Edinburgh Imaging

06 Feb 20. Featured Paper

Manganese-enhanced T1 mapping to quantify myocardial viability: validation with 18F-fluorodeoxyglucose positron emission tomography.

Link to paper on Springer Nature



Nick Spath, Adriana Tavares, Gillian A. Gray, Andrew H. Baker, Ross J. Lennen, Carlos J. Alcaide-Corral, Marc R. Dweck, David E. Newby, Phillip C. Yang, Maurits A. Jansen & Scott I. Semple



Gadolinium chelates are widely used in cardiovascular magnetic resonance imaging (MRI) as passive intravascular & extracellular space markers.

Manganese, a biologically active paramagnetic calcium analogue, provides novel intracellular myocardial tissue characterisation.

We previously showed manganese-enhanced MRI (MEMRI) more accurately quantifies myocardial infarction than gadolinium delayed-enhancement MRI (DEMRI).

Here, we evaluated the potential of MEMRI to assess myocardial viability compared to gold-standard 18F-fluorodeoxyglucose (18F-FDG) positron emission tomography (PET) viability.

Coronary artery ligation surgery was performed in male Sprague-Dawley rats (n = 13) followed by dual MEMRI & 18F-FDG PET imaging at 10–12 weeks.

MEMRI was achieved with unchelated (EVP1001-1) or chelated (mangafodipir) manganese.

T1 mapping MRI was followed by 18F-FDG micro-PET, with tissue taken for histological correlation.

MEMRI & PET demonstrated good agreement with histology but native T1 underestimated infarct size.

Quantification of viability by MEMRI, PET & MTC were similar, irrespective of manganese agent.

MEMRI showed superior agreement with PET than native T1.

MEMRI showed excellent agreement with PET & MTC viability.

Myocardial MEMRI T1 correlated with 18F-FDG standard uptake values & influx constant but not native T1.

Our findings indicate that MEMRI identifies & quantifies myocardial viability & has major potential for clinical application in myocardial disease & regenerative therapies.