Tomosynthesis Better at Identifiying Architectural Distortion

Digital breast tomosynthesis (DBT) may provide radiologists with better visualization of architectural distortion and may help to identify malignancies that are not seen using digital mammography alone, a new study indicates.

DBT, sometimes called 3D mammography, allows sequential analysis of thin breast sections through the reconstruction of images in multiple projections.

“DBT - as a screening tool - can detect certain subtle manifestations of cancer that standard digital mammography cannot,” study author Luke Partyka, department of radiology, Alpert Medical School of Brown University, told Diagnostic Imaging. “In this regard, this relatively new modality offers some distinct advantages over conventional mammography.”

Partyka and colleagues conducted a retrospective review of BI-RADS category 0 reports from 9,982 digital mammography examinations that had adjunct DBT. Results of these examinations were analyzed by three radiologists who ranked the architectural distortion by whether they were seen better on digital mammography or DBT, equally on both or were occult on either. The researchers sought to determine if the increased architectural distortion typically seen on DBT increased the detection of cancer.The results of the study were published in the American Journal of Roentgenology.

The radiologists agreed that architectural distortion was found on 26 examinations. They found architectural distortions to be better visualized on six (26 percent) of the DBT examinations compared with digital mammography; 73 percent of architectural distortions were seen only on DBT.

Of the 19 lesions seen only on DBT, nine were classified as BI-RADS 4 or higher. Eight lesions underwent subsequent biopsy where two benign lesions, four high-risk lesions and two malignancies were identified. Of the six cases identified better on DBT than digital mammography, five underwent biopsy, revealing two radial sclerosing lesions and three invasive carcinomas.

The cancer detection rate for DBT in mammographically occult architectural distortion was 21 percent.

According to Partyka, this highlights that new biopsy systems that facilitate tissue sampling of lesions seen only on tomosynthesis are of great value to practices that routinely perform many DBT examinations.

“As more and more centers incorporate new technologies such as tomosynthesis into their practice, it is important for these types of investigations to be conducted,” Partyka said. “They not only help to guide radiologists in their daily work but also allow us to better understand how introduction of a new modality affects our capacity to detect cancer.”