Neuronal Tissue Deposition of Gadolinium following Single in Vivo Intravenous Exposure of Low Doses Of Gadodiamide In the Brains of Healthy Dogs and Comparison of Single- And Multi-Voxel Spectroscopy in the Normal Canine Brain at 3 Tesla

Abstract

Proton MR spectroscopy is a tool that provides quantified brain bioprofiles. Two methods exist: single- and multi-voxel spectroscopy. No studies compare their clinical validity in vivo. Gadolinium based MR contrast agents are used to improve lesional conspicuity. Adverse events are reported. Brain deposition occurs following administration in people and murine models. In dogs, doses are anecdotal and deposition is not described. Eight normal dogs underwent MRI at 3 Tesla with two methods of spectroscopy and were administered varying doses of gadodiamide. No differences were seen between single- and multi-voxel spectroscopy when interrogating identical regions of interest. Brains were harvested and evaluated for gadolinium depots using inductively coupled plasma mass spectrometry. Gadolinium was found in the brains of all dogs with dose dependency. Further, adequate normal brain conspicuity was seen at a dose of 0.5 mmol/kg. Thus, clinical trials of gadolinium chelated contrast agents at this dose are recommended