• Journal of the Society of Disaster Information
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• v.9 no.4
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• pp.449-461
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• 2013

As the hydrofluoric acid leak in Gumi-si, Gyeongsangbuk-do or hydrochloric acid leak in Ulsan, Gyeongsangnam-do demonstrated, chemical related accidents are mostly caused by large amounts of volatile toxic substances leaking due to the damages of storage tank or pipe lines of transporter. Safety assessment is the most important concern because such toxic material accidents cause human and material damages to the environment and atmosphere of the surrounding area. Therefore, in this study, a hydrofluoric acid leaked from a storage tank was selected as the study example to simulate the leaked substance diffusing into the atmosphere and result analysis was performed through the numerical Analysis and diffusion simulation of ALOHA(Areal Location of Hazardous Atmospheres). the results of a qualitative evaluation of HAZOP (Hazard Operability)was looked at to find that the flange leak, operation delay due to leakage of the valve and the hose, and toxic gas leak were danger factors. Possibility of fire from temperature, pressure and corrosion, nitrogen supply overpressure and toxic leak from internal corrosion of tank or pipe joints were also found to be high. ALOHA resulting effects were a little different depending on the input data of Dense Gas Model, however, the wind direction and speed, rather than atmospheric stability, played bigger role. Higher wind speed affected the diffusion of contaminant. In term of the diffusion concentration, both liquid and gas leaks resulted in almost the same $LC_{50}$ and ALOHA AEGL-3(Acute Exposure Guidline Level) values. Each scenarios showed almost identical results in ALOHA model. Therefore, a buffer distance of toxic gas can be determined by comparing the numerical analysis and the diffusion concentration to the IDLH(Immediately Dangerous to Life and Health). Such study will help perform the risk assessment of toxic leak more efficiently and be utilized in establishing community emergency response system properly.

• Journal of radiological science and technology
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• v.29 no.4
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• pp.267-274
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• 2006

The evaluation of GB stones with ultrasound has proved to be useful procedure in patient with symptoms of cholelithiasis. GB is evaluated for size, wall thickness, presence of internal reflections within the lumen and posterior acoustic shadowing or enhancement in Ultrsonography. The patient position should be shifted during procedure to demonstrate further the presence of stone within the GB. Patient scanned at the Rt. subcostal region in supine, right lateral, Lt. down decubitus, and upright sitting position. So GB stone should shift to dependent area of GB. Often, GB is not markedly distended in the presence of cholethiasis, and so the diagnosis becomes more difficult. One of the more difficult areas for detection of a GB stones are embeded in the cystic duct region. And since the GB is adjacent to the duodenum and hepatic flexure, its may be difficult to visualizing a GB stone. When patient study position changes frome supine to other position, stones displaced the site. But if its are polyps, not changes the site whatever patient positions. It is very important to what make different GB stones or polyps. We have studied about mobility of GB stones according to the patients position(supine, Lt. down decubitus, $30^{\circ} LAO. sitting and hand-knee). So we have a result, stones wherever localized within the GB, changed 100% its position in the hand-knee position and the others appeared at least 90%. In this study, when a large stones are located through fundus-body and body-neck, does not changing the stones position in spite of varied patient's positions. But hand-knee positions can identified GB stones, because its make changed the position of stons from posterior wall to anterior wall within the GB. We recommend the hand-knee position for differentiation GB stones from polyps.

• Radiation Oncology Journal
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• v.12 no.1
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• pp.73-80
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• 1994

From December 1989 to February 1993, 108 patients with Non-Small Cell Lung Cancers(NSCLC) were studied retrospectively to evaluate radiotherapeutic significance of serum levels of NSE. We considered elevated serum neuron specific enolase(S-NSE) level as one of the neuroendocrine features in NSCLC. Histopathologic evaluation revealed 86 squamous cell carcinomas, 11 adenocarcinomas.3 large cell carcinomas, 3 mucoepidermoid carcinomas, and 5 unknown pathology. Eight Patients had stage 1,40 stage IlIA, and 60 stage lIIB.S-NSE level greater than 15 ng/ml was considered as elevated, and below this considered as normal. All patients recieved radiotherapy as primary treatment modality. The responders to radiotherapy had significantly higher mean S-NSE level than non-responders (28.5 ng/ml vs 20 ng/ml, p=0.01). Overall 2-year survival rate(YSR) was 23.6$ \% $. According to radiotherapy response, 2 YSR for Patients with CR, PR, and NR were 39.2$ \% $, 28.6$ \% $, and 6.2$ \% $ respectively(p=0.001). 2 YSR for patients with elevated and normal S-NSE were 14.6$ \% $ and 31.7$ \% $(p=0.02). The patients with NR showed no difference in survival according to S-NSE level. When we considered all patients, S-NSE level showed no significant impact on response. But for squamous cell carcinomas alone, patients with elevated S-NSE had more responders(80$ \% $ vs 61$ \% $, p=0.05). There was no correlation between tumor characteristics and S-NSE level. But the patients with elevated S-NSE had more patients with higher nodal stage, Based on our and other datas, NSCLC with neuroendocrine features have different response to treatment and clinical behavior compared to other NSCLC. Thus, this subgroup may need different treatment modality, and S-NSE level may have prognostic significance.

• Radiation Oncology Journal
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• v.12 no.1
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• pp.59-66
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• 1994

Seventy-five patients with tumors of the head and neck treated with either radiation therapy alone or combined with surgery or chemotherapy were studied prospectively to evaluate the effects of radiation therapy to the neck on thyroid gland between September 1986 and October 1992. All patients were serially monitored for thyroid function tests before and after radiation therapy. Radiation dose to the thyroid gland ranged from 35 to 60 Gy with a median dose of 50 Gy. Median follow-up time was 30 months with a range of 11 to 85 months. The incidence of thyroid dysfunction was 40$ \% $: forty-five patients(60$ \% $) euthyroid, 2 patients(3$ \% $) clinical hypothyroidism, 27 patients(36$ \% $) subclinical hypothyroidism and 1 patient(1$ \% $) hyperthyroidism. No thyroid nodules or thyroid cancer were detected in any patients. Thyroid dysfunction appeared earlier in patients who underwent surgery than in those patients treated with radiation therapy alone or combination of chemotherapy and radiation therapy(P=0.0013). By multivariate analysis, risk factors that significantly influenced a higher incidence of thyroid dysfunction were female sex(p=0.0293) and combination of total laryngectomy and radiation therapy(p : 0.0045). In conclusion, evaluation of thyroid function before and after radiation therapy with periodic thyroid function tests are recommended to detect thyroid dysfunction in time and thyroid hormone replacement therapy is recommended whenever thyroid dysfunction develops.

• Journal of the Korean Society of Radiology
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• v.14 no.2
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• pp.129-138
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• 2020

Due to the nature of the Rosenberg Method, the patient needs to maintain posture for a certain period of time, and the joint space is observed in various forms depending on the angle of knee flexion, which causes difficulties in examination. In order to solve these problems, Image quality was evaluated in order to evaluate the usefulness of the assistive device by making the assistive device itself. SNR and CNR analysis about the presence or absence of an assistive device using the extremity phantom and the angle of the assistive device itself were not statistically significant(p < 0.05). As a result of measuring the distance between the right and left edges of the medial condyle based on the presence or absence of an assist device, and the absence of assist device (96.00±40.6 mm) and presence of an assist device (134.86±17.68 mm) were statistically significant (p <0.05). To find the aLDFA relationship about the femur and tibia, we measured the right and left aLDFA based on the presence or absence of assist device. As a result, the absence of the right-side aLDFA assist device (74.63°±4.87) and the presence of assist device (79.64°±3.65) were statistically significant (p <0.05). The absence of the left-side aLDFA assist device (76.39°±4.62) and the presence of assist device (79.64°±3.65) were statistically significant (p < 0.05). but, As a result of measuring the distance of the overlapping parts of the right and left proximal tibiofibular joint and the lateral condyle, There were no statistically significant differences between the right and left sides. In conclusion, we confirmed that we can obtain Diagnostically valuable images with a constant knee-to-knee spacing using an assist device we self-created. In addition, we could learn through aLDFA relationship between femur and tibial that the smaller the angle, the more medial condyle overlaps with JSW, We also confirmed the significance by deriving similar values on the normal range values of aLDFA using assist devices. However, it is considered necessary to pay attention to internal and external rotations in order to obtain good quality images by evaluating the distance of overlapping parts between proximal tibiofibular joint and lateral condyle.

• The Korean Journal of Nuclear Medicine
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• v.29 no.1
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• pp.84-91
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• 1995

Many clinical and laboratory tests have been employed to evaluate disease activity in rheumatioid arthritis. $^{99m}Tc$-labelled polyclonal IgG(HIG) has been demonstrated to accumulate in focal sites of infection or inflammation in both animals and human subjects. The purpose of this study was to distinguish arthritis with active inflammation from those without active inflammation and to correlate relative intensities of $^{99m}Tc$-labelled HIG uptake of the rheumatoid arthritis with clinical and MR indices of the joint inflammation. This study included twelve patients with active rheumatoid arthritis, two with ankylosing spondylitis and one with degenerative osteoarthritis without active inflammation. A Whole-body and spot images were obtained 4 hours after intravenous injection of 20mCi of $^{99m}Tc$-labelled HIG. Scintigrams were assessed visually by 3 experienced radiologists, and graded as normal or mildly and markedly increased uptake within the joints, and the degree of uptake was compared with clinical and radiologic severity of synovial inflammation. MRI studies were done on the involved joints consisted of wrist(n = 11), knee(n = 2) and hip joint(n= 2). Active synovitis was defined when marked elevation of ESR and gadolinium enhancement of synovium on MRI were demonstrated. Markedly increased radiotracer uptake was seen in 10 of 11 rheumatoid arthritic patients with active synovitis whereas normal or mildly increased uptakes were noted in others, including rheumatoid arthritic patient(n=1) and non-rheumatoid patients(n = 3) without active synovitis. This study showed that the localization of involved joints in rheumatoid arthritis could be detected with $^{99m}Tc$-labelled HIG and that the degree of uptake correlated well with the degree and activity of inflammation. In conclusion, $^{99m}Tc$-labelled HIG scan is a useful method in the evaluation of active inflammation in rheumatoid arthritis.

• The Korean Journal of Nuclear Medicine Technology
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• v.18 no.1
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• pp.98-103
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• 2014

Purpose: The effective half life of I-131 is useful to calculate radiation dose, period of hospitalization, and exposure dose of surrounding people from patient. However, it is difficult to measure. This study estimates the effective half life in whole body and thyroid in using of value of residual radioactivity obtained from the early and delay images of Dual time I-131 whole body scan. Also, the correlations between the effective half life and serum creatinine, GFR, and administration dose were investigated in this study. Materials and Methods: The targets were 50 patients administration high dose of I-131 from February to August in 2013, having normal range of serum creatinine and over $30{\mu}IU/mL$ of TSH levels. After administration radioactive I-131, the early scan in the 3rd day and the delay scan in the 5-6th days were performed. To measure the residual radioactivity in the whole body and thyroid, ROI was set and then background radioactivity was corrected to estimate. The effective half life was estimated by calculating the ratio of measured values between the early and delay images. To compare the effective half lives of the whole body and thyroid, it was analyzed by Independent t-test, and each correlation of the effective half life, GFR, serum creatinine, and the dose of administration were analyzed by calculating the pearson's correlation coefficient. All of the analysis were determined to be statistically significant when P<0.05. Results: The effective half life of the whole body was $17.06{\pm}5.50$ hours and of the thyroid was $17.22{\pm}5.41$ hours. The two effective half life did not show significant difference (P=0.887). As the value of GFR was increased, the effective half life of whole body (r=-0.407, P=0.003) and of thyroid (r=-0.473, P=0.001) were significantly decreased; as the value of serum creatinine was increased, the effective half life of whole body (r=0.309, P=0.029) and of thyroid (r=0.371, P=0.008) were significantly increased. In the administration dose, effective half life did not have correlations. Conclusion: The effective half life of I-131 of patients treated for their thyroids were estimated only by using the images of Dual time I-131 whole body scan. Also, the correlations with the effective life, GFR, and serum creatinine were examined. This study might be utilized for a study on optimization for the period of hospitalization of patients treated by high dose of I-131 and on evaluation for internal absorbed dose of MIRD schema in application of the effective half life.

• Journal of Oral Medicine and Pain
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• v.38 no.2
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• pp.137-142
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• 2013

Oral Medicine includes temporomandibular disorder, orofacial pains such as neuropathic pain, soft tissue diseases, halitosis, laser treatment, snoring, sleep apnea and identification through forensic dentistry etc. Such diseases are relatively common and cause great inconvenience and pain to the patients, as well as incur fatal health scare at times. In terms of oral medicine, the number of orofacial patients is growing due to a change in the life style and an increased stress as time goes in contemporary society and the demand of areas requiring oral medical professionalism, such as soft tissue lesions, snoring and sleep apnea, forensic dentistry evaluation and others are rapidly ascending. Consequently, among the areas in dental science, the calls for the expertism in oral medicine and its role are mounting. Analyzing the distribution according to disease entity, symptoms, duration of disease, and the prehistory courses of new patients visiting the department of oral medicine in a year provides information of the role and the relative importance of oral medicine in prospect and enables effective diagnosis and treatments for the patients. Therefore, in the present study, by analyzing new patients visiting the oral medicine clinic in our dental hospital for a year and by evaluating the role and the professionalism in future oral medicine, the authors concluded the followings: 1. It was founded that new patients to oral medicine mainly had temporomandibular disorders, soft tissue diseases, and neuropathic pains. 2. The number of patients with temporomandibular disorder appeared to be the highest percentage and the order within this was the patients with combined disorders, muscle disorder, and internal derangement of joint disc. 3. The number of patients with xerostomia appeared to be the highest percentage within soft tissue disease, followed by lichen planus and recurrent apthous ulcers. 4. The number of patients with burning mouth syndrome appeared to be the highest percentage within neuropathic pain.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.33 no.2
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• pp.152-161
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• 2007

This study was conducted to patients visited oral maxillo-facial surgery, KNUH and the purpose of the study was to assess skeletal and dento-alveolar stability after surgical-orthodontic correction treated by skeletal Class III malocclusion patients with open bite versus non-open bite. This retrospective study was based on the examination of 40 patient, 19 males and 21 females, with a mean age 22.3 years. The patients were divided into two groups based on open bite and non-open bite skeletal Class III malocclusion patients. The cephalometric records of 40 skeletal Class III malocclusion patients (open bite: n = 18, non-open bite: n = 22) were examined at different time point, i.e. before surgery(T1), immediately after surgery(T2), one year after surgery(T3). Bilateral sagittal split ramus osteotomy was performed in 40 patients. Rigid internal fixation was standard method used in all patient. Through analysis and evaluation of the cephalometric records, we were able to achieve following results of post-surgical stability and relapse. 1. There was no significant statistical differences between open bite and non-open bite with skeletal Class III malocclusion patients in maxillary occlusal plane angle of pre-operative stage(p>0.05). 2. Mean vertical relapses of skeletal Class III malocclusion patients with open bite were $0.02{\pm}1.43mm$ at B point and $0.42{\pm}1.56mm$ at Pogonion point. In skeletal Class III malocclusion patients with non-open bite, $0.12{\pm}1.55mm$ at B point and $0.08{\pm}1.57mm$ at Pogonion point. There was no significant statistical differences between open bite and non-open bite with skeletal Class III malocclusion patients in vertical relapse(p>0.05). 3. Mean horizontal relapses of skeletal Class III malocclusion patients with open bite were $1.22{\pm}2.21mm$ at B point and $0.74{\pm}2.25mm$ at Pogonion point. In skeletal Class III malocclusion patients with non-open bite, $0.92{\pm}1.81mm$ at B point and $0.83{\pm}2.11mm$ at Pogonion point. There was no significant statistical differences between open bite and non-open bite with skeletal Class III malocclusion patients in horizontal relapse(p>0.05). 4. There were no significant statistical differences between open bite and non-open bite with skeletal Class III malocclusion patients in post-surgical mandibular stability(p>0.05). and we believe this is due to minimized mandibular condylar positional change using mandibular condylar positioning system and also rigid fixation using miniplate 5. Although there was no significant relapse tendency observed at chin points, according to the Pearson correlation analysis, the mandibular relapse was influenced by the amount of vertical and horizontal movement of mandibular set-back(p=0.05, r>0.304).

• Tuberculosis and Respiratory Diseases
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• v.46 no.6
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• pp.846-855
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• 1999

Background : Secondary pulmonary hypertension is an important final endpoint in patients with chronic hypoxic lung disease, accompanied by deterioration of pulmonary hemodynamics. The clinical diagnosis of pulmonary hypertension and/or cor pulmonale could be difficult, and simple noninvasive evaluation of pulmonary artery pressures has been an relevant clinical challenge for many years. Doppler echocardiography might to be a more reliable method for evaluating pulmonary hemodynamics in such patients in terms of the accuracy, reproducibility and easiness for obtaining an appropriate echocardiographic window than M-mode echocardiography. The aim of this study was to assess echocardiographic parameters associated with pulmonary arterial hypertension, defined by increasing right ventricular systolic pressure(RVSP), calculated from trans-tricuspid gradient in patients with chronic hypoxic lungs. Method : We examined 19 patients with chronic hypoxic lung disease, suspected pulmonary hypertension under the clinical guidelines by two dimensional echocardiography via the left parasternal and subcostal approach in a supine position. Doppler echocardiography measured RVSP from tricuspid regurgitant velocity in continuous wave with 2.5MHz transducer and acceleration time(AT) on right ventricular outflow tract in pulsed wave for the estimation of pulmonary arterial pressure. Results : On echocardiography, moderate to severe degree of pulmonary arterial hypertension was defined as RVSP more than 40mmHg, presenting tricuspid regurgitation. Increased right ventricular endsystolic diameter and shortened AT were noted in the increased RVSP group. Increased RVSP was correlated negatively with the shortening of AT. Other clinical data, including pulmonary functional parameters, arterial blood gas analysis and M mode echocardiographic parameters were not changed significantly with the increased RVSP. Conclusion : These findings suggest that shortened AT on pulsed doppler can be useful when quantifying pulmonary arterial pressure with increased RVSP in patients with chronic lung disease with hypoxemia. Doppler echocardiography in pulmonary hypertension of chronic hypoxic lungs is an useful option, based on noninvasiveness under routine clinical practice.