เรายังต้องการการตรวจเอกซเรย์คอมพิวเตอร์อย่างเป็นประจำเพื่อใช้ ในการประเมินขั้นต้นในผู้ป่วยที่ได้รับบาดเจ็บทรวงอกจากการกระแทกโดยของแข็งไม่มีคม ที่มีประจันอกที่กว้างขึ้นจากภาพถ่ายรังสีทรวงอกอยู่หรือไม่

Abstract

Purpose: To evaluate the sensitivity, specificity and validity of the initial chest radiographs with mediastinal widening for predicting acute traumatic aortic injury (ATAI) in blunt traumatic chest patients and to assess the optimal mediastinal width for suggesting the ATAI in Thai population. Materials and methods: From January 2008 to July 2014, the initial antero-posterior chest radiographs of 358 patients with blunt chest trauma were retrospectively reviewed by two blinded reviewers. The mediastinal width at the aortic knob level was measured in each initial chest film to evaluate mediastinal widening. The presences of other chest radiographic features suggesting diagnosis of ATAI, including irregular aortic knob contour, aortopulmonary window opacification, indistinct shadow of the descending thoracic aorta, rightward displacement of the esophagus or trachea, depression of the left mainstem bronchus, left apical cap, left hemothorax and upper ribs or scapular fractures were also recorded.CTA thoracic aorta was the reference investigation in this study for detecting ATAI. Sensitivity, specificity, positive and negative productive values, accuracy and positive and negative likelihood ratios of each finding were calculated. Results: Among the 323 chest radiographs with widening mediastinum (greater than 8 cm at the aortic knob level), 27 (8.36%) had ATAI and 296 (91.64%) had no ATAI. Sensitivity for mediastinal widening for predicting ATAI was 93.1%; specificity, 10.03%; positive predictive value, 8.36%; negative predictive value, 94.29%; accuracy, 51.57%. The positive likelihood ratio for the presence of aortic injury was 1.03, and the negative likelihood ratio was 0.69. The most appropriate mediastinal width for suggestive of ATAI in our study was 10.7 cm. Conclusion: Widened mediastinum from initial antero-posterior supine chest radiograph alone is neither diagnostic of ATAI nor mediastinal hematoma due to very low specificity and accuracy. Clinical correlation and mechanism of injury should be included to avoid the unnecessary further thoracic CTA. Mediastinal width 10.7 cm favors the optimal upper limit for suggesting the ATAI.