees

HOLOGIC, INC.

Dates

Publication Date: 20260507
Application Date: 20251008

Claims (20)

1 . (canceled)
2 . A method of imaging a breast of a patient with a breast imaging system, the method comprising: supporting the breast on a breast support platform; applying a compressive force to the breast with a breast immobilization element comprising a rigid substrate, a foam compressive element secured below the rigid substrate, and at least one force sensor, and wherein the foam compressive element is in contact with the breast during application of the compressive force; during application of the compressive force, detecting a force signal at the at least one force sensor; determining a compressed thickness of the foam compressive element at the at least one force sensor based at least in part on the force signal; and determining a compressed thickness of the breast at the at least one force sensor.
3 . The method of claim 2 , further comprising identifying the foam compressive element.
4 . The method of claim 3 , wherein identifying the foam compressive element includes receiving one or more of manufacturer, material, thickness, or spring rate information.
5 . The method of claim 3 , wherein identifying the foam compressive element includes receiving a user selection.
6 . The method of claim 2 , wherein determining the compressed thickness of the foam compressive element at the at least one force sensor comprises obtaining a foam thickness measurement from a look-up table comprising a plurality of force signals and a plurality of corresponding foam thickness measurements.
7 . The method of claim 6 , further comprising identifying a foam compressive element type, and wherein the look-up table is associated with the foam compressive element type.
8 . The method of claim 7 , wherein identifying the foam compressive element type comprises receiving an identification signal.
9 . The method of claim 2 , wherein determining the compressed thickness of the foam compressive element at the at least one force sensor comprises algorithmically calculating the compressed thickness of the foam compressive element via applied force data.
10 . The method of claim 2 , wherein determining the compressed thickness of the breast is based at least in part on the determined thickness of the foam compressive element at the at least one force sensor and a separation distance between the breast support platform and the rigid substrate.
11 . The method of claim 2 , wherein the compressed thickness of the foam compressive element is at a location of the foam compressive element substantially vertically aligned with the at least one force sensor.
12 . The method of claim 11 , further comprising determining a compressed profile of an upper surface of the breast.
13 . The method of claim 2 , further comprising setting an automatic exposure control based at least in part on the determined thickness of the breast proximate at the at least one force sensor.
14 . The method of claim 13 , wherein setting the automatic exposure control is further based at least in part on at least one of the compressed thickness of the foam and a foam density.
15 . The method of claim 2 , wherein the at least one force sensor comprises a plurality of force sensors arranged in a grid pattern on the rigid substrate.
16 . An imaging system comprising: an x-ray source; an x-ray detector; an immobilization system disposed at least partially between the x-ray source and the x-ray detector, the immobilization system comprising: a breast support platform; and a breast immobilization element having a rigid substrate, a foam compressive element secured below the rigid substrate, and at least one force sensor; at least one processor; and memory storing instructions that, when executed by the at least one processor, cause the imaging system to perform a set of operations comprising: applying a compressive force to a breast of a patient via the breast immobilization element with the foam compressive element in contact with the breast; detecting a force signal at the at least one force sensor during application of the compressive force; determining a compressed thickness of the foam compressive element at the at least one force sensor and based at least in part on the force signal; and determining a compressed thickness of the breast at the at least one force sensor.
17 . The imaging system of claim 16 , wherein the at least one force sensor comprises a plurality of force sensors arranged in a grid pattern on the rigid substrate.
18 . The imaging system of claim 16 , wherein the at least one force sensor comprises a plurality of force sensors disposed along a line extending from a front edge of the breast immobilization element.
19 . The imaging system of claim 18 , wherein the line is disposed along a central region of the rigid substrate.
20 . The imaging system of claim 16 , wherein the at least one force sensor is disposed between the rigid substrate and the foam compressive element.

Description

CROSS-REFERENCE TO RELATED APPLICATION This application is a continuation of U.S. patent application Ser. No. 18/556,153, filed Oct. 19, 2023, which is a National Stage Application of PCT/US 2022/026336, filed Apr. 26, 2022, which claims the benefit of U.S. Provisional Application No. 63/179,816, filed Apr. 26, 2021, the entire disclosures of which are incorporated herein by reference in their entireties. To the extent appropriate, a claim of priority is made to each of the above disclosed applications. BACKGROUND Compression during mammography and tomosynthesis imaging serves a number of purposes. For example, it: (1) makes the breast thinner in the direction of x-ray flux and thereby reduces patient radiation exposure from the level required to image the thicker parts of a breast that are not compressed; (2) makes the breast more uniform in thickness in the direction of x-ray flux and thereby facilitates more uniform exposure at the image plane over the entire breast image; (3) immobilizes the breast during the x-ray exposure and thereby reduces image blurring; and (4) brings breast tissues out from the chest wall into the imaging exposure field and thus allows for more tissue imaging. As the breast is being compressed, typically a technologist manipulates the breast to position it appropriately and counter the tendency that compression has of pushing breast tissue toward the chest wall and out of the image field. Standard compression methods for mammography and tomosynthesis use a movable, rigid, radiolucent compression paddle. The breast is placed on a breast support platform that typically is flat, and the paddle then compresses the breast, usually while a technologist or other health professional is holding the breast in place. The technologist may also manipulate the breast to ensure proper tissue coverage in the image receptor's field of view. One known challenge in mammography and breast tomosynthesis is the discomfort the patient may feel when the breast is compressed, which must be done with sufficient force to immobilize the breast and spread out the breast tissues for x-ray imaging. Discomfort may potentially cause the patient to move, which negatively impacts image quality. Discomfort may also potentially dissuade patients from getting screened for breast cancer. Another known challenge is to ensure that the imaged field includes the desired amount of breast tissue. SUMMARY In one aspect, the technology relates to a method of imaging a breast of a patient with a breast imaging system, the method including: supporting the breast on a breast support platform; applying a compressive force to the breast with a breast immobilization element including a rigid substrate, a foam compressive element secured below the rigid substrate, and a force sensor, and wherein the foam compressive element is in contact with the breast during application of the compressive force; detecting a force signal at the force sensor based on the applied compressive force; determining a compressed thickness of the breast proximate the force sensor based at least in part on the detected force signal at the force sensor; and setting an automatic exposure control based at least in part on the determined thickness of the breast proximate the force sensor. In an example, determining the compressed thickness of the breast proximate the force sensor includes: determining a separation distance between the breast support platform and the rigid substrate; obtaining a compressed foam thickness proximate the force sensor based at least in part on the detected force signal at the force sensor; and subtracting the compressed foam thickness proximate the force sensor from the separation distance to determine the compressed thickness of the breast proximate the force sensor. In another example, the force sensor is disposed proximate a front wall of the rigid substrate and proximate a centerline extending from the front wall. In yet another example, setting the automatic exposure control is further based at least in part on at least one of the compressed foam thickness and a foam density. In still another example, the force sensor includes a plurality of force sensors. In another example of the above aspect, the plurality of force sensors are arranged in a grid pattern on the rigid substrate. In an example, the plurality of force sensors are arranged disposed along a centerline extending from a front wall of the rigid substrate. In another example, the compressed foam thickness proximate the force sensor, and the compressed thickness of the breast proximate the force sensor are substantially vertically aligned. In yet another example, the compressed foam thickness proximate the force sensor, the compressed thickness of the breast proximate the force sensor, and the force sensor are substantially vertically aligned. In still another example, the at least one force sensor includes a plurality of force sensors disposed along a line extending fr