Keywords:
Emergency, Musculoskeletal spine, CT, MR, Technical aspects, Trauma
Authors:
G. Harisis, H. Kavnoudias, A. Zia, E. Paul, P. Marovic; Melbourne, VIC/AU
DOI:
10.26044/ranzcr2021/R-0272
Results
1. Demographics and mechanism of injury
- Over the 5 year period, 1035 patients fulfilled the study critery and were included in the analysis
- Patient population had an average age of 45.5 years, the majority of whom were males (58.9%)
- Predominant mechanism of injury was motor vehicle accident (30.5%)
- Summary of demographic data (Figure 2)
- Summary of mechanism of injury (Figure 3)
2. Subjective anterior disc space widening is a poor predictor of ALL injury
3. ALL injury and mechanism of injury
- Mechanism of injury was dichotomised into high and low impact (Figure 9)
- Sensitivity of CT-ADW for ALL injury remained low when assessed on the subset of patients with low and high impact mechanisms (Figure 10)
3. Limitations
- Low incidence of isolated ALL injury
- As a result, the 95% confidence interval for sensitivities of CT-ADW is relatively wide.
- Furthermore, care needs to be taken when interpreting sensitivity, specificity as well as positive and negative predictive values of subjective CT-ADW as these measures have been shown to vary with disease prevalence7.
- Influence of verification bias
- MRI was not performed for every patient who underwent a trauma CT cervical spine that was reported as normal.
- Interobserver variability
- Subjective CT-ADW was recoreded from the radiology reports of CTs reported by a wide variety of radiologists/radiology registrars with varying subspecialty and training experience.
- While all MRIs were reported (or consultant approved) by radiologists with MRI or neuro/MSK subspecialty training, CTs were reported (or consultant approved) by either subspecialty trained or general radiologists.
- Given inherently subjective nature of CT-ADW, it may be that more experienced radiologists would have a higher threshold for reporting these signs on CT.