Efficacy of sequential use of superparamagnetic iron oxide and gadolinium in liver MR imaging.

Purpose: To evaluate the efficacy of combined (double contrast) use of superparamagnetic iron particles (SPIOs) and gadolinium (Gd) in liver MR imaging.

Material And Methods: Unenhanced, Gd-enhanced, SPIO-enhanced, and both SPIO- and Gd-enhanced images were acquired at 1.5 T. Twenty patients with previously detected liver lesions were included. Fast SE-STIR, and breath-hold true FISP, fat-suppressed T1- and T2-weighted sequences were obtained with all techniques. Lesion count was assessed by consensus reading.

Results: Collective evaluation of all MR sequences revealed 61 lesions in 16 patients; SPIO-enhanced MR detected lesions with a sensitivity of 95% (n=58). The sensitivity of unenhanced MR imaging was 90% (n=55). There was no statistical difference between SPIO-enhanced and unenhanced MR images. From single sequences, the greatest number of lesions was detected with the SPIO-enhanced fast SE-STIR sequence (n=56, sensitivity 92%). By using the fat-suppressed T1-weighted sequence, Gd-enhanced and both SPIO- and Gd-enhanced MR images demonstrated sensitivities of 77% (n=47) and 80% (n=49), respectively. Despite the combined use of both contrast media, this sequence was significantly less sensitive in lesion detection when compared to SPIO-enhanced imaging.

Conclusion: SPIO-enhanced MR imaging was the most sensitive method in lesion detection. The benefit of the combined use of SPIO and Gd was negligible.