Comparison of Cardiac MR with PET CT in Evaluation of Myocardial Viability: Single-Center Experience

The aim of this study was to compare the efficacy of various cardiac magnetic resonance imaging (MRI) parameters in assessing myocardial viability with positron emission tomography-computed tomography (PET-CT) as the gold standard.

This was a prospective analytical study comprising 28 adult patients with perfusion/metabolism matched or mismatched defects in PET-CT. These patients were taken up for MR evaluation, mainly assessing end-diastolic wall thickness (EDWT), regional wall motion abnormalities, and late gadolinium enhancement (LGE) for infarcted tissue. EDWT was measured manually and using semiautomatic software, and means were calculated.

Of 448 (28 × 16) myocardial segments, 6% ( n  = 27) of the segments were considered not viable with matched defect, 56.5% ( n  = 253) were normal, and 37.5% ( n  = 168) were hibernating according to PET-CT. 51.1% ( n  = 86) of the hibernating segments showed no wall motion and 48% ( n  = 82) showed some wall motion, with a sensitivity of 66.03% ( p  < 0.001). There is good concordance of motion abnormalities detected using tagging with LGE. LGE and EDWT showed good sensitivity, 91.7 and 89.5%, respectively, as compared with PET CT in identifying viable but hibernating myocardium.

MRI parameter shows increased specificity and positive predictive value in identifying non-viable myocardium compared with PET/CT. All parameters had good sensitivity in identifying hibernating myocardium but had significantly low specificities.Clinical relevance Cardiac MRI, when used in combination with PET CT, improves the sensitivity in identifying the viable but hibernating myocardium.