Department of Dentistry and Oral Health

TY - JOUR

T1 - Influence of head positioning during cone-beam CT imaging on the accuracy of virtual 3d models

AU - van Eijnatten, Maureen

AU - Wolff, Jan

AU - Pauwels, Ruben

AU - Karhu, Kalle

AU - Hietanen, Ari

AU - der Sarkissian, Henry

AU - Koivisto, Juha H

PY - 2022/9

Y1 - 2022/9

N2 - OBJECTIVE: Cone beam computed tomography (CBCT) images are being increasingly used to acquire three-dimensional (3D) models of the skull for additive manufacturing purposes. However, the accuracy of such models remains a challenge, especially in the orbital area. The aim of this study is to assess the impact of four different CBCT imaging positions on the accuracy of the resulting 3D models in the orbital area. METHODS: An anthropomorphic head phantom was manufactured by submerging a dry human skull in silicon to mimic the soft tissue attenuation and scattering properties of the human head. The phantom was scanned on a ProMax 3D MAX CBCT scanner using 90 and 120 kV for four different field of view positions: standard; elevated; backwards tilted; and forward tilted. All CBCT images were subsequently converted into 3D models and geometrically compared with a "gold-standard" optical scan of the dry skull. RESULTS: Mean absolute deviations of the 3D models ranged between 0.15 ± 0.11 mm and 0.56 ± 0.28 mm. The elevated imaging position in combination with 120 kV tube voltage resulted in an improved representation of the orbital walls in the resulting 3D model without compromising the accuracy. CONCLUSIONS: Head positioning during CBCT imaging can influence the accuracy of the resulting 3D model. The accuracy of such models may be improved by positioning the region of interest (e.g. the orbital area) in the focal plane (Figure 2a) of the CBCT X-ray beam.

AB - OBJECTIVE: Cone beam computed tomography (CBCT) images are being increasingly used to acquire three-dimensional (3D) models of the skull for additive manufacturing purposes. However, the accuracy of such models remains a challenge, especially in the orbital area. The aim of this study is to assess the impact of four different CBCT imaging positions on the accuracy of the resulting 3D models in the orbital area. METHODS: An anthropomorphic head phantom was manufactured by submerging a dry human skull in silicon to mimic the soft tissue attenuation and scattering properties of the human head. The phantom was scanned on a ProMax 3D MAX CBCT scanner using 90 and 120 kV for four different field of view positions: standard; elevated; backwards tilted; and forward tilted. All CBCT images were subsequently converted into 3D models and geometrically compared with a "gold-standard" optical scan of the dry skull. RESULTS: Mean absolute deviations of the 3D models ranged between 0.15 ± 0.11 mm and 0.56 ± 0.28 mm. The elevated imaging position in combination with 120 kV tube voltage resulted in an improved representation of the orbital walls in the resulting 3D model without compromising the accuracy. CONCLUSIONS: Head positioning during CBCT imaging can influence the accuracy of the resulting 3D model. The accuracy of such models may be improved by positioning the region of interest (e.g. the orbital area) in the focal plane (Figure 2a) of the CBCT X-ray beam.

KW - Cone-Beam Computed Tomography

KW - Dimensional Measurement Accuracy

KW - Orbit

KW - Printing

KW - Three-Dimensional

KW - Head/diagnostic imaging

KW - Skull/diagnostic imaging

KW - Imaging, Three-Dimensional/methods

KW - Humans

KW - Silicon

KW - Phantoms, Imaging

KW - Cone-Beam Computed Tomography/methods

U2 - 10.1259/dmfr.20220104

DO - 10.1259/dmfr.20220104

M3 - Journal article

C2 - 35766951

VL - 51

JO - Dentomaxillofacial Radiology

JF - Dentomaxillofacial Radiology

SN - 0250-832X

IS - 7

M1 - 20220104

ER -