ABSTRACT
Ojective To investigate the clinical application value of low dose contrast agent in computerized tomography pulmonary angiography (CTPA) with spectral CT imaging.Methods Totally 52 patients suspected with pulmonary embolism underwent multi-slice spiral CT pulmonary angiography,and were randomly divided into a control group (n =27) and a research group (n=25).The research group used spectral CT with 35 ml of contrast medium and the control group used 64-slice CT with conventional 80 to 90 ml of contrast medium.The CT values of the pulmonary trunk,left pulmonary artery (LPA),right pulmonary artery (RPA),pulmonary vein and ascending aorta were measured.The contrast to noise ratio (CNR) of the pulmonary artery was also calculated.In addition,the image quality of CTPA was evaluated independently by two experienced radiologists.Results The CT values (HU) of the pulmonary trunk,left pulmonary artery(LPA),right pulmonary artery (RPA) in the research group were (432.2±63.4),(373.5±48.8),(381.4±53.6) and (62.5-±6.4),respectively,and significantly higher than those in the control group,showing statistical differences (P＜0.05).The evaluation results of the CTPA images by two radiologists showed that the image quality in the research group was better than that in the control group (P＜0.05).Conclusion The image quality of pulmonary angiography with spectral CT using low contrast medium dose can be improved compared with the conventional spiral CT.