Tehran University Medical Journal

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.

Background: Shortness of breath is a common disorder and means difficulty in breathing and shortness and shallow breathing that the patient feels unpleasant, difficulty and shallow breathing. The main purpose of this study was to analyze patients undergoing pulmonary angiography with a prognosis of pulmonary embolism in the emergency department.
Methods: This descriptive-analytical study was performed in the adult emergency department of Shahid Mostafa Hospital in Ilam in March2018-March2020 after receiving permission from the ethics committee. This study evaluated patients over 18 years of age who underwent CTPA with a pre-diagnosis of PE.
Results: The highest frequency was reported in CT findings of 31.9% normal, 27.6% PE. In our study based on CT results, 30.2% of patients suffered from PE. The highest frequency was reported in CT findings of 31.9% normal, 27.6% PE. In the present study, 65.5% of patients presented with shortness of breath, of which CT results showed 28.9% (PE), 38.2% (Non PE) and 98% (Normal). Other complaints of patients with shortness of breath were reported with CP (7.8%), lower edema (6%), respiratory distress (8.6%), CP and fever (5.2%) and hemotypy (1.7%).
Conclusion: Based on the above study, we conclude that the criterion for selecting patients for CT angiography to rule out PTE is the most important criterion for clinical examination and the Welsh Criteria score. As we can see, the results showed that patients with a Wales score above 8-12 had 80% PTE and patients with a Wales score of 3-6 had 23.5% PTE and the rest had a negative answer, so the Wells criteria were good criteria which unfortunately Due to some conditions, the diagnosis of a general practitioner or carelessness in examinations are not taken into account and causes a large percentage of patients with complaints of shortness of breath to undergo CT angiography while not having the necessary criteria based on Wells scores and clinical examination. CT angiography is either normal or another condition that does not require CT angiography and radiation.