Extrahepatic abdominal imaging in patients with malignancy: Comparison of MR imaging and helical CT, with subsequent surgical correlation

PURPOSE: To compare state-of-the-art magnetic resonance (MR) imaging with,s ingle-phase helical computed tomography (CT) in abdominal screening for ext ra hepatic disease in patients with proved malignancy. MATERIALS AND METHODS: Fifty-seven patients with known malignancy underwent abdominal contrast material-enhanced helical CT and MR imaging from 1994 t hrough 1997. Prospective interpretations of CT scans and MR images were use d to assess each modality's sensitivity in depicting malignant extrahepatic tumor at 17 anatomic sites. Imaging findings were compared with surgical r esults in all patients. RESULTS: Helical CT depicted 101 (66%) of 154 surgically confirmed extrahep atic tumor sites; MR imaging depicted 139 (90%) (P < .001). MR imaging depi cted tumor in more patients at 11 of the 17 anatomic sites; at six sites, M R imaging and;;; helical CT were equivalent. MR imaging showed significantl y greater depiction of extrahepatic tumor for the peritoneum (P < .05), bow el (P < .01), and mesentery (P < .05). False-negative interpretations would have altered patient care had the extrahepatic tumor remained undetected i n 13 patients for helical CT and in six patients for MR imaging. CONCLUSION: State-of-the-art MR imaging can be used for effective abdominal screening for extrahepatic tumor in patients with malignancy. Compared wit h single-phase helical CT, MR imaging depicted more sites of extrahepatic t umor and :was particularly advantageous for the peritoneum, mesentery, and bower.