DETECTION OF FOCAL HEPATIC-LESIONS - EFFECTS OF SUPERPARAMAGNETIC IRON-OXIDE (AMI-25) ON MAGNETIC-RESONANCE-IMAGING OF THE LIVER USING T2-WEIGHTED FAST SPIN-ECHO SEQUENCES AND GRADIENT-AND-SPIN-ECHO SEQUENCES AT 1.0 TESLA

RATIONALE AND OBJECTIVES. The authors evaluate the value of two fast s pin-echo sequences (FSE) with different T-2-weighting (repetition time [TR]/echo time [TE] = 2000/90 mseconds and TR/TE = 2000/40 mseconds) and combined gradient-and-spin-echo sequences (TR/TE = 2000/90 msecond s) for contrast-enhanced liver imaging with superparamagnetic iron oxi de (AMI-25). METHODS. Forty-seven patients with focal liver lesions un derwent magnetic resonance imaging at 1.0 tesla. AMI-25 was administer ed intravenously at a dose of 15 mu mol iron/kg. RESULTS. Administrati on of AMI-25 resulted in a significant increase of lesion/liver contra st-to-noise ratio (C/N) for all T2-weighted sequences (P < 0.001). On the precontrast images, the FSE sequence with a TE of 90 mseconds had the highest C/N (16.0 +/- 4.5) whereas the best postcontrast C/N (27.9 +/- 7.6) was obtained with the mild T-2-weighted FSE sequence with a TE of 40 mseconds. CONCLUSIONS. Fast spin-echo sequences are valuable sequences for imaging of the liver at 1.0 tesla. For AMI-25-enhanced m agnetic resonance imaging, a mild T-2-weighted FSE sequence is recomme nded.