MRI Best for Whole Body Detect

By Laurie Barclay, MD
Medscape Medical News

May 7, 2003 — Magnetic resonance imaging (MRI) was better than scintigraphy or positron emission tomography (PET) for whole body detection of skeletal metastases, according to the results of a comparison trial presented on May 7 during the American Roentgen Ray Society annual meeting in San Diego, California.

"Whole body MR imaging was outstanding in predicting possible complications, such as fractures," lead author Nadir Ghanem, MD, from University Hospital Freiburg in Germany, says in a news release.

Using a rolling table platform, or "bodysurf," allowing a broader view, patients could be imaged nearly head to toe in a relatively short time.

In 40 of 98 patients studied, both whole body MRI and a bone scan detected skeletal metastatic disease. In 21 of these patients, MRI revealed more extensive disease than did bone scans. Compared with MRI, the bone scan showed more extensive disease in the arms, legs, and ribs in six patients. MRI detected skeletal metastases in 11 cases with negative bone scans.

In 80 of the 98 patients studied, MRI "yielded additional morphological information about the primary tumor, lymph node involvement, and visceral and soft tissue metastases," Dr. Ghanem says.

Of the 98 patients, 45 had whole-body FDG-PET, including 19 patients with negative MRI and PET, and 10 in whom both MRI and PET were positive for skeletal metastases. In seven of the 10 patients with skeletal metastases, MRI revealed more extensive metastatic disease.

In six patients with discordant findings using the two techniques, five had positive MRI and negative PET. The positive MRI findings were confirmed by clinical follow-up.

Advantages of this MRI technique are that it takes less than 10 minutes, compared with 15 to 20 minutes for bone scans and 90 minutes for PET scans. Unlike bone scans and PET, which both require the use of a radioisotope, the MRI uses no radiation or contrast media.

"This particular study included 98 patients, but we have done more than 250 investigations using whole body MR imaging combined with a rolling table platform," Dr. Ghanem says.

ARRS 103rd Annual Meeting: Abstract 203. Presented May 7, 2003.

Reviewed by Gary D. Vogin, MD