E1206. Gantry-Free High-Resolution Cone-Beam CT: A New Imaging Standard in Acute Elbow Trauma?
  1. Andreas Kunz; University Hospital Würzburg
  2. Jan-Peter Grunz; University Hospital Würzburg
This study aims to investigate the diagnostic accuracy of gantry-free cone-beam CT (CBCT) in a real-world population with acute elbow trauma.

Materials and Methods:
Patients with elbow trauma who underwent 3D elbow imaging with a twin robotic x-ray scanner were enrolled between January and December 2021. Radiography and CBCT reports were analyzed for fracture detection, articular affliction, and multi-fragment injuries. The combined results of additional MRI scans, surgical reports and clinical follow-up of at least four weeks served as reference standard. Diagnostic test accuracy was calculated per elbow joint and for each bone individually. Differences in diagnostic test accuracy between radiography and CBCT were compared with the McNemar test.

Elbow examinations of 49 individuals (mean age 48.8 years, 19 women) were included with individual assessment of 145 bones. Gantry-free CBCT provided a higher diagnostic accuracy than radiography in the detection of elbow joint fractures (95.9% versus 81.6%; p = 0.039) and fractures of individual bones of the elbow joint (93.1% versus 84.1%; p = 0.004). Diagnostic test accuracy of CBCT was also substantially higher for articular surface involvement (per joint: 93.9% versus 73.5%, p = 0.003; per bone: 96.6% versus 86.9%, p = 0.001) and multi-fragmentary fracture patterns (per joint: 93.9% versus 61.2%, p < 0.001; per bone: 94.5% versus 82.8%, p < 0.001). Median estimated effective dose was 11.5 µSv for CBCT and 0.4 µSv for conventional x-ray imaging.

In acute elbow injuries, gantry-free CBCT facilitates reliable detection and exclusion of fractures, articular affliction, and multi-fragmentary patterns with very low radiation exposure. Compared to conventional gantry-based CT scanners, the additional positioning options allow for low-dose examinations even in individuals with limited joint mobility.