Detection of hepatic metastases: Ferumoxides-enhanced MR imaging versus unenhanced MR imaging and CT during arterial portography

PURPOSE: To prospectively compare the diagnostic accuracy of computed tomography (CT) during arterial portography (CTAP) with that of unenhanced and ferumoxides-enhanced magnetic resonance (MR) imaging at 0.5 T in the detection of hepatic metastases. MATERIALS AND METHODS: Four pairs of radiologists independently assessed the metastatic involvement of 134 hepatic segments (31 with and 103 without metastasis) in 17 patients at unenhanced and ferumoxides-enhanced spin-echo and gradient-echo MR imaging (alone and in combination) and at CTAP. The diagnostic performance of the various imaging modalities was assessed by means of receiver operating characteristic analysis. RESULTS: The accuracy of CTAP, unenhanced MR imaging (combined unenhanced sequences), and ferumoxides-enhanced MR imaging (combined contrast material-enhanced sequences) was 0.925, 0.908, and 0.951, respectively. Ferumoxides-enhanced MR imaging was significantly more accurate (P < .05) than unenhanced MR imaging and CTAP. When 14 segments containing cysts were excluded, the difference between ferumoxides-enhanced MR imaging and CTAP was no longer statistically significant (P = .1). CONCLUSION: Ferumoxides-enhanced MR imaging is more accurate than unenhanced MR imaging and at least as accurate as CTAP for the detection of hepatic metastases.