Spectra and appearance of late gadolinium enhancement in magnetic resonance imaging of non-ischemic myocardial disease - from pattern to diagnosis

Objective: Value of late gadolinium enhancement (LGE) in diagnosis of ischemic disorders in cardiac magnetic resonance is well-known. The purpose of the present paper was to describe more details and characteristics of LGE patterns arising in several non-ischemic myocardial diseases. Methods: Cardiac MRI was performed in 1,905 patients at a 1.5-T MR system and showed LGE with 1,646/1,905 demonstrating LGE patterns or other diagnostic criteria (e.g. laboratory results, ECG, coronary angiography findings) regarded typical for ischemic heart disease. The remaining 259/1,905 patients revealed LGE related to non-ischemic myocardial disease. Two experts (radiologists and/or cardiologist) qualitatively described LGE pattern in consensus reading with regard to its site (left or right ventricle), extent (subendocardial, midmyocardial, subepicardial, transmural, pericardial), segment (according to the 17- segment model of left ventricle (LV)), distribution (streaky, patchy, punctual, spotty, crescent, diffuse), and intensity (weak, moderate, strong). Thereafter, results were correlated to final diagnosis based on synopsis of clinical features, laboratory results, ECG, biopsy, or other imaging procedures. Results: In 250/259 patients (96.5%) only the LV was affected by LGE, most frequently midmyocardial (166/259). In most cases this was due to peri-/myocarditis (especially if of weak-moderate intensity), while a weaker, streaky or spotty LGE basal or lateral pointed to HCM (39/166) and streaky and lateral to DCM (20/166). A midmyocardial, patchy LGE in segment 3 and 5 was caused by Fabry’s disease (6x). In case of a transmural, spotty or patchy pattern LGE pointed to HCM, if intensity was weak-moderate, or to peri-/myocarditis, when LGE was moderate-strong. In addition to that, subepicardial LGE in basal segments with patchy, streaky, or spotty distribution and moderate intensity was also due to peri-/myocarditis, while it was located midventricular, spotty and weak in TASH (transcoronary ablation of septum hypertrophy). Conclusions: Several LGE patterns point to certain non-ischemic myocardial diseases and thereby might facilitate and confine differential diagnosis and might be useful in biopsy planing.