en رادیولوژی دهان، فک و صورت Oral and Maxillofacial Radiology پژوهشي Research <p> <strong>Objectives:</strong> 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. </p><p> <strong>Methods:</strong> 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. </p><p> <strong>Results:</strong> 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. </p><p> <strong>Conclusions</strong>: Head motion of any type resulted in artefacts in CBCT images. The impact on IQ depended on the region and level in the skull. </p><hr><p></p><p> <strong>Source: </strong>DentoMaxilloFacial Radiology </p><p> <a href="http://dmfr.birjournals.org/content/42/2/32310645.abstract" target="_blank"><font color="#0000ff">Full Text</font></a></p> cone beam computed tomography, artefacts, image quality 0 0 http://idai.ir/browse.php?a_code=A-10-32-1353&slc_lang=en&sid=1 R Spin-Neto rsn@odont.au.dk 10031947532846006039 10031947532846006039 Yes Oral Radiology, Department of Dentistry, Aarhus University, Aarhus, Denmark J Mudrak 10031947532846006040 10031947532846006040 No Oral Surgery, Gemeinschaftspraxis für Zahnheilkunde, Gelnhausen, Germany LH Matzen 10031947532846006041 10031947532846006041 No Oral Radiology, Department of Dentistry, Aarhus University, Aarhus, Denmark J Christensen 10031947532846006042 10031947532846006042 No Oral Radiology, Department of Dentistry, Aarhus University, Aarhus, Denmark E Gotfredsen 10031947532846006043 10031947532846006043 No Oral Radiology, Department of Dentistry, Aarhus University, Aarhus, Denmark A Wenzel 10031947532846006044 10031947532846006044 No Oral Radiology, Department of Dentistry, Aarhus University, Aarhus, Denmark