Dual contrast enhanced magnetic resonance imaging of the liver with superparamagnetic iron oxide followed by gadolinium for lesion detection and characterization

AIM: Iron oxide contrast agents are useful for lesion detection, and extrac ellular gadolinium chelates are advocated for lesion characterization. We u ndertook a study to determine if dual contrast enhanced liver imaging with sequential use of ferumoxides particles and gadolinium (Gd)-DTPA can be per formed in the same imaging protocol. MATERIALS AND METHODS: Sixteen patients underwent dual contrast magnetic re sonance imaging (MRT) of the liver for evaluation of known/suspected focal lesions which included, metastases (n = 5), hepatocellular carcinoma (HCC; n = 3), cholangiocharcinoma (n = 1) and focal nodular hyperplasia (FNH; n = 3). Pre- and post-iron oxide T1-weighted gradient recalled echo (GRE) and T2-weighted fast spin echo (FSE) sequences were obtained, followed by post- Gd-DTPA (0.1 mmol/kg) multi-phase dynamic T1-weighted out-of-phase GRE imag ing. Images were analysed in a blinded fashion by three experts using a thr ee-point scoring system for lesion conspicuity on pre- and post-iron oxide T1 images as well as for reader's confidence in characterizing liver lesion s on post Gd-DTPA T1 images. RESULTS: No statistically significant difference in lesion conspicuity was observed on pre- and post-iron oxide T1-GRE images in this small study coho rt. The presence of iron oxide did not appreciably diminish image quality o f post-gadolinium sequences and did not prevent characterization of liver l esions. CONCLUSION: Our results suggest that characterization of focal liver lesion with Gd-enhanced liver MRI is still possible following iron oxide enhanced imaging. Radiology, 56, 410-415 (C) 2001 The Royal College of Radiology.