TUESDAY, May 3 (HealthDay News) -- Magnetic resonance imaging (MRI) can distinguish between endometrial and cervical cancer in most cases where a biopsy fails to do so, a new study says.

It found that radiologists using MRI were able to correctly identify the type of cancer in 38 of 48 patients, or 79 percent, who had inconclusive biopsy results.

More than 43,000 women were newly diagnosed with endometrial cancer, which starts in the lining of the uterus, in the United States last year, according to the U.S. National Cancer Institute.

There were about 12,200 newly diagnosed cases of cervical cancer, which starts in the cervix, or the lower part of the uterus that opens into the vagina, according to the NCI.

"In about 3 percent of the cases, there is difficulty determining the primary cancer site," said study author Dr. Heather He, of the M.D. Anderson Cancer Center in Houston, in an American Roentgen Ray Society news release. "Knowing the primary cancer site means that we can give the patients the most appropriate therapy and save some patients from unnecessary surgery."

The MRI images used in the study were examined by two radiologists, one with five years' experience and the other with 18 years' experience. Their diagnoses matched most of the time, which shows that extensive experience isn't crucial, according to He.

The study was presented Tuesday at the society's annual meeting in Chicago.

Because this study was presented at a medical meeting, the data and conclusions should be viewed as preliminary until published in a peer-reviewed journal.

More information

The American Cancer Society has more about endometrial cancer.