• The Journal of Korean Society for Radiation Therapy
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• v.21 no.1
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• pp.33-39
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• 2009

Purpose: The aim of this study is to compare patient's body posture and its position at the time of simulation with one at the treatment room using On-board Imaging (OBI) and CT (CBCT). The detected offsets are compared with position errors of Rando Phantom that are practically applied. After that, Rando Phantom's position is selected by moving couch based on detected deviations. In addition, the errors between real measured values of Rando Phantom position and theoretical ones is compared. And we will evaluate target position's accuracy of KV X-ray imaging's 2D and CBCT's 3D one. Materials and Methods: Using the Rando Phantom (Alderson Research Laboratories Inc. Stanford. CT, USA) which simulated human body's internal structure, we will set up Rando Phantom on the treatment couch after implementing simulation and RTP according to the same ways as the real radioactive treatment. We tested Rando Phantom that are assumed to have accurate position with different 3 methods. We measured setup errors on the axis of X, Y and Z, and got mean standard deviation errors by repeating tests 10 times on each tests. Results: The difference between mean detection error and standard deviation are as follows; lateral 0.4+/-0.3 mm, longitudinal 0.6+/-0.5 mm, vertical 0.4+/-0.2 mm which all within 0~10 mm. The couch shift variable after positioning that are comparable to residual errors are 0.3+/-0.1, 0.5+/-0.1, and 0.3+/-0.1 mm. The mean detection errors by longitudinal shift between 20~40 mm are 0.4+/-0.3 in lateral, 0.6+/-0.5 in longitudinal, 0.5+/-0.3 in vertical direction. The detection errors are all within range of 0.3~0.5 mm. Residual errors are within 0.2~0.5 mm. Each values are mean values based on 3 tests. Conclusion: Phantom is based on treatment couch shift and error within the average 5mm can be gained by the diminution detected by image registration based on OBI and CBCT. Therefore, the selection of target position which depends on OBI and CBCT could be considered as useful.

• Journal of the Korean Society of Radiology
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• v.11 no.6
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• pp.509-515
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• 2017

The purpose of this study is to measure the 3 dimensional dose distribution of Gamma knife $Perfection^{TM}$, make a comparative analysis of the result and establish the measurement method for the procedures using EBT3 film. The dose distributions of the Gamma knife $Perfection^{TM}$ installed in two hospitals were evaluated in accuracy and precision. For accuracy, the difference between the mechanical center axis and the dose center axis was assessed on a 4 mm collimator. The allowed difference in accuracy is within 0.3 mm and it was measured as 0.098 mm, 0.195 mm for A hospital and 0.229 mm, and 0.223 mm for B hospital. For precision the difference between the FWHM(Full Width at Half Maximum) of Gamma Plan and measurement in the 4, 8, and 16 mm collimators was calculated. The allowed difference in precision is less than ${\pm}1mm$. The value of the hospital A was -0.283 ~ 0.583 mm, and the hospital B was -0.857 ~ 0.810 mm. When analyzing the dose distributions using the image-j program, it is necessary to establish a clearer reference point of the measurement point, and it is considered that the comparison of the dose distribution should be performed in actual treatment irradiation dose with a high dose usable film.

• Journal of Technologic Dentistry
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• v.33 no.4
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• pp.331-337
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• 2011

Purpose: The purpose of this study was to impact of force system change in finger spring that add helical coil one round on orthodontic force. Methods: The following conclusions were drawn from the experiment conducted after bending 90 samples with a CNC wire forming machine while changing the height and lumen size to 1mm - 3mm - 5mm and 2mm - 3mm - 4mm respectively in the coil of the force system in finger spring added with one wheel of helical coil of 18-8 stainless steel round wire (${\Phi}0.5mm$, spring hard) from Jinsung Co. in domestic market under the following conditions: Laboratory name = Instron 5942; Temperature($deg^{\circ}C$) = 18.00; Humidity(%) = 50.00; Rate 1 = 10.00000 mm/min; Compressive extension = 5.0mm. Results: When Coil height is 1, 3, 5mm and lumen size is 2, 3, 4mm reduce finger spring as mean value of compressive extension occasion maximum load(mN) increases as coil height rises, and lumen size grows to 5.0mm. And was expose that compressive load(mN) increases as coil position of finger spring rises and increase as lumen size is decrescent. Conclusion: As the adherence height of coil was raised from 1mm through 3mm to 5mm, compressive load increased. As the lumen size increased from 2mm through 3mm to 4mm, compressive load decreased. Therefore, these results suggest that it is desirable to lower the coil height and enlarge the lumen size to enhance the biomechanical efficiency of finger spring when manufacturing the finger spring for removable orthodontic devices.

• The Journal of Korean Society for Radiation Therapy
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• v.29 no.2
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• pp.83-91
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• 2017

Objectives: The purpose of this study was to evaluate the error of the leaf position accuracy of the MLC due to the gravity effect according to the gantry angle by using picket fence test using EPID and GafChromic EBT3 film. Materials and Methods: A 5 cm solid phantom was placed on the table and the SAD was set to 100 cm. The EBT3 film was placed exactly over the solid phantom and covered a 1.5 cm solid phantom and the picket fence test was performed. The EPID was measured under the same conditions as the EBT3 film at SID 100 cm. The gantry angles were measured at $0^{\circ}$, $90^{\circ}$, $180^{\circ}$ and $270^{\circ}$ in order to evaluate the position of the MLC according to the gantry angle. For the geometric evaluation of the MLC, the leaf position accuracy of the MLC was analyzed using the analysis program. Results: In case of EPID, when the gantry angle was changed to $0^{\circ}$, $90^{\circ}$, $180^{\circ}$, $270^{\circ}$, the difference of the position errors of the leaves was 0.18 mm, 0.31 mm, 0.20 mm, 0.26 mm on the average and the maximum values of the errors were respectively 0.44 mm, 0.54 mm, 0.34 mm, 0.44 mm. In case of EBT3 film, when the gantry angle was changed to $0^{\circ}$, $90^{\circ}$, $180^{\circ}$, $270^{\circ}$, the difference of the position errors of the leaves was 0.19 mm, 0.21 mm, 0.19 mm, 0.31 mm on the average and the maximum values of the errors were respectively 0.35 mm, 0.45 mm, 0.36 mm, 0.48 mm. Conclusion: In this study, we analyzed the position error of the leaf of the MLC according to the gantry angle, and confirmed the position error of the leaf by gravity effect. As a result of comparing the leaf position accuracy using EPID and EBT3 film according to the variation of gantry angle, a larger error occurred in the error analysis method using EPID than that of EBT3 film. Therefore, in the case of IMRT based on MLC, as well as verification of accurate dosimetry should be conducted, it is considered that the quality control and verification for the precise operation of the MLC will be needed. and it is necessary to compare and verify the method of analysis.

• The Journal of Korean Academy of Prosthodontics
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• v.33 no.4
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• pp.753-768
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• 1995

For accurate impression taking of dental patient and esthetic denture treatment of ednetulous patient, measuring between intraoral anatomic landmarks is useful.In this study the subjects selected at a random were two-jundred forty persons with a mean age 22.5(range 21-24) and were taken impression of by irreversible hydrocolloid impression material(Alginate). On the study model made by dental stone, each individual tray was made and final impresion was taken by border moilding. On final model measurings were performed with 3-dimensional measuring device and the values were analyzed by t-test The results is following : ABOUT THE MEASURED VALUES. 1. The width between maxillary right and left canine cusp tip was average 36.44mm(s.d. 2.48), man 36.67mm, woman 35.83mm(p<0.05). 2. The width between labial height of contour of maxillary right and left canine was average 40.08mm(s.d. 2.42), man 40.29mm, woman 39.52mm(p<0.05). 3. The width between mesio-lingual cusps of maxillary first molar was average 43.14mm(s.d. 3.33), man 43.56mm, woman 42.05mm(p<0.05). 4. The width between buccal alveolar ridge on axis of mesiolingual cusp of right and left maxillary first molar was average 64.89mm(s.d. 3.88), man 65.58mm, woman 62.92mm(p<0.05). 5. The width between buccal alveolar ridge on axis of mesiolingual cusp of right and left maxillary second molar was average 68.58mm(s.d. 3.91), man 69.29mm, woman 66.30mm (p<0.05). 6. The width between right and left hamular notch was average 49.80mm(s.d. 3.96), man 50.70mm, woman 48.20mm(p<0.05). 7. The length from labial heigth of contour of maxillary central incisor to center of incisive papilla was average 9.52mm(s.d. 1.18), man 9.46mm, woman 9.63mm(p>0.05). 8. The length from labial heigth of contour of maxillary central incisor to palatine fovea was average 53.27mm(s.d. 2.93), man 53.93mm, woman 52.08mm(p<0.05). 9. The center of incisive papilla ws located posterior to intercanine line at 0.40mm(s.d. 1.16), man 0.51mm, woman 0.11mm(p<0.05). 10. The height from incisal edge of maxillary central incisor to the labial vestibule was average 21.84mm(s.d. 1.38), man 22.01mm, woman 21.00mm(p<0.05). 11. The height from mesiolingual cusp of maxillary first molar to buccalvestible was average 17.45mm(s.d. 1.42), man 17.56mm, woman 17.08mm(p>0.05). 12. The height from hamular notch to standard occlusal plane was average 6.84mm(s.d. 1.06), man 6.91mm, woman 6.70mm(p>0.05). 13. The height from the deepest point of palatal vault to standard occlsalplane was average 19.95 mm(s.d. 2.03), man 20.19mm, woman 19.12mm(p<0.05). ABOUT THE ARCH FORM 1. The arch form was able to classify into four typr by the rate of the measured values. Each arch form distribution was that the 1 group had 32.46% the 2 group 2.19%, the 3 group 52.83%, the 4 group 12.72%. The sexual composition was that in 1 group man had 73.5%, woman 26.5%, in 2 group man had 40.0%, woman 60.0%, in 3 group man had 83.3%, woman 16.7%, and in 4 group man had 55.17%, woman 44.83%. 2. When canine cusp tip was marked as point O, the intersection point between labial height of contour of maxillary central incisor and intermaxillary suture as point A, height of contour of maxillary second molar buccal alveolar ridge as B point, ${\angle}$AOB was measured $133.8^{\circ}$for the 1 group, $133.0^{\circ}$for the 2 group, $132.3^{\circ}$for the 3 group, $128.9^{\circ}$for the 4 group.

• Progress in Medical Physics
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• v.20 no.3
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• pp.180-190
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• 2009

Depth of prostate volume from the skin can vary due to intra-fractional and inter-fractional movements, which may result in dose reduction to the target volume. Therefore we evaluated the feasibility of automated depth determination-based adaptive proton therapy to minimize the effect of inter-fractional movements of the prostate. Based on the center of mass method, using three fiducial gold markers in the prostate target volume, we determined the differences between the planning and treatment stages in prostate target location. Thirty-eight images from 10 patients were used to assess the automated depth determination method, which was also compared with manually determined depth values. The mean differences in prostate target location for the left to right (LR) and superior to inferior (SI) directions were 0.9 mm and 2.3 mm, respectively, while the maximum discrepancies in location in individual patients were 3.3 mm and 7.2 mm, respectively. In the bilateral beam configuration, the difference in the LR direction represents the target depth changes from 0.7 mm to 3.3 mm in this study. We found that 42.1%, 26.3% and 2.6% of thirty-eight inspections showed greater than 1 mm, 2 mm and 3 mm depth differences, respectively, between the planning and treatment stages. Adaptive planning based on automated depth determination may be a solution for inter-fractional movements of the prostate in proton therapy since small depth changes of the target can significantly reduce target dose during proton treatment of prostate cancer patients.

• Korean Journal of Ichthyology
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• v.12 no.2
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• pp.124-128
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• 2000

A total of 46 Gnathagnus elongatus larvae, 2.7~8.7 mm BL (Body length), were collected by bongo net and trawl-shaped fish larvae net in the coastal area of Cheju Island during 1997~1999. This species was found in the coastal area of Cheju Island and the Korea Strait. This paper describes morphological features of these specimens throughout their development. 1) The soft ray of fin appeared at about 5 mm BL and attained to a fixed number at about 8.7 mm BL. 2) Pigments pattern changed suddenly about 3 mm BL. 3) A series of pigments in the upper and the lower part of the urostyle were found less than 4.3 mm BL. 4) The pigments of caudal peduncle were found more than 6 mm BL.

• Journal of Korean Neurosurgical Society
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• v.50 no.1
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• pp.30-35
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• 2011

Objective : Morphometric data for the sympathetic ganglia (SG) of the upper thoracic spine was investigated to identify the exact location of the SG in order to reduce normal tissue injury in the thoracic cavity during thoracoscopic sympathectomy. Methods : In 46 specimens from 23 formalin-fixed adult cadavers, the authors measured the shortest distance from the medial margin of the T1, T2 and T3 SG to the most prominent point and medial margin of the corresponding rib heads, and to the lateral margin of the longus colli muscle. In addition, the distance between the most prominent point of the rib head and the lateral margin of longus colli muscle and the width of each SG were measured. Results : The shortest distance from the medial margin of the SG to the prominent point of corresponding rib head was on average 1.9 mm on T1, 4.2 mm, and 4.1 mm on T2, T3. The distance from the medial margin of the SG to the medial margin of the corresponding rib head was 4.2 mm on T1, 5.9 mm, and 6.3 mm on T2, T3. The mean distance from the medial margin of the SG to the lateral margin of the longus colli muscle was 6.7 mm on T1, 8.8 mm, 9.9 and mm on T2, T3. The mean distance between the prominent point of the rib head and the lateral margin of the longus colli muscle was 4.8 mm on T1, 4.6 mm, and 5.9 mm on T2, T3. The mean width of SG was 6.1 mm on T1, 4.1 mm, and 3.1 mm on T2, T3. Conclusion : We present morphometric data to assist in surgical planning and the localization of the upper thoracic SG during thoracoscopic sympathectomy.

• Korean Journal of Ichthyology
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• v.24 no.2
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• pp.67-76
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• 2012

Skeletal development in the oblong rockfish, Sebastes oblongus, was studied based on extensive larval rearing conditions from December 2007 to March 2008. Newly-hatched larvae lacked osteological elements. After 3 days of bearing, jaw bones were ossified almost simultaneously with the frontal, parietal, clavicle, opercle, preopercle and branchiostegal rays at 8.0 mm average total length (TL). Ossification of the opercular was completed by 12.3 mm and the full complement of ossified elements of cranium and pectoral girdle were completed by 16.2 mm. Ossification of the cartilaginous caudal complex began to at 9.8 mm, and completely ossified by 18.0 mm. The fusing of the first and second, and the third and fourth hypurals initially occurred by 10.8 mm, and their fusion was finally completed at 18.0 mm. Notochord flexion occurred and formed an individual centrum by 8.5 mm and 10.8 mm, respectively, and all 26 centra were ossified by 13.2 mm. The preorbital bone began to ossify on the anterior region of eye at 10.8 mm, and the $1^{st}$ suborbital bone appeared ossified on the lower of eye by 12.3 mm, and all elements were ossified at 27.5 mm. Finally, after 71 days of bearing, the juveniles became 27.5 mm, and ossification was completed at this stage.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.8
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• pp.240-247
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• 2017

The increased investigation of the cerebral arteries with magnetic resonance angiography has resulted in an increase in the identification of unruptured intracranial aneurysms (UIAs). Knowledge of the distribution and factors associated with UIAs might be helpful for understanding the pathological mechanism of unruptured aneurysms. This study examined patients who visited a health care center and had a health examination from January 2007 to December 2016. Subjects who underwent magnetic resonance angiography with a health examination at the Health Screening were enrolled in this study. The incidence and risk factors of UIAs (age, sex, hypertension, diabetes mellitus, smoking, alcohol, and coronary artery disease) were investigated by comparing the size (more than 3 mm vs. less than 3 mm) and multiple aneurysm (single vs. multiple aneurysms). The frequency of aneurysm according to the site was also analyzed. Among the 187166 subjects, who received a health examination, 18954 underwent magnetic resonance angiography. Of them, 367 (1.93%) had UIAs. A comparison of the size of more than 3 mm and less than 3 mm showed that the mean age of the more than 3 mm group of patients was significantly higher than the other size groups (more than 3 mm $57.16{\pm}8.47$ vs. less than 3 mm $55.12{\pm}8.19$; p=0.07). High-density lipoprotein was significantly higher in the more than 3 mm group than in the less than 3 mm($55.95{\pm}16.03$ vs. less than 3 mm $50.85{\pm}13.65$; p=0.007). Hypertension was significantly higher in the multiple aneurysm group (single 153 in 399 (38.3%) VS multiple 19 in 35 (54.3%); p=0.065). An aneurysm of less than 3 mm in size was frequent in the distal internal carotid artery (34.3%) and MCA-bifurcation (16.4%) (p=0.003). Aneurysms of more than 3 mm were frequent in the distal internal carotid artery (43.4%) and MCA-bifurcation (13.4%), and anterior communicating artery (13.4%) (p=0.003). The difference in size and single or multiple aneurysm revealed other risk factors. These risk factors suggest that degenerative and hemodynamic disorders may lead to the presence of aneurysms.