Nghiên cứu vai trò của chụp cắt lớp vi tính 256 dãy trong đánh giá chức năng thất trái trên bệnh nhân có chỉ định chụp MSCT mạch vành

SUMMARY

Objective: To compare DSCT using 256-slice coronary CT angiography (SOMATOMA Definition FLASH, Siemens Medical Solution, Germany) with echocardiography for the determination of left ventrical dimentions, left ventricular ejection fraction (LVEF), end-diastolic volume (EDV), end-systolic volume (ESV), regional wall motion as well as assessing coronary artery image quality and patient radiation dose.

Materials and Methods: One-hundred twelve patients were referred for DSCT for evaluation of coronary artery and underwent DSCT and transthoracal echocardiography within 1 week. LV dimentions, EF, EDV and ESV were determined for both DSCT and echocardiography, and the correlation coefficients were assessed. Measurements of dimensions were obtained in standardized planes in end-systole and end-diastole and included the septal and posterior wall thickness, and inner diameter of the left ventricle. Global left ventricular (LV) functional parameters [end-systolic volume (ESV), end-diastolic volume (EDV), ejection fraction] were computed using automated software. ESV, EDV were normalized to the body-surface-area (BSA). Correlation between DSCT and echocardiography was tested through linear regression and Bland- Altman analysis. Regional wall motion is collected by visual (1, normal, 2, hypokinesia, 3, dysphagia or akinesia). Coronary artery segment subjective image quality (1, excellent; 4, poor) and radiation dose were recorded.

Results: A direct comparison between 256 slice Dual-Source CT and 2D-echocardiography was performed in 112 patients (43men; 61,26 ± 11,68 mean age years) who were clinically referred for MSCT coronary angiography. LV end-diastolic volumes (LVEDV) and LV endsystolic volumes (LVESV) were determined and the LV ejection fraction (LVEF) was derived. Average LVEF was 66,24± 13,52% (range 23-85%) as determined on DSCT, compared with 65,72±11,31% (range 25-84%) on 2D echocardiography. Evaluation of LVEF by linear regression analysis showed a good correlation between DSCT and 2D-echocardiography (r= 0,715; P < .001). Good correlations between DSCT and 2D-echocardiography were demonstrated for the assessment of LVEDV (r=0,732 ; P < .001) and LVESV (r= 0,841; P < .001). At Bland-Altman analysis, mean differences (±SD) of 1,78 ± 24,10 mL (p <0 .05) and 0,766 ± 13,7 mL (p < 0.05) were observed between DSCT and 2D-echocardiography for LVEDV and LVESV, respectively. LVEF was slightly overestimated with DSCT (0.52 ± 9,59%; p < 0.05). Resultly, the LVEFs calculated by DSCT and echocardiography were not statistically different. However, LVEF, EDV and ESV from MDCT were statistically higher than those from echocardiography (p < 0.05).The average image quality score of the coronary artery segment was 1,79. The mean patient radiation dose was 3,78 ±1,88 mSv.

Conclusion: In conclusion, the use of 256-slice DSCT can provide comparable results to those using 2D-TTE for LV funtion include EF, EDV, ESV and regional wall motion assessment in a heterogeneous population.

Keywords: DSCT; Coronary Artery Disease; Left ventricular function; Echocardiography; Radiation