Browsing by Author "Chen, Chia-Hui"

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Estimated radiation risk of cancer from dental cone-beam computed tomography imaging in orthodontics patients
(2018-08-03)
Yeh, Jih-Kuei
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Chen, Chia-Hui
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光電學院
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College of Photonics
Background: Radiation dose evaluation is important to cone-beam computed tomography (CBCT) for routine orthodontic treatment planning, especially for a significant proportion of children in orthodontic patients. This study evaluated the patient radiation dose and estimated the radiation cancer risk on dental CBCT according to the calculations by the Monte Carlo simulation method. Methods: The dental CBCT scanner evaluated in this project was the i- CAT (R) (Imaging Sciences International Inc., PA, U.S.A.) device. Organ doses and effective doses were calculated by using personal computer-based Monte Carlo simulation (PCXMC 2.0 Rotation) software. The cancer risk resulting from the exposure to ionizing radiation was estimated by using the BEIR VII (Biologic Effects of Ionizing Radiation VII) report model, and the risk of exposure-induced death (REID) was assessed by PCXMC 2.0 Rotation software. Results: The largest contribution to the organ dose and effective dose at Zref 83 cm positioned in the dental CBCT x-ray beam centerline was from the salivary glands (738.29 mu Gy, 7.38 mu Sv). The different organ doses showed the maximum values at the different Zref locations, and the largest contribution to the organ dose and effective dose of all simulated positions was from the thyroid (928.77 mu Gy, 37.5 mu Sv). The REID values in the 10-year olds (22.6 x 10(-7), female; 19 x 10(-7), male) were approximately double than those in 30-year olds (10.4 x 10(-7), female; 8.88 x 10(-7), male) for all cancers. The highest change during age range from 10 to 30 was shown in breast cancer of females. Conclusions: Although individual cancer risk estimates as a function of gender and age are small, the concern about the risks from dental CBCT is related to the rapid increase in its use for orthodontic practice, especially in children patients.
Magnetic Resonance Elastography in the Assessment of Acute Effects of Kinesio Taping on Lumbar Paraspinal Muscles
(2019-04-01)
Wang, Chien-Kuo
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Fang, Yu-Hua Dean
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Lin, Liang-Ching
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Lin, Cheng-Feng
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Kuo, Li-Chieh
Background Kinesio tape (KT) is an elastic therapeutic tape used for treating sports-related injuries and a number of other disorders. To date, the objective evidence to link pathophysiological effects and actual reactions triggered by KT is limited. Purpose To explore the effect of KT on the lumbar paraspinal muscles by magnetic resonance (MR) elastography. Study Type Prospective observational study. Population Sixty-six asymptomatic volunteers with 31 women and 35 men. Field Strength/Sequence 3.0T MRI and elastography with vibration frequency of 120 Hz. Assessment The 5-cm-width KT with full tension was placed on a single side of the lumbar paraspinal muscle. The taping side and adhering direction were randomly decided. Two rectangular regions of interest (ROIs) of 5- and 2.5-cm-width were positioned at the bilateral paraspinal regions from the L2 to L4 level on the confidence map of MR elastography before and after KT taping. The mean shear stiffness values of the ROIs at the superficial, middle, and deep depths were recorded; then the differences between the taping and reference sides were calculated. Statistical Tests Paired t-test and Pearson correlations were used to evaluate the stiffness changes after KT application and intraoperator errors of the stiffness measures on the reference side, respectively. Results A significant decrease in the muscle stiffness value between taping and reference sides (-0.71 kPa +/- 0.60 with KT and -0.25 kPa +/- 0.78 without KT, P < 0.0001 for 5-cm ROI; -0.67 kPa +/- 1.12 with KT and -0.16 kPa +/- 1.17 without KT, P = 0.0004 for 2.5-cm ROI) was found in the superficial depth, but no significant differences in the middle and deep depths (P = 0.25 and P = 0.79 for 5-cm ROI; P = 0.09 and P = 0.67 for 2.5-cm ROI, respectively). There were no significant differences of muscle stiffness differences between gender (P = 0.11 for superficial, P = 0.37 for middle, P = 0.78 for deep) and taping direction (P = 0.18 for superficial, P = 0.13 for middle, P = 0.15 for deep). Data Conclusion Our results demonstrate that KT can reduce the MR elastography-derived shear stiffness in the superficial depth of paraspinal muscles.