• The Korean Journal of Nuclear Medicine
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• v.8 no.1_2
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• pp.29-37
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• 1974

The $^{99m}Tc$-pertechnetate thyroid uptake rates(20 min) were measured in 24 healthy normal subjects, 140 patients with nontoxic goiter and 98 patients with thyrotoxicosis who were treated at the Thyroid Clinic, Seoul National University Hospital, from August 1972 to August 1973. Diagnostic reliabilities and correlations between $^{99m}TcO_4$-thyroid uptake rate (20 min) and other thyroid function tests were evaluated. The observed results were as follows 1. The $^{99m}TcO_4$-thyroid uptake rates (20 min) in normal subjects, euthyroid group and hyperthyroid group were $4.1{\pm}0.9%,\;5.2{\pm}1.8%\;and\;29.7{\pm}10.6%$. There was a significant difference between the mean of the euthyroid group and the mean of the hyperthyroid group and so differentiation between them can be easy. 2. In the diagnosis of hyperthyroidism, the reliabilities of $^{99m}TcO_4$- thyroid uptake rate(20 min), $^{131}I$ thyroid uptake rate(24hrs), serum $T_3$ resin uptake rate, serum $T_4\;and\;T_7\;were\;87.9{\sim}97.9%,\;81.2{\sim}94.4%,\;87.9{\sim}97.9%,\;90.5{\sim}99.3%\;and\;93.7{\sim}100%$. $^{99m}TcO_4$-thyroid uptake rate(20 min) is more accurate than $^{131}I$ thyroid uptake rate (24 hrs) in the diagnosis of hyperthyroidism. 3. $^{99m}TcO_4$-thyroid uptake rate (20 min) was well correlated with $^{131}I$ thyroid uptake rate (24 hrs), serum $T_3$ resin uptake rate, serum $T_4\;and\;T_7$. Points in favor of $^{99m}Tc$ are that it gives a small radiation dose to the thyroid, that tests can be repeated at the short interval, the study can be completed at a single patient visit and it is particularly well suited for the assessment of thyroid function in patients being treated with an antithyroid drug.

• Journal of the Korean Society of Radiology
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• v.12 no.3
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• pp.343-349
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• 2018

Dose rate regulated tracking is known to be an efficient method which adaptively delivers tracking treatments when patient breathing is irregular. The Motion Management Interface (MMI, Varian Medical System, CA), which provides beam on/off switching during treatment is available for clinic. Study is to test if delivering the adaptive tumor tracking is feasible for irregular breathing using beam switching with MMI. 55 free breathing RPM traces acquired from lung cancer patients are used. The first day RPM traces of the patients are utilized to design preprogrammed tracking MLC patterns, of which periods are intentionally reduced by 20% in order to catch up the variation of patient breathing irregularity in the treatment day. Eligibility criteria for this technique are the variation of amplitude and period less than 20%. An algorithm which determines beam on/off every 100 ms by considering the preprogrammed (MLC) positions and current breathing positions is developed. Tracking error and delivery efficacy are calculated by simulating the beam-switching adaptive tracking from the RPM traces. Breathing patterns of 38 patients (70%) met the eligibility criteria. Tracking errors of all of the cases who meet the criteria are less than 2 mm (average 1.4 mm) and the average delivery efficacy was 71%. Those of rest of the cases are 1.9 mm and 48%. Adaptive tracking with beam switching is feasible if patient selection is based on the eligibility criteria.

• The Korean Journal of Nuclear Medicine
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• v.24 no.2
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• pp.237-243
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• 1990

Pulmonary embolism demands rapid and accurate diagnosis. And ventilation imaging has greatly improved the diagnostic accuracy of pulmonary embolism in addition to perfusion imaging. Agents currently used include xenon-133, krypton-81m and technetium-99m radioaerosols. However radioactive gases are compromised by availability and cost for krypton-81m, radiation dose, gamma energy and non?physiologic behaviour for xenon-133. Radioaerosols of technetium-99m componds are rapidly cleared from the lung after inhalation, and their relative low effeciency (specific radioactivity) and wide distribution of particle sizes make them also suboptimum. A new ventilation agent, Technegas is a suspension of structured graphite ellipsoids with diameter below 20nm, labelled with $^{99m}Tc$ in a carrier gas of Argon. This report describes the authors' clinical experience with Technegas. This is the first reported clinical study of this agent in Korea. A comparison of Technegas and $^{99m}Tc-DTPA$ aerosol was performed in 12 patients with various pulmonary diseases such as COPD, pulmonary tuberculosis and pleural effusion. All patients were studied with $^{99m}Tc-DTPA$ aerosol inhalation and Technegas ventilation. In both studies image quality was assessed (1) semiquantitatively by scoring bronchial and gastric activity, (2) subjectively by direct visual comparison of peripheral lung images and (3) quantitatively by computing the peripheral penetration index(PI) for each lungs. The bronchial activites were seen in 7 out of 12 cases with $^{99m}Tc-DTPA$ aerosol and in 5/12 with Technegas. The gastric activities were seen in 5/12 and 1/12 cases respectively. The average values of PI were 61.26% with $^{99m}Tc-DTPA$ aerosol and 69.20% with Technegas (p>0.05). Using $^{99m}Tc-DTPA$ aerosol, COPD patients showed deposition in the central airways with poor visualization of the peripheral areas of the lungs. In Technegas studies these phenomena were less prominent, and the examination is well tolerated by pateients and requires only a minimum of patient cooperation. With superiority of easy availability and handling, better physical characteristics and favorable Image quality, Technegas is a Promising agent for lung ventilation scanning.

• Korean Journal of Radiology
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• v.24 no.6
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• pp.529-540
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• 2023

Objective: To compare the diagnostic performance and clinical outcomes of 2-mSv computed tomography (CT) and conventional-dose CT (CDCT), following radiology residents' interpretation of CT examinations for suspected appendicitis. Materials and Methods: Altogether, 3074 patients with suspected appendicitis aged 15-44 years (28 ± 9 years, 1672 females) from 20 hospitals were randomly assigned to the 2-mSv CT (n = 1535) or CDCT (n = 1539) groups in a pragmatic trial from December 2013 and August 2016. Overall, 107 radiology residents participated in the trial as readers in the form of daily practice after online training for 2-mSv CT. They made preliminary CT reports, which were later finalized by attending radiologists via addendum reports, for 640 and 657 patients in the 2-mSv CT and CDCT groups, respectively. We compared the diagnostic performance of the residents, discrepancies between preliminary and addendum reports, and clinical outcomes between the two groups. Results: Patient characteristics were similar between the 640 and 657 patients. Residents' diagnostic performance was not significantly different between the 2-mSv CT and CDCT groups, with a sensitivity of 96.0% and 97.1%, respectively (difference [95% confidence interval {CI}], -1.1% [-4.9%, 2.6%]; P = 0.69) and specificity of 93.2% and 93.1%, respectively (0.1% [-3.6%, 3.7%]; P > 0.99). The 2-mSv CT and CDCT groups did not significantly differ in discrepancies between the preliminary and addendum reports regarding the presence of appendicitis (3.3% vs. 5.2%; -1.9% [-4.2%, 0.4%]; P = 0.12) and alternative diagnosis (5.5% vs. 6.4%; -0.9% [-3.6%, 1.8%]; P = 0.56). The rates of perforated appendicitis (12.0% vs. 12.6%; -0.6% [-4.3%, 3.1%]; P = 0.81) and negative appendectomies (1.9% vs. 1.1%; 0.8% [-0.7%, 2.3%]; P = 0.33) were not significantly different between the two groups. Conclusion: Diagnostic performance and clinical outcomes were not significantly different between the 2-mSv CT and CDCT groups following radiology residents' CT readings for suspected appendicitis.

• Clinical and Experimental Pediatrics
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• v.57 no.10
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• pp.434-439
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• 2014

Treatment outcomes of pediatric cancers have improved greatly with the development of improved treatment protocols, new drugs, and better supportive measures, resulting in overall survival rates greater than 70%. Survival rates are highest in acute lymphoblastic leukemia, reaching more than 90%, owing to risk-based treatment through multicenter clinical trials and protocols developed to prevent central nervous system relapse and testicular relapse in boys. New drugs including clofarabine and nelarabine are currently being evaluated in clinical trials, and other targeted agents are continuously being developed. Chimeric antigen receptor-modified T cells are now attracting interest for the treatment of recurrent or refractory disease. Stem cell transplantation is still the most effective treatment for pediatric acute myeloid leukemia (AML). However, in order to reduce treatment-related death after stem cell transplantation, there is need for improved treatments. New drugs and targeted agents are also needed for improved outcome of AML. Surgery and radiation therapy have been the mainstay for brain tumor treatment. However, chemotherapy is becoming more important for patients who are not eligible for radiotherapy owing to age. Stem cell transplant as a means of high dose chemotherapy and stem cell rescue is a new treatment modality and is often repeated for improved survival. Drugs such as temozolomide are new chemotherapeutic options. In order to achieve 100% cure in children with pediatric cancer, every possible treatment modality and effort should be considered.

• Journal of the Korea Safety Management & Science
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• v.17 no.1
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• pp.111-117
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• 2015

When scanning PET/CT, dose not unwrinkle gastric folds can be difficult to diagnose gastric cancer. In this study, we use an blowing agent to evaluate the extension the stomach and usefulness of it. The study enrolled 30 patients who patient with uptake in stomach between January and February 2013. Stomach extension was described as the vertical length of the Water drink group was $61.7{\pm}9.7mm$, horizontal length was $102.5{\pm}17.6mm$ and the vertical length of the Blowing agent group was $74.1{\pm}10.7mm$, horizontal length was $101.5{\pm}14.8mm$ in transverse section. Stomach extension was described as the vertical length of the Water drink group was $109.3{\pm}18.8mm$, horizontal length was $62.7{\pm}18.4mm$ and the vertical length of the Blowing agent group was $123.1{\pm}23.1mm$, horizontal length was $87.6{\pm}14.9mm$ in coronal section. Water drink group SUV decreased 35% and Blowing agent group SUV decreased 56%. Blowing agent group extension was similar or superior than water drink group. Therefore, when using a blowing agent will be able to help clinical.

• Tuberculosis and Respiratory Diseases
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• v.75 no.4
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• pp.165-169
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• 2013

An inflammatory myofibroblastic tumor (IMT) is a rare disease entity reported to arise in various organs. It is thought to be a neoplastic or reactive inflammatory condition, controversially. The treatment of choice for myofibroblastic tumor is surgery, and recurrence is known to be rare. The optimal treatment method is not well-known for patients ineligible for surgery. We report a 47-year-old patient with aggressive recurrent IMT of the lungs. The patient had been admitted for an evaluation of back-pain two years after a complete resection of pulmonary IMT. Radiation therapy was performed for multiple bone recurrences, and the symptoms were improved. However the patient presented again with aggravated back-pain six months later. High-dose steroid and non-steroidal anti-inflammatory drugs were administered, but the disease progressed aggressively, resulting in spinal cord compression and metastasis to intra-abdominal organs. This is a very rare case of aggressively recurrent pulmonary IMT with multi-organ metastasis.

• Journal of radiological science and technology
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• v.21 no.1
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• pp.69-78
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• 1998

In this study, I examined the morphological influence of radiation on rats stomach tissue, the difference between NPO and CON(contrast) in the rats stomach was measured after a single irradiation to 15 Gy dose, the results follow; In histological observation; focal congestion and epithelial denudation were observed from NPO rats of a day after irradiation. Fibrosis was showed from both of NPO and CON rats of 28day after irradiation, but in it's area, NPO rats have been more wider than CON rats. In PAS reaction; secreted mucin was reacted very weakly from both of NPO and CON rats of 7 days and 14 days after irradiation, whereas CON rats of 28 days after irradiation were reacted like to control rats. On the basis of this results, we know obviously that NPO will be a factor of stomach abnomalities while hospital patients are treated with high-energy irradiation.

• Journal of radiological science and technology
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• v.3 no.1
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• pp.57-66
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• 1980

X-ray grid is the most important means to reduce the scattered ray from patients, but alternative way is air gap technique that is another name of Groedel technique. This technique is mainly used in chest radiography. Authors performed an experimental study on the air gap technique for chest radiography and obtained the results as follows; 1. In using the high voltage air technique, scattered ray could be reduced effectively, while the percentage of scattered ray was slightly increased than conventional grid technique. 2. In film contrast, 30cm air gap technique was inferior to 12:1 grid technique and contrast improvement was increased when the object was thicker and higher voltage was used. 3. The patient exposure dose was reduced about $25{\sim}45%$ compared with conventional grid technique by air gap technique used.

• Nuclear Medicine and Molecular Imaging
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• v.40 no.2
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• pp.82-89
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• 2006

Bone metastasis is a common sequelae of solid malignant tumors such as prostate, breast, lung, and renal cancers, which can lead to various complications, including fractures, hypercalcemia, and bone pain, as well as reduced performance status and quality of life it occurs as a result of a complex pathophysiologic process between host and tumor cells leading to cellular invasion, migration adhesion, and stimulation of osteoclastic and osteoblastic activity. Several sequelae occur as a result of osseous metastases and resulting bone pain can lead to significant debilitation. A multidisciplinary approach is usually required not only to address the etiology of the pain and its complicating factors but also to treat the patient appropriately. Pharmaceutical therapy of bone pain, includes non-steroidal analgesics, opiates, steroids, hormones, bisphosphonates, and chemotherapy. While external beam radiation therapy remains the mainstay of pain palliation of a solitary lesions, bone seeking radiopharmaceuticals have entered the therapeutic armamentarium for the treatment of multiple painful osseous lesions. $^{32}P,\;^{89}SrCl,\;^{153}Sm-EDTMP,\;^{188}Re/^{186}Re-HEDP,\;and\;^{177}Lu-EDTMP$ can be used to treat painful osseous metastases. These various radiopharmaceuticals have shown good efficacy in relieving bone pain secondary to bone metastasis. This systemic form of metabolic radiotherapy is simple to administer and complements other treatment options. This has been associated with improved mobility in many patients, reduced dependence on narcotic and non-narcotic analgesics, improved performance status and quality of life, and, in some studios, improved survival. All of these agents, although comprising different physical and chemical characteristics, offer certain advantages in that they are simple to administer, are well tolerated by the patient if used appropriately, and can be used alone or in combination with the other forms of treatment. This article illustrates the salient features of these radiopharmaceuticals, including the usual therapuetic dose, method of administration, and indications for use and also describe about the pre-management checklists, and jndication/contraindication and follow-up protocol.