• Transactions of the Korean Society of Mechanical Engineers A
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• v.38 no.5
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• pp.497-503
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• 2014

Minimally invasive intramedullary nail insertion or plate osteosynthesis has shown good results for the treatment of long bone fractures. However, directly seeing the fracture site is impossible; surgeons can only confirm bone fragments through a fluoroscopic imaging system. The narrow field of view of the equipment causes malalignment of the fracture reduction, and radiation exposure to medical staff is inevitable. This paper suggests two methods to solve these problems: surgical navigation using 3D models reconstructed from computed tomography (CT) images to show the real positions of bone fragments and estimating the rotational angle of proximal bone fragments from 2D fluoroscopic images. The suggested methods were implemented using open-source code or software and evaluated using a model bone. The registration error was about 2 mm with surgical navigation, and the rotation estimation software could discern differences of $2.5^{\circ}$ within a range of $15^{\circ}$ through a comparison with the image of a normal bone.

• The Korean Journal of Nuclear Medicine
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• v.26 no.2
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• pp.257-264
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• 1992

Diagnostic approaches such as angiography, ultrasound, computed tomography and nuclear magnetic resonance have limitation for contributing to the early clinical diagnosis of atherosclerosis. Recently, $^{99m}Tc-labelled$ low density lipoprotein was developed to detect early atherosclerotic lesion by external imaging with gamma camera. To determine whether $^{99m}Tc-LDL$ scintigraphy can visualize the active atherosclerotic lesion, rabbits were injected with $^{99m}Tc-LDL$, 3 months after feeding dietary fat (lanolin) and we obtained following results. 1) Labelling efficiency of $^{99m}Tc-LDL$ was $79\sim88%$. 2) Biodistribution study of normal rabbits with $^{99m}Tc-LDL$ revealed the high activities in spleen, adrenal gland, liver, kidney which are major organs of high metabolic rate of LDL. 3) Three months after feeding lanolin, serum cholesterol was markedly increased from $74{\pm}17mg/dl$ to $979{\pm}153mg/dl$ and histologic study of aorta after sacrificing the rabbit demonstrated marked atherosclerotic changes. 4) Atherosclerotic lesion of abdominal aorta which was confirmed with histologic study could be demonstrated in $^{99m}Tc-LDL$ scintigraphy after feeding lanolin for 3 months. In conclusion, the results of this preliminary investigation suggest that it may be possible to image active atheromatous lesion with $^{99m}Tc-LDL$. It is anticipated that this promising agent may allow the in vivo monitoring of preclinical atherosclerotic lesions and may be useful to evaluate the metabolic pathway of LDL in humans.

• Fire Science and Engineering
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• v.27 no.5
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• pp.75-79
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• 2013

Application of the left lateral tilt position has been recommended during cardiopulmonary resuscitation (CPR) of pregnant patients. However, the left lateral tilt could displace the left ventricle (LV) besides the gravid uterus and may compromise the cardiac pump mechanism of CPR. Thus, we investigated the effect of left lateral tilt on the spatial relationship between the anterior-posterior axis (AP axis), which represents the direction of sternal displacement during CPR, and the LV. We retrospectively reviewed the medical records and multidetector computed tomography (MDCT) scans of 90 patients who underwent virtual gastroscopy using MDCT. Virtual gastroscopy was performed with the patient both in the left lateral tilt position and in the supine position. On an axial image showing the maximal area of the LV, the angle between the AP axis and the LV axis ($Angle_{AP-LV}$), the shortest distance between the AP axis and the mid-point of LV cavity ($D_{AP-MidLV}$) and the shortest distance between the AP axis and the LV apex ($D_{AP-Apex}$) were measured. In the supine scans, the LV was situated on the left side of the AP axis in 87 patients (96.7%). On the left lateral tilt scans, the mean tilt angle was $43.4{\pm}11.0^{\circ}$. $D_{AP-MidLV}$ and $D_{AP-Apex}$ were significantly longer in the left lateral tilt position (p<0.001), but $Angle_{AP-LV}$ was comparable between the positions. This study indicates that the left lateral tilt position may compromise the cardiac pump mechanism of chest compression in pregnant cardiac arrest patients.

• Journal of Trauma and Injury
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• v.26 no.4
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• pp.273-279
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• 2013

Purpose: In patients with splenic trauma, Computed Tomography (CT) scan is helpful in selecting treatment options and evaluating resolution after NOM (Non-Operative Management). The purpose of this study was to suggest a CT based hemoperitoneum (HP) scoring system that can easily be used by clinicians to evaluate the severity of injury and recovery. Methods: A retrospective review of patients with splenic trauma admitted to our hospital between May 2003 and January 2013 was conducted. Patients diagnosed with isolated spleen injury who had a CT scan on admission were included. 1 or 2 points were given according to location and amount of hematoma in the CT image. Using the existing ultrasonography (US) based HP scoring system, the same method was applied to obtain our CT based HP scoring (CBHS) system, which ranges from 0 to 8 points. The CBHS system can be easily used by clinicians for a quick assessment of splenic injury. Results: Of the 39 patients meeting the inclusion criteria, 6 patients were managed operatively and 33 nonoperatively. There was a significant difference in CBHS between the OM (operative management) group and the NOM group.(p=0.03) CBHS showed correlation with Hb (hemoglobin), Hct (hematocrit), spleen injury grade(AAST), and Hounsfield unit of ROI (Region of interest). (p=0.17, p=0.18, p<0.000, p=0.02, respectively) After successful NOM with stabilized Hb level, the amount of hemoperitoneum was scored in the follow-up CT. CBHS demonstrated correlation with decreased spleen injury grade, decreased Hounsfield unit of ROI (Region of interest) (p=0.039, p=0.049, respectively), and also objectively reflected patient recovery. Conclusion: CBHS can be used as an objective and intuitive tool for clinicians in grading the severity of splenic injury by scoring the amount of hemoperitoneum, and in assessing recovery.

• Journal of Radiation Protection and Research
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• v.39 no.4
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• pp.206-212
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• 2014

We report here on the results of evaluating the radiation doses using chest computed tomography (CT) for patients with pneumoconiosis complication. For the first time, we visited the 17 MIPs to evaluate the dose-length product (DLP, $mGy{\cdot}cm$), CT unit, and protocols of scanning and image reconstruction those is routinely used for treating patients with pneumoconiosis who have complication. All statistical analysis was performed using the Statistical Program for Social Sciences (SPSS ver. 19.0, Chicago, IL, USA). Mean of total DLP was $727.7mGy{\cdot}cm$, ranging from 272.0 to $1228.7mGy{\cdot}cm$. DLP from obtaining parenchymal lung images was significantly reduced than that from obtaining total lung images (555.9 vs. 707.2, p<0.001). Third quartile of total and pre-scanning DLP was 1036.1 and $504.1mGy{\cdot}cm$, respectively. Chest CT radiation doses for patients with pneumoconiosis complication are similar with korean diagnostic reference level as well as international guidelines.

• Journal of Dental Rehabilitation and Applied Science
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• v.25 no.2
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• pp.171-181
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• 2009

The objective of this study was to analyse stress distribution of maxillary complex by use of face mask. The construction of the three-dimensional FEM model was based on the computed tomography(CT) scans of 13.5 years-old male subject. The CT image were digitized and converted to the finite element model by using the mimics program, with PATRAN. An anteriorly directed force of 500g was applied at the first premolar 45 degrees downwards to the FH plane and at the first molar 20 degrees downwards to the FH plane. When 45 degrees force was applied at maxillary first premolar, there were observed expansion at molar part and constriction at premolar part. The largest displacement was 0.00011mm in the x-axis. In the y-axis, anterior displacement observed generally 0.00030mm at maximum. In the z-axis, maxillary complex was displaced 0.00036 mm forward and downward. When 20 degrees force was applied at maxilla first molar, there were observed expansion at lateral nasal wall and constriction at molar part. The largest displacement was 0.001mm in the X-axis. In the Y-axis, anterior displacement observed generally 0.004mm at maximum. In the Z-axis, ANS was displaced upward and pterygoid complex was displaced downward. The largest displacement was 0.002mm.

• Radiation Oncology Journal
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• v.38 no.1
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• pp.68-76
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• 2020

Purpose: The present study was conducted to compare dosimetric parameters for the heart and left lung between free breathing (FB) and deep inspiration breath hold (DIBH) and determine the most important potential factors associated with increasing the lung dose for left-sided breast radiotherapy using image analysis with 3D Slicer software. Materials and Methods: Computed tomography-simulation scans in FB and DIBH were obtained from 17 patients with left-sided breast cancer. After contouring, three-dimensional conformal plans were generated for them. The prescribed dose was 50 Gy to the clinical target volume. In addition to the dosimetric parameters, the irradiated volumes and both displacement magnitudes and vectors for the heart and left lung were assessed using 3D Slicer software. Results: The average of the heart mean dose (D_mean) decreased from 5.97 to 3.83 Gy and V₂₅ from 7.60% to 3.29% using DIBH (p < 0.001). Furthermore, the average of D_mean for the left lung was changed from 8.67 to 8.95 Gy (p = 0.389) and V₂₀ from 14.84% to 15.44% (p = 0.387). Both of the absolute and relative irradiated heart volumes decreased from 42.12 to 15.82 mL and 8.16% to 3.17%, respectively (p < 0.001); however, these parameters for the left lung increased from 124.32 to 223.27 mL (p < 0.001) and 13.33% to 13.99% (p = 0.350). In addition, the average of heart and left lung displacement magnitudes were calculated at 7.32 and 20.91 mm, respectively. Conclusion: The DIBH is an effective technique in the reduction of the heart dose for tangentially treated left sided-breast cancer patients, without a detrimental effect on the left lung.

• Annals of Clinical Neurophysiology
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• v.18 no.1
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• pp.1-6
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• 2016

Background: Moyamoya disease is characterized by a progressive stenosis or occlusion of the intracranial internal carotid artery and/or the proximal portion of the anterior cerebral artery and middle cerebral artery. Whether the onset time was childhood or adulthood, the bony carotid canal diameter might be different, but reflects the size of internal carotid artery passing through the bony carotid canal. In this study, we aimed to identify the relationship between bony carotid canal diameter and clinical manifestation. Methods: 146 consecutive patients diagnosed with moyamoya disease by brain imaging studies were included. We measured the diameter of a transverse portion of bony carotid canal on bone window of a brain computed tomography(CT) image. Patients were divided into two groups, ischemic or hemorrhagic stroke according to clinical manifestation. As a result, 115 patients were included. The Suzuki stage was used as criteria for disease progression. Results: Bony carotid canal diameter was $3.6{\pm}0.5$ (right) and $3.6{\pm}0.4$ (left) in the hemorrhagic stroke group, and $3.7{\pm}0.4$ (right) and $3.6{\pm}0.4$ (left) in the ischemic stroke group. The bony carotid canal diameter of the moyamoya vessels (3.6 mm) was smaller than the diameter of non-moyamoya vessels (3.8 mm), significantly (p = 0.042). However, there was no difference in the collateral patterns and clinical manifestation in a comparison of both groups. Conclusions: In our study, there was no significant difference of clinical manifestations and collateral patterns depend on the bony carotid canal diameter in patients with moyamoya disease. These findings suggest that the clinical presentations of moyamoya disease are not related to the onset time of the disease.

• Journal of Dental Rehabilitation and Applied Science
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• v.29 no.4
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• pp.337-346
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• 2013

It is necessary to consider the median lingual foramen carefully to prevent the bleeding due to the damage of the sublingual artery for implant surgery. This study is to evaluate the frequency, location, diameter and the number of the Mandibular median lingual foramen regarding gender and age in the CBCT. Sixty two images of cone beam computed tomography (CBCT) whose visited the Chonnam National University Dental hospital from Sept. 2010 to Apr. 2011 were evaluated. Frequency, number, location and the diameter of Mandibular median lingual foramen shown in the CBCT image were evaluated. Sixty two patients (100%) had at least one median lingual foramen and fifty six patients (90.32%) had multiple foramens. Forty patients (66.13%) showed the median lingual foramen on the location between Mn. central incisors. The mean vertical position of the genial spine and the median lingual foramen was 24.21 mm and 14.52 mm, respectively. And the relative mean vertical dimension of median lingual foramen was 0.45. The mean diameter of the foramen was 0.93 mm. CBCT demonstrated the frequency, location, diameter and the number of median lingual foramen. It is necessary to take CBCT before implant placement to prevent the bleeding.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.33 no.5
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• pp.511-517
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• 2007

Purpose: The aim of this study is to determine whether a difference in the amount of bone graft material is needed between edentulous patients and dentulous patients and to calculate the amount of augmentation for a sinus lift procedure. Methods: 19 patients(20 sinuses) were included to measure maxillary sinus volume. Facial CT scanning was performed using MX 8000 IDT CT devices(Philips, USA). And it was used for IDLvm(The IDL Virtual Machine) 6.0, CT Volume Analyzer Ver 2.3 program to measure maxillary sinus volumes Results: At edentulous patients, volumes(mean${\pm}SD$) of the inferior portion of the sinuses were $0.56{\pm}0.13cm^3$(5mm height), $2.35{\pm}0.57cm^3$(10mm height), $4.85{\pm}1.10cm^3$(15mm height). At dentulous patients, volumes(mean${\pm}SD$) of the inferior portion of the sinuses were $0.41{\pm}0.18cm^3$(5mm height), $1.76{\pm}0.42cm^3$(10mm height), $3.80{\pm}0.84cm^3$ (15mm height). A significant correlation was found between augmentation height(5mm, 10mm, 15mm) and the calculated sinus volume.(p=0.027, p=0.018, p=0.044) Conclusions: A significant correlation was found between augmentation height(5mm, 10mm, 15mm) and the calculated sinus volume. Detailed preoperative knowledge of sinus lift augmentation volume is helpful in determining the appropriate amount of the bone graft material.