Suboptimal patient positioning with panoramic and CBCT imaging: effects on dose

Jonathan Colin LaPrade; K Brandon Johnson; Angela M Broome; Marija Ivanovic; André Mol; John B Ludlow

doi:10.1016/j.oooo.2024.11.079

Suboptimal patient positioning with panoramic and CBCT imaging: effects on dose

Oral Surg Oral Med Oral Pathol Oral Radiol. 2024 Nov 17:S2212-4403(24)00892-7. doi: 10.1016/j.oooo.2024.11.079. Online ahead of print.

Authors

Jonathan Colin LaPrade¹, K Brandon Johnson², Angela M Broome², Marija Ivanovic³, André Mol², John B Ludlow²

Affiliations

¹ Department of Oral and Maxillofacial Radiology, UNC Adams School of Dentistry, University of North Carolina - Chapel Hill, Chapel Hill, North Carolina. Electronic address: cl8127@nyu.edu.
² Department of Oral and Maxillofacial Radiology, UNC Adams School of Dentistry, University of North Carolina - Chapel Hill, Chapel Hill, North Carolina.
³ Department of Radiology, UNC School of Medicine, University of North Carolina - Chapel Hill, Chapel Hill, North Carolina.

PMID: 39757069
DOI: 10.1016/j.oooo.2024.11.079

Abstract

Objective: This study examined the effects of changes in patient positioning on radiation exposure for panoramic and cone beam computed tomography (CBCT) radiographic examinations by measuring effective dose (E) and equivalent doses.

Study design: Simulated radiographic examinations with optimal and suboptimal positioning-anterior shift by 1 centimeter (cm), posterior shift by 1 cm, chin lowered by 10 degrees (°), chin elevated by 10°, rotation by 10°, and lateral shift by 1 cm-were conducted using a tissue-equivalent phantom and optically-stimulated luminescent dosimeters. Exposures were made with the RAYSCAN Alpha Plus 160 X-ray unit using the following exposure parameters: panoramic, 80 kVp, 14 mA, and 13.9s; CBCT (10 x 10 cm FOV), 90 kVp, 10 mA, and 14.0s; CBCT (16 x 10 cm FOV), 90 kVp, 11 mA, and 14.0 s.

Results: All suboptimal panoramic conditions except rotation demonstrated significant decreases in E. Chin elevation during CBCT imaging reduced E with the 10 × 10 cm FOV (P = .0003) and 16 × 10 cm FOV (P < .0001), as well as the equivalent dose to the thyroid gland (P < .0001 for both FOVs).

Conclusions: Suboptimal positioning did not significantly increase E for either panoramic or CBCT exposures. Chin elevation decreased E in the CBCT protocols, with notable decreases in equivalent dose to the thyroid gland.