Daisuke Kanamori, DDS, DMSc, Hitoshi Kagaya, MD, DMSc, Naoko Fujii, MD, DMSc, Yoko Inamoto, SLHT, MSc, Enri Nakayama, DDS, Shoichi Suzuki, RT, PhD, Hideki Mizutani, DDS, DMSc, Sumiko Okada, SLHT, PhD, Kazuhiro Katada, MD, DMSc, Eiichi Saitoh, MD, DMSc
Jpn J Compr Rehabil Sci 2: 18-23, 2011
Purpose: The purpose of this study was to compare
the distance measurement error and exposed dose in
320-row area detector computed tomography (320-
ADCT) and videofl uoroscopic examination of
swallowing (VF).
Method: We used markers of radiopacity attached to
adult skull specimens to measure the distances between
various sets of 2 points. In VF, we made the corrections
using the mentalis marker. In 320-ADCT, we used a
distance measurement tool. After obtaining the distance
measurements, we compared the errors from VF and
320-ADCT. We used a RANDO Phantom to calculate
the exposed dose by using thermoluminescence
dosimeter (TLD) elements.
Results: In the case of VF, the relative error associated
with the actual measured values was largest (12.9%)
in the area between the mentalis and the left mandibular
angle. In 320-ADCT, even the measurements with the
largest error had a relative error within 0.34%. In VF,
the dose absorbed through the skin on the incident side
was 4.8 to 12.1 times higher than the dose absorbed on
the opposite side, up to a maximum of 25.30 mGy; the
effective dose was 1.05 mSv. Using 320-ADCT, the
maximum dose absorbed through the skin was 47.07
mGy, and the effective dose was 1.65 mSv.
Conclusion: Compared with VF, the 320-ADCT
approach produces a smaller measurement error, and
observation is possible from a variety of directions.
However, because the exposed dose is greater, a
combination of both approaches should be skillfully
used to evaluate eating and swallowing functions.
Key words: Videofl uoroscopic examination of swallowing, 320-ADCT, distance measurement, exposed dose