确定成人腹部CT图像质量客观评价测量的最佳层面区域的比较性研究

Determine the Optimal Region to Measure and Evaluate Image Quality in Adult Abdominal CT Objectively

目的确定成人腹部CT图像质量客观评价测量时的最佳层面区域。方法对144例受检者的个体化因素进行测量,选择与图像质量相关性高的个体化参数作为评价图像质量的基础水平。分别选择腹部常规CT检查图像的肝顶、第一肝门、肾门、肾下极4个层面的腹主动脉区以及第一肝门层面出现的其他代表性的6个测量区(门静脉、肝实质周边、肝实质中心、脾、竖脊肌、前腹壁皮下脂肪)进行图像噪声测量。比较在相关性较高的个体化参数作为基础水平下所有测量区的噪声值与图像质量间的相关性系数,从而最终确定成人腹部常规CT检查图像的客观评价测量的最佳区域。结果在固定管电流扫描模式下,以腹平均径为基础水平,4个层面腹主动脉区测量的噪声值与图像质量的相关性系数R为0.522~0.765,第一肝门层面相关性最高。以相关性较高的个体化因素为不同的基础水平,第一肝门层面的肝实质周边测量区的噪声值与图像质量相关性最高(R 0.74~0.802),腹主动脉次之(R 0.712~0.765)。前腹壁皮下脂肪与图像质量的相关性最差(R=0.412,P>0.05)。结论第一肝门层面的腹主动脉区是成人腹部常规CT检查图像质量客观评价测量的最佳区域,其噪声测量值在一定程度上可指标腹部常规CT扫描的客观图像质量。

Objective To determine the optimal region to measure and evaluate image quality in adult abdominal CT objectively. Me,otis The individualized factors in one hun- dred and forty-four patients were measured, and a individual parameter of high relationships with image quality was selected as the basal level of the evaluation of image quality. The image noise was measured respectively at ten re^ions in the abdomen conventional CT images： the abdominal aortic of four levels （the liver top, the first hepatic portal, the renal hilum and the kidney pole）,and six areas in the first hepatic portal level （the aorta the portal vein, the periph- eral and the central hepatic portions, the spleen, the erector spinae, the anterior abdominal wall subcutaneous fat）. The correlative coefficients between the noise value and the image qualiv,, of the measured region were compared at the base level of individualized factors of higher relationships, which ultimately determined the optimal area of the objective evaluation of the adult abdonfinal CT images. Resu/tThe correlative coefficien~ between the noise value and the image quality of the abdominal aortic re~,ions of four levels was 0.522 ~ 0.765 at the base level of the average diameter of abdomen in the constant tube current tube mode, and the first hepatic portal level showed ~reat est relationship. The correlative coefficients between the noise value and the image quality of the peripheral hepatic portions in the first hepatic portal level,the abdominal aortic, and the anterior abdominal wall subcutaneous fat were 0.74 ~ 0. 802, 0.712 ~ 0.765, and 0.412 （P〉0.05） at the base level of individualized factors of higher relationships respectively. CondusiorJ The abdonfinal aortic re,on in the first hepatic portal level was the optimal region to measure and evaluate image quality in adult abdominal CT obiectively,and its noise value can be a indicator of objective image quality in the abdominal routine CT scanning.