• The Journal of the Korea Contents Association
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• v.12 no.10
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• pp.340-348
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• 2012

To evaluate the usefulness of tomosynthesis in the chest area, simple radiograph, low-dose CT, and tomosynthesis examinations were performed, and their absorbed doses were compared, and finally the images were evaluated. The absorbed dose recorded with the simple Radiograph examination was $0.33{\pm}0.27$ mGy, that of low-dose CT $1.26{\pm}0.56$ mGy, and that of tomosynthesis $0.55{\pm}0.02$ mGy, which indicate significance differences in absorbed doses among the examinations(p<0.001). Based on the evaluations of the images, The simple radiograph scores were $1.66{\pm}0.72$, $1.61{\pm}0.63$, and $1.57{\pm}0.73$, respectively; low-dose CT scores were $2.92{\pm}0.26$, $2.91{\pm}0.29$, and $2.88{\pm}0.32$, respectively; and tomosynthesis scores were $2.69{\pm}0.51$, $2.76{\pm}0.43$, and $2.66{\pm}0.61$, respectively. That is, there were statistically significant differences among the examinations(p<0.001), although there was no significant difference between low-dose CT and tomosynthesis examinations. Therefore, tomosynthesis is judged to be a useful examination that can minimize radiation doses to patients during chest examinations and enhance diagnostic efficacy.

• Imaging Science in Dentistry
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• v.50 no.2
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• pp.161-168
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• 2020

Purpose: The aim of this study was to evaluate the influence of voxel size and different post-processing algorithms on the analysis of dental materials using micro-computed tomography (micro-CT). Materials and Methods: Root-end cavities were prepared in extracted maxillary premolars, filled with mineral trioxide aggregate (MTA), Biodentine, and Intermediate Restorative Material (IRM), and scanned using micro-CT. The volume and porosity of materials were evaluated and compared using voxel sizes of 5, 10, and 20 ㎛, as well as different software tools(post-processing algorithms). The CTAn or MeVisLab/Materialise 3-matic software package was used to perform volume and morphological analyses, and the CTAn or MeVisLab/Amira software was used to evaluate porosity. Data were analyzed using 1-way ANOVA and the Tukey test(P<0.05). Results: Using MeVisLab/Materialise 3-matic, a consistent tendency was observed for volume to increase at larger voxel sizes. CTAn showed higher volumes for MTA and IRM at 20 ㎛. Using CTAn, porosity values decreased as voxel size increased, with statistically significant differences for all materials. MeVisLab/Amira showed a difference for MTA and IRM at 5 ㎛, and for Biodentine at 20 ㎛. Significant differences in volume and porosity were observed in all software packages for Biodentine across all voxel sizes. Conclusion: Some differences in volume and porosity were found according to voxel size, image-processing software, and the radiopacity of the material. Consistent protocols are needed for research evaluating dental materials.

• Journal of Korean Neurosurgical Society
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• v.47 no.5
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• pp.345-351
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• 2010

Objective : In this study, the Mindfulness Based Stress Reduction (MBSR) program was applied to patients presenting with depression and anxiety after surgery from spontaneous subarachnoid hemorrhage (SAH) and the effects were assessed. Methods : The subjects were patients admitted for cerebral aneurysm rupture and treated by means of surgery from March to December, 2007. More than 6 months had passed after surgery, without any special lesions showing up on computed tomography (CT), and the Glasgow outcome scale (GOS) was 5 points. Among patients with anxiety and depression symptoms, 11 patients completed the program. The MBSR program was conducted once a week, 2.5 hours each, for 8 weeks. The evaluation criteria were : 1) the Beck Depression Inventory (BDI): it measures the type and level of depression, 2) the State-Trait Anxiety Inventory : the anxiety state of normal adults without mental disorder, and 3) Heart Rate Variability (HRV) : the influence of the autonomous nervous system on the sinoarterial node varies continuously in response to the change of the internal/external environment. Results : The BDI value was decreased from 18.5 ${\pm}$ 10.9 to 9.5 ${\pm}$ 7.1 (p = 0.013) : it was statistically significant, and the depression level of patients was lowered. The state anxiety was decreased from 51.3 ${\pm}$ 13.9 to 42.3 ${\pm}$ 15.2; the trait anxiety was reduced from 50.9 ${\pm}$ 12.3 to 41.3 ${\pm}$ 12.8, and a borderline significant difference was shown (p = 0.091, p = 0.056). In other words, after the treatment, although it was not statistically significant, a decreased tendency in anxiety was shown. In the HRV measurement, standard deviation normal to normal (SDNN), square root of the square root of the mean sum of squared differences between adjacent normal to normal intervals (RMSSD), and total power (TP) showed significant increase, Physical Stress Index (PSI) showed a significant reduction, and thus an improvement in the homeostatic control mechanism of the autonomic nervous system was ween. Conclusion : The MBSR program was applied to the patients showing anxiety and depression reaction after SAH treatment, and a reduction in depression symptoms and physiological reactions were observed. The application of the MBSR program may be considered as a new tool in improving the quality of life for patients after surgery.

• Journal of Nutrition and Health
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• v.40 no.2
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• pp.162-171
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• 2007

Obesity is an independent risk factor fur coronary artery disease in the postmenopausal women, which may be mediated by alteration of blood lipid metabolism. We are aimed to evaluate the effects of low energy diet, restriction of high fat foods and exercise education on weight, fat mass and blood lipid profile. Fifteen postmenopausal obese women were studied. Subjects received detailed advice about how to achieve a reduction of weight by a low-energy diet (1,200kcal), restriction of high fat food and increased exercise in every 4 wks during 8 wk. To evaluate the effectiveness for education programs, dietary fat habit and daily nutrient intakes, exercise were tested before and after intervention. Anthropometry, computerized tomography, and blood lipid profile were assessed before and after intervention. According to the nutrition education, energy intake (from 1776.1 ${\pm}$ 28.2 kcal to 1268.7 ${\pm}$ 115.2 kcal, p < 0.001) and percent of energy from fat (21.9%, p < 0.01) were significantly decreased. However, the index of nutritional quality was over 1.0. On the contrary, exercise (from 341.3 ${\pm}$ 222.1 kcal to 569.4 ${\pm}$ 309.8 kcal, p < 0.05) was increased and dietary fat habit scores (from 30.8 ${\pm}$ 5.2 to 36.1 ${\pm}$ 3.0, p < 0.01) were improved. Also, body weight (4.2%, p < 0.001), BMI (4.5%, p < 0.001), body fat mass (3.4%, p < 0.05) and waist to hip ratio (1.1%, p < 0.05) were decreased. Among abdominal fat, visceral fat (26.1%, p < 0.05) and subcutaneous fat (14.8%, p < 0.01) were decreased. But there was no difference in visceral fat to subcutaneous fat ratio. We observed HDL-cholesterol increase (11.7%, p < 0.05), triglyceride reduction(14.8%, p < 0.05) and atherogenic index improvement (from 2.7 ${\pm}$ 0.7 to 2.3 ${\pm}$ 0.7, p < 0.05) However, there was no change in LDL-cholesterol and total cholesterol. Theses results showed that low energy diet, restriction of high fat foods and exercise education could result in reduction of body weight, fat mass, visceral and subcutaneous fat, and in improvement of blood lipid profile in the postmenopausal obese women.

• Journal of Biomedical Engineering Research
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• v.30 no.1
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• pp.49-55
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• 2009

Purpose : The aim of this study is to evaluate a possibility of clinical application for the effects of low intensity ultrasound stimulation (LIUS) in morphological characteristics (i.e., structure, bone mineral density) of bone on osteoporotic fracturesprevention. Materials and Methods : Eight virgin 14-week-old ICR mice (approximate weight 25g) were used and ovariectomized (OVX) to induce osteoporosis. Right tibia (US) for each mouse served as the LIUS (1.5MHz frequency, 1.0 kHz pulse repetition on frequency, $30mW/cm^2$ intensity, $200{\mu}s$ pulse length, and stimulation for 20 minutes a day and 5 days a week over a 6-week period). Left tibia (CON) for each mouse served as the non-stimulated controls. Structural parameters and bone mineral density ($g/cm^3$) on trabecular bone of tibiae were calculated and measured from images derived in-vivo micro computed tomography (micro-CT) at 0 week and after 6weeks. Results : The BV/TV and Tb.N in US group were significantly bigger than those in CON group. The Tb.Pf in US group, moreover, was significantly smaller than that in CON group (p<0.05).For the others structural parameters and BMD, however, there were no significant difference between US group and CON group (p>0.05). Conclusion : The LIUS might prevent bone loss and keep bone connectivity in osteoporotic bones. Therefore, the LIUS might prevent effectively the osteoporotic fractures in clinics.

• The Journal of the Korean dental association
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• v.53 no.2
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• pp.120-131
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• 2015

Objective: The purpose of this study is to compare the surgical treatment with conservative treatment and to evaluate the effectiveness of drug-holiday in bisphosphonate related osteonecrosis of the jaw (BRONJ) patients who were diagnosed as stage 2. Patients and Method: From January 2012 to October 2014, seventy-two patients who visit to Pusan National University of Dental Hospital were diagnosed as stage 2 of BRONJ. All the patients had taken computed tomography(CT) and panoramic radiography. The surgical treatment including sequestrectomy of necrotic bone and curettage of soft tissue around the sequestrum were performed to fifty patients. Twenty-two patients underwent conservative treatment such as antibiotics medications, mouth rinsing and follow up checking for every two weeks. Prognosis of treatment was classified into 3 groups - response, unresponse, and worsens - according to clinical, radiographic symptoms. P-value less than 0.05 were regarded as significant. Results: In surgery group, forty-five patients (90%) were healed without recurrence or any complication and five patients (10%) showed the wound dehiscence or infection. In conservative treatment group, fifteen patients (68.2%) were healed without any complication, four patients (18.2%) did not show improvement and three(4.2%) patients$^{\circ}{\emptyset}$ symptoms increased. P-value among groups was 0.014. Evaluation of preoperative drug-holiday in surgery group did not show the effectiveness(p=0.478). Conclusion: Statistically, the prognosis of patients with stage 2 BRONJ treated with surgery was significantly better than conservative treatment. There was no statistical difference for the preoperative drug-holiday.

• Journal of Dental Rehabilitation and Applied Science
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• v.29 no.1
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• pp.23-36
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• 2013

To evaluate the 3-dimensional features of the grafted bone with maxillary sinus augmentation and to assess the relation between the degree of bone resorption and the type of bone grafting source and implant, and the operation method. A retrospective chart review of patients receiving sinus augmentation procedures for implant positioning was conducted: radiographic analysis of the volume and area of bone grafts was performed. The volumetric remodeling.measured at 6 months after implant positioning as the percentage of residual bone graft.was correlated to type of graft materials and operation methods. 53 dental implants positioned with sinus bone graft in 15 patients at Wonkwang University Sanbon Dental Hospital. Computed tomography scans,taken implant positioning after 6 months, showed greater resorption values for the group of $Puros^{(R)}$ graft alone from the group of mixed with $Puros^{(R)}$ and various bone graft (P<0.05, respectively). And resorption values according to operation methods have statistically significant difference(P<0.05). Volume change ratio of bone graft showed greater values for the group of delayed implant position from the group of simultaneously implant placement with bone graft. Retrospective data analysis shows that the method of graft with $Puros^{(R)}$ alone may occur greater resorption of graft materials than mixed graft material with $Puros^{(R)}$ and other graft materials. The group of simultaneously implant placement with bone graft also display smaller resorption ratio of bone graft than the group of delayed implant placement.

• Progress in Medical Physics
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• v.28 no.3
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• pp.100-105
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• 2017

The purpose of the present study was to develop and evaluate patient-customized helmets with a three-dimensional (3D) printer for radiation therapy of malignant scalp tumors. Computed tomography was performed in a case an Alderson RANDO phantom without bolus (Non_Bolus), in a case with a dental wax bolus on the scalp (Wax_Bolus), and in a case with a patient-customized helmet fabricated using a 3D printer (3D Printing_Bolus); treatment plans for each of the 3 cases were compared. When wax bolus was used to fabricate a bolus, a drier was used to apply heat to the bolus to make the helmet. $3-matic^{(R)}$ (Materialise) was used for modeling and polyamide 12 (PA-12) was used as a material, 3D Printing bolus was fabricated using a HP JET Fusion 3D 4200. The average Hounsfield Unit (HU) for the Wax_Bolus was -100, and that of the 3D Printing_Bolus was -10. The average radiation doses to the normal brain with the Non_Bolus, Wax_Bolus, and 3D Printing_Bolus methods were 36.3%, 40.2%, and 36.9%, and the minimum radiation dose were 0.9%, 1.6%, 1.4%, respectively. The organs at risk dose were not significantly difference. However, the 95% radiation doses into the planning target volume (PTV) were 61.85%, 94.53%, and 97.82%, and the minimum doses were 0%, 77.1%, and 82.8%, respectively. The technique used to fabricate patient-customized helmets with a 3D printer for radiation therapy of malignant scalp tumors is highly useful, and is expected to accurately deliver doses by reducing the air gap between the patient and bolus.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.36 no.11
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• pp.1081-1090
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• 2012

This study aims to track the longitudinal alteration pattern on the trabecular bone microarchitecture at tibial epiphysis induced by T-OA over time using in vivo micro computed tomography (${\mu}CT$). Ten SD rats were divided into control (n = 5) and T-OA (n = 5) groups. Anterior cruciate ligament transaction was performed for the T-OA group. The results showed that the alteration pattern on the trabecular bone microarchitecture at tibial epiphysis in the T.OA group was definitely different compared with that in the CON group from 0 to 8 weeks (approximately 4-16%, P > 0.05). In particular, a difference was observed in the bone formation and density distributions over time (from 0 or 4 to 8 weeks; approximately 5.15%, P < 0.05). An improved understanding of the alteration pattern on the trabecular bone microarchitecture at tibial epiphysis may assist in developing more targeted treatment interventions for T-OA.

• Progress in Medical Physics
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• v.29 no.1
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• pp.1-7
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• 2018

The $TomoTherapy^{(R)}$ beam-delivery method creates helical beam-junctioning patterns in the dose distribution within the target. In addition, the dose discrepancy results in the particular region where the resonance by pattern of dose delivery occurs owing to the change in the position and shape of internal organs with a patient's respiration during long treatment times. In this study, we evaluated the dose pattern of the longitudinal profile with the change in respiration. The superior-inferior motion signal of the programmable respiratory motion phantom was obtained using AbChes as a four-dimensional computed tomography (4DCT) original moving signal. We delineated virtual targets in the phantom and planned to deliver the prescription dose of 300 cGy using field widths of 1.0 cm, 2.5 cm, and 5.0 cm. An original moving signal was fitted to reflecting the beam delivery time of the $TomoTherapy^{(R)}$. The EBT3 film was inserted into the phantom movement cassette, and static, without the movement and with the original movement, was measured with signal changes of 2.0 s, 4.0 s, and 5.0 s periods, and 2.0 mm and 4.0 mm amplitudes. It was found that a dose fluctuation within ${\pm}4.0%$ occurred in all longitudinal profiles. Compared with the original movement, the region of the gamma index above 1 partially appeared within the target and the border of the target when the period and amplitude were changed. Gamma passing rates were 95.00% or more. However, cases for a 5.0 s period and 4.0 mm amplitude at a field width of 2.5 cm and for 2.0 s and 5.0 s periods at a field width of 5.0 cm have gamma passing rates of 92.73%, 90.31%, 90.31%, and 93.60%. $TomoTherapy^{(R)}$ shows a small difference in dose distribution according to the changes of period and amplitude of respiration. Therefore, to treat a variable respiratory motion region, a margin reflecting the degree of change of respiration signal is required.