Superparamagnetic particles as oral contrast medium in magnetic resonance imaging of patients with treated ovarian cancer--comparison with plain MRI.

In 23 patients with treated ovarian cancer, 24 magnetic resonance (MR) examinations of the abdomen and pelvis were performed before and after administration of an oral superparamagnetic contrast medium. Depiction of bowel loops was judged sufficient in 47% with plain scans and in 85% with enhanced scans. Minor artefacts attributed to the agent were noted in 32% of examinations and were classified as disturbing in 8%. The diagnostic information obtained after contrast enhancement was estimated to be superior to that from plain MRI in 20% of patients. The use of oral contrast medium did not alter the MR diagnosis of "tumour recurrence" or "disease-free" in any patient. Our results suggest that superparamagnetic iron oxide is an effective and reliable approach to negative bowel contrast enhancement, increasing the confidence level when distinguishing intestines from solid structures.