MANGANESE BASED CONTRAST AGENT (MBCA): LIKELY TO REPLACE GBCA

Abstract

Gadolinium based contrast agents (GBCA) are an integral part of MRI imaging suite as these induce enhancement on MRI images to improve diagnostic accuracy.   Gadolinium ion has seven unpaired electrons and it shortens spin-lattice relaxation time (T1) of voxels in which they are present and this gives brighter signals to T1 weighted images. GBCAs are well tolerated by the patients; however, the previous decade has seen safety concerns associated with these agents. Importantly in 2007 an association between GBCA and nephrogenic systemic fibrosis (NSF) was reported in patients with impaired renal function. Based on reported data, FDA issued a contraindication to use of GBCAs in patients with glomerulation  filtration rate less than 30 ml/min/1.73 m². However, current American College of Radiology (ACR) guidelines discourage use of GBCA in patients with GFR <40 ml/min/1.73 m². However, in 2016, 4 cases of NSF were reported in patients with normal renal function as well. Furthermore, there is evidence of further deterioration of impaired renal status in some patients which requires hemodialysis.  In last 6 years, GBCA related safety concerns have been raised in patients with normal renal function. This is based on various authentic reports revealing long term retention of gadolinium in central nervous system and skin of patients who had had contrast enhanced MRI. It is assumed that NSF and CNS retention is caused by release of gadolinium from GBCA.