Signal suppression of normal liver tissue by phase corrected inversion recovery: a screening technique.

Abstract

A new pulse sequence characterized by simultaneous multislice spin echo (SE) and short inversion time (TI) with inversion recovery (STIR) acquisitions is demonstrated. For the STIR component, a repetition time of 1,000 ms and TI of 210 ms were chosen to suppress the signal from normal liver at 0.5 T and create a fast sequence suitable for screening purposes. Phase correction of the STIR with the SE's signal as a reference resulted in high contrast real IR images that were free of phase error artifact. In 13 min the entire liver could be imaged in 14 adjacent slices, each slice portrayed in an ensemble of four images: a T1-weighted SE image, IR real and modulus images, and a T1 map. Forty-one patients with liver pathology and 10 normal volunteers were examined with the sequence implemented on a commercially available 0.5 T imager (Gyroscan; Phillips). Images demonstrated high liver-lesion contrast and sensitivity to liver lesions. Lesions of less than 1 cm in diameter and lymphomatous lesions, commonly occult to magnetic resonance, were detected.