Jae Yong Cho MD, Presenter: Nothing to Disclose

Joo Sung Sun MD, Abstract Co-Author: Nothing to Disclose

Sung Jung Kim, Abstract Co-Author: Nothing to Disclose

Kyu-Sung Kwack MD, PhD, Abstract Co-Author: Nothing to Disclose

Sung Hoon Park MD, Abstract Co-Author: Nothing to Disclose

Kyung Joo Park MD, Abstract Co-Author: Nothing to Disclose

Young Gi Min MD, Abstract Co-Author: Nothing to Disclose

To evaluate the feasibility of low dose chest CT (LDCT) for initial evaluation of blunt chest trauma.

A total of 71 patients who met criteria indicative of major trauma (76% male; age range, 16-85) were included. All patients underwent LDCT without IV contrast and standard CT with IV contrast using parameters as followings: LDCT, 40mAs with ATCM and 100kVp or 120kVp (based on BMI); standard post-contrast CT, 180mAs with ATCM and 120kVp. Transverse, coronal, saggital images were reconstructed with 3-mm slice thickness without gap. Reference standard images were reconstructed using standard CT data (1-mm slice thickness without gap). Reference standard was established by 2 radiologist by consensus. Four readers independently evaluated chest injury (fractures of bony thoracic cage, aortic injury, tracheobonchial injury, esophageal injury, hemothorax, pneumothorax, pulmonary contusion). Four investigators recorded results with 4 confidence scale (0-3 point). Comparison of radiation dose was done.

Radiation doses (CTDIvol) of LDCT (average 2.67mGy) was significantly lower than those of standard CT (average 13.4mGy)(78% dose reduction). ROC analysis and intraclass correlation coefficient ICC measurement demonstrated that LDCT was comparable to standard dose CT for evaluation of chest injury. ROC comparison analysis revealed no significant difference of diagnostic performance between LDCT and standard dose CT for the diagnosis of bony thoracic cage fracture, pulmonary contusion, hemothorax ,pneumothorax, chest wall injury (p>0.05). ICC was measured for inter-observer consistency and revealed that there was good inter-observer consistency in each examination of LDCT and standard dose CT for evaluation of chest injury (0.83~0.94). Aortic injury could not be appropriately compared due to LDCT underwent without using contrast materials and this was limitation of this study.

Our conclusion is that there is a great potential benefit to use LDCT for initial evaluation of blunt chest trauma because LDCT could maintain diagnostic image quality as standard dose MDCT and provide significant radiation dose reduction. Further study of LDCT with IV contrast for evaluation of aortic injury is needed.

This preliminary study suggest LDCT could be adequate initial imaging modality for blunt chest trauma patients with maintaining diagnostic image quality and reducing radiation dose.

Cho, J, Sun, J, Kim, S, Kwack, K, Park, S, Park, K, Min, Y, Feasibility Study of Low Dose Chest CT for Initial Evaluation of Blunt Chest Trauma Patients.  Radiological Society of North America 2013 Scientific Assembly and Annual Meeting, December 1 - December 6, 2013 ,Chicago IL. http://archive.rsna.org/2013/13020797.html