ABSTRACT
Objective:To investigate the characteristics of early myocardial mechanics changes in diabetic cardiomyopathy (DCM).Method:Sixty healthy 4-week-old male C57BL/6J mice were randomly divided into the T2DM group ( n=30) and the control group ( n=30). The T2DM group was fed with high-fat diet for 4 weeks, and accepted injection of a single high-dose of streptozotocin (STZ) intraperitoneally. Finally, the model was established successfully in 23 mice. The control group was fed with a normal diet and treated with citrate buffer liquid at an equal dose as T2DM group. Then, nine mice were randomly selected from each of the two groups every 4 weeks until the end of the 24th week. Six of the nine mice were randomly selected to perform 7.0 T MR scanning after measuring blood glucose and body weight. Cine images were acquired through cardiovascular MR feature tracking (CMR-FT). The obtained parameters included the left ventricle global peak circumferential strain (LV-GPCS), left ventricle global peak radial strain(GPRS) and the ejection fraction (EF), etc. The rest three mice were sacrificed for observation of the changes of interstitial fibers and micro-vessels in myocardial tissue with Sirius red staining. One-way analysis of variance (ANOVA) and t test were used for comparison. Results:There were significant differences in blood glucose levels between the two groups during the observation period ( P<0.05). In the 4 th-24 th week, the value of GPCS in T2DM group showed a downward trend, and the difference was statistically significant ( F = 8.23, P<0.001). Compared with the control group, the value of GPCS in T2DM group was statistically significant at the 20 th and 24 th week (the 20 th week: -11.4%±2.1% in the T2DM group vs. -14.3%±1.9% in the control group, t=2.54, P=0.029;the 24 th week: -12.3%±1.7% in the T2DM group vs. -14.6%±1.8% in the control group, t=2.35 , P=0.040), while the EF value was different at the 24 th week (51%±5% in the T2DM group vs. 62%±6% in the control group, t=3.38, P=0.007). There was no significant difference in the GPRS of the T2DM mice group over time or compared with the controls ( P>0.05). Moreover, the pathological results showed that the myocardial interstitial fibers in the T2DM group had remarkably increased since the 12 th week. Conclusions:The alterations in myocardial interstitial fibers and myocardial contractility appeared early in T2DM mice. Especially, the left ventricle global peak circumferential strain value is superior to the EF value in reflecting the early changes in DCM.
ABSTRACT
Objective:To evaluate the feasibility and diagnostic efficacy of the coronary fractional flow reserve derived from CT (CT-FFR) measurement method based on tracer pharmacokinetic principle.Methods:A total of 130 patients (159 coronary artery vessels) who were admitted to Beijing Anzhen Hospital from January 2015 to March 2019 were included in this study retrospectively. All patients had completed coronary CT angiography (CCTA) and invasive coronary angiography with invasive FFR. Subjective assessment of stenosis degree was performed on CCTA images and non-invasive FFR measurement was performed by using a tracer-kinetics based on CT-FFR measurement method. The Bland-Altman method was used to evaluate the diagnostic consistency of the two methods. Compared with the invasive FFR results, the sensitivity, specificity, positive predictive value, negative predictive value, and area under the ROC curve (AUC) of tracer-kinetics based on CT-FFR results for the diagnosis of coronary ischemic lesions were evaluated. All cases were divided into two heart rate groups:>65 bpm and ≤65 bpm. The diagnostic efficacy of tracer-kinetics based on CT-FFR in different heart rate groups was evaluated. χ 2 test and DeLong test were used to compare diagnostic performance in different evaluation methods and heart rate groups. Logistic regression analysis was used to evaluate the impact of factors such as heart rate, image thickness, image enhancement, and noise on the accuracy of diagnosis. Results:Bland-Altman analysis showed that the average difference between the two methods was -0.01. (-0.11-0.10). Compared with invasive FFR results, the tracer-kinetics based on CT-FFR method had a diagnostic sensitivity of 92.4%, specificity of 82.1%, positive predictive value of 87.6%, negative predictive value of 88.7%, and the area under ROC curve (AUC) value was 0.94. Compared with the diagnostic efficacy of luminal stenosis evaluated based on CCTA images, the difference was significantly statistical ( P<0.05). The diagnostic performance of CT-FFR had no statistically significant difference between the two heart rate groups. Factors such as heart rate, image thickness, image enhancement, and noise had no significant effect on the diagnostic accuracy of the tracer-kinetics based on CT-FFR method. Conclusions:The tracer-kinetics based on CT-FFR method may quickly complete the non-invasive FFR measurement on CCTA images with image quality that meets the needs of clinical diagnosis. It has a good diagnostic performance in the diagnosis of coronary ischemic lesions even for those cases with a faster heart rate. The diagnostic accuracy of tracer-kinetics based on CT-FFR method is not significantly affected by factors such as heart rate, image thickness, image enhancement, and image noise.
ABSTRACT
Objective To investigate the value of phase-contrast magnetic resonance imaging (PC-MRI)in evaluating pulmonary artery blood flow and right ventricular(RV)function in elderly patients with chronic obstructive pulmonary disease (COPD).Methods Twenty-four elderly patients with COPD admitted to Beijing Anzhen Hospital between February 2016 and June 2017 were enrolled in this retrospective study.Based on pulmonary artery pressure evaluated by right heart catheterization,COPD patients were divided into a pulmonary hypertension group (PH group,n =12)and a non-PH group(n=12).Pulmonary artery blood flow velocity and volume,pulmonary arterial compliance and right heart function parameters including ejection fraction,end diastolic volume,endsystolic volume and cardiac output,and 6-min walking distance evaluated by PC-MRI were compared between the two groups.Results There were significant differences in peak flow velocity[(88.1 ±16.0)cm/s vs.(59.8± 13.8) cm/s,P =0.005],flow volume [(80.7± 22.0) ml/s vs.(53.2± 26.7)ml/s,P=0.012],main pulmonary artery compliance[(42.3± 14.6)vs.(22.7± 10.8),P =0.001],right ventricular ejection fraction [(48.4 ± 13.4) ％ vs.(37.6 ± 11.1) ％,P =0.000],end-diastolic volume[(64.6±22.5)ml vs.(72.5±22.8)ml,P =0.030]and end-systolic volume[(50.6±33.1)ml vs.(41.7±33.1)ml,P =0.040]between the non-PH and PH groups,while there was no significant difference in cardiac output between the non-PH and PH groups[(34.2±10.8)ml vs.(34.4±8.3)ml,P =0.080].Pearson's correlation analysis showed that 6-minute walking distance had good correlations with right ventricular ejection fraction(r =0.49),forced expiratory volume in 1 s(FEV1)(r=0.60)and main pulmonary artery diameter(r=0.61).Conclusions PC-MRI is a noninvasive imaging method for quantitative analysis of pulmonary artery dynamics and right heart function for the elderly with COPD,and it can provide information for evaluating therapeutic effects and prognosis.
ABSTRACT
Objective To analyze the correlation between calcification factors and fractional flow reserve derived from CT (CT?FFR). And to evaluate the diagnostic efficacy of CT?FFR in coronary artery lesions with calcification compared with that of invasive FFR. Methods Sixty?five patients (74 coronary artery vessels) who were admitted to Beijing Anzhen Hospital from July 2014 to December 2016 were included in this study retrospectively. All patients had completed CCTA (coronary CT angiography), coronary angiography and invasive FFR measurements, and had coronary lesions contain calcifications. The evaluation of CCTA data included quantitative analyses of plaque components, coronary artery stenosis, and CT?FFR measurements. The patients′basic data were grouped and compared according to the FFR values. The measurement data was tested by independent?samples t tests, and the categorical data were analyzed by χ2 tests. Quantitative measurements of plaques were compared between groups using independent?sample t tests or rank sum tests based on FFR and CT?FFR values. The reproducibility of CT?FFR measurement software was evaluated by inter?class correlation coefficient (ICC) and the Youden index was calculated to determine the threshold for CT?FFR diagnosis of ischemia. Pearson or Spearman correlation analyses were used to assess the correlations between CT plaque quantitative indicators, CT?FFR and invasive FFR. Multivariate logistic regression analysis was used to analyze the predictors of ischemia by FFR and CT?FFR. In contrast to invasive FFR results, the sensitivity, specificity, negative predictive value, positive predictive value (PPV) of CT?FFR in the diagnosis of coronary ischemic lesions were evaluated, and the diagnostic consistency was evaluated by the Bland?Altman method. Results Compared with invasive FFR, CT?FFR had a more significant correlation with calcification volume and ratio of calcification in plaques (r=-0.519 and－0.547, respectively, both P=0.001). Multivariate logistic regression analysis showed that plaque length was a predictor of invasive FFR in the diagnosis of pathological ischemia ( OR=1.13, 95%CI : 1.05—1.23, P=0.002), and was associated with CT?FFR to determine pathological ischemia. In addition to plaque length ( OR=1.10, 95%CI : 1.02—1.18, P=0.010), the predictor also included ratio of calcification in plaque ( OR=1.09, 95%CI: 1.03—1.15, P=0.003). Compared with invasive FFR results, the diagnostic sensitivity of CT?FFR was 79.1%, the specificity was 80.6%, the PPV was 85.0%, and the area under the ROC curve was 0.78. The result for the diagnosis of ischemia lesion by using CT?FFR had significant statistical differences with the results by according coronary artery stenosis (χ2=10.05, P=0.002; χ2=34.71, P=0.001; χ2=7.65, P=0.006; Z=2.10, P=0.029). The Bland?Altman analysis showed a mean difference of －0.01 (-0.26—0.25) between the CT?FFR and the invasive FFR. Conclusions There is no significant correlation between the proportion of calcification components of coronary plaque and the presence or absence of myocardial ischemia, but the proportion of calcification in plaque will affect the result that is evaluated by CT?FFR. However, compared with CT?based stenosis evaluation, CT?FFR can still significantly improve the ability of CCTA to diagnose ischemia lesion with calcification.
ABSTRACT
Objective To evaluate the feasibility and accuracy of cardiac CT (CCT) in quantitation of extracellular volume (ECV) fraction in patients with heart failure, with 3 T Cardiac MR (CMR) as the reference. Methods Twenty?eight patients with variety reasons of heart failure were enrolled in this study. ECVs was calculated, the correlation between CCT and CMR ECV value and other cardiac function parameters (left ventricular end systolic volume LVESV, left ventricular end diastolic volume LVEDV, cardiac output CO and ejection fraction LVEF, and clinical bio?marker BNP) was determined. Interclass correlation coefficient (ICC) was used to evaluate the agreement of measurement by two radiologists. Results The average of ECV on CCT and CMR was 33% ± 8% and 31% ± 6%, respectively. A good correlation was revealed between myocardial ECV at CCT and that at CMR (r=0.854, P<0.001). Bland?Altman analysis between CCT and CMR showed a small bias (4.6%), with 95% limits of agreement of-18.2% to 27.4%. ICC for ECV at CCT was excellent (ICC=0.910). For both CCT and CMR, ECV was inversely related to LVEF. The radiation dose for CCT?ECV was (1.60±0.04) mSv. Conclusions ECV at CCT and that at CMR showed good correlation, suggesting the potential for myocardial tissue characterization using CCT. However, CCT?ECV would possibly overestimate the extent of ECV.
ABSTRACT
Objective To analyze the impact of dual energy monochromatic reconstructions (50-160 keV) on coronary calcified plaque stenosis quantification in a cardiac phantom with the real stenosis as standard of reference.Methods Signal-to-noise(SNR)and contrast-to-noise ratios(CNR)were calculated. In conventional 120 kV coronary CT angiography (CCTA) images as well as 12 monochromatic series(50-160 keV),luminal narrowing of calcified plaque was measured and compared to the real stenosis. Bland-Altman plots were performed to analyze the correlation of reference standard with conventional 120 kV and 12 monochromatic series (50-160 keV). The sensitivity, specificity, and accuracy of CCTA for detection of≥50% stenosis were calculated and receiver operating characteristic(ROC)curve was analyzed with the real stenosis as reference standard.Results The SNR and CNR were decreased with the increase of keV from 70 keV.The SNR and CNR of monochromatic imaging were lower compared with conventional 120 kV images(SNR:76.4±16.1;CNR:274.7±54.1)(P<0.05).The Bland-Altman plots presented a smaller measurement bias towards 90-160 keV than conventional 120 kV, and smallest measurement bias was revealed in 100-130 keV imaging(100-130 keV:bias 17.2% vs 120 kV:21.4%).Using the stenosis≥50% as cut-off value, the specificity were higher in the monochromatic series (70-160 keV) than conventional 120 kV CCTA.The specificity(75.0%)were the highest in the 120 keV and 130 keV images.The area under the ROC curve(AUC)of 90-130 keV(0.991-0.995)was higher than that in conventional 120 kV imaging (0.990). Conclusions The use of monochromatic imaging improves the overall accuracy of stenosis evaluation in coronary calcified plaques. Reconstructions at 100-130 keV for calcified lesions yielded the optimal results.
ABSTRACT
Objective Cardiac MRI is the "gold standard" for non-invasively assessing the structure and function of the heart.Compared with conventional cine imaging,MR strain technique can identify the abnormalities of segmental myocardial motion of heart diseases in the early stage by quantifying the displacement of myocardial tissue,which is of great value in evaluating the disease condition as well as guiding treatment and assessing prognosis.Myocardial strain can quantify the segmental wall motion,which is less impacted by other factors.The application of MR strain imaging in cardiac diseases were reviewed in this paper.
ABSTRACT
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.
ABSTRACT
Objective To compare the diagnostic accuracy of clinically significant prostate cancer by general radiologist and uroradiology specialist based on the Prostate Imaging Reporting and Data System (PI-RADS).Methods A total of 45 men from Beijing United Family Hospital and Clinics undergoing prostate mpMRI examination and subsequent MRI-targeted biopsy were included in the study.The age of patients was (60.0 ± 8.0) years,the median PSA level was 7.2 ng/ml (1.2-95.8 ng/ml) and the median prostate volume was 45.0 ml (18.3-127.0 ml).The general radiologists from Beijing United Family Hospital and Clinics made the diagnosis according to PI-RADS 2.0.One uroradiology specialist from Beijing Anzhen hospital reviewed all the mpMRIs retrospectively and marked new PI-RADS score based on PI-RADS 2.0.The PI-RADS ≥ 3 lesion was recognized as suspicious of clinically significant prostate cancer.The distribution of PI-RADS score from different doctors and the diagnostic accuracy of clinically significant prostate cancer was compared.Results All the 45 patients underwent MRI-targeted cognitive biopsy and 14 cases of prostate cancer were detected,including 9 cases of clinically significant prostate cancer.There was no significant difference in the distribution of PI-RADS by general radiologist and uroradiology specialist (P =0.064).82.8％ (37/45) and 37.8％ (17/45) patients were diagnosed with PI-RADS ≥ 3 by general radiologist and uroradiology specialist respectively.The interobserver agreement was only 17.8％ (8/45).The positive predictive value of PI-RADS≥3 was 35.1％ (13/37) and 76.5％ (13/17) for prostate cancer by general radiologist and uroradiology specialist respectively,and for clinically significant prostate cancer,the positive predictive value of PI-RADS ≥ 3 was 21.6％ (8/37) and 52.9％ (9/17) respectively.Conclusions Uroradiology specialist achieved significantly superior in predictive value of PI-RADS for clinically significant prostate cancer compared with general radiologist.In the experienced centers,MRI-targeted biopsy could be performed only on high PI-RADS score lesions,thus to reduce unnecessary biopsies and to avoid over diagnosis and over treatment of prostate cancer.
ABSTRACT
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.
ABSTRACT
Objective To evaluate the diffuse myocardial fibrosis of the left ventricle (LV) in patients with atrial fibrillation (AF) by cardiac MR (CMR) T1 mapping methods.Methods Totally 60 subjects (30 paroxysmal AF patients and 30 persistent AF patients) and 59 normal control underwent MR cardiac cine,late gadolinium enhancement,and LV T1 mapping.For T1 mapping,modified Look-Locker inversion recovery sequence was used.Compared with control,pre-contrast ventricular T1 times were quantified and extracellular volume (ECV) was calculated.Results All subjects completed the CMR exam,no myocardial delay enhanced lesion was found.Pre-contrast ventricular T1 time in healthy controls was lower than that in patients with persistent and paroxysmal AF,and the pre-comrast ventricular T1 time in persistent AF patients was higher than that of paroxysmal AF patients (all P＜0.05).The mean LV myocardial ECV had no statistical difference between healthy controls and paroxysmal AF patients (P＞ 0.05),while lower than persistent AF patients (P ＜ 0.05).The mean LV myocardial ECV in patients with persistent AF was larger than that in patients with paroxysmal AF (P＜0.05).LV functional indexes were positive correlated with pre-contrast ventricular T1 time and ECV in patients with AF (all P＜0.05).Conclusion There is LV myocardial fibrosis in patients with AF,and the degree in patients with persistent AF is more severe than that in patients with paroxysmal AF.
ABSTRACT
Objective To investigate the feasibility of coronary CT angiography in single cardiac cycle and to analyze the image quality and radiation dose in patients with high heart rate(HR) using 256-row detector CT. Methods Ninety-two consecutive patients between October and November 2015 who were suspected coronary artery disease underwent coronary CT angiography(CCTA) were enrolled, which was performed with a 256-row detector CT(Revolution CT, GE Healthcare) using prospective ECG-triggered volume CCTA within a single cardiac cycle with snapshot freeze(SSF) technique. The patients were grouped by HR during CT scans: group A(80—89 bpm, n=56), group B(90—99 bpm, n=20), and group C(≥100 bpm, n=16). Image quality was compared before and after using SSF technique reconstructions in seventy-four patients. The image quality of coronary artery was evaluated blindly by 2 experienced radiologists using a four-point scale based on the 18-segment model according to the Society of Cardiovascular Computed Tomography guidelines. The differences in age, body mass index, heart rate and CT dose index volume,effective dose(ED) among the three groups were compared by using ANOVA analysis or Kruskal-Wallis test, the image quality and interpretability using χ2 test. Comparisons of image quality between standard and SSF were performed with paired Wilcoxon rank sum test. Kappa coefficient was used to test inter-observer agreement. Results A total of 1 065 coronary artery segments, 98.97%(1 054/1 065) met the requirements for diagnosis. No significant difference was found(χ2=1.274, P=0.563) for the diagnostic image quality of coronary artery segments among the 3 groups with 98.64%(651/660), 99.57%(232/233), 99.42%(171/172), respectively. Significant difference(χ2=68.811, P0.05). Conclusions Single cardiac cycle scan is feasibility for coronary CT angiography in patients with high heart rate using 256-row detector CT. This scan mode can maintain the diagnostic image quality with low radiation dose. SSF technique can improve the image quality.
ABSTRACT
Objective@#To retrospectively analyze the potential correlation between cardiac magnetic resonance (CMR) imaging and clinical features and idiopathic arrhythmia in patients with straight back syndrome (SBS).@*Methods@#Patients receiving CMR imaging examination from April 2015 to March 2016 at our department (n=1 432) were screened, 76 patients met the diagnosis criteria of flat chest (anteroposterior diameter/transthoracic diameter (APD/TTD) ratio<0.37 at the T8 vertebra). After excluding 33 patients with structural heart disease, 43 SBS patients were divided into two groups: SBS without obvious morphological change in the heart (group A, n=19) and SBS with morphological change of the heart (group B, n=24). CMR images were analyzed, focusing the heart morphological changes induced by SBS. The clinical data were collected to comprehensively analyze the medical history, electrocardiogram and electrophysiological examination in order to observe the relationship between SBS induced heart morphological change and the arrhythmia type and origin.@*Results@#There were 21 male patients in this cohort, mean age was (28.5±11.5) years (13-58 years). APD/TTD ratio was similar between the two groups (0.30±0.03 vs. 0.29±0.04, P>0.05). LVEF tended to be lower in group B than in group A ((47.48±12.77)%vs. (59.31±9.04)%, P>0.05) . In group B, there were 15 patients with left ventricular enlargement, 2 with left ventricular wall thickening, 5 with uncoordinated ventricular wall motion, 5 with tricuspid regurgitation, 3 with mitral regurgitation, 2 with myocardial fibrosis, 5 with increased trabecular and 16 with decreased left ventricular function. Direct compression sign of right ventricle (disappeared precordial fat tissue space, secondary right atria enlargement and tricuspid regurgitation) and left atria (with or without secondary left ventricular enlargement and mitral regurgitation) were evidenced in patients of group B. CMR revealed that the arrhythmia origin corresponded the compression site of the heart in 8 cases (42.1%) in group A and 13 cases (54.2%) in group B, not corresponded to the compression site in 6 patients (31.6%) in group A and in 7 patients (29.2%) in group B, not attributable in 5 patients (26.3%) in group A and 4 patients (16.7%) in group B. The percent of arrhythmia origin corresponded the compression site of the heart tended to be higher in group B as compared to group A (P>0.05).@*Conclusion@#SBS can induce changes of cardiac morphology and cardiac function. SBS induced cardiac compression is linked with the development of arrhythmias and might be one of the reasons of arrhythmias in these patients.
ABSTRACT
Objective To explore the changes of hemodynamics in acute kidney injury (AKI) after acute severe Stanford type A aortic dissection.Methods Forty patients with acute Stanford A type aortic dissection were enrolled.Arterial peak systolic velocity (PSV),end diastolic velocity (EDV),pulsative index (PI),resistive index (RI),Serum creatinine (SCr) and urine volume were recorded and measured 1 day before operation,immediately after operation (enter the intensive care unit),6 h after operation,24 h after operation and 48 h after operation.Patients were divided into AKI group and non-AKI.group taking AKIN as a standard.Results Twenty-seven patients were in AKI group and 13 were in non-AKI group.The EDV,PI and RI had significantly differences between AKI group and non-AKI group at 6 h,24 h after operation.Correlation analysis showed that EDV negatively correlated with SCr (r=-0.508,P=0.001),while PI,RI positively correlated with SCr (r=0.411,0.443,P=0.009,0.005).Conclusion EDV,PI and RI in the interlobular arteries can be used to predict AKI early in the interosseous arteries,and the optimal time for ultrasonic measurement of renal arterial hemodynamics to predict is at 6 h and 24 h after operation.
ABSTRACT
Objective To explore the changes of hemodynamics in acute kidney injury (AKI) after acute severe Stanford type A aortic dissection.Methods Forty patients with acute Stanford A type aortic dissection were enrolled.Arterial peak systolic velocity (PSV),end diastolic velocity (EDV),pulsative index (PI),resistive index (RI),Serum creatinine (SCr) and urine volume were recorded and measured 1 day before operation,immediately after operation (enter the intensive care unit),6 h after operation,24 h after operation and 48 h after operation.Patients were divided into AKI group and non-AKI.group taking AKIN as a standard.Results Twenty-seven patients were in AKI group and 13 were in non-AKI group.The EDV,PI and RI had significantly differences between AKI group and non-AKI group at 6 h,24 h after operation.Correlation analysis showed that EDV negatively correlated with SCr (r=-0.508,P=0.001),while PI,RI positively correlated with SCr (r=0.411,0.443,P=0.009,0.005).Conclusion EDV,PI and RI in the interlobular arteries can be used to predict AKI early in the interosseous arteries,and the optimal time for ultrasonic measurement of renal arterial hemodynamics to predict is at 6 h and 24 h after operation.
ABSTRACT
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.
ABSTRACT
Objective:To investigate the training of writing research paper for graduate students majoring in medical imaging, therefore improving international academic communication. Methods: Analyzing the problems existed in English paper writing for the graduate students majoring in medical imaging. According to the feature of English paper writing in the field of medical imaging, the new teaching model was used and the problem-based-learning method was introduced.Results: The new training model of English research paper writing is practical and helpful for graduate students majoring in medical imaging to improve their writing skill and research ability.Conclusion: The training of English research paper writing is efficient for graduate students majoring in medical imaging. The training process can lay good foundation for their future research careers.
ABSTRACT
Objective To investigate the value of contrast enhancement T1 mapping in detection of diffuse myocardial fibrosis in cardiomyopathy, and the relationship between myocardial fibrosis and cardiac function. Methods From September 2013 to September 2014, 76 cases of cardiomyopathy patients (including myocarditis) and 33 cases of healthy controls were enrolled in our study. All the subjects underwent cardiac MR (CMR) examination. Scan sequences included cine MR, pre-contrast and post-contrast T1 mapping and late gadolinium enhancement (LGE) imaging. The pre-/post-contrast left ventricle average T1 value and cardiac function of patients and controls were measured and compared by using independent-samples t test. According to the LGE imaging, all the subjects were subsequently divided into LGE positive group, LGE negative group and control group. The myocardial average T1 value and cardiac function among the three sub-groups were compared by using one-way ANOVA, and the relationship among them were analyzed by using Pearson correlation. Results Among the 76 cases of non-ischemia cardiomyopathy patients, 51 cases (67.1%) had LGE. Compared with controls, cardiomyopathy patients presented with higher pre-contrast T1 value [(1 306.4 ± 84.6)ms vs. (1 266.6 ± 57.3)ms, t=2.10, P0.05). There were correlation between pre-/post-contrast left ventricle T1 value and ejection fraction (EF) in cardiomyopathy patients (r=-0.252,-0.217, P0.05). Conclusions The average pre-/post-contrast T1 value in left ventricle myocardium are helpful for detection of diffuse fibrosis in cardiomyopathy patients. The LGE positive is a sign that can greatly change the T1 value of the myocardial tissue, meanwhile, myocardial fibrosis is negative correlated with ejection fraction in cardiomyopathy patients.
ABSTRACT
Objective:To study the feasible training model of graduate students with professional degree. Methods:According to the purpose of training-clinical skills of graduate students with professional degree in department of radiology, we have made several ways to ensure the procedural and standardization of the training from course setting, multiple level clinical operation training, the ability of study and evaluation system. Results:To introduce the mode by using evaluation system and to standardize the steps. Conclusion:The model which includes proper course setting, multiple level clinical operation training, the ability of study and evaluation system can enhance the clinical skill training and advance the professionalism of the students.
ABSTRACT
PurposeTo determine the feasibility and accuracy of dual source CT (DSCT) in assessing myocardial delayed-enhancement and left ventricular wall thickness of hypertrophic cardiomyopathy (HCM) in comparison with cardiac magnetic resonance (CMR).Materials and MethodsEighty patients with HCM confirmed by clinical diagnosis were enrolled in the study. DSCT images and CMR images were acquired at the arterial and lag phases. According to 17-segment model provided by American Heart Association, the left ventricular wall thickness and location of delayed-enhancement were verified, and the correlation of these two methods were analyzed in terms of the diagnosis of myocardial delayed enhancement (MDE).Results1360 myocardial segments for 80 patients were assessed. The left ventricular wall thickness determined by DSCT was significantly correlated with MR results (r=0.88,P<0.01). DSCT and MDE showed substantial agreement on per-patient (n=74,Kappa=0.751,P<0.05) and per-segment (n=1238, Kappa=0.746,P<0.01) levels. For dense myocardial delayed enhancement, CT findings were significantly correlated with those of CMR (r=0.89, P<0.01), but CT scan slightly underestimated the lesion scope of fibrosis. Bland-Altman analysis showed that CT and MRI were different in measuring the lesion volume of myocardial delayed enhancement (mean standard deviation was 2.71%).ConclusionThe cardiac CT examination provides comprehensive information in coronary artery and myocardial assessment, and MDE-DSCT is also effective in the diagnosis of myocardial fibrosis in HCM since it can be used in assessing myocardial fibrosis.