Objective To evaluate the coronary microvascular dysfunction in patients with hypertrophic cardiomyopathy(HCM) by MR first-pass perfusion and late gadolinium enhancement. Methods From January 2011 to May 2015, 47 cases with HCM (HCM group) from the second affiliated hospital of Nanchang University were retrospectively analyzed. Additionally, 21 healthy volunteers were recruited as the control group. HCM group and control group underwent cardiac MR examinations at rest, including short axial cine, first-pass myocardial perfusion and late gadolinium enhancement scanning. Time to peak(tpeak), maximal upslope of time-intensity curve(Slopemax), peak signal intensity(SIpeak), myocardial thickening, and late myocardial gadolinium enhancement(LGE) were assessed for each myocardial segment. HCM group were divided into LGE segments group and non-LGE segments group. LGE segments group were divided into mild, moderate and severe LGE segments group. The SIpeak, Slopemax and tpeak in multiple groups were compared by one-way ANOVA and Kruskal-Wallis test. Spearman correlation tests were used to determine the relationships between perfusion parameter and LGE. Results The average values of tpeak in non-LGE segments group (527 segments), LGE segments group (225 segments) and control group (336 segments) were (67.0±27.4), (79.4±27.4), (59.7±21.6)s, respectively. The average values of Slopemax in the three groups were 17.2±7.0, 16.4±7.4, 20.4±6.3, respectively. The average values of SIpeak in the three groups were 442.7±143.2, 465.1±138.4, 521.9±146.7, respectively. Compared to the control group, tpeak increased and Slopemax, SIpeak decreased in non-LGE segments group and LGE segments group (P 0.05). There were significant differences among LGE segments groups, as the tpeak and SIpeak increased with increasing degrees of myocardial LGE (P 0.05). The degree of LGE were positively correlated with tpeak (r=0.237, P<0.01). Conclusions 3.0 T magnetic resonance myocardial perfusion imaging can show microvascular dysfunction accurately and reliably in non-LGE segments. It may be helpful in the early diagnosis of coronary microvascular dysfunction for HCM. Key words: Cardiomyopathy, hypertrophic; Myocardial perfusion imaging; Microcirculation
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