The Role of Spiral CT Pulmonary Angiography in the Diagnosis of Postoperative Complications in Patients with Acute Pulmonary Embolism

Abstract

The purpose is to explore the effect of iterative model reconstruction (IMR) algorithm on improving quality of spiral computed tomography angiography (SCTA) image and its clinical application in the diagnosis of acute pulmonary embolism (PE) complications. 88 patients with acute PE who visited Chongqing Zhongxian People’s Hospital hospital from October 2017 to October 2019 were selected as the study objects, and their CT values, standard deviation (SD) value of background noise, CT volume dose index, and dose length product of pulmonary artery trunk and the erector spines of the spinal column were measured by spiral CT scanning at the tube voltage of 80 kv and 100 kv, respectively. As for image reconstruction, IMR, IDose4 algorithm in hybrid iterative reconstruction (HIR) and Filtering back-projection (FBP) were utilized. By comparing signal-noise ratio (SNR), contrast-noise ratio (CNR) and figure of merit (FOM), the image quality, radiation dose, sensitivity and specificity of different reconstruction algorithms in diagnosis of acute PE were analyzed. The results showed that the background noise of the IMR reconstruction algorithm was lower than that of IDose4 and FBP, and the difference was statistically significant (P < 0.05). The CT value of IMR reconstruction algorithm was significantly higher than that of IDose4 and FBP reconstruction algorithm, and the difference was not statistically significant (P > 0.05). The SNR and CNR of IMR were significantly higher than those of IDose4 and FBP, and the difference was statistically significant (P < 0.05). The FOM values of IMR were significantly higher than those of IDose4 and FBP, and the differences were statistically significant (P < 0.05). CT volume dose index, dose length product, and effective dose of the 80 kv tube voltage group were all lower than that of the 100 kv tube voltage group, accounting for 49.34%, 50.50%, and 52.53% of the 100 kv tube voltage group. And the FOM of 80 kv tube voltage group was higher than that of 100 kv tube voltage group. The sensitivity and specificity of IMR reconstructed images in diagnosis of acute PE complications were higher than those of reconstructed images of IDose4 and FBP, which were 97.67% and 92.0%, respectively. Therefore, the improved SCTA information technology based on the IMR algorithm has better image quality than the IDose4 and FBP reconstruction algorithms, and the image quality index of low-dose scan (80 kv) of the improved SCTA information technology based on the IMR algorithm is higher than that of normal-dose scan (100 kv).