Emergency (****); * (*): *-* This open-access article distributed under the terms of the Creative Commons Attribution Noncommercial 3.0 License (CC BY-NC 3.0). Copyright © 2015 Shahid Beheshti University of Medical Sciences. All rights reserved. Downloaded from: www.jemerg.com 114 Emergency (2015); 3 (3): 114-116 BRIEF REPORT Diagnostic Accuracy of Chest x-Ray and Ultrasonography in Detection of Community Acquired Pneumonia; a Brief Report Ali Taghizadieh1, Alireza Ala2, Farzad Rahmani3*, Akbar Nadi4 1. Tuberculosis and Lung Disease Research Center, Tabriz University of Medical Sciences, Tabriz, Iran. 2. Emergency Medicine Department, Tabriz University of Medical Sciences, Tabriz, Iran. 3. Road Traffic Injury Research Center, Tabriz University of Medical Sciences, Tabriz, Iran 4. Students’ Research Committee, Tabriz University of Medical Sciences, Tabriz, Iran *Corresponding Author: Farzad Rahmani; Emergency Medicine Department, Imam Reza hospital, Tabriz University of Medical Sciences, 5166614756, Ta- briz, Iran. Tel:+984113352078; Fax: +984113352078; Email: rahmanif@tbzmed.ac.ir Received: November 2014; Accepted: January 2015 Abstract Introduction: Chest x-ray (CXR) is the simplest diagnostic tool of Community Acquired Pneumonia (CAP), but it has some limitation. Therefore, the aim of this study is comparing the diagnostic accuracy of CXR and chest ultra- sonography (CUS) in detection of CAP. Methods: In the present study, a consecutive sample of suspected patients with CAP was underwent CUS, CXR, and chest computed tomography (CT) scan. Diagnostic accuracy of CUS and CXR was assessed by calculating the sensitivity, specificity, predictive values, and likelihood ratios using SPSS 20 statistical software. Results: 30 patients with CAP were enrolled (93.3% male with mean age of 63.8 ± 18.3 years). Sensitivity of CUS and CXR in detection of CAP were 100.0% (95% Cl: 85.4-100.0) and 93.1% (95% Cl: 75.8-98.8), respectively. Specificity of CXR was 0.0 (95% Cl: 0.0-94.5), while the CUS specificity was not calculable. Conclusion: Findings of the present study demonstrated on the higher diagnostic accuracy of CUS versus CXR in detection of pneumonia. Key words: Pneumonia; ultrasonography; emergency department; radiography, thoracic; tomography, x-ray computed Cite this article as: Taghizadieh A, Ala A, Rahmani F, Nadi A. Diagnostic accuracy of chest x-ray and ultrasonography in detection of community acquired pneumonia; a brief report. Emergency. 2015;3(3):114-16 Introduction: ommunity acquired pneumonia (CAP) is one of the main concerns of health services which only causes to 1.7 million cases of hospitalization annu- ally in the United States (1, 2). It is one of the most com- mon infectious diseases and important causes of mortal- ity and morbidity in worldwide (3). Streptococcus pneu- monia, Hemophilic influenza, and Moraxella catarrhalis are typical bacterial pathogens in approximately 85% of CAP cases (4). The presentation of CAP includes fever, cough, and pleuritic chest pain. Beside the physical ex- amination, chest x-ray (CXR), as the simplest diagnostic tool, is suggested to exclude conditions mimic CAP (1). However, CXR findings may be negative in patients if CAP presents at early stages of the disease. Moreover, noticing to high costs and the need for more irradiation, the routine usage of computed tomography (CT) Scan in diagnosis of pneumonia in emergency departments is not recommended (5). Ultrasonography (CUS) has been recently applied in detection of pulmonary diseases such as pulmonary edema, pulmonary embolisms, pericardial and pleural effusion, and pneumothorax (6, 7). However, only few data have been published to show its efficiency in detecting pneumonia. Therefore, the aim of this study was evaluating diagnostic accuracy of CXR and CUS in findings of pneumonia. Methods: Study design and setting The present study was conducted to evaluate diagnostic accuracy of CUS and CXR in detection of pneumonia. It was performed in the emergency department (ED) of Imam Reza Medical Research and Training Hospital, Ta- briz, East Azerbaijan, Iran, through February to April 2014. The local Ethical Committee of Tabriz University of Medical Sciences approved the protocol of the study and written consent was obtained from all patients after describing the aims and methods of the study. The con- secutive samples of suspected CAP patients were under- went CUS, CXR, and CT scan. Presence of fever, cough, pleuritic pain, sputum production, and dyspnea were considered as signs and symptoms of CAP (8). Patients with asthma, acute coronary syndrome, septic shock, C This open-access article distributed under the terms of the Creative Commons Attribution Noncommercial 3.0 License (CC BY-NC 3.0). Copyright © 2015 Shahid Beheshti University of Medical Sciences. All rights reserved. Downloaded from: www.jemerg.com 115 Emergency (2015); 3 (3): 114-116 pulmonary embolism, chronic obstructive pulmonary disease (COPD), cardiac and pleural disorders were ex- cluded. After clinical examinations, Patients with clinical suspicion of CAP underwent CXR, CUS, and chest CT scan. Clinical examinations and CUS were done with bedside machine available in the ED (GH Healthcare; LOGIQ 200, PRO series; Korea) with a convex 3.5-MHz transducer by a trained emergency medicine specialist. Then, patient referred to radiology unit to perform CXR and chest CT scan (as a gold standard) with Toshiba Asteion 16 slices scanner with considering one-millimeter distance be- tween image slices. The radiography and CT scan find- ings were interpreted by a radiologist blinded to clinical examinations. Data was analyzed using SPSS 20 soft- ware. Diagnostic accuracy of CUS and CXR were assessed by calculating the sensitivity, specificity, positive and negative predictive values, and positive and negative likelihood ratios. Results: We studied imaging findings of 30 patients with clinical suspicion of community-acquired pneumonia (93.3% male, mean age 63.8±18.3 years). CT scan findings showed 29 (96.7%) cases of pneumonia, while CUS re- vealed the diagnosis of pneumonia for all 30 cases (1 case of false positive). CXR also showed 28 (93.3%) pneumonia cases (2 false negative and 1 false positive) (Table1). The sensitivity of CUS in pneumonia detection was calculated 100.0% (95% CI: 85.4-100.0), but its specificity was not calculable because of being positive of all subjects. However, sensitivity and specificity of CXR in pneumonia detection were 93.1% (95% CI: 75.8- 98.8) and 0.0% (95% CI: 0.0-94.5), respectively. Based on CT scan findings, finally 13 (43.3%) cases had evi- dence of pleural effusion. CUS detected 12 (40%) sub- jects (1 false negative), while CXR could only detect 8 (26.7%) patients (4 false positive and 4 false negative). Sensitivity and specificity of CUS in detection of pleural effusion were 92.3% (95% CI: 62.1-99.6) and 100.0% (95% CI: 77.1-100.0), respectively. Sensitivity and spec- ificity of CXR were also 66.7% (95% CI: 35.4-88.7) and 77.8% (95% CI: 51.9-92.6), respectively (Table 1). Discussion: Findings of the present study demonstrated that diag- nostic accuracy of CUS in detection of pneumonia and plural effusion were higher than CXR. Several studies stated that CUS is a simple, fast, and effective diagnostic tool for detection of pulmonary diseases. For example, in a study done by Mathis and colleagues, authors recom- mended that ultrasonography is the simplest and most sensitive imaging tool for measurement of pleural fluid (9). Bsrilleni and colleagues concluded that ultrasonog- raphy is a useful and reliable method in diagnosing the pulmonary diseases (10). In another study conducted by Lichtenstein et al., it was stated that CUS is a fast and cost effective method in detecting pulmonary diseases, with- out radiation exposure (11). Neesse and colleagues eval- uated the results of CXR in pulmonary diseases and con- cluded that ultrasonography is a rapid tool in detecting the pulmonary diseases, leads to accurate diagnosis in 68% of cases (12). These findings are along with Ad- vanced Trauma Life Support (ATLS), represented that ul- trasonography can be used in detection of abdominal free fluid, organ trauma, and pneumothorax. However, it should be considered that ultrasonography is highly op- erator dependent. One of the most important solving is the exact and long-term training of ED specialists regard- ing performing and interpreting of ultrasonography finding. The small sample size was the limitation of this study and consequently specificity of CUS was not calculable. In addition, the small sample size caused that no true negative case was seen by CXR; therefore, the power of Table 1: Diagnostic accuracy of chest ultrasonography and radiography in detection of pneumonia and plural effusion (95% confidence interval) Diagnostic test Pneumonia Plural effusion Ultrasonography Sensitivity 100.0 (85.4-100.0) 92.3 (62.1-99.6) Specificity NaN 100.0 (77.1-100.0) Positive predictive value 100.0 (85.4-100.0) 100.0 (70.0-100.0) Negative predictive value 0.0 (0.0-14.5) 94.4 (70.6-99.7) Positive likelihood ratio NaN NaN Negative likelihood ratio NaN 0.08 (0.01-0.5) Radiography Sensitivity 93.1 (75.8-98.8) 66.7 (35.4-88.7) Specificity 0.0 (0.0-94.5) 77.8 (51.9-92.6) Positive predictive value 96.4 (79.8-99.8) 66.7 (35.4-88.7) Negative predictive value 0.0 (0.0-80.2) 77.8 (51.9-92.6) Positive likelihood ratio 0.93 (0.84-1.03) 3.0 (1.2-7.8) Negative likelihood ratio NaN 0.4 (0.2-1.0) This open-access article distributed under the terms of the Creative Commons Attribution Noncommercial 3.0 License (CC BY-NC 3.0). Copyright © 2015 Shahid Beheshti University of Medical Sciences. All rights reserved. Downloaded from: www.jemerg.com Taghizadieh et al 116 calculated specificity of CXR was week. The CUS operator was not blind to the clinical presentation of patients, while the radiologist did not aware from the clinical presentation of patients and less diagnostic accuracy of CXR might be derived from that. Conclusion: Finding of the present study demonstrates that diagnos- tic accuracy of CUS in detection of pneumonia and plural effusion were higher than CXR. Acknowledgments: The authors are grateful to all the health personnel, data collectors, supervisors, administrative staff of the Emer- gency Department of Imam Reza Hospital, and patients participated in the study. This article was written based on a dataset of medical doctor thesis, registered in Tabriz University of Medical Sciences. Conflict of interest: None Funding support: None Authors’ contributions: All authors have read and approved the manuscript .Ali Taghizadieh, Alireza Ala, and Akbar Nadi performed the data collection, literature review, and drafting of the manuscript. Farzad Rahmani undertook the major parts of the study design and performed the statistical analy- sis. References: 1. Spellberg B. Community-acquired pneumonia. N Engl J Med. 2014;370(19):1861-2. 2. File Jr TM. Streptococcus pneumoniae and community- acquired pneumonia: A cause for concern. Am J Med Supp. 2004;117(3):39-50. 3. Solomon CG, Wunderink RG, Waterer GW. Community- Acquired Pneumonia. N Engl J Med. 2014;370(6):543-51. 4. Ellis A, Kinasewitz G, Matousek S. Morbidity And Mortality Of Severe Sepsis Patients With Community Acquired Vs. Health Care Associated Pneumonia. Am J Respir Crit Care Med. 2014;189:A3130. 5. Llinares P, Menéndez R, Mujal A, Navas E, Barberán J. 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