Significance of backboard artifacts on portable trauma series chest radiographs

Purpose: To evaluate the degree to which the artifacts created by the radio-opaque components of a backboard obscure the findings on the initial trauma series chest radiograph (BBCXR). Methods: We reviewed 40 consecutive trauma victims admitted to our level I trauma center over a 3-month period who underwent a follow-up portable supine chest radiograph (PCXR) off the backboard no longer than 1 h after the initial trauma BBCXR. The original interpretation of the BBCXR was compared to the reading of the PCXR as well as to a retrospective analysis of the BBCXR performed by two radiologists blinded as to the findings on the original report. Results: The initial interpretation of the BBCXR failed to identify abnormalities reported in the follow-up PCXR of 10 individuals (25 %), most frequently bone fractures, misplaced hardware, and pleural effusions. Of these missed abnormalities, 80 % were identified retrospectively. Conversely, the initial reading of the BBCXR described a widened mediastinum in five cases, right upper lobe opacities in two, and cardiomegaly in one. Of these eight reported findings, only five (63 %) – the cardiomegaly and four of the mediastinal abnormalities – were also reported upon retrospective analysis, while the PCXR taken with the patient off the backboard confirmed widened mediastinum in only three cases. Conclusions: The initial, often hurried reading of a portable chest radiograph taken on a backboard as part of a trauma series often misses significant pathology, most of which can be detected upon more thorough examination of the original film. The backboard also tends to magnify mediastinal structures more than routine PCXR. Therefore, we advocate a more cautious analysis of the original BBCXR and routine utilization of a follow-up PCXR to confirm mediastinal abnormalities.