Objective To evaluate the methods and the factors of affecting imaging quality of 3D CE MRA of carotid arteries.Methods 3D CE MRA in 48 patients were performed using 1.5T super conductive MR scanner,cervical and lumbar combination phased array coils. All patients were examined using intravenous injection Gd-DTPA and breath-hold 3D FLASH sequence. Results Imaging quality was satisfied in 46/48 patients (96%). MIP and MPR could clearly showed normal anatomy. The site,size and stenosis degree of the lesion were also demonstrated. Compared to surgery,DSA and/or ultrasound results , in 23 patients, the sensitivity and specificity of 3D CE MRA were 100% and 100% respeectively for the lesion of carotid arteries. Conclusion High quality images of 3D CE MRA mainly depends on determining the best acquisition delay time,optimizing injection volume and rate of contrast material,using reasonable sequence parameters and skilled level of operators.

Objective To evaluate different detection methods in the diagnosis of severe fever with thrombocytopenia syndrome (SFTS), and find the most quick and accurate one for the identification of new bunyavirus infection. Methods Real-time PCR and ELISA-IgM were used to detect serum samples of 158 patients with acute phase of SFTS, which were collected from the special monitoring system of SFTS in Henan Province in 2014. IgM and IgG antibodies were detected by ELISA in 109 acute and convalescent paired serum specimens. The differences of the positive rates were compared between the three methods, and the influence of the collected interval time on the detection results was analyzed. Results For 158 acute phase serum samples of SFTS patients, the positive rate detected by real-time PCR (76.58%) was higher than that of ELISA-IgM (47.47%), and the difference was statistically significant (χ2=34.13, P < 0.05). For 109 cases with acute and convalescent paired serum samples, there was no significant difference in the positive rates between ELISA-IgG ( 75.23%) and real-time PCR (72.48%) detections (χ2=0.18, P>0.05). In both the acute phase and convalescent phase, the positive rate of IgM was higher than that of IgG, and the difference was statistically significant (χ2=41.68 and 6.25, P<0.05). With the extension of collected interral time, the positive rates of IgM and IgG antibodies were both increased ( Z=6.42 and 10.08, P < 0.05). Conclusion Real-time PCR is the most sensitive method for the early diagnosis of the SFTS. ELISA-IgG is suitable for the detection of SFTS at recovery period. ELISA-IgM can be used as an assistant method to guide clinical diagnosis.

Objective To compare the diagnostic performance of multi-contrast atherosclerosis characterization (MATCH) and magnetization-prepared rapid acquisition gradient-echo (MPRAGE) for the detection of IPH with histologic analysis as the reference standard.Methods Thirty individuals were collected in this study.They were diagnosed to have carotid stenosis＞50％ by ultrasound and scheduled for carotid endarterectomy from 2014 to 2015.3 T carotid MR examinations using MPRAGE,MATCH and 3D TOF were performed in these patients.Axial images covered all plaques and centered at the bifurcation of the carotid artery.All image data sets were processed on a semi-automatic software (MRI-Plaque View,VPDiagnostics,US) to analyze the component of IPH for vulnerable plaques.The consistency between MATCH and MPRAGE was analyzed by using Cohen Kappa analysis.Comparison of the two sequences to the pathological results was performed in a similar manner.The sensitivity and specificity of the two sequences were obtained.The SNR,CNR and contrast ratio(CR) of the two regions of interest were calculated and Wilcoxon rank sum test was used to compare the difference between the two methods.Results Among 30 patients,a total of 602 available sections and 95 correponding histology specimens were included in the analysis.When all 602 available sections were included in the analysis,MATCH yielded good agreement with MPRAGE(Kappa=0.773) on the detection of IPH.With pathological specimens as the gold standard,moderate to good agreement was shown for both MATCH and MPRAGE (Kappa=0.778,0.685).The sensitivity and specificity for the detection of IPH was 93.2％ (68/73) and 90.9％ (20/22) for MATCH.For MPRAGE,the sensitivity and specificity was 87.7％(64/73) and 90.9％(20/22) respectively.The difference between MATCH and MPRAGE was statistically significant for SNR,CNR and CR.That is to say,SNR and CNR of MPRAGE were higher than those of MATCH(P＜0.05),while CR of MATCH was higher than that of MPRAGE(P＜0.05).Conclusion Compared to the MPRAGE sequence,MATCH technique demonstrates similar diagnostic performance for the detection of IPH.

Objective To investigate the diagnostic performance of stress cardiac magnetic resonance(CMR) for evaluating low-risk patients with suspected acute coronary syndrome(ACS).Methods Twenty-two patients with low risk of suspected ACS were prospectively and consecutively enrolled in this study.Diagnostic performance of stress CMR was compared with single-photon emission computed tomography(SPECT) for diagnosis of myocardial ischemia with coronary angiography (CAG) as the reference method.Results On the patient-based level analysis,the diagnostic performance of CMR for detection of ACS was sensitivity 93% and specificity 75%.The corresponding value of SPECT was 79%,63%.The area under the ROC (AUC) of CMR was 0.897, which was slightly superior to that of SPECT at 0.723 (P=0.19).On the per-vessel assessment, the diagnostic value of CMR was sensitivity 89%,specificity 87%, while the corresponding value of SPECT was 68%,83%.The AUC of CMR was 0.923,which was significantly higher than that of SPECT at 0.774 (P<0.05).Furthermore, the AUC of CMR was significantly superior to that of SPECT with AUC being 0.900 and 0.553 in the left anterior descending (LAD) vessels (P=0.009 6).Conclusion Stress perfusion CMR has excellent diagnostic performance in low risk ACS patients.Compared with SPECT,stress perfusion CMR performed better in the low-risk ACS populations.

Objective To prospectively evaluate the feasibility and reliablity of low kilovoltage contrast-enhanced multi-slice CT(MSCT)to detect the myocardial viability in chronic myocardial infarcetion.with comparison to magnetic resonance(MR)myocardial perfusion and viability imaging.Methods Thirty-two patients with clinical diagnosed chronic myocardial infarction underwent the first pass and delayenhanced myocardial imaging with 64-slice MSCT and MR Left ventricle was divided into 16 segments.MSCT and MR images of all the patients were blindly analyzed.The size and extent of hypoenhanced regions in first pass phase and hyperenhanced regions in delayed phase were define.The Kappa test was used to assess the ability of identifying the viable myocardium between the two methods.Results In 32 patients with chronic myocardial infarction,MSCT showed hypoenhanced regions in 41 segments and normal in 471 segments during the first phase,while MRI revealed hypoenhanced regions in 47 segments and normal regions in 465 segments.The Kappa value was 0.650 and the concordance rate of the two techniques was 94.5%(484/512).MSCT showed 135 hyperenhanced regions which were non-transmural in 50 segments and transmural in 85 segments.And the other 377 normal segments showed no enhancement in the delayed phase.MRI revealed 120 hyperenhanced regions which were non-transmural in 56 segments and transmural in 64 segments.And the other 392 normal segments showed no enhancement in the delayed phase.The Kappa value of the two techniques was 0.609 and the concordance rate of the two techniques was 80.7% (413/512).Conclusion The study showed that low kilovolrage CE MSCT has a good concordance with MRI and has high feasibility and reliability in evaluating the myocardial viability in chronic myocardial infarction.The radiation dose is still the important aspect of MSCT application.

Objective To explore the clinical application value of left atrial function with feature tracking cardiac magnetic resonance imaging (FT-CMR) by evaluating preliminarily left atrial strain and strain rate in patients with atrial fibrillation. Methods Thirty patients with paroxysmal atrial fibrillation, thirty patients with persistent atrial fibrillation and twenty-two healthy subjects were enrolled. All the subjects underwent cardiac magnetic resonance imaging with the real steady-state free precession(SSFP) sequence. FT-CMR parameters included left atrial strain and strain rate parameters, left atrial volume and function parameters were detected by using offline cardiovascular analysis software, respectively. Left atrial strain and strain rate parameters included left atrial total strain(Εs), passive strain(Εe), active strain(Εa), peak positive strain rate(SRs), peak early negative strain rate(SRe)and peak late negative strain rate(SRa). Volume and function parameters included maximum of left atrial volume(LAVmax), minimum of left atrial volume(LAVmin), total left atrial emptying fraction(LATEF), passive left atrial emptying fraction(LAPEF)and active left atrial emptying fraction(LAAEF). The differences in the general data among the paroxysmal atrial fibrillation group, the persistent atrial fibrillation group and the control group were compared by usingχ2 test or ANOVA analysis. The differences in all parameters between the atrial fibrillation group and the control group, the paroxysmal atrial fibrillation group and the persistent atrial fibrillation group were compared by using independent t test. Left atrial strain and strain rate parameters on an intra-observer and inter-observer were determined by intraclass correlation coefficient(ICC)analyses. Results Compared to control group, LAVmax and LAVmin in atrial fibrillation group were significantly increased(t=9.737,7.889,P<0.001);The LATEF and LAPEF had no significant difference, the LAAEF in two groups had statistically significant difference(t=-4.762,P<0.001).The absolute value of Es, Ee, Ea, SRs, SRe, SRa in atrial fibrillation group were significantly reduced than in control group(t=-7.732,-6.610,-6.493,-7.546, 6.864, 5.917,P<0.001). Compared with paroxysmal atrial fibrillation group, LAVmax and LAVmin in persistent atrial fibrillation group were increased obviously, LATEF and LAPEF were significantly decreased, and the differences were statistically significant(t=-4.575,-5.524, 4.002, 4.028,P<0.001).The LAAEF in two groups had no statistically significant difference. Compared with strain and strain rate in two groups, absolute value of Es, Ee, Ea, SRs, SRe, SRa in persistent atrial fibrillation group significantly decreased than in paroxysmal atrial fibrillation(t=4.310, 3.128, 4.465, 5.496,-3.290,-3.863,P<0.001). The intra-group and inter-group had well correlation coefficients between the observers in the left atrial strain and strain rate parameters of the subjects(ICC=0.85—0.94,0.81—0.90). Conclusions FT-CMR technique can be used to assess the left atrial strain and strain rate in patients with atrial fibrillation;Left atrial reservoir, conduit and booster-pump functions in patients with atrial fibrillation were impaired. Patients with persistent atrial fibrillation had worse left atrial function throughout the entire cardiac cycle compared with those with paroxysmal atrial fibrillation.

ObjectiveAnalyzing the left atrium and pulmonary vein morphologicallv by 64 multislice spiral CT(MSCT)scan to guide the catheter ablation of Atrial fibrillation.MethodsTwo hundred and thirty-two patients(146 cases in atrial fibrillation group and 86 cases in control group)received 64 MSCT examination of the left atrium and pulmonary vein.The incidence of anatomical variation of pulmonary vein was compared between atrial fibrillation group and control group. For each group,the anatomical morphology ot every pulmonary vein and the auricle of left atrium was analyzed, the diameter of the orifice of each pulmonary vein and the size of left atrium were measured.ResultsSixty-four MSCT of left atrium and pulmonary vein could demonstrate detailed connecting type between left atrium and pulmonary Veins and the possible anatomieal variation. Anatomical variation of pulmonary vein in this study accounted for 16.8% (39/232)of total sample. For both groups,orifices of pulmonary veins appeared oval and their superoinferior diameters were larger than their anteroposterior diameters. There was significant difference in the inner diameter of left atrium between atrial fibrillation group and control group[atrial fibrillation group:(39.47±8.98)mm,control group:(36.94 ±5.49)mm,P=0.02],while there was no difference in the diameters of orifices ot puhnonary veins between two groups [ superoinferior diameters of pulmonary veins in atrial fibrillation group:left-up(18.15±1.35)mm,left-down(16.96 ±1.18)mm,right-up(17.50±

Objective To observe the value of optimized temporal parallel acquisition technique (TPAT) sequence in evaluating cardiac structure and function in arrhythmia patients.Methods Totally 33 arrhythmia patients (arrhythmia group) and 48 normal rhythm subjects (normal group) underwent cardiac MRI with conventional cine (balanced steadystate free-precession [bSSFP]) sequence and optimized TPAT sequence.Myocardial thickness,cardiac function,myocardial strain parameters of left ventricle and image quality of 2 sequences were compared in the two groups,respectively.Results In arrhythmia group,there was statistical difference of myocardial thickness in 12 myocardial segments between the 2 sequences (all P ＜ 0.05),as well as peak and average values of myocardial radial and circumferential strain (all P＜0.05).In normal group,there was no statistical difference of myocardial thickness and stain parameters between the 2 sequences (all P＞0.05).Additionally,no statistical difference of cardiac function was found between the 2 sequences in two groups (all P＞0.05).In arrhythmia group,the image quality of optimized TPAT sequence was better than that of bSSFP sequence (P＜0.05).Conclusion For arrhythmia patients,optimized TPAT cine sequence could improve image quality of cardiac MRI.

Objective To evaluate the value of cardiac MR imaging in chronic ischemie mitral regurgitation (IMR) in patients with myocardial infarction. Methods All patients clinically diagnosed with coronary heart disease and myocardial infarction in our hospital from January 2016 to September 2018 were retrospectively selected, myocardial infarction time more than 3 months and confirmed to have necrotic myocardium by cardiac magnetic resonance examination. All patients underwent echocardiography at the same time. Based on the results of echocardiography, patients were divided into the myocardial infarction group without IMR (40 cases), the mild IMR group (39 cases) and the moderate to severe IMR group (51 cases). Cardiac MR and delayed enhancement (LGE) scan images were analyzed. Cardiac function indexes were measured and left ventricular LGE positive segments were recorded. The indexes of myocardial global longitudinal strain (GLS), global peripheral strain (GCS) and global radial strain (GRS) of left ventricle of IMR patients were measured by feature tracking(FT). Cardiovascular history, coronary artery stenosis and location of myocardial infarction were compared by chi?square test between the without IMR, mild IMR and moderate to severe IMR groups.Univariate analysis of variance was used to compare the measurement data of left ventricular myocardial infarction volume, left heart function and left ventricular myocardial globle strain, and LSD test was used for pair?wise comparison. Results There was no difference in age, sex and cardiovascular history among the three groups. Comparison of myocardial infarction patients in the three groups: (1) There was no statistically significant difference in the myocardial infarction volume between the three groups (P=0.052), while the myocardial infarction volume tended to increase as the grade of mitral regurgitation increased. The number of patients with myocardial infarction in the inferior wall and the inferolateral wall in the moderate to severe IMR group were significantly higher than those of the other two groups (P<0.05), and there was no significant difference in the volume of myocardial infarction between the without IMR group and mild IMR group, and no difference in the number of patients with inferior wall and inferolateral wall. (2) Cardiac function measured by CMR: ejection fraction (EF) was significantly reduced in the moderate to severe IMR group compared with the without IMR group and the mild IMR group (P<0.05), the end diastolic volume (EDV) increased significantly and the end systolic volume (ESV) increased significantly (P<0.05). Mass of myocardium increased significantly (P<0.05); Stroke volume (SV) and cardiac output (CO) there was no significant difference among the three groups. (3) Comparison of the moderate to severe IMR group to the without IMR group and the mild IMR group respectively: left ventricular GLS and GRS decreased (P<0.05), the difference of the GCS was no statistically significant. There was no statistical difference in the three strain values between the without IMR group and the mild IMR group. Conclusion The globe myocardial strain of the left ventricle in myocardial infarction patients with chronic moderate to severe IMR was significantly impaired, the myocardial infarction in the inferior wall and the inferolateral wall in the level of the papillary muscle may be correlated with chronic moderate to severe IMR, and the myocardial infarction volume of the left ventricle may also be related.

Objective:To assess the current state of care for Severe Postpartum Hemorrhage(SPPH)in refer-ral centers and non-referral centers,and to propose enhanced strategies for the regional prevention and manage-ment of SPPH.Methods:The clinical data of patients with SPPH,defined as postpartum blood loss≥1500 ml or transfusion of blood products≥1000 ml,in two districts of Beijing from January 2021 to June 2023 were retrospec-tively analyzed.A total of 201 cases of SPPH were included and they were divided into 125 cases in the referral center group and 76 cases in the non-referral center group based on whether they were city level referral centers.The clinical characteristics between these two groups were compared.Furthermore,a stratified analysis was con-ducted using a Logistic regression model to identify the risk factors associated with massive postpartum hemor-rhage,defined as postpartum hemorrhage≥4000 ml,transfusion requirements exceeding suspended red blood cells(RBC)>10 U and(or)plasma>1000 ml.Results:Analysis of cases presenting with SPPH between the two study groups showed that patients in the referral center group exhibited advanced maternal age,smaller gestation-al weeks at delivery and a higher proportion of high-risk factors compared to those in the non-referral center group,and the difference was statistically significant(P<0.05).The primary cause of SPPH in the referral center group was placental factors,while uterine atony was identified as the main factor in the non-referral center group,and this difference was statistically significant(P<0.05).Additionally,within the non-referral center group,there was a higher amount of blood loss during cesarean section,lower proportion of B-Lynch suture/vascular suture ligation,and higher proportion of uterine packing(P<0.05).Furthermore,compared to the referral center group,there were significantly higher incidences of plasma transfution volume,return to operating room for further inter-vention or exploratory laparotomy procedures after initial delivery and complications related to postpartum hemor-rhage observed in the non-referral center group(P<0.05).Moreover,it was noted that there were more cases of massive postpartum hemorrhagic disease reported in the non-referral center group than in the referral center group(P<0.05).In massive postpartum hemorrhage cases analyzed,referring centers had a higher percentage of patients presenting with multiple high-risk factors for postpartum hemorrhage during pregnancy when compared to non-referring centers(71.4%vs.33.3%,P<0.05).Placental factors accounted for majority causes leading to hemorrhage within referring centers(57.1%),whereas both uterine atony and placental factors played major roles within non-referring centers′cases(42.9%,28.6%).The multivariate Logistic regression analysis revealed that non-referral center delivery(aOR 3.47,95%CI 1.40-9.18)and a history of multiple intrauterine operations(aOR 12.63,95%CI 1.24-131.30)were identified as significant risk factors for massive postpartum hemor-rhage.Conclusions:The outcomes of high-risk pregnant women referral management in the region exhibit an im-provement,necessitating the reinforcement of training in non-referral midwifery institutions regarding identification of high-risk factors,surgical suture techniques,and comprehensive SPPH management to avert excessive bleed-ing and blood transfusion.