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Objective:To explore the technical feasibility of CT feature tracking (CT-FT) technique in evaluating left ventricular myocardial strain and evaluate the change of myocardial strain in patients with coronary heart disease.Methods:Eighty-one patients with coronary heart disease (lesion group) and 33 patients with normal coronary artery (control group) matched with age and sex were collected retrospectively from the Second Affiliated Hospital of Nanchang University from April 2019 to October 2020. The lesion group was first divided into single vessel stenosis group (42 cases) and multi vessel stenosis group (39 cases) according to the number of coronary artery stenosis branches, and the global myocardial strains of the left ventricle between the groups were analyzed. Lesion site included the left anterior descending branch (LAD), right coronary artery (RCA) and left circumflex branch (LCX), respectively. According to the degree of vascular stenosis, the lesion groups were divided into normal group, mild stenosis group, moderate stenosis group and severe stenosis group. The segmental myocardial strains of the branch segment of LAD, RCA or LCX were analyzed between groups. All CCTA examinations were performed with retrospective electrocardiogram gating. CVI 42 cardiac postprocessing software was used to obtain myocardial strain parameters, including global peak longitudinal strain (GPLS), global peak circumferential strain (GPCS), global peak radial strain (GPRS), and the segmental myocardial strains of the branch segment of LAD, RCA or LCX. The segmental myocardial strains included the peak longitudinal strain (PLS), peak circumferential strain (PCS) and peak radial strain (PRS). One way ANOVA or Kruskal Wallis H test were used for multi group analysis. Results:With the increased number of coronary artery stenosis branches, the absolute value of GPLS gradually decreased. The GPLS of the control group, single vessel stenosis group and multi vessel stenosis group were -14.1%±2.7%, -11.5%±2.3% and -8.8%±2.0%, respectively. The difference of GPLS between the 3 groups or any 2 groups was statistically significant (all P<0.001). The absolute values of GPRS and GPRS in multi vessel stenosis group were significantly lower than those in control group and single vessel stenosis group (all P<0.001). There was no significant difference in GPRS or GPRS between single vessel stenosis group and control group ( P=0.083, 0.118). And there were significant differences in the segmental myocardial strains of the branch segment of LAD, RCA or LCX among 3 groups ( P<0.001). In severe stenosis group, the absolute values of PRS, PCS and PLS in LAD, RCA or LCX were significantly lower than those in moderate stenosis group, mild stenosis group and normal group (all P<0.05). In the moderate stenosis group, the absolute value of PLS in each branch segment was lower than that of the mild stenosis and normal group (all P<0.05), and there was no significant difference in any 2 other myocardial strain parameters of each branch (all P>0.05). Conclusions:CT-FT technique was feasible to evaluate left ventricular myocardial function. With the increased number or degree of coronary artery stenosis, the global and segmental myocardial strain parameters of left ventricle gradually decreased, and the longitudinal strain was more sensitive.
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Objective@#To investigate the application value of cardiovascular magnetic resonance tissue-tracking (CMR-TT) in the quantitative assessment of global and segmental myocardial strain after myocardial infarction.@*Methods@#From June 2013 to June 2017, 45 patients with chronic myocardial infarction from the Second Affiliated Hospital of Nanchang University and eighteen normal volunteers as a control group were included in our research. All participants received CMR examination on a 3.0 T MRI scanner. Imaging protocol including FIESTA cine sequence (left ventricle short-axis planes, four chamber and two chamber long-axis planes) and late gadolinium enhancement (LGE). CMR-TT was undertaken using cvi 42 dedicated commercial software, global peak systolic circumferential, longitudinal, radial strains (GPCS, GPLS, GPRS) and segmental peak systolic circumferential, longitudinal, radial strains (PCS, PLS, PRS) in accordance with the American Heart Association's sixteen segment model were all derived. All segments were divided into five groups according to transmural extent expressed as enhanced area per segment: 0% as non-LGE segments group, 1 %-25 % as mild LGE segments group, 26%-50 % as moderate LGE segments group, 51%-75% as severe LGE segments group and >75% as complete LGE segments group. Two-independent samples t-test and Kruskal-Wallis H test were used, respectively, to compare means of 2 and 3 or more groups of continuous variables. Variables with normal distribution were presented as ±s, non-normal variables were reported as median (interquartile range).@*Results@#Patients showed significant lower GPRS, GPCS and GPLS than the control group (15.13%±8.18%, -8.25%±3.23%, -7.11%±2.41% versus 32.41%±12.99%, -14.92%±3.32%, -11.50%±2.51%). PRS, PCS and PLS statistically significantly decreased with increasing extent of myocardial enhancement (t=-6.35,7.33,6.44, P<0.001).Segmental peak systolic strains of five groups were:PRS:24.87% (10.95%,39.02%), 13.26%(5.94%,24.24)%, 9.47%(4.01%,18.40%), 5.98%(-3.74%,11.86%), -2.65%(-6.62%,8.59%), respectively; PCS: -11.84%±5.34%, -8.60%±5.48%, -7.32%±5.59%, -5.30%±5.52%, -2.74%±5.24%, respectively; PLS: -9.47%±6.82%, -7.72%±6.22%, -7.07%±6.49%, -5.55%±5.95%, -3.54%±5.44%, respectively. The differences in the groups were statistically significant (H=164.47,166.61, 59.06, P<0.001). GPRS was positively correlated with LVEF(r=0.543, P<0.001), while GPCS and GPLS were both negatively associated with LVEF (r=-0.654, P<0.001; r=-0.682, P<0.001, respectively).@*Conclusions@#CMR-TT can quantitatively assess the severity of myocardial infarction accurately and reliably.Strain parameters have a good correlation with cardiac function indexes, this may be helpful in the recognition of left ventricular remodel after MI.
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Objective To explore clinical value of cardiac MRI feature tracking (CMR-FT) in evaluation of left ventricular global and regional myocardial strain in hypertrophic cardiomyopathy (HCM).Methods Totally 60 patients with HCM (HCM group) and 10 healthy volunteers (control group) were enrolled and underwent cardiac MR.MR Sequences included fast imaging employing steady state acquisition (FIESTA) and late gadalinum enhancement (LGE) at ventricular short-axis,two-chamber and four-chamber planes.The patients in HCM group were divided into LGE negative subgroup and LGE positive subgroup.CMR-FT processing software was used to measure myocardial global radial peak strain (GPSR),global circumferential peak strain (GPSC) and global longitudinal peak strain (GPSL).The radial,circumferential and longitudinal peak strain (PSR,PSC and PSL) at the apex,middle and basal parts of left ventricular were also measured as well.Resuits GPSR,GPSC,GPSL in LGE positive subgroup,LGE negative subgroup and control group had significant differences (all P＜0.05),and showed upward trends.Except PSL at the apex had no significent difference among three groups,PSR,PSC and PSL at the apex,middle and basal parts had significant differences (all P＜0.05),and also showed upward trends.There were positive correlations between the LVEF,SV and GPSR,GPSC,GPSL (all P＜0.05).The area under ROC curve of GPSR,GPSC and GPSL in diagnosis of HCM were 0.79,0.82,0.77 (all P＜0.05),and the area under ROC curve of GPSC was the largest.Conclusion The CMR-FT technology can find myocardial strain dysfunction in HCM sensitively,and the longitudinal strain is damaged earlier or worse than circumferential and radial strains.