RSNA News - August 2005

RSNA Grant Recipient Sees Bright Future for MR Colonography

The technology is evolving so rapidly that I know things will look a lot better for MR colonography in five years and our work will have contributed to that progress. — Martina Morrin, M.D.

MR colonography may be just what the doctor ordered for increasing the number of patients screened for colon cancer.

Martina Morrin, M.D. 1999 RSNA Research Seed Grant Recipient

Colorectal cancer is the third leading cause of cancer death in the United States with more than 57,000 fatalities per year, according to the National Cancer Institute. More than 147,000 new cases are diagnosed each year, a slight decrease over recent years.

Despite public information campaigns urging Americans to undergo screening, fewer than 50 percent do so. Many complain about the uncomfortable prep and sedation, and report anxiety about the delicate nature of the procedure itself. In addition, there is growing concern among patients and medical professionals about the use of radiation for screening purposes.

Martina Morrin, M.D., a staff radiologist at Beth Israel Deaconess Medical Center and an assistant professor of radiology at Harvard Medical School, used her 1999 RSNA Research Seed Grant to help develop MR colonography. The technique requires very little prep, is minimally invasive and uses air as the luminal contrast agent.

“We are on the path to developing a nearly prep-free screening and unlike CT colonography, MR colonography does not expose the patient to radiation,” she said.

In addition, MR colonography demonstrates all organs in the abdomen giving it a distinct advantage over traditional colonoscopy. “In my work with MR, I have found some potentially cancerous complex renal cysts that would not have been found with colonoscopy,” explained Dr. Morrin.

Dr. Morrin said patients have found the technique much more tolerable than colonoscopy. When surveyed, she said 43 percent of patients preferred MR screening, 29 percent preferred colonoscopy and the remainder had no preference.

“Dr. Morrin’s work addresses an extremely important area of research and development for future application in virtual imaging,” said Melvin Clouse, M.D., vice-chairman and director of Research at Beth Israel Deaconess Medical Center and professor of radiology at Harvard Medical School. “Advances in cutting-edge image processing have created a unique opportunity for the radiologist to take a more active and pivotal role in the detection of colorectal cancer.”

When Dr. Morrin began her research of MR colonography in 1999, she scanned 22 patients with a 1.5 Tesla MR system. She was able to identify three out of five polyps that were one centimeter or larger, representing a 60 percent sensitivity for large polyps. Identifying smaller polyps was difficult using the available technology.

With the preliminary data obtained through her RSNA Research Seed Grant, Dr. Morrin applied for and received another research grant, this one from the Association of University Radiologists. She began to build her database by scanning an additional 40 patients using newer computer software and an up-to-date protocol. The sensitivity increased dramatically. She garnered 100 percent sensitivity for polyps one centimeter and larger, 80 percent for medium-sized polyps (5-10 mm) and 20 percent for polyp less than five millimeters.”

“Over the past five years there has been a real evolution in hardware and software and our research has evolved with the technology. There seems to be a new advance every couple of months that makes a huge impact on the field,” said Dr. Morrin.

But while MR colonography is showing real promise, going from bench to bedside has been tricky, especially with the increased use of CT colonography.

“A lot of software companies are very interested in CT and have been part of the force that has pushed it forward. It has been a bit more challenging to get people in the software companies involved in MR because they’re so involved in CT,” said Dr. Morrin. “We are nowhere near where CT is today. But the technology is evolving so rapidly that I know things will look a lot better for MR colonography in five years and our work will have contributed to that progress.”

Dr. Morrin says she loves the diversity of her work and credits the RSNA grant with kick-starting her research career. “I have learned so much through research that I can apply to my everyday clinical work. It has given me a much better understanding of the field in general,” said Dr. Morrin. “I’m more confident now and consider myself a capable independent researcher, which is a wonderful scenario particularly now that I am moving back to the European scene.”

Dr. Morrin received her medical degree from the University College in Dublin, Ireland, and completed her radiology residency at Mater Misericordiae Hospital in Dublin. She and her husband, a gastroenterologist, came to the United States in 1997 to complete their fellowships at Beth Israel Deaconess Medical Center and subsequently joined the staff in 1999. They plan to return to Ireland in the fall where Dr. Morrin says she will continue her research on MR.