Evaluation Of Microcirculation Abnormalities In Hypertrophic Cardiomyopathy By IVIM Imaging

Objetive: To analyze the microcirculation dysfunction in patients with hypertrophic cardiomyopathy by IVIM technique,and to explore its feasibility and clinical application value.Materials and Methods: A total of 32 patients with hypertrophic cardiomyopathy and 16 normal volunteers were enrolled in the First Hospital of Lanzhou University from August 2016 to December 2018.All of them completed the Skyra 3.0T cardiac magnetic resonance examination.The scan sequence included Conventional anatomical scans,cine sequences,IVIM scans,first pass perfusion,and delayed-enhanced scans.After the post processing of the Siemens Body Diffusion Toolbox tool,the f,D,D* parameter maps are obtained.After the parameter map is imported into the Siemens MRWP workstation,the f,D,D* values and the thickness of left ventricular wall at the end of diastole(LVEDTH)of all the segments except the 17 th segment are measured.The HCM group was divided into non-hypertrophic segment group(NH group)and hypertrophic segment group(H group)according to the degree of hypertrophy.Group H was further divided into H1 group(15mm≤LVEDTH<18mm)and H2 group(18mm≤LVEDTH<21mm).),H3 group(21mm ≤ LVEDTH <24mm),and H4 group(LVEDTH ≥ 24mm).According to the delayed-enhanced image,the myocardial was evaluated for delayed enhancement,and the three-chamber movie image was used to determine whether the left ventricular outflow tract obstruction was grouped(delay-enhanced HCM group and non-delayenhanced HCM group,obstructive HCM group and non-obstructive HCM group).All data Statistical analysis was performed using the SPSS 22.0 software package,using the t-test or the LSD-t test in the One-way ANOVA,and the non-normal distribution using the non-parametric test,and the consistency of the data measurements at different time use Internal correlation coefficient-ICC test.About the correlation between the variables,the Pearson correlation coefficient is used in accordance with the normal distribution,and the Spearman rank correlation coefficient is used in the non-normal distribution.Results:(1)The f value(755.78±216.45)and D* value(318.83±221.71)in the HCM group were significantly lower than the f value(833.08±137.04)and D* value(332.66±108.99)of the normal group,P<0.05;(2)There were significant differences between f-value,D-value and D* value in hypertrophic segment and non-hypertrophic segment,P<0.01.There was significant difference in D* value between different hypertrophy groups,P<0.01;The f-values(793.26±183.28,833.08±137.04)and D* values(332.66±108.99,309.44±258.44)were differences statistically between nonhypertrophic segments and normal segments(P<0.05),among which D* values were more significant.(P<0.01);(3)The f-value and D*-value of the obstructive HCM group and the delayed-enhanced group were decreased,which was statistically significant.(4)As the degree of ventricular wall hypertrophy increases,the D* value decrease.The degree of ventricular wall hypertrophy is not correlated with the f-value and D-value.Conclusion: IVIM imaging technology can be used to assess microcirculation perfusion abnormalities in hypertrophic cardiomyopathy.IVIM can be used to evaluate microcirculation perfusion in patients with hypertrophic cardiomyopathy with different left ventricular wall hypertrophy,delayed myocardial infarction,and left ventricular outflow tract obstruction.D* values are more sensitive to monitoring microcirculatory perfusion abnormalities.IVIM imaging technology provides effective clinical evidence for the absolute non-invasive and early assessment of HCM microcirculatory disorders.