Optimum conditions for iron colloid enhanced fast spin echo imaging in hepatocellular carcinoma.

Abstract

The optimum conditions for iron colloid enhanced fast spin echo (FSE) in the detection of hepatocellular carcinoma have not been clearly established as yet. MRI was performed on 14 patients with hepatocellular carcinoma (45 nodules) before and after administration of chondroitin sulphate iron colloid (CSIC). One type of conventional spin echo (CSE) (TR/TE = 1800/80) was then quantitatively and qualitatively compared with three types of FSE (FSE 1800 (TR/effective TE/echo factor = 1800/90/7); FSE 7 (3500/90/7); and FSE 11 (3500/99/11)). The liver signal-to-noise ratio (SNR) was significantly decreased after CSIC administration in all sequences, while the tumour-to-liver contrast-to-noise ratio (CNR) was significantly increased. Although the decreased ratio of the liver SNR was smaller on the three FSE sequences compared with CSE, the increased ratio of the tumour-to-liver CNR was higher on the FSE sequences. The highest increase of the tumour-to-liver CNR was on the FSE 7 sequence. The number of detectable tumours, both before and after the administration of CSIC, was largest on FSE 7. In conclusion, FSE with longer TR and TE, and decreased echo factor, was especially useful for CSIC enhanced liver MRI.