Archives of Academic Emergency Medicine. 2019; 7 (1): e60 BR I E F RE P O RT Incidental Findings of Computed Tomography Angiogra- phy in Patients Suspected to Pulmonary Embolism; a Brief Report Mustafa Korkut1, Cihan Bedel1∗, Kürsat Erman2, Serkan Yüksel3 1. Department of Emergency Medicine, Health Science University, Antalya Training and Research Hospital, Antalya, Turkey. 2. Department of Radiology, Akdeniz University Faculty of Medicine, Antalya, Turkey. 3. Department of Radiology, Health Science University, Antalya Training and Research Hospital, Antalya, Turkey. Received: August 2019; Accepted: September 2019; Published online: 22 October 2019 Abstract: Introduction: Computed tomography pulmonary angiography (CTPA) scans are increasingly used in emergency department (ED). Therefore, the observation of incidental findings (IFs) has also increased. This study aimed to evaluate the frequency of IFs in patients who underwent CTPA. Methods: All consecutive patients that un- derwent CTPA scanning for pulmonary embolism (PE) rule out between January 2017 and June 2018 were anal- ysed. Incidental findings were divided into and reported in three categories: group 1 potentially life-threatening, group 2 required follow up, and group 3 with limited clinical significance. Results: 151 cases with the mean age of 61.2 ± 17.6 years were studied (54.3% female). PE was documented in 77 cases (50.9%). 448 IFs were de- tected (3 IFs were found per patient). 60 (13.3%) IFs were classified as group 1, 180 (40.1%) as group 2, and 208 (46.6%) as group 3. Cardiomegaly was the most frequent finding in group 1 (n=32), followed by aortic aneurysm (n=13). In group 2, pleural effusion (n=58) and pneumonia (n=36) were the most frequent incidental findings. Lung structure changes (n=92) and thoracic bone related findings (n=43) were the most common IFs observed in group 3. Conclusion: IFs were detected in the majority of patients that underwent CTPA. Most of these find- ings do not require follow-up or treatment. However, more than 50% of cases may require further diagnostic evaluation (40.1%) or immediate treatment (13.3%). Keywords: Pulmonary embolism; tomography; incidental findings; emergencies Cite this article as: Korkut M, Bedel C, Erman K, Yüksel S. Incidental Findings of Computed Tomography Angiography in Patients Suspected to Pulmonary Embolism; a Brief Report. Arch acad Emerg Med. 2019; 7(1): e60. 1. Introduction Pulmonary embolism (PE) is a challenging diagnosis in emergency department (ED) characterized by high morbid- ity and mortality (1). Early diagnosis and treatment can re- duce the mortality rate of this disease (2). The symptoms and clinical signs of PE are non-specific and many thoracic pathologies such as pneumonia and aortic dissection cause similar symptoms (3, 4). Computed tomography pulmonary angiography (CTPA) scanning is increasingly used as a diag- nostic technique in PE patients. The disadvantages of CTPA ∗Corresponding Author: Cihan Bedel; Health Science University, Antalya Training And Research Hospital, Kazim Karabekir Street, Muratpasa, Antalya, Turkey. postal zip code: 07100, Tel: +905075641254, Fax: +902422494487, Email: cihanbedel@hotmail.com are radiation exposure, contrast induced nephropathy, and cost (5). The main advantage of this imaging concept is being quick and providing information on all thoracic structures including lung parenchyma (6). Another point of interest is the observation of incidental findings (IFs) on PE scanning. These findings can be irrelevant to the clinical scenario and might necessitate further investigations and treatment (7). Based on the above-mentioned points, the aim of this study was to evaluate the frequency of IFs in patients who under- went CTPA scanning for PE rule out. 2. Methods 2.1. Study design and setting This retrospective cross-sectional study was performed on patients who underwent CTPA in ED of Health Science University Antalya Training and Research Hospital, Antalya, This open-access article distributed under the terms of the Creative Commons Attribution NonCommercial 3.0 License (CC BY-NC 3.0). Downloaded from: http://journals.sbmu.ac.ir/aaem M. Korkut et al. 2 Turkey, between January 1, 2017 and June 30, 2018. The study protocol was approved by ethics committee of the hospital (Ethics code: 2019-235). 2.2. Participants The study population consisted of all patients for whom a CTPA was ordered in the ED evaluation. The CTPA images of the patients included in the study were interpreted by two radiologist. CTPAs obtained in other hospitals, were not in- cluded if the images were not retrievable on the workstation to be submitted for interpretation. 2.3. Data gathering The patients’ data were accessed via the automation system of the hospital and admission files. The CTPA was read as positive for PE if filling defects were noted in the pulmonary arterial tree. If the scan yielded a positive result for thrombo- sis, intravenous localization was also recorded. If there were any IFs, they were observed as well. A negative scan result was also registered. All patients were examined using ECLOS 16-section computed tomography scanner (Hitachi Medical Systems, Tokyo, Japan) in the ED. The CTPA images were ob- tained from the Picture Archival Computer System (PACS). IFs were classified into three categories (major, moderate, and minor) by Lumbreras et al. depending on severity (8). As in literature, in our study IFs were classified into three groups, too. Group 1 included major or potentially life- threatening findings such as abdominal aortic aneurysm and a new-found malignancy. Group 2 included moderate find- ings that could require diagnostic follow-up and group 3 in- cluded minor findings with limited clinical significance like anatomic variants. 2.4. Statistical analysis Descriptive statistical analysis of all variables was performed using SPSS 18.0. Mean ± standard deviation for continuous variables and number (%) of non parametric data were cal- culated and reported. 3. Results: 151 cases with the mean age of 61.2 ± 17.6 years were stud- ied (54.3% female). PE was documented in 77 cases (50.9%). Thrombus was detected in main pulmonary arteries in 27 (16.7%) patients, segmental arteries in 62 (38.5%), and sub- segmental arteries in 72 (44.7%) cases. 448 IFs were detected (3 IFs were found per patient). 60 (13.3%) IFs were classified as group 1, 180 (40.1%) as group 2, and 208 (46.6%) as group 3 (table 1). Cardiomegaly was the most frequent finding in group 1 (n=32), followed by aortic aneurysm (n=13) and ma- lignancies such as adrenal tumor. In group 2, pleural effusion (n=58) and pneumonia (n=36) were the most frequent inci- Table 1: Incidental findings in cases suspected to pulmonary em- bolism who underwent computed tomography angiogarpgy Incidental findings Number (%) Group1 (n = 60) Bronchial cancer 3 (5.0) Aortic aneurysm 13 (21.7) Liver metastasis 5 (8.3) Adrenal tumour 1 (1.7) Pulmonary mass 2 (3.3) Mediastinal mass 4 (6.7) Cardiomegaly 32 (53.3) Group 2 (n = 180) Pulmonary nodules 21 (11.7) Pleural effusion 58 (32.2) Cholecystolithiasis 4 (2.2) Pneumonia 36 (20) Thyroid nodule 13 (7.2) Pancreatitis 1 (0.6) Pericardial effusion 6 (3.3) Significant atelectasis 17 (9.4) Hiatal hernia 8 (4.4) Ascites 2 (1.1) Ileus 1 (0.6) Pulmonary artery enlargement 10 (5.6) Atrophic kidney 1 (0.6) Bochdalek hernia 2 (1.1) Group 3 (n = 208) Renal cyst 23 (11.1) Hepatic cyst 4 (1.9) Lung structure changes 92 (44.2) Splenomegaly 3 (1.4) Adenopathy 10 (4.8) Coronary artery calcification 31(14.9) Bone finding 43 (20.7) Hemangioma 1 (0.5) Atrophic kidney 1 (0.5) Data are presented as mean ± standard deviation or number (%). There is missing data in some variables. GCS: Glasgow coma scale. dental findings. Lung structure changes (n=92) and thoracic bone-related findings (n=43) were the most common ones observed in group 3. Figure 1 shows examples of some de- tected IFs. 4. Discussion The present study showed that CTPA detected IFs in the ma- jority of patients. Most of these findings do not require fur- ther evaluation or treatment. However, some may require follow-up and immediate treatment. In this study, 13.3% of detected IFs required emergent evaluation and 40.1% were in need for further diagnostic evaluation. CTPA has become the imaging test of choice in many institu- tions for diagnosis of PE because of high interobserver agree- ment, detection of other pathologies and cost-effectiveness This open-access article distributed under the terms of the Creative Commons Attribution NonCommercial 3.0 License (CC BY-NC 3.0). Downloaded from: http://journals.sbmu.ac.ir/aaem 3 Archives of Academic Emergency Medicine. 2019; 7 (1): e60 Figure 1: Examples of incidental finding among cases that underwent computed tomography angiography. (9). When we compare other imaging modalities, such as ventilation / perfusion scintigraphy, with CTPA, one of the most important advantages of CTPA is allowing us to per- form pulmonary vascular examination as well as parenchy- mal, mediastinal, cardiac, pleural structures, thoracic wall, and upper abdominal organ evaluations (9, 10). Another in- teresting point is the incidence of IFs in many patients, even though embolism is detected in approximately 1 in 5 with this imaging method. Although most of these are benign, age-related changes, there may be findings that may require immediate treatment and follow-up. In this study, the preva- lence of PE in CTPA was 51%. In previous studies this rate ranged from 19% to 79% (11). In this study, IFs were very common (about 3 findings for each patient). But more im- portantly, almost half of the patients had findings that re- quired follow-up. Approximately 13.3% of the studied cases had findings re- quiring immediate treatment; mostly pleural effusion (n=58). This frequency is consistent with a previous study on a sim- ilar population (12). Frequency of patients with group 1 cat- egory IFs varied between 15% to 24% in previous studies (13, 14). Hall et al. evaluated 589 patients and found a greater fre- queny of IFs in need of emergent evaluation compared to our study. However, their high rate is due to inclusion of patients with major or potentially life-threatening findings and those with moderate findings that required diagnostic follow-up in the same category. The prevalence rate of pneumonia requiring follow-up has been reported to be 7.1% in CTPAs in one study (14). In our case, the prevalence was (approximately 8%); however, it is significantly lower than that observed by Hall et al. (13). The prevalence of lung nodules requiring follow-up was reported to be 25% in those undergoing CTPA (13). In our study, this prevalence was significantly lower. This can be partly due to the number of sections and image quality. Since the number of CTPA slices in our study was low, incidental findings such as lung nodules could be expected to be less. We also observed a high rate of minor findings with no need for further examination. This trend was also observed in other studies examining the prevalence of incidental findings in CTPAs (13, 15). Turkvatan et al. reported a 56.2% incidence for clinically insignificant findings in 242 cohorts of patients screened with 16-line CT (16). However, Perelas et al. re- ported 48.1% minor findings with no need for further exami- nation, without classifing them by severity, in a cohort of 641 patients also scanned using a 16-slice CT (14). More impor- tantly, relatively old studies reported innocent findings with diagnostic value for alternative diagnosis (9, 17). We believe that this ratio will increase with increase in image quality. It seems that, emergency physicians should be aware of these important IFs, and EDs should also develop mechanisms to ensure appropriate follow-up for these patients. 5. Limitation The study was conducted in a single center and in a retro- spective manner and these results may not apply to differ- ent patient populations. Lack of patient follow-up is one of our most important limitations. In some cases although the findings may appear to be characteristic tomography find- ings, the final histopathological diagnosis may be different. This may have caused overreporting of some findings, such as malignancy. 6. Conclusion The present study showed that CTPA detected IFs in the majority of patients. Most of these findings do not require follow-up or treatment. However, some may require follow- up and immediate treatment. In our study, 13.3% of IFs re- quired emergent evaluation and 40.1% were in need for fur- ther evaluation according to their symptoms. 7. Appendix 7.1. Acknowledgements The author would like to thank MD. Asli BEDEL for helping in preparation of this paper. This open-access article distributed under the terms of the Creative Commons Attribution NonCommercial 3.0 License (CC BY-NC 3.0). Downloaded from: http://journals.sbmu.ac.ir/aaem M. Korkut et al. 4 7.2. Author contribution All the authors have a substantial contribution in the study design, data interpretation and writing and reviewing the manuscript. Authors ORCIDs Mustafa Korkut: 0000-0003-1665-1601 Cihan Bedel: 0000-0002-3823-2929 7.3. 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This open-access article distributed under the terms of the Creative Commons Attribution NonCommercial 3.0 License (CC BY-NC 3.0). Downloaded from: http://journals.sbmu.ac.ir/aaem Introduction Methods Results: Discussion Limitation Conclusion Appendix References