Use of half-dose gadolinium-enhanced MRI and magnetization transfer saturation in brain tumors

The aim of this study was to search if half-dose gadolinium (Gd)-enhanced M R imaging with magnetization transfer saturation (MT) can replace standard- dose T1-weighted spin echo (SE) without MT saturation in brain tumors. Thir ty patients with a total of 33 brain tumors (14 gliomas, 13 meningiomas, 6 metastases) were prospectively studied using T1-weighted SE half-dose of Gd with MT, and T1-weighted SE standard-dose Gd without MT. The contrast-to-n oise ratio (CNR) of the two sequences was calculated and four radiologists reviewed qualitatively the images of the two sequences. There was no signif icant difference between both techniques for quantitative analysis (Wilcoxo n test). However, there was a good agreement between sequences to evidence an intraclass correlation coefficient (r = 0.70) of all lesions. In cases o f meningioma, the agreement was better (r = 0.84). The results show a diffe rence in the qualitative data between the two sequences, suggesting the use of the T1-weighted MR images with MT and half-dose of Gd with good results in the whole tested parameters except the lesional edema and the presence of artifacts. Half-dose T1-weighted SE with MT can replace standard-dose T1 -weighted SE without MT with no loss of contrast enhancement in investigati on of meningiomas and saving 50 % of the contrast material.