Image artifact in dental cone-beam CT.
OBJECTIVE
The purpose of this study was to investigate the appearance and possible cause of an artifact seen in limited-volume cone-beam CT imaging.


METHODS
A water-filled plastic cylinder was used as a phantom of the head. A test object was constructed as a bone-equivalent phantom to be imaged. The test object was variously positioned at the center of the phantom and near its margins. CT images of the test object were acquired using a 3DX Accuitomo system.


RESULTS
In slice images with the test object positioned near the margin of the phantom, arch-shaped defects or deformities were observed on the side of the object. There was a negative correlation between the artifact and the CT value of the object. The artifact was larger in images scanned with a higher voltage.


CONCLUSIONS
The probability that this artifact is caused by halation from the image intensifier (II) system is suggested.
Katsumata
Akitoshi
A
Department of Oral Radiology, Asahi University School of Dentistry, Gifu, Japan. kawamata@dent.asahi-u.ac.jp
Hirukawa
Akiko
A
Noujeim
Marcel
M
Okumura
Shinji
S
Naitoh
Munetaka
M
Fujishita
Masami
M
Ariji
Eiichiro
E
Langlais
Robert P
RP
D016477:Artifacts; D006801:Humans; D019047:Phantoms, Imaging; D011861:Radiography, Dental / Q000379:methods; D036542:Tomography, Spiral Computed; D014963:X-Ray Intensifying Screens