OBJECTIVES: The aim of this study was to assess artefacts and their impact on cone beam CT (CBCT) image quality (IQ) after head motion simulated by a robot skull. METHODS: A fully dentate human skull incorporated into a robot simulated pre-determined patient movements. Ten head motion patterns were selected based on the movement of the C-arm of the CBCT units (no motion as reference). Three CBCT units were used [a three-dimensional eXam (K) (KaVo Dental GmbH, Biberach, Germany), a Promax 3D MAX (P) (Planmeca Oy, Helsinki, Finland) and a Scanora(®) 3D (S) (Soredex Oy, Tuusula, Finland)]. Axial images were qualitatively assessed at three levels: mental foramen (MF), infraorbital foramen and supraorbital foramen, and artefacts characterized as stripe-like, double contours, unsharpness or ring-like. A 100 mm visual analogue scale (VAS) was used to quantitatively assess IQ. Cross-sectional images of the lower third molar and MF bilaterally were also evaluated by VAS. Four blinded examiners assessed the images. RESULTS: For all units and motion patterns, stripe-like artefacts were the most common. The four observers agreed on the presence of at least one artefact type in 90% of the images. Axial images showed lower overall IQ after motion (VAS = 72.4 ± 24.0 mm) than reference images (VAS = 97.3 ± 2.6 mm). The most severe artefacts were seen at the MF level. For cross-sectional images, IQ was lowest after tremor. The mean IQ range was 74-89 and 57-90 for isolated (tilting, rotation and nodding) and combined (nodding + tilting and rotation + tilting) movements, respectively. IQ for MF was lower than for third molar for any movement except tremor. CONCLUSIONS: Head motion of any type resulted in artefacts in CBCT images. The impact on IQ depended on the region and level in the skull.
OBJECTIVES: The aim of this study was to assess artefacts and their impact on cone beam CT (CBCT) image quality (IQ) after head motion simulated by a robot skull. METHODS: A fully dentate human skull incorporated into a robot simulated pre-determined patient movements. Ten head motion patterns were selected based on the movement of the C-arm of the CBCT units (no motion as reference). Three CBCT units were used [a three-dimensional eXam (K) (KaVo Dental GmbH, Biberach, Germany), a Promax 3D MAX (P) (Planmeca Oy, Helsinki, Finland) and a Scanora(®) 3D (S) (Soredex Oy, Tuusula, Finland)]. Axial images were qualitatively assessed at three levels: mental foramen (MF), infraorbital foramen and supraorbital foramen, and artefacts characterized as stripe-like, double contours, unsharpness or ring-like. A 100 mm visual analogue scale (VAS) was used to quantitatively assess IQ. Cross-sectional images of the lower third molar and MF bilaterally were also evaluated by VAS. Four blinded examiners assessed the images. RESULTS: For all units and motion patterns, stripe-like artefacts were the most common. The four observers agreed on the presence of at least one artefact type in 90% of the images. Axial images showed lower overall IQ after motion (VAS = 72.4 ± 24.0 mm) than reference images (VAS = 97.3 ± 2.6 mm). The most severe artefacts were seen at the MF level. For cross-sectional images, IQ was lowest after tremor. The mean IQ range was 74-89 and 57-90 for isolated (tilting, rotation and nodding) and combined (nodding + tilting and rotation + tilting) movements, respectively. IQ for MF was lower than for third molar for any movement except tremor. CONCLUSIONS: Head motion of any type resulted in artefacts in CBCT images. The impact on IQ depended on the region and level in the skull.
Authors: Laurence Gaalaas; Donald Tyndall; André Mol; Eric T Everett; Ananta Bangdiwala Journal: Dentomaxillofac Radiol Date: 2015-12-16 Impact factor: 2.419
Authors: Rubens Spin-Neto; Louise H Matzen; Lars Schropp; Erik Gotfredsen; Ann Wenzel Journal: Dentomaxillofac Radiol Date: 2016-02-26 Impact factor: 2.419
Authors: Rubens Spin-Neto; Louise H Matzen; Lars W Schropp; Thomas S Sørensen; Ann Wenzel Journal: Dentomaxillofac Radiol Date: 2018-03-22 Impact factor: 2.419
Authors: R Pauwels; L Seynaeve; J C G Henriques; C de Oliveira-Santos; P C Souza; F H Westphalen; I R F Rubira-Bullen; R F Ribeiro-Rotta; M I B Rockenbach; F Haiter-Neto; P Pittayapat; H Bosmans; R Bogaerts; R Jacobs Journal: Dentomaxillofac Radiol Date: 2015-06-19 Impact factor: 2.419