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.

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.

Objective To study the protective effect of lipoxin A4(LXA4)against sepsis-induced acute kidney in-jury(SAKI)in rats and its effect on the expression of toll-like receptor 4(TLR4),myeloid differentiation factor88(MyD88),nuclear factor kappa B(NF-κB)in the kidney.Methods Forty male specific pathogen-free C57BL/6J mice were randomly divided into SAKI group,SAKI+LXA4 group,sham procedure group,sham procedure+LXA4 group.The mice in SAKI group and SAKI+LXA4 group were given cecum ligation and puncture(CLP)to establish SAKI animal models.The mice in SAKI+LXA4 group and sham procedure+LXA4 group were given LXA4(40 ng/kg)with intraperitoneal injection 30 mins after CLP.All mice were sacrificed at the 24th hour after CLP to collect serum,urine and kidney tissues.The enzyme linked immunosorbent assay(ELISA)was used to test the serum creat-inine(Scr),blood urea nitrogen(Bun),interleukin-1 β(IL-1β),IL-6,tumor necrosis factor-α(TNF-α)and urine neutrophil gelatinase-associated lipocalin(NGAL),kidney injury molecule 1(KIM-1)levels of mice.The pathologi-cal changes were examined through hematoxylin-eosin(HE)staining and Periodic Acid-Schiff(PAS)staining.And the mRNA levels of TLR4,MyD88,NF-κB p65 were detected through real-time PCR(RT-PCR);the expression lev-els of TLR4,MyD88,NF-κB p65,phospho-NF-KB p65(p-NF-KB p65)were detected through immunohistochemistry(IHC)and Western blot assay.Results ELISA showed that the values of Scr,Bun,IL-1 β,IL-6,TNF-α,NGAL,KIM-1 in SAKI group were higher than those in SAKI+LXA4 group(P＜0.05),and there were no significant differences in Scr,Bun,IL-1 β,IL-6,TNF-α,NGAL,KIM-1 between sham procedure group and sham procedure+LXA4 group.HE and PAS staining showed that SAKI group had severer pathological changes than SAKI+LXA4 group in the kidney structure(P＜0.05),while pathological structures of the kidney were normal in sham proce-dure group and sham procedure+LXA4 group.RT-PCR showed that the mRNA levels of TLR4,MyD88,N F-κB p65 in SAKI group,SAKI+LXA4 group were higher than sham procedure group and sham procedure+LXA4 group(P＜0.05);the mRNA levels of TLR4,MyD88,NF-κB p65 in SAKI group were higher than SAKI+LXA4 group(P＜0.05);The results of IHC,Western blot assay were as follows:The expression levels of TLR4,MyD88,NF-κB p65,p-NF-κB p65 in SAKI group,SAKI+LXA4 group were higher than sham procedure group and sham procedure+LXA4 group(P＜0.05);the expression levels of TLR4,MyD88,NF-κB p65,p-NF-κB p65 in SAKI group were higher than SAKI+LXA4 group(P＜0.05).Conclusion TLR4/MyD88/NF-KB pathway plays an important role in the occurrence and development of SAKI,and LXA4 may reduce SAKI by inhibiting TLR4/MyD88/NF-κB sig-naling pathway.