Available online 19 September 2018
Summary
Purpose
Three-dimensional
(3D) radiological imaging plays an important role in surgical planning
used in modern dentistry. The aim of this study was to optimize imaging
parameters with a special focus on voxel size and scan time.
Material and Methods
A
virtual 3D master model of a macerated human skull was generated using
an industrial optical noncontact white light scanner. The skull was
X-rayed with cone-beam computed tomography that was applied using
different settings for voxel size and acquisition time (voxel edge
length of 0.3 mm, scan times 4.8 s and 8.9 s; voxel edge length of 0.2
mm, scan times 14.7 s and 26.9 s). The scan was repeated 10 times at
each setting. The CBCT scans were converted into 3D virtual models
(actual value), which were superimposed with the 3D master model
(reference value) to detect absolute differences.
Results
The
mean value of deviation increased with increasing voxel size and
decreasing scan time. For a voxel edge length of 0.3 mm, the mean values
of deviation were 0.33 mm and 0.22 mm with scan times of 4.8 s and 8.9
s, respectively. For a voxel edge length of 0.2 mm, the mean deviations
were 0.16 mm and 0.14 mm with scan times of 14.7 s and 26.9 s,
respectively.
Conclusions
When
using small voxel sizes, the scan time does not have a significant
impact on image accuracy and therefore the scan time can be shortened.
However, for larger voxel sizes, shorter scan times can lead to
increased inaccuracy.
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