TUESDAY, Oct. 21 (HealthDay News) -- Combining the use of MRI with a special vaginal coil, doctors can now assess the extent of cervical cancer and make more informed treatment decisions, a new study suggests.

"The main use is in women with small cervical cancers, in whom it is necessary to delineate accurately the extent of disease prior to fertility-sparing surgery," explained study author Dr. Nandita deSouza, co-director of the MRI Unit at the Institute of Cancer Research and Royal Marsden Hospital, in London.

The new technique, described in the November issue of Radiology, is called endocavitary MRI. The MRI component, called "diffusion-weighted imaging," helps measure the movement of water within cervical tissue. "The ring coil enables the high-resolution MRI -- it is the equivalent of using a zoom lens on a camera," deSouza said.

When used in combination with the vaginal coil, endocavitary MRI helps researchers spot smaller tumors and then decide on treatment options based on how extensive the cancer is.

The entire procedure using the MRI with the coil takes about 15 minutes.

According to the American Cancer Society, an estimated 11,070 women in the United States will be diagnosed with invasive cervical cancer in 2008.

In the study, deSouza's group looked at 59 women, aged 24 to 83, separated into two groups. The first group included 20 women who were awaiting biopsies due to abnormal cervical tissue development when they were screened for cancer, and another 18 women who had invasive cervical cancer confirmed by biopsy. The second group included 21 women awaiting evaluation for invasive cervical cancer.

As deSouza explained, the diffusion of water is reduced in cancerous tissue versus normal tissue, allowing the investigators to use the MRI to determine the extent of the malignancy.

The authors reported no commercial interest related to the device.

The study adds to what is known about using the coil with MRI, one expert said.

"Studies already published show that the coil is more sensitive for small cancers," noted Dr. Susanna I. Lee, vice chairman of the American College of Radiology Panel on Women's Imaging, chief of women's imaging at Massachusetts General Hospital and an assistant professor of radiology at Harvard Medical School.

The new technique "looks at the function of the tissue, the ability of extracellular water in the tissue to diffuse. What diffusion imaging does is point out tissue that is abnormal. It's routinely used for brain imaging. This [new] technique is used after a Pap test tells you have cervical cancer," Lee said.

More information

There's more on MRI at the American College of Radiology.