Background: Since pulmonary angiography is the only non-invasive method for diagnosing pulmonary embolism, the use of radiation reduction methods without affecting the quality of images seems necessary. One of the simplest reasons for unnecessarily increasing of patient exposure is repetitive imaging due to poor image quality. Therefore, it is necessary to identify and eliminate the factors that reduce the image quality, which leads to duplication of imaging or reduced accuracy. In this study, the reasons for decreasing the image quality of pulmonary computed tomography (CT) angiography were investigated.
Methods: This cross-sectional study was performed over a period of 6 months (May to November 2018) in a university-affiliated hospital. Data of 75 patients suspected of pulmonary embolism who were referred for CT angiography were collected. All CT scans were performed by a 16-slice CT scanner (Lights Speed, GE Healthcare) with fixed imaging parameters including 100 kVp and 100 mA. In order to evaluate the adequacy of pulmonary artery enhancement, the Hounsfield unit (HU) of the main pulmonary artery was measured in the aortic arch, upper, and lower segmental parts. Also, 8 factors affecting the image quality were examined.
