Assessment of right ventricular function for patients with rheumatic mitral stenosis by 64-slice multi-detector row computed tomography: comparison with magnetic resonance imaging.

BACKGROUND: Right ventricular (RV) dysfunction ensues due to rheumatic mitral stenosis (RMS). The evaluation of RV function is clinically important for the diagnosis, treatment, and follow-up for patients with different degrees of RMS. The purpose of this study was to determine whether the 64-slice multi-detector row computed tomography (64-slice MDCT) can assess the RV function in RMS with high accuracy and reproducibility when compared to MR imaging (MRI). METHODS: Right ventricular end-diastolic and end-systolic volumes (RV-EDV and RV-ESV), stroke volume (RV-SV), ejection fraction (RV-EF), cardiac output (RV-CO), and wall mass (RV-Mass) were measured with dedicated cardiac analysis software on 64-slice MDCT and compared with values measured with MRI in 43 consecutive patients with RMS. Agreement between MRI and 64-MDCT results were compared with Bland and Altman analysis and linear regression analysis. Repeated measurements were performed to determine intraobserver and interobserver variability. RESULTS: No significant differences were revealed in calculated RV function parameters between the two methods. RV-EDV, RV-ESV, RV-SV, RV-EF, RV-CO, and RV-Mass by 64-slice MDCT were similar to those by MRI (P > 0.05). There were good correlations (r = 0.98, 0.97, 0.96, 0.96, 0.95 and 0.77, respectively) and close agreement (bias = -0.2 ml, -1.0 ml, 0.8 ml, 0.5%, 26.1 ml, and 0.5 g, respectively, P > 0.05). The variability in 64-slice MDCT measurements was similar to that in MRI values. CONCLUSION: ECG-gated 64-slice MDCT could assess the RV function in RMS with high accuracy and reproducibility when compared to MRI.

[Regional atmospheric environment risk source identification and assessment].

Identification and assessment for atmospheric environment risk source plays an important role in regional atmospheric risk assessment and regional atmospheric pollution prevention and control. The likelihood exposure and consequence assessment method (LEC method) and the Delphi method were employed to build a fast and effective method for identification and assessment of regional atmospheric environment risk sources. This method was applied to the case study of a large coal transportation port in North China. The assessment results showed that the risk characteristics and the harm degree of regional atmospheric environment risk source were in line with the actual situation. Fast and effective identification and assessment of risk source has laid an important foundation for the regional atmospheric environmental risk assessment and regional atmospheric pollution prevention and control.

Isolated mitral regurgitation: quantitative assessment with 64-section multidetector CT--comparison with MR imaging and echocardiography.

PURPOSE: To evaluate the accuracy of 64-section multidetector computed tomography (CT) for the assessment of the severity of isolated mitral regurgitation by measuring ventricular volumetrics compared with those at magnetic resonance (MR) imaging and echocardiography. MATERIALS AND METHODS: This study was approved by an institutional review board; patient informed consent was obtained. Forty-nine patients (22 men, 27 women; mean age, 39 years +/- 11 [standard deviation]) with isolated mitral regurgitation underwent retrospective electrocardiographically (ECG) gated 64-section CT, echocardiography, and MR imaging for the assessment of the severity of mitral regurgitation. Stroke volumes of the left and right ventricles were measured at 64-section CT and MR imaging. With these measurements, regurgitant volumes (RVs) and regurgitant fractions (RFs) were calculated and compared. The agreement between CT and MR imaging was tested by using linear regression and Bland-Altman analyses. RFs were compared with corresponding echocardiographic grades (grades I-IV) based on the absolute area of the regurgitation jet and in relation to the size of the left atrium by using Spearman rank order correlation and a weighted kappa test. RESULTS: No significant differences were found in calculated RV and RF between 64-section CT and MR imaging (P = .56 and .87, respectively; paired t test). Regression analysis showed that 64-section CT correlated well with MR imaging for the measurement of RV (r = 0.89; 95% confidence interval [CI]: 0.81, 0.94) and for calculating the RF (r = 0.91; 95% CI: 0.84, 0.95). Bland-Altman analysis showed no significant differences in RV (bias, -1.0 mL) and RF (bias, 0.2%) between 64-section CT and MR imaging. The severity of regurgitation estimated by using echocardiography correlated well with that estimated by using 64-section CT (r = 0.95; 95% CI: 0.92, 0.97) and MR imaging (r = 0.94; 95% CI: 0.91, 0.96). CONCLUSION: ECG-gated 64-section CT helps provide quantitative information with high accuracy for determining the severity of isolated mitral regurgitation.