Original Article

Examination of the distance measurement error and exposed dose when using a 320-row area detector CT: A comparison with videofl uoroscopic examination of swallowing

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

Contents (volume 2)