Development of clinical diagnostic reference levels (DRLs) is an important means to guide protocols that use as-low-as-diagnostically-acceptable (ALADA) doses.
Based on pre-clinical ALADA reference quality studies a CTDIvol of 3mGy was suggested as a new clinical diagnostic reference level (DRL) for computed tomography (CT) of maxillofacial trauma, which is substantially lower than current DRLs in sinus imaging of CTDIvol 8 mGy [1-3]. Purpose was to prove the new DRL in clinical reality.
Description of activity and work performed
From a clinical database of 413 inpatients from 04.01.2015 to 28.08.2017, 88 patients fulfilled the inclusion criteria of a surgically treated fracture in the midface with preoperative CT examination and postoperative cone beam CT imaging.
All images were independently evaluated by two readers and classified using the AO Comprehensive Injury Automatic Classifier (AOCOIAC, Version 4.0) of the AO foundation (see Fig. 1).
After completion, the preoperative diagnoses were checked with the intraoperative report and postoperative cone beam CT.
Conclusion and recommendations
All fractures could be correctly identified independently from the applied dose: CTDIvol > 9 mGy (n=51) (Fig. 2), CTDIvol 4-9 mGy (n=19) (Fig. 3), and CTDIvol 2.64 mGy (n=20) (Fig. 4).
The evaluation of both examiners showed a comparable result with only minimal non-clinically relevant sub-classification differences due to minor interpretational differences.
This study shows that a CTDIvol of 3mGy may be implemented as a new clinical DRL in maxillofacial trauma. Preclinical ALADA reference quality studies are useful for the development of clinical DRLs.
G. Widmann; Innsbruck/AT - nothing to disclose M. Dangl; Innsbruck/AT - nothing to disclose L. Lutz; Innsbruck/AT - nothing to disclose V. Offermanns; Innsbruck/AT - nothing to disclose W. Puelacher; Innsbruck/AT - nothing to disclose W. Jaschke; Innsbruck/AT - nothing to disclose
 Widmann G, Schullian P, Gassner EM, Hoermann R, Bale R, Puelacher W. Ultralow-dose CT of the craniofacial bone for navigated surgery using adaptive statistical iterative reconstruction and model-based iterative reconstruction: 2D and 3D image quality. Ajr. 2015 Mar;204(3):563-9.
 Widmann G, Dalla Torre D, Hoermann R, Schullian P, Gassner EM, Bale R, et al. Ultralow-dose computed tomography imaging for surgery of midfacial and orbital fractures using ASIR and MBIR. Int J Oral Maxillofac Surg. 2015 Apr;44(4):441-6.
 Widmann G, Juranek D, Waldenberger F, Schullian...