MR -specific characteristics of left ventricular noncompaction and dilated cardiomyopathy

Background: The differentiation of dilated cardiomyopathy (DCM) and left ventricular noncompaction (LVNC) is a recurring issue during cardiac imaging processes; thus, we aimed to compare the left ventricular (LV) cardiac MRI characteristics of these patients.

Methods: Thirty-one nonischemic DCM patients, 42 LVNC patients with reduced ejection fraction and 42 healthy controls were included in this retrospective study. LV volumetric, functional and myocardial mass parameters were measured with a threshold-based technique, while global and segmental strain values and rotational patterns were analyzed with feature-tracking strain analysis.

Results: Of the LV volumetric and myocardial mass parameters, only the trabeculated and papillary muscle mass (TPMi) values differed significantly between the patient groups and were higher in the LVNC group (DCM vs LVNC: 43.2 ± 8.9 vs 51.6 ± 13.6 g/m², p < 0.002). The global longitudinal and circumferential strains were similar between the patient groups and significantly worse than those of the controls. In comparing the segmental strains between the patient groups, only the circumferential apical strain was significantly lower in the LVNC group (DCM vs LVNC: -30.5 ± 13.5 vs -24.5 ± 12.0%, p < 0.05). There was no difference in the rotational pattern between the patient groups, and both healthy and patient populations showed heterogeneous rotational patterns.

Conclusions: Despite the similarities between DCM and LVNC in volumetric, global strain parameters, and rotational patterns, we found some differences between the patient groups, as the TPMi was higher and the apical circumferential strains were significantly lower in LVNC. These minor alterations might be due to the morphological characteristics of LVNC with a trabeculated apical region.