Comparison of Fast Spin Echo, Fast Multiplanar Spoiled Gradient Recalled and Conventional T1 and T2 Weighted Imaging for Experimentally Induced Hepatic Tumors in Rats

ABSTRACT

PURPOSE: To compare the ability of tumor detection and the lesion conspicuity between T1- and T2-weighted fast scanning sequences and T1- and T2-weighted conventional spin echo techniques in MR imaging of hepatic tumors. MATERIALS AND METHOD: Hepatic tumors were induced on 13 male Sprague-Dawley rats by feeding 3'-methyl-dimethylethylaminoazobenzene mixed with Miller's III formula for 12 weeks. MR images were obtained with 1.5T magnet with dual TMJ coil(Signa, GE Medical Systems, Milwaukee, USA). Animals were anesthesized with 150mg/kg of ketamine hydrochloride. T2 weighted fast spin echo(FSE), conventional spin echo(CSE) T2- and T1WI, fast multiplanar spoiled gradient recalled(FMPSPGR) imaging were obtained. Number of detected, tumors and contrast-to-noise ratio of the tumors were compared for each sequence. RESULTS: Overall 110 tumors were developed. 75% of the tumors were detected on FSE, 65% on FMPSPGR, 41% on conventional T2WI, and 41% on T1WI images. For tumors more than 5mm in diameter, sensitivity was 88% on FMPSPGR, 65% on conventional T2WI, and 81% on TIWI images respectively. CNR of the tumor was 28.94 +/- 21.6 on FSE, 13.57 +/- 8.64 on FMPSPGR, 12.62 +/- 10.65 on CSE T2WI, and 9.47 +/- 8.05 on CSE TIWI images, which was significantly high on FSE (p<0.05). CONCLUSION: Fast spin echo T2 WI shows highest sensitivity and tumor-to-liver contrast. FMPSPGR imaging is also favorably comparable with conventional T1WI. Therfore, these two pulse sequences can be useful in clinical condition for hepatic MR imaging.