Influence of scan mode (partial/full rotations) and FOV size in the formation of artefacts in cone beam CT.

Autor: Costa EDD; 1 Department of Oral Diagnosis, Area of Oral Radiology, Piracicaba Dental School, University of Campinas , Piracicaba, São Paulo , Brazil., Queiroz PM; 1 Department of Oral Diagnosis, Area of Oral Radiology, Piracicaba Dental School, University of Campinas , Piracicaba, São Paulo , Brazil., Santaella GM; 1 Department of Oral Diagnosis, Area of Oral Radiology, Piracicaba Dental School, University of Campinas , Piracicaba, São Paulo , Brazil., Capelozza ALA; 2 Department of Stomatology, Area of Oral Radiology, Bauru Dental School, University of São Paulo , Bauru, São Paulo , Brazil., Ambrosano GMB; 1 Department of Oral Diagnosis, Area of Oral Radiology, Piracicaba Dental School, University of Campinas , Piracicaba, São Paulo , Brazil., Freitas DQ; 1 Department of Oral Diagnosis, Area of Oral Radiology, Piracicaba Dental School, University of Campinas , Piracicaba, São Paulo , Brazil.
Jazyk: angličtina
Zdroj: Dento maxillo facial radiology [Dentomaxillofac Radiol] 2019 May; Vol. 48 (4), pp. 20180340. Date of Electronic Publication: 2019 Jan 11.
DOI: 10.1259/dmfr.20180340
Abstrakt: Objective: To evaluate the influence of rotation degree and field of view (FOV) size on the amount of artefacts produced in cone beam CT (CBCT) images.
Methods: A cylindrical wax utility phantom, with a metallic sample in its interior, was scanned with two FOV sizes (100 x 100 and 40 x 40 mm) and in full (360°) and partial (~180°) rotations. After the acquisitions, images were objectively assessed in the ImageJ software, obtaining the standard deviation in areas around the metal sample. The influence of artefacts produced by the several FOVs and rotation degrees was compared by two-way analysis of variance (α = 0.05).
Results: The images obtained with a large FOV presented a higher amount of noise compared to a restricted FOV, both for partial ( p = 0.0037) and full ( p = 0.0023) rotation degrees. For images obtained with a restricted FOV, full rotation resulted in images with less noise ( p = 0.0259). For images obtained with large FOV, there was no statistically significant difference ( p = 0.1494) in noise for both rotation protocols.
Conclusions: As there were no significant differences in the amount of artefacts in rotation protocols for large FOVs, the partial rotation can be indicated due to its lower exposure to radiation. For acquiring images with restricted FOVs, the full rotation is recommended.
Databáze: MEDLINE
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