New device could reduce radiation in 3-D breast cancer imaging

Variable angle slant hole collimator--Courtesy of Jefferson Lab

A Department of Energy lab has devised a new component for 3-D molecular breast imagers that could increase the contrast of tumors sixfold while preserving image quality, with the potential to halve the radiation dose to patients undergoing imaging.

Molecular imaging is used in conjunction with mammography to reduce the number of false positives in women with dense breasts and therefore a higher risk of developing cancer. The DOE's Thomas Jefferson National Accelerator Facility designed a device to improve molecular imaging further.

In traditional imaging, a collimator, a rectangular plate with a grid of holes to filter gamma rays that come out of the breast, is used. The Jefferson Lab developed a variable angle slant hole collimator to replace the traditional collimator in molecular breast imagers. It comprises a stack of 49 thin tungsten sheets with the same array of holes. Two motors can alter the angle of the sheets, changing the focusing angle during imaging.

"Now, you can get a whole range of angles of projections of the breast without moving the breast or moving the imager. You're able to come in real close, you're able to compress the breast, and you can get a one-to-one comparison to a 3D mammogram," said Drew Weisenberger, leader of the Jefferson Lab Radiation Detector and Imaging Group, in the statement.

Investigators tested the device in a plastic mockup of a breast containing four beads to simulate tumors of varying diameters marked with a radiotracer. The VASH collimator achieved 6 times better contrast while maintaining the same or improved image quality, which could potentially reduce the amount of radiation required for imaging. A University of Florida team analyzed the test results with funding from the Commonwealth of Virginia and Dilon Technologies.

- here's the statement