MRI, CT fine tune genitourinary imaging applications

Genitourinary scientific papers to be released at the 2009 RSNA meeting underscore attempts to address diagnostic challenges as old as the subspecialty itself by taking advantage of recent technological developments.

RSNA genitourinary imaging subcommittee chair Dr. Erick M. Remer described a number of intriguing papers that advance novel CT and MRI techniques, particularly for prostate, kidney, and ob/gyn indications.

"We are pushing the existing technologies further and identifying ways that we can better use them to answer clinical questions that have been around for a long time," Remer told Diagnostic Imaging.

One of the most pressing issues for GU imagers in recent times has been to define the role of MRI in imaging patients with prostate cancer. Techniques proposed for the assessment of patients with suspected prostate cancer are legion. But imagers still struggle to find MRI protocols that balance technical expertise and the time needed to perform them, Remer said.

According to Remer, submissions in that category are strong this year and include research on diffusion-weighted imaging, newer contrast agents, and PET/CT applications.

Another session will explore the use of MRI and CT for the diagnosis of adrenal nodules. As institutions use either one modality or the other, RSNA attendees should become acquainted with at least one study that compares the two directly, Remer said.

Renal calculi imaging has also caught the fancy of researchers. Studies in this year's session explore the assessment of lower radiation dose CT scanning and advanced postprocessing techniques to quantify stone volumes and predict the chance of spontaneous passage. Another area of focus features the use of dual-energy CT for the accurate characterization of nephrolithiasis.

This year's sessions will also explore imaging during pregnancy, with a focus on fetal MRI and novel MRI applications for placental evaluation. Perhaps the most intriguing papers will be those that look at MRI of pelvic floor abnormalities. They remain a common clinical problem for many women and their physicians, who still look for a good test to help them plan therapy, Remer said.

The current standard of care includes fluoroscopy with multisite contrast injections to the bladder, rectum, and small bowel. These pose important radiation safety and patient comfort issues that need addressing.

"MRI could replace fluoroscopic imaging," Remer said.