Magnetic resonance diagnostic criteria of non-compaction cardiomyopathy: new diagnostic criteria still needed?

Non-compaction cardiomyopathy (NCC) is a rare pathology, but the exact rates of its prevalence are not known due to the lack of a diagnostic gold standard. The purpose of this article is to analyse the available cardiovascular magnetic resonance (CMR) diagnostic criteria of non-compaction described in the literature and to compare their sensitivity and specificity in the diagnosis of NCC. A search of available literature related to the CMR diagnostic criteria of myocardial non-compaction was conducted in the medical database PubMed in February of 2022. The period of publication of scientific articles covered the years from 1996 to 2022. A total of 7 full-text scientific articles were included in the final literature review. The main diagnostic criteria were used: the maximum non-compact (NCM) to compact myocardial layers (CM) ratio (NCM:CM), the percentage of trabeculated left ventricular (LV) myocardial mass, the percentage of trabeculated LV myocardial volume, the non-compact myocardial mass index of the total LV, and the determination of the total LV and the maximal fractal dimension (FD) of the apex with the use of fractal analysis. The lack of accurate diagnostic criteria results in an overdiagnosis of NCC. The highest sensitivity and specificity are associated with the maximum FD > 1.30 of the apex established by applying the fractal analysis method. Fractal analysis requires dedicated software, and this method is difficult to apply in routine clinical practice. Thus, the diagnostic criteria for the NCC using magnetic resonance imaging with higher diagnostic value remain to be sought.