[Gadolinium-DTPA combined with a fat suppression technique in studies with magnetic resonance at 0.5 T in soft-tissue neoplasms]

Abstract

Combination of fat suppression techniques with intravenous paramagnetic contrast administration is usually performed using high-field MR systems. We combined a modified three-point Dixon technique for fat suppression with gadolinium-DTPA administration in the investigation of soft tissue neoplasms at 0.5 T. Nineteen patients with 21 neoplasms (14 primary malignant, 2 metastatic, 5 benign tumors) were examined. Examination protocol included unenhanced SE T1, PD and T2-weighted images. After the intravenous administration of gadolinium-DTPA (0.1 mmol/kg), a modified three-point Dixon technique provided three image sets, i.e., conventional T1-weighted SE images, fat-suppressed T1-weighted images and water-suppressed T1-weighted images. Two observers evaluated the lesions for conspicuity and size in three image groups: unenhanced T1-, PD and T2-weighted images, enhanced conventional T1-weighted images, enhanced T1-weighted images with fat suppression. Ten lesions showed greater conspicuity on enhanced fat-suppressed images than on unenhanced T1-, PD and T2- and enhanced conventional T1-weighted images. In 16 cases lesions were more conspicuous on enhanced water images than on conventional enhanced T1 images. Ten tumors exhibited a larger size (difference exceeding 20%) on enhanced fat-suppressed images. The combination of gadolinium with the modified Dixon technique improves the demonstration of soft tissue neoplasms at 0.5 T and allows lesion size to be measured more accurately.