Computer-aided detection could nearly halve the time needed to perform breast cancer screens, enabling women to have more personal consultations and to undergo more routine x-rays. Current procedures require that two radiologists review each mammogram, but research performed at the Universities of Aberdeen and Manchester and at Cancer Research UK in London, all in the UK, suggests that only a single review is necessary with the use of a specialized computer system.

The system — made by R2 Technology of Sunnyvale, Calif. — digitizes the mammograms and displays them on a flat panel screen as low-spatial-resolution images. It then uses algorithms to generate several regions of interest on the display, prompting doctors to determine whether the regions mark tumors.

As reported in the October issue of Radiology, the investigators studied more than 10,000 mammograms that had been previously reviewed by two radiologists without computer assistance. A different set of experienced radiologists read the x-rays with the assistance of the computer-aided detection system, and their decisions were compared with those of the original reviewers. Researchers knew whether the patients were recalled for further testing or were diagnosed with cancer.

Overall, single readers using the computer system detected cancer with 15 percent greater accuracy but required 32 percent more recalls. Nonetheless, the scientists concluded that the sensitivities of both methods were equivalent.

They noted that improved image quality and an increase in reader performance over the time between the two studies, regardless of the use of computer systems, could have caused the detection rate to appear greater than it was. They also contended that doctors may have requested more recalls because they would not have any clinical consequences. Nevertheless, the results were sufficiently encouraging for them to begin a trial of the detection system in a live clinical setting.