Aug. 10 (Bloomberg) -- Doctors diagnosed more cases of an invasive form of breast cancer using magnetic resonance imaging than with standard mammography technique, according to a study published in The Lancet today.

Researchers at the University of Bonn in Germany found that out of 167 women diagnosed with ductal carcinoma in situ, often a precursor to invasive breast cancer, 92 percent were diagnosed using MRI scans, while only 56 percent were found using mammography, the diagnostic standard.

These findings suggest that MRI could improve the ability of doctors to catch the condition, which is found in 60,000 women in the U.S. each year, according to the American Cancer Society. Previous studies dismissed MRI screenings as not sensitive enough to find pre-cancer. Mammography detects about 20 percent of early, non-invasive breast cancers, the researchers said.

``MRI outperforms mammography in tumor detection and diagnosis,'' Dr. Carla Boetes and Dr. Ritse Mann, of the Dutch Radboud University Nijmegen Medical Centre, said in a separate comment published in The Lancet. ``MRI should thus no longer be regarded as an adjunct to mammography but as a distinct method to detect breast cancer in its earliest stage.''

The study compared the MRI scans and mammograms of more than 7,000 women over a five-year period in order to assess the relative sensitivity of the two detection methods. Researchers also accounted for the varying biological profiles of the women who took part in the study.

Almost half of the cases of ``high-grade'' DCIS, the most aggressive form of the disease, were missed by mammography screenings, the researchers said. MRI detected 98 percent of the cases, missing only two, which were found by mammography. The two methods had a similar rate of false positive diagnoses.

Makers of MRI machines include General Electric Co., Siemens AG and Royal Philips Electronics NV.

To contact the reporter on this story: Kari Lundgren in London at klundgren2@bloomberg.net

Last Updated: August 9, 2007 19:01 EDT