MDCT in emergency radiology: is a standardized chest or abdominal protocol sufficient for evaluation of thoracic and lumbar spine trauma?

Abstract

The objective of our study was to assess the diagnostic performance of a standardized 4-MDCT trauma protocol for the evaluation of the thoracic and lumbar spine in patients with multiple injuries. Eighty-two patients with multiple injuries underwent MDCT for the chest and abdomen using a standardized 4-MDCT trauma protocol (collimation, 4 x 2.5 mm). Secondary reconstructions targeted to the spine were performed (slice width, 3 mm; reconstruction interval, 1.5 mm). All spinal fractures were additionally scanned using a collimation of 4 x 1 mm, and these images served as the standard of reference for fracture classification. An additional 50 patients with no spinal fracture served as the control group. A total of 65 major spinal fractures were present in 55 of the patients with multiple injuries. Two observers (observer 1 and observer 2) independently evaluated all CT data for spinal fractures using a 5-point confidence scale, classified the different fracture types, and rated the image quality of spinal structures on axial images and multiplanar reformations. Image quality for axial images was excellent in 80% and in 68% using 4 x 1 mm and 4 x 2.5 mm collimation, respectively. Image quality of the multiplanar reformations was excellent in 75% and good in 65% using 4 x 1 mm and 4 x 2.5 mm collimation, respectively. Spinal fractures were detected by observer 1 and observer 2 with a sensitivity and specificity of 98% and 97% and of 97% and 97%, respectively. Interobserver agreement regarding the confidence scale for fracture detection was substantial (kappa = 0.80), and agreement between the different imaging protocols for fracture classification was excellent for observer 1 (kappa = 0.95) and observer 2 (kappa = 0.97). Accurate evaluation of the thoracolumbar spine is possible with targeted image reconstruction based on a standardized 4-MDCT trauma protocol of the chest and abdomen.