Impact of introducing extremity cone-beam CT in an emergency radiology department: a population-based study

Abstract Background: Musculoskeletal cone-beam CT (CBCT) recently appeared on the market, with image quality comparable to that of high-resolution CT. It was previously implemented mainly in craniofacial surgery and in orthopedic limb surgery for weight-bearing imaging, but without large-scale assessment in emergency settings. We therefore conducted a retrospective comparative study in an emergency radiology department: 1) to assess whether introduction of CBCT dedicated to extremity traumatology reduced radiation dose delivered to the patient undergoing cross-sectional imaging, 2) to assess whether it increased turnover, and 3) to study the feasibility and practical consequences. Study hypothesis: Introducing CBCT dedicated to traumatology in an emergency radiology department reduces radiation dose related to cross-sectional imaging in extremity trauma. Patients and methods: Two periods were distinguished: in May-November 2016, the only cross-sectional imaging available in our emergency radiology department was multi-detector CT (MDCT); in May-November 2017, both MDCT and CBCT were available. Thus, the population in period 1 (n=165) had undergone only MDCT extremity imaging, while patients in period 2 underwent either CBCT (n=139) or MDCT (n=85). Study parameters notably included dose-length product (DLP) and length of patient stay in the radiology department (turnover). Results: Mean DLP was significantly reduced with the introduction of CBCT: 210.3 ± 133.6 mGy.cm (range, 20-595) in period 1, versus 138.4 ± 92.7 mGy.cm (range, 32-623) in period 2 (p Turnover accelerated with the introduction of CBCT, with mean stay of 84.9 minutes in period 1 versus 72.1 minutes in period 2 (p=0.011). In period 2, turnover was 23.6% faster with CBCT than MDCT: respectively, 64.9 minutes versus 85.0 minutes (p=0.0004). Discussion: Introducing CBCT dedicated to the extremities in an emergency radiology department was feasible. It reduced overall radiation dose and accelerated turnover. Level of Evidence: III; comparative case-control study.