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CT冠脉成像中胸廓径线与图像质量的相关性研究
Image Quality Adapted Thoracic Diameters in CT Coronary Artery Imaging
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摘要: 目的 探讨双源CT冠脉成像中胸廓前后径及左右径与图像质量的相关性,以获得最优化降低辐射剂量的可能性。 方法 收集我院双源CT冠脉成像检查的患者118例,分为A[25 kg/m2 ≤体质量指数(BMI)值<30]、B(BMI值<25 kg/m2)两组。A组患者58例,平均年龄59.9岁;B组患者60例,平均年龄60.1岁。扫描参数:准直64×0.6 mm,重建层厚0.75 mm,重建间隔0.7 mm,FOV 150~180 mm,根据心率自动调整螺距。A组:管电压100 kV,管电流330 mAs;B组:管电压100 kV,管电流220 mAs。采集图像后,测量胸廓前后径(AP)、左右径(RL),及所在层面(共5个层面)冠脉、背脊肌的CT值和噪声(SD),并计算冠脉相对于背脊肌的对比噪声比(CNRa)、信噪比(SNRa)。应用统计学软件进行CNRa、SNRa与胸廓AP、RL、BMI的相关性检验。 结果 A、B两组RL的5个层面与CNRa具有相关性(P<0.05),A、B两组中除A组第iii、iv层外,均与CNRa具有相关性(P<0.05),除A组第ii、iv层、B组第v层外,BMI均与CNRa具有相关性(P<0.05)。A组CNRa与RL的相关系数除第ii层面外,都大于其与AP的相关系数,B组CNRa、SNRa与RL的相关系数均大于其与AP的相关系数。A组除第iii层面外,CNRa、SNRa与AP的相关系数大于其与BMI的相关系数;B组除第ii层面外,CNRa与AP的相关系数大于其与BMI的相关系数。 结论 在双源CT冠脉成像检查中,图像质量与胸廓径线(左右径、前后径)的相关性大于与BMI的相关性。采用胸廓径线作为降低射线剂量的参考标准更具有临床实用意义。Abstract: Objective To evaluate the correlation between image quality and thoracic diameters, anteroposterior diameter (AP) and right-left diameter(RL) for the optimization of reducing radiation dose in coronary artery imaging with Dual-source CT. Methods 118 patients underwent CT coronary artery imaging(CTCA)were divided into two groups (A and B) according to body mass index (BMI). There were 58 patients in group A with BMI values ≥ 25 kg/m2 and <30 kg/m2; and 60 patients in group B with BMI values <25 kg/m2. Scan parameters:collimation 64×0.6 mm, reconstruction slice thickness 0.75 mm, reconstructin interval 0.7 mm, FOV 150-180 mm, the pitch adjusted according to heart rate automatically. CT imagings were obtained with tube voltage 100 kV, tube current 330 mAs (group A) and 100 kV, tube current 220 mAs (group B). The contrast-noise ratio (CNR), signal to noise ratio (SNR),as well as blind correlation test score values were calculated to establish the relationship among BMI, AP, RL and CNR, SNR; Results RL of five levels in groups of A, B were correlated to CNRa (P<0.05). In group A and B (except iii, iv level of Group A), AP were associated with CNRa (P<0.05). In addition to ii, iv level of group A, v level of group B, BMI were associated with CNRa (P<0.05). The correlation coefficient of CNRa and RL of group A except ii level was greater than that of CNRa and AP. The correlation coefficient of CNRa, SNRa and RL of group B was greater than that of CNRa, SNRa and AP. Except iii level, the correlation coefficient of CNRa, SNRa and AP of group A was greater than that of CNRa, SNRa and BMI. Except ii level, the correlation coefficient of CNRa and AP of group B was greater than that of CNRa and Conclusion Thoracic diameter of RL can be used as a guider to select the appropriate scan protocol in the coronary imaging acqusition with dual-source CT.
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Keywords:
- Dual-source CT /
- Coronary artery imaging /
- Body mass index /
- Thoracic diameters
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[1] Raff GL, Gallagher MJ, O'neill WW, et al. Diagnostic accuracy of noninvasive coronary angiography using 64-slice spiral computed tomography. J Am Coll Cardiol,2005;46(3):552-557.
[2] Mccollough CH, Primak AN, Osama S, et al. Dose performance of a 64-channel dual-source CT scanner. Radiology,2007;243(3):775-784.
[3] Einstein AJ, Henzlova MJ, Rajagopalan S. Estimating risk of cancer associated with radiation exposure from 64-slice computed tomography coronary angiography. JAMA,2007;298(3):317-323.
[4] Brenner DJ, Hall EJ. Computed tomography——an increasing source of radiation exposure. N Engl J Med,2007;357(22):2277-2284.
[5] 高建华, 孙宪昶, 李剑颖等.后置滤过器C2对64排螺旋CT冠状动脉成像质量的影响. 中国医学影像技术,2007;23(1):73-76. [6] 高建华, 戴汝平, 郑静晨等. 应用后滤过重组降低64层螺旋CT心脏检查X线剂量的初步研究.中华放射学杂志,2007;41(18):1014-1018. [7] Snedecor GW, Cochran WG. Statistical Methods. New York:Iow a State University Press,1980:185-188.
[8] Cohen J, Cohen P. Applied multiple regression/correlation analysis for the behavioral sciences. Second Edition. Mahwah New Jersey:Lawrence Erlbaum Associates,1983:436-501.
[9] Jenny KH, Lynne MH, Daniel TB. Optimization of tube current in coronary multidetector computed tomography angiography:assessment of a standardized method to individualize current selection based on body habitus. J Comput Assist Tomogr,2009;33(4):498-504.
[10] Pflederer T, Rudofsky L, Ropers D, et al. Image quality in a low radiation exposure protocol for retrospectively ECG-gated coronary CT angiography. AJR Am J Roentgenol,2009;192(4):1045-1050.
[11] Lee EJ, Lee SK, Agid R, et al. Comparison of image quality and radiation dose between fixed tube current and combined automatic tube current modulation in craniocervical CT angiography. AJNR Am J Neuroradiol,2009;30(9):1754-1759.
[12] 王贵生, 高建华, 李剑颖等.64层螺旋CT心脏检查中体重指数与射线剂量关系的研究.医学影像学杂志,2008;18(5):473-477. [13] Reid J, Gamberoni J, Dong F, et al. Optimization of kVp and mAs for pediatric low-dose simulated abdominal CT:is it best to base parameter selection on object circumference? AJR Am J Roentgenol,2010;195(4):1015-1020.
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