3.0 T cardiac magnetic resonance intravoxel incoherent motion in evaluating microvascular dysfunction of hypertrophic cardiomyopathy patients / 第二军医大学学报

ABSTRACT

Objective To explore the value of 3.0 T cardiac magnetic resonance (CMR) intravoxel incoherent motion (IVIM) for evaluating microvascular dysfunction in hypertrophic cardiomyopathy (HCM) patients. Methods Twenty-six HCM patients and 12 healthy controls, who received CMR examination in the First Hospital of Lanzhou University from Apr. 2016 to Oct. 2017, were enrolled. All volunteers underwent short-axis cardiac cine and IVIM scans, and HCM patients underwent late gadolinium enhancement (LGE) scan. The fraction of fast apparent diffusion coefficient (f), fast apparent diffusion coefficient (ADCfast) and slow apparent diffusion coefficient (ADCslow) were measured using MITK-Diffusion post-processing software. End-diastolic thickness (EDTH) was measured on short-axis cine image. HCM patients were grouped according to the severity of the left ventricular hypertrophy and whether having LGE or not. The differences of f value, ADCfast and ADCslow were compared between HCM patients and healthy controls, non-hypertrophic segments and hypertrophic segments of HCM patients, LGE segments and non-LGE segments of HCM patients, and different hypertrophic subgroups in hypertrophic segment group. Spearman correlation analysis was performed to explore the correlation between IVIM parameters (f value, ADCfast and ADCslow) and EDTH in each segment. Results The ADCslow and ADCfast of the HCM patients were lower than those of the healthy controls (ADCslow 0.003 [0.002, 0.005] mm2/s vs 0.004 [0.002, 0.007] mm2/s, ADCfast 0.046 [0.025, 0.074] mm2/s vs 0.069 [0.052, 0.086] mm2/s), and the differences were significant (Z=-2.434 and -7.268, both P0.05). The ADCfast values of the non-hypertrophic segment group and the hypertrophic segment group in the HCM patients were 0.051 (0.029, 0.077) mm2/s and 0.027 (0.019, 0.052) mm2/s, respectively, which were both significantly lower than that of the healthy controls (Z=-5.505 and -8.144, both P0.05). The f value and ADCfast of the segmental myocardia with LGE were significantly lower than those without LGE (Z=-2.704 and -2.143, P=0.007 and 0.032). Spearman correlation analysis showed that EDTH was significantly negatively correlated with f value and ADCfast (r=-0.195 and -0.282, both P<0.01). Conclusion CMR IVIM technology can non-invasively and quantitatively reflect cardiac microvascular dysfunction in HCM patients. The severity of microvascular dysfunction is related to the severity of myocardial hypertrophy. Microvascular dysfunction is also present in non-hypertrophic and non-LGE myocardia.