Three-D viewing technique slashes false-positive rate in mammography

Yet another new technology contender has emerged to help overcome the 2D flaws of mammography and save women from false positives, anxiety, and needless biopsies.

Just as viewing devices have enabled moviegoers to watch movies in 3D, a "stereo mammography" display station allows radiologists to see the breast structure in 3D on digital images. In contrast, with conventional mammography, superimposed overlying and underlying tissue can mask the presence of a lesion.

An Emory University study of 1093 patients found the technique resulted in nearly a 50% reduction in the false-positive rate. Radiologists compared standard digital mammography and digital with the stereo display independently. Based on follow-up, researchers determined there were 150 false-positive cases. Standard mammography had 103 false positives, versus just 53 for stereo mammography, said Dr. David Getty, division scientist at BBN technologies of Cambridge, MA.

"The implication of reduced false positives is that many fewer women will be recalled unnecessarily for diagnostic workup, resulting in greatly reduced healthcare costs and a reduction in patient anxiety," Getty said during a press conference at the RSNA meeting on Wednesday.

Of 259 suspicious findings reported by one or both modalities, 109 findings were true positives. Standard digital mammography failed to detect 40 true lesions, while stereo mammography missed 24. Additional data are needed to achieve statistical significance, but the initial results suggest that stereo mammography could help detect more true lesions and result in earlier diagnosis. Stereo mammography appears to be particularly useful in cases of clustered calcifications.

By the end of 2007, researchers expect to have data for 1500 women.

Stereoscopic image capture is very easy to implement in new and developing digital mammography systems, according to Getty. In an interview after the press conference, he suggested it is possible that the technology could be approved as a variation of an existing product and may therefore not face a long, drawn-out approval process used for completely new products.