Imaging Aids Reduce Diagnostic Accuracy

I've sometimes been described as a Luddite because of my resistance to adopt certain technologies (though my iPod and laptop would beg to differ). In a recent case of man vs. machine published in the New England Journal of Medicine compares mammograms subjected to computer-aided detection (CAD) to those screened without computer assistance. CAD software, approved for use in 1998, analyzes mammogram images and marks suspicious areas which are then reviewed by a radiologist. The NCI sponsored study found that CAD did not increase cancer-detection rate, in contrast to early studies that showed a 10-15% increase in diagnosis rate - similar to the increase found with a second human opinion. Instead, this much more comprehensive study found a significant increase in false positive rate, resulting in more call-backs and biopsies, and increased burden on the system and ulitmately an increase in cost for breast screening.

From the NCI press release:

"This study points out the need for the use of other techniques to find cancer at its earliest stages. NCI is incorporating techniques for imaging at the molecular level into many of its studies and is also conducting studies to improve the use of CAD and conventional mammography," said John E. Niederhuber, M.D., NCI Director. "In the end, technology facilitates screening. Ultimately, treatment requires radiologists working with the examining physician and the responsible surgeon to put everything together. We worry about false positives, but we certainly don't want to miss any cancers, either."