The Effectiveness of Full Body EOS Compared to Conventional Chest X-ray in Preoperative Evaluation of the Chest for Patients Undergoing Spine Operations: A Preliminary Study.

Study Design. A prospective radiographic comparative study. Objective. The aim of this study was to compare full-body EOS with conventional chest X-ray (CXR) for use in the preoperative evaluation of the chest in patients undergoing spine operations. Summary of Background Data. The full-body EOS reproduces an image of the chest similar to a routine CXR. The potential for the former replacing the latter is plausible. This is especially applicable in spine patients who would routinely have a preoperative full-body EOS performed. Methods. A radiographic comparative study of 266 patients was conducted at a single tertiary center from January 2013 to July 2016. Each patient had EOS and CXR done in random order <2 weeks apart. Two radiologists reported the image findings using a checklist. A third radiologist was consulted in cases of discrepancy. Interobserver agreement was calculated using Gwet AC1 and a comparison between EOS and CXR findings was analyzed using paired Chi-squared test. Multivariate analysis was performed to identify predictors for abnormal radiological findings. The institutional ethics committee approved this prospective study and waiver of informed consent was obtained. Results. There were 84 males (31.6%) and 182 females (68.4%). The mean age was 38.9 years (SD = 25.0 years). High interobserver agreement was found for EOS and CXR (Gwet AC1 0.993 and 0.988, respectively). There were no significant differences between both imaging modalities. Rare diagnoses precluded comparison of certain conditions. Age > 18 years [odds ratio (OR) 7.69; P = 0.009] and American Society of Anesthesiologists physical status 3 (OR 6.64; P = 0.018) were independent predictors of abnormal radiological findings. Conclusion. EOS is not inferior to, and may be used to replace CXR in preoperative radiological screening of thoracic conditions especially in low-risk patients <= 18 years old and patients with ASA <3. Preoperative assessment should never rely on a single modality. High-risk patients should be sent for a thorough work-up before spine surgery.