Stability of voxel values from cone-beam computed tomography for dental use in evaluating bone mineral content.
OBJECTIVE
The objective of this study was to investigate the stability of voxel values from cone-beam CT (CBCT) using a flat panel detector in changing surrounding circumstances mimicking clinical situations.


METHODS
Seven hydroxyapatite (HA) rods (0, 40, 80, 120, 160, 199, and 239 mg Ca/cm(3) ) were set in a 16 cm diameter water phantom and scanned with CBCT (FineCube) and also with multislice CT (MSCT) used as reference. The voxel values from CBCT were measured by the obtained images with OsiriX software (http://www.osirix-viewer.com), and compared with the CT numbers from MSCT. We examined the correlation between the voxel values and the HA contents, the variance of voxel values, and the influence of changing surrounding circumstances on the voxel values.


RESULTS
The voxel values from CBCT were different from the CT numbers from MSCT, but there was a linear Pearson correlation between the voxel values and the HA contents. The voxel values were greatly influenced when the samples were scanned surrounded in air. However, the voxel values were not affected significantly in the existence of materials simulating oral hard tissues and/or a metal core post.


CONCLUSIONS
There was a linear correlation between the voxel values of CBCT and the contents of HA rod samples. Our study indicated that it might be possible to evaluate bone mineral content(BMC) from the voxel values of CBCT for dental implant treatment.
Oral and Maxillofacial Radiology, Tokyo Medical and Dental University, Tokyo, Japan.
Yoshikazu
Y
Nomura
Hiroshi
H
Watanabe
Kazuya
K
Shirotsu
Eiichi
E
Honda
Yasunori
Y
Sumi
Tohru
T
Kurabayshi
D015519:Bone Density; D054893:Cone-Beam Computed Tomography; D017886:Durapatite; D019047:Phantoms, Imaging; D012984:Software; D014963:X-Ray Intensifying Screens
D017886:Durapatite