Absence of T1 Hyperintensity in the Brain of High-risk Patients After Multiple Administrations of High-dose Gadobutrol for Cardiac Magnetic Resonance.

PURPOSE: A prospective study was conducted to evaluate signal changes in the dentate nucleus, globus pallidus, pons, and thalamus (normalized to the deep cerebellum white matter) in T1-weighted magnetic resonance (MR) images after serial injections of gadobutrol in patients with thalassemia without neurological lesions. METHODS: In this study three groups were scanned at both 1.5 T and 3 T: 15 thalassemia patients transfused and chelated with ≥4 gadobutrol administrations at a high dose (0.2 mmol/kg per scan) for late gadolinium enhancement (LGE) cardiovascular MR, 8 thalassemia patients and 13 healthy subjects who had never received gadolinium-based contrast agents (GBCA). RESULTS: Signal intensity (SI) ratios at 1.5 T in all regions were comparable among the three groups and were not correlated with the number of gadobutrol administrations. In healthy subjects SI ratios were significantly different among the 4 regions, being higher in the pallidus. The SI ratios at 1.5 T were significantly higher and not correlated with SI ratios at 3 T or with iron overload in the same regions assessed by the T2* technique. CONCLUSION: This article describes the lack of increased SI in T1-weighted MR images after repeated administration of gadobutrol for cardiovascular MR studies in a high-risk population (high dose per scan, iron overload that can facilitate the transmetalation of gadolinium) scanned at 3 T and 1.5 T.