Liver metastases: detection with MR imaging at 0.5 and 1.5 T

Nineteen patients with known liver metastases were examined with two magnetic resonance (MR) pulse sequences at 0.5 T and three pulse sequences at 1.5 T. In addition, the patients were studied with computed tomography (CT) enhanced with ethiodized oil emulsion-13 (EOE-13). At 0.5 T a spin-echo (SE) 300/22 (repetition time/echo time, msec) sequence prospectively demonstrated 92.4% of the detectable liver metastases, while an SE 2,000/80 sequence showed 52.1% of the lesions. At 1.5 T, an SE 300/25 sequence depicted 68.3% and an SE 2,000/80 sequence 71.6%, while the more T1-weighted inversion recovery (IR) 2,000/600 (repetition time/inversion time, msec) sequence demonstrated 89.5% of the lesions. EOE-13 CT scans depicted 93.3%. These findings suggest that T1-weighted imaging is as successful at demonstrating liver metastases at 1.5 T with an IR 2,000/600 sequence as at 0.5 T with an SE 300/22 sequence. At both field strengths, MR imaging of the liver is comparable to state-of-the-art CT.