• Journal of radiological science and technology
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• v.40 no.2
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• pp.187-195
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• 2017

Early diagnosis for upper facial trauma is difficult by using the standard Water's view (S-Water's) in general radiograph due to overlapping of anatomical structures, the uncertainty of patient positioning, and specific patients with obese, pediatric, old, or high-risk. The purpose of this study was to analyze appropriate exposure angles through a comparison of two different protocols (S-Water's vs. reverse Water's view (R-Water's)) by using a head phantom. A head phantom and general radiograph with 75 kVp, 400 mA, 45 ms 18 mAs, and SID 100 cm. Images of R-Water's were obtained by different angles in the range of $0^{\circ}$ to $50^{\circ}$, which adjusted an angle at 1 degree interval in supine position. Survey elements were developed and three observers were evaluated with four elements including the maxillary sinus, zygomatic arch, petrous ridge, and image distortion. Statistical significant analysis were used the Krippendorff's alpha and Fleiss' kappa. The intra-class correlation (ICC) coefficient for three observers were high with maxillary, 0.957 (0.903, 0.995); zygomatic arch, 0.939 (0.866, 0.987); petrous ridge, 0.972 (0.897, 1.000); and image distortion, 0.949 (0.830, 1.000). The high-quality image (HI) and perfect agreement (PA) for acquired exposure angles were high in range of the maxillary sinus ($36^{\circ}-44^{\circ}C$), zygomatic arch ($33^{\circ}-40^{\circ}$), petrous ridge ($32^{\circ}-50^{\circ}$), and image distortion ($44^{\circ}-50^{\circ}$). Consequently, an appropriate exposure angles for the R-Water's view in the supine position for patients with facial trauma are in the from $36^{\circ}$ to $40^{\circ}$ in this phantom study. The results of this study will be helpful for the rapid diagnosis of facial fractures by simple radiography.

• Journal of Biomedical Engineering Research
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• v.25 no.4
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• pp.261-268
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• 2004

Osteoporosis is a clinical condition in which the amount of bone tissue is reduced and the likelihood of fracture is increased. It is known that the electrical property of the bone is related to its density, and, in particular, the electrical resistance of the bone decreases as the bone loss increases. This implies that the electrical property of bone may be an useful parameter to diagnose osteoporosis, provided that it can be readily measured. The study attempted to evaluate the electrical conductivity of bone using a technique of electrical impedance tomography (EIT). It nay not be easy in general to get an EIT for the bone due to the big difference (an order of 2) of electrical properties between the bone and the surrounding soft tissue. In the present study, we took an adaptive mesh regeneration technique originally developed for the detection of two phase boundaries and modified it to be able to reconstruct the electrical conductivity inside the boundary provided that the geometry of the boundary was given. Numerical simulation was carried out for a tibia phantom, circular cylindrical phantom (radius of 40 mm) inside of which there is an ellipsoidal homeogenous tibia bone (short and long radius are 17 mm and 15 mm, respectively) surrounded by the soft tissue. The bone was located in the 15 mm above from the center of the circular cross section of the phantom. The electrical conductivity of the soft tissue was set to be 4 mS/cm and varies from 0.01 to 1 ms/cm for the bone. The simulation considered measurement errors in order to look into its effects. The simulated results showed that, if the measurement error was maintained less than 5 %, the reconstructed electrical conductivity of the bone was within 10 % errors. The accuracy increased with the electrical conductivity of the bone, as expected. This indicates that the present technique provides more accurate information for osteoporotic bones. It should be noted that tile simulation is based on a simple two phase image for the bone and the surrounding soft tissue when its anatomical information is provided. Nevertheless, the study indicates the possibility that the EIT technique may be used as a new means to detect the bone loss leading to osteoporotic fractures.

• Radiation Oncology Journal
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• v.14 no.2
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• pp.149-158
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• 1996

Purpose : To get an accute steepness of dose gradients at outside the target volume in intracranial lesion and a less limitation of beam selection avoiding the high dose at normal brain tissue, this Photon Knife Radiosurgery System was developed in order to provide the three-dimensional dose distribution through the reconstruction of CT scan and the combined stereotactic trans-multiarc beam mode based on linear accelerator photon beam. Materials and methods : This stereotactic radiosurgery, Photon Knife based on linear accelerator photon beam was provided the non-coplanar multiarc and trans-multiarc irradiations. The stereotactic trans-multiarc beam mode can be obtained from the patient position in decubitus. This study has provided the 3-dimensional isodose curve and anatomical structures with the surface rendering technique. The dose distribution from the combined two trans-multiarcs (2M 2TM) was compared to that of four non-coplanar multiarcs (4M) with same collimator size of 25 mm in a diameter and total gantry movements. Results : In this study, it shows that the dose distributions of stereotactic beam mode are significantly depended on the selected couch and gantry angle in same collimator size. Practical dose distribution of combined stereotactic trans-multiarc beam has shown a more small rim thickness than that of the non-coplanar multiarc beam mode in axial, sagittal and coronal plane in our study. 3-Dimensional dose line displayed with surface rendering of irregular target shape is helpful to determine the target dose and to predict the prognosis in follow-up radiosurgery. Conclusions : 3-Dimensional dose line displayed with surface rendering of irregular target shape is essential in stereotactic radiosurgery. This combined stereotactic trans-multiarc beam has shown a less limitation of the selection couch and gantry beam angles for the target surrounding critical organs. It has shown that the dose distribution of combined trans-multiarc beam greatly depended on the couch and gantry angles. In our experiments, the absorbed dose has been decreased to $27%$ / mm in maximum at the interval of $50\%$ to $80\%$ of isodose line.

• The korean journal of orthodontics
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• v.25 no.3 s.50
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• pp.355-373
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• 1995

Craniofacial region is a musculodentoskeletal system that consists of many anatomical structures ; cranioskeletal structures, dental arches, and formation and functions of masticatory muscles have close correlations. Growth and development of craniofacial region are influenced by not only hereditory factors, but also environmental factors such as craniofacial muscles and surrounding tissues. On the contrary, however, study on changes in functions or adaptations of craniofacial muscles following changes of craniofacial skeletal structures has been somewhat insufficient. The author's purpose was to observe correlations between masticatory muscular functions and change patterns according to cranial skeletal structures and occlusion patterns, for this, comparative study of muscle activity changes of preand post- orthognathic surgery states in skeletal Cl III malocclusion patients was peformed. The selected sample groups were 15 normal male patients, 15 skeletal Cl III pre-orthognatic surgery patients and 15 skeletal Cl III post-orthognatic surgery patients. For each sample groups, cephalometric x-ray taking, masticatory efficiency test and measurements of muscle activities in anterior temporal muscle, masseter and upper lip in rest, clenching, chewing and swallowing were carried out. The following results were obtained : 1. In resting state of mandible, pre-surgery malocclusion group showed higher m. activities in ant. temporalis, masseter and upper lip than post-surgery group. Post-surg. malocc. group showed significantly high m. activity only in upper lip compared to the normal group. 2. In clenching state, post-surg. malocc. group showed higher m. activities in ut. temporalis, masseter and upper lip than pre-surg. malocc. group. 3. In chewing state, post-surg. malocc. group showed higher m. activities in ant. temporalis and masseter than pre-surg. malocc. group, on the other hand, decreased upper lip activity was noticed. 4. In swallowing state, post-surg. malocc. group showed lower upper lip activity than pre-surg. malocc. group but higher than that of the normal group. No significant difference in m. activities of ant, temporalis and masseter was noticed among the three groups. 5. Masticatory efficiency was lower in pre-surg. malocc. group than normal group, masticatory efficiency showed an increase in post-surg. malocc. group compared to the pre-surg. malocc. group. However, both groups showed significant differences compared to the normal group.

• Tuberculosis and Respiratory Diseases
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• v.42 no.2
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• pp.156-164
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• 1995

Background: We had undergone this study to investigate clinical progress of this disease and to decide the role of aggressive diagnostic approaches, the efficacy of treatments and prognoses. Methods: A retrospective study was done on 113 patients who had been diagnosed to metastatic adenocarcinoma of pleura by pleural fluid cytology(106 cases) or pleural needle biopsy(22 cases), at Presbyterian Medical Center, from Jan. 1990 to Dec. 1994. Results: 1) The patients were composed of 59 males(52.2%) and 54 females(47.8%), and the mean age distribution was $57.4{\pm}12.1$ years. 2) The site of origin was lung cancer 46.9%(53/113), stomach cancer 20.4%(23/113), breast cancer 11.5%(13/113), and unknown primary site 6.2%(7/113 cases), as a whole. In male, lung cancer was 55.9%(33/59), stomach cancer was 28.8%(17/59), and in female, lung cancer was 37%(20/54), breast cancer was 24.1%(13/54) of cases. 3) The cardinal symptoms were dyspnea(69%), cough(61%), chest pain(50%), weight loss(50%), anorexia(49%), sputum(43%), malaise(30%). 4) The pleural fluid findings were exudative in 94.4%(102/108), serosanguinous or bloody in 36~53%, unilateral involvement in 74.3%(84/113) of cases, and lymphocyte predominance($71{\pm}27%$) in differential count of WBC. 5) CEA levels in pleural fluid or plasma were over 10ng/ml in 60.6%(40/66), and ADA levels in pleural fluid were under 40U/L in 95%(57/60) of cases. 6) The patients were managed by various methods, but the efficacy of treatment was uncertain. 7) The mean survival time was $12.7{\pm}13.5$ weeks. Conclusion: It seems to be no effective treatment methods yet and the prognosis was very poor in this disease, so the objectives of diagnostic approaches and treatment methods should be directed to early diagnosis, treatment and prevention of curable disease. And we must make our best endeavors to lengthen the survival time and improve the quality of patients' life.

• Tuberculosis and Respiratory Diseases
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• v.47 no.5
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• pp.669-680
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• 1999

Background: Pulmonary thromboembolism(PTE) is a life threatening disease that needs early diagnosis. Spiral CT angiography depict thromboemboli in the central pulmonary vessels with greater than 90% sensitivity and specificity, which approaches the results of pulmonary angiography in the Prospective Investigation of Pulmonary Embolism Diagnosis(PIOPED) study. This study was performed to evaluate the findings and the diagnostic value(clinical utility) of the spiral CT angiography with 2D image(multiplanar reformation) and 3D images(Shaded surface display, Minimal intensity projection) in the pulmonary thromboembolism. Methods: We retrospectively analysed spiral CT angiography and pulmonary angiography, lung scan and clinical recordings of 20 patients who had PTE diagnosed by spiral CT angiography(n=19 cases) or pulmonary angiography(n=l case) from September 1997 to August 1998. Among 20 patients who had underwent spiral CT angiography, 14 patients could be performed lung perfusion scan at the same time. We analyzed the vascular and parenchymal change in spiral CT angiogram. Results: Anatomical distribution of PTE was as follows: 1) left lung(n= 103)

• Childhood Kidney Diseases
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• v.2 no.2
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• pp.118-124
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• 1998

Purpose : There is no specific treatment guidelines for Henoch-$Sch{\ddot{o}}nlein$(HS) nephritis. Therefore we performed this study to observe the effect of long term steroid therapy combined with azathioprine Methods : Treatment protocols; 1) Steroid pulse therapy: methylprednisolon 30 mg/kg/dose, maximum 1 gm, intravenolisly 6 times for alternate day. 2) Oral steroid was given 2 mg/kg/day for 1 month, 1 mg/kg/day for following 1 month and alternate day oral steroid combined with azathioprine 2 mg/kg/day for 2 years. Results : Time period from HSP to onset of HS nephritis was between 2 weeks to 5 months with mean $7.4{\pm}7.4$ weeks. Clinical remission were seen in 4 cases out of 5 ($80\%$). Mean time period with disappearance of proteinuria and microscopic hematuria were $5{\pm}2.4$ month and $13.3{\pm}2.9$ month respectively. On pathologic findings by ISKDC, 3 cases were grade IIIb, 2 cases were grade IV in first kidney biopsies and showed pathologic improvement in follow up tidneybiopsiesafterlyearstreatment. Conclusion : As there is no definitive treatment for HS nephritis so far, our study of long term oral steroid therapy with azathioprine was effective in clinical and histologic aspect. Therefore further study in HS nephritis with in a large group will be needed in the future.

• Journal of Preventive Medicine and Public Health
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• v.19 no.1 s.19
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• pp.85-90
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• 1986

This study was conducted in July-August, 1984, to define the causes of chronic gastrointestinal symptoms in rural population and to provide data for the management of such patients. A household survey was conducted to identify all the residents of Youngchun and Sungiu counties in Kyungpook province who were over 20 years of age, had chronic upper gastrointestinal symptoms for over the last 6 months, never had medical examination for the symptoms, and volunteered to participate in the gastroscopic examination. Gastroscopy was done for 106 males and 108 females. Gastric ulcer was found in 16.8% of all the examinees, duodenal ulcer in 15.4%, gastritis in 14.0%, and gastric cancer in 3.7%. No lesion was found by gastroscopy in 52.3%. Gastric ulcer more common in male(26.4%) than in female(7.4%) (p<0.01) and the same was true for duodenal ulcer(20.8% of male, 10.2% of female). Gastric cancer was found in 7.5% of the male while none of the female had gastric cancer. A higher proportion of the female (68.5%) showed normal finding in the gastroscopy than the male(35.9%) (p<0.01). No significant association was found between the upper gastrointestinal symptoms and the gastroscopic findings. The higher prevalence rate of gastric ulcer than that of duodenal ulcer in this study which is the reverse of the study findings of urban area in Korea and western countries may be related in part with the dietary habit and social environment of the rural population. Although early diagnosis is the most important for the treatment of gastric cancer, many of the people with chronic upper gastrointestinal complaints defer the diagnosis and treatment. It is may be due to lack of the knowledge of diseases and the health care attitude of the rural people. A national program for the health education and mass screening for the gastric cancer should be developed.

• Progress in Medical Physics
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• v.12 no.1
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• pp.41-50
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• 2001

The quantification analysis of renal scintigraphy is strongly affected by the location, shape and size of region of interest(ROI). When ROIs are drawn manually, these ROIs are not reproducible due to the operators' subjective point of view, and may lead to inconsistent results even if the same data were analyzed. In this study, the effect of the ROI variation on the analysis of renal scintigraphy when the ROIs are drawn manually was investigated, and in order to obtain more consistent results, methods for automated ROI definition were developed and the results from the application of the developed methods were analyzed. Relative renal function, glomerular filtration rate and mean transit time were selected as clinical parameters for the analysis of the effect of ROI and the analysis tools were designed with the programming language of IDL5.2. To obtain renal scintigraphy, $^{99m}$Tc-DTPA was injected to the 11 adults of normal condition and to study the inter-operator variability, 9 researchers executed the analyses. The calculation of threshold using the gradient value of pixels and border tracing technique were used to define renal ROI and then the background ROI and aorta ROI were defined automatically considering anatomical information and pixel value. The automatic methods to define renal ROI were classified to 4 groups according to the exclusion of operator's subjectiveness. These automatic methods reduced the inter-operator variability remarkably in comparison with manual method and proved the effective tool to obtain reasonable and consistent results in analyzing the renal scintigraphy quantitatively.

• Progress in Medical Physics
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• v.22 no.1
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• pp.18-27
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• 2011

The purpose of this study was to identify different cerebral areas of the human brain associated with rural and urban picture stimulation using a 3.0 Tesla functional magnetic resonance imaging (fMRI) and further to investigate the human suitability for rural and urban environments. A total of 27 right-handed participants (mean age: $27.3{\pm}3.7$) underwent fMRI study on a 3.0T MR scanner. The brain activation patterns were induced by visual stimulation with each rural and urban sceneries. The participants were divided into two groups as 26 subjects favorable to rural scenery and 14 subjects unfavorable to urban scenery based on their filled-in questionnaire. The differences of the brain activation in response to two extreme types of pictures by the two sample t-test were characterized as follows: the activation areas observed in rural scenery over urban were the insula, middle frontal gyrus, precuneus, caudate nucleus, superior parietal gyrus, superior occipital gyrus, fusiform gyrus, and globus pallidus. In urban scenery over rural, the inferior frontal gyrus, parahippocampal gyrus, postcentral gyrus, superior temporal gyrus, amygdala, and posterior cingulate gyrus were activated. The fMRI patterns also clearly show that rural scenery elevated positive emotion such as happiness and comfort. On the contrary, urban scenery elevated negative emotion, resulting in activation of the amygdala which is the key region for the feelings of fear, anxiety and unpleasantness. This study evaluated differential cerebral areas of the human brain associated with rural and urban picture stimulation using a 3.0 Tesla fMRI. These findings will be useful as an objective evaluation guide to human suitability for ecological environments that are related to brain activation with joy, anger, sorrow and pleasure.