Courtesy of Dr Scott Semple, this image shows cardiac MRI tissue characterisation in a patient with myocardial infarction, comparing native T1 mapping at left (A) with manganese-enhanced MRI (MEMRI) T1 mapping at right (B). Shortened T1 in remote myocardium is evident on MEMRI, discriminable from infarcted myocardium.
Manganese-based contrast agents in MRI reduce the T1 relaxation time of water, enabling contrast in tissues where it accumulates (such as the myocardium). As a calcium analogue, manganese is taken up avidly by voltage-gated calcium channels into cells with active calcium handling, therefore its uptake is absent in infarcted tissue. With its ability to label viable myocardium directly, and the natural occurrence of manganese in vivo making its safety and toxicity profile more attractive than gadolinium, MEMRI offers exciting potential for myocardial viability assessment and wider clinical translation.
The image is taken from a recent review published in Heart:
Spath NB, Thompson G, Baker AH, Dweck MR, Newby DE, Semple SIK. Manganese-enhanced MRI of the myocardium. Heart 2019; Epub ahead of print.