Focal Hepatic Tumors Using Inversion Recovery Sequence of 0.1-T MRI - Basic : Clinical Evaluation Gray Scale Vs T1 Values

Optimum conditions for image quality contrast were studied with phantom method by means of MRI system (of constant conduction type ; 0.1-T) in order to detect tumor lesions of liver that show no distinct contrast by usual roentgeno-graphic methods. Signal intensity of liver, fat and muscle were maximally suppressed at 1000 ms of TR and 100 ms of TI by the short inversion time inversion recovery (STIR) method, resulting in distinct visualization of liver tumor with extremely good contrast. Clinical investigation with the usual T1- and T2- weighted images under the same conditions identified hepatocellular carcinoma in 22 out of 31 patients (37 of 58 nodules, 64%), cholangiocellular carcinoma 3 of 5 (3 of 6 nodules, 50%), metastatic liver cancer in 55 out of 68 (111 of 143 nodules, 78%), hepatic hemangioma in 32 out of 36 (41 of 47 nodules, 87%) and liver cyst in 8 out of 8 (100%). In contrast, hepatocellular carcinoma was visualized in 30 out of 31 patients (54 of 58 nodules, 93%), cholangiocellular carcinoma in 5 out of 5 (6 of 6 nodules, 100%), metastatic liver cancer in 66 out of 68 (139 of 143 nod-ules, 97%), hepatic hemangioma in 36 out of 36 (47 of 47 nodules, 100%) and liver cyst in 8 out of 8 (100%). The results suggest that STIR (TR : 1000 ms, TI : 100 ms, TE : 18 ms) is extremely useful in screening tumor lesions of the liver