Another View of Breast Density
Improving accuracy makes breast ultrasound a useful adjunct to mammography.
Looking at new breast ultrasound tools, it's clear that some technologies are turning over traditional processes, while others are incorporating software with an eye for human assessments. Regardless of the technology, it appears that the future of breast ultrasound comes with a clear, consistent view of possible cancerous lesions, found as an adjunct to mammography during the screening process and as a diagnostic tool.
Developments in breast ultrasound have been spurred by the heightened awareness of dense breast tissue. More than 40% of women in the United States have dense breast tissue. If those women live in one of 31 states with mandatory dense breast notification, they're finding out about their condition and asking their doctors what they should do. Answering that question involves finding the best way to look through the white matter of dense breast tissue to find potentially hidden lesions.
"Tools that can provide a more accurate view of what's in the breast, better detection of lesions, and better diagnosis, while reducing the number of unnecessary breast biopsies and false positives and callbacks, are some of the drivers behind developments within breast ultrasound," says Alberto Goldszal, PhD, chief operating officer of University Radiology, the largest provider of subspecialty radiology and teleradiology services in New Jersey. "There are a few ultrasound modalities now dedicated to perform breast screening. The industry is dedicated to this modality, looking at it as being complementary to traditional X-ray-based mammography."
Facedown Breast Ultrasound In one case, Delphinus Medical Technologies is turning breast ultrasound upside down, literally, with SoftVue, a 3D whole breast ultrasound that allows women to lie facedown on the exam table. SoftVue, approved for diagnostic screening, generates tomographic image volumes of the entire breast. While the patient lies prone on a padded table with one breast submerged in warm water, a ring-shaped transducer, 22 cm in diameter, encircles the breast and pulses low-frequency sound waves through the water and into the breast tissue. More than 2,000 elements in the transducer's 360-degree array emit and receive ultrasound signals to analyze echoes from the breast anatomy in all directions, from the chest wall to the nipple. SoftVue captures data from the reflection of the sound waves off of tissue boundaries and structures within the breast and also captures signals that are transmitted through the breast.
"SoftVue scans the entire breast in two to four minutes, with no breast compression and no radiation exposure to the patient," says Mark Forchette, president and CEO of Delphinus. "We're looking for options to improve specificity and reduce false positives. While mammography remains the gold standard in breast screening, there's still an opportunity to do a better job of screening and diagnosing breast cancer, particularly for women with dense breast tissue."
During the scanning process, three distinct imaging volumes, also called sequences, are created, showing reflection, speed of sound, and attenuation.
"With three imaging views, we're able to look at breast tissue in three different modes," says Linda Hovanessian Larsen, MD, director of women's imaging in the department of radiology at Keck School of Medicine at the University of Southern California. "This is extremely helpful in screening women with dense breasts and can help reduce the number of false positives and the anxiety that comes with them."
The repetitive, automatic nature of SoftVue also helps reduce false positives by bringing consistency to a breast ultrasound scan, Forchette says.
"It's easier to duplicate a study with automatic breast ultrasound vs handheld ultrasound," he says. "Handheld isn't as consistent."
SoftVue Clinical Study Data are a big part of proving the benefits of new ultrasound technology. For that reason, Delphinus is spearheading the SoftVue Discover Breast Ultrasound Prospective Case Collection project, a 10,000-patient clinical study of asymptomatic women with heterogeneously or extremely dense breast tissue that is being conducted at eight sites across the country. Qualified participants will have both screening mammography and SoftVue exams. Imaging information gathered from the project will compare SoftVue with digital mammography and measure the effectiveness of So