• Journal of the Korean Society of Radiology
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• v.84 no.5
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• pp.1009-1016
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• 2023

Radiofrequency ablation (RFA) is a minimally invasive treatment modality used as an alternative to surgery in patients with benign thyroid nodules and recurrent thyroid cancers. In Korea, RFA for thyroid nodules was first performed in 2002, and a large population study was published in 2008. The Task Force Committee of the Korean Society of Thyroid Radiology (KSThR) developed its first recommendations for RFA in 2009, which were revised in 2012 and 2018. The KSThR guideline was the first guideline for RFA of thyroid nodules worldwide and has become a guideline for physicians to perform thyroid RFA in Korea and other countries around the world. These guidelines have contributed significantly to the establishment and widespread use of RFA worldwide. In addition, since 2015, the KSThR has conducted intensive hands-on courses depending on the level of the participants. In this article, the authors introduce the history of eduction for RFA conducted by the KSThR and describe the learning curve of RFA and current training programs in Korea, along with future directions for training programs.

• Tuberculosis and Respiratory Diseases
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• v.43 no.4
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• pp.519-526
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• 1996

Background : Clinical and Radiographic studies to differentiate benign from malignant pulmonary nodules have previously focused on clinical status and the morphologic and the computed tomographic attenuation characteristics of the lung nodules. Distinctive differences in the vascularity and pathophysiology of malignant versus benign pulmonary nodules were identified. We evaluated the diagnostic method for differentiating malignant from benign solitary pulmonary nodule by contrast enhancement on the spiral CT. Method : Sixteen patients with solitary pulmonary nodule were examined(Tuberculoma 8, primary lung cancer 8). Serial thin section on the spiral CT was performed before and after(45second, 2min, 5min) the onset of the injection of 100mL of nonionic contrast material(2mL/sec). Results : There was no difference in size of nodule and pre-contrast CT number (Hounsfield unit) between benign and malignant nodules. At forty-five second after the onset of the injection, malignant neoplasms($19.6{\pm}7.9$ HU) enhanced significantly more than tuberculomas($4.9{\pm}9.4$ HU, p=0.008). At 2minute and 5 minute after, malignant neoplasms($34.0{\pm}19.2$HU, $34.0{\pm}15.4$HU) enhanced significantly more than tuberculomas ($6.7{\pm}9.7$HU, p=0.007 and $7.7{\pm}11.5$HU, p=0.011). On cut-off value 20HU(contrast enhancement) 2minute after the injection of contrast media, sensitivity was 87% and specificity was 87%. No correlation between the contrast enhancement and size of the nodules was observed. Conclusion : Studies with the use of an intravenously administered noniodinated contrast medium in examining the enhancement properties of lung nodules was performed. The contrast enhancement was useful in differential diagnosis of solitary pulmonary nodules.

• Journal of radiological science and technology
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• v.38 no.2
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• pp.145-153
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• 2015

Thyroid nodules are an endocrine disease often found in clinical practice, and patients with thyroid nodules found by chance have rapidly increased alongside development of thyroid ultrasound techniques for health examination purposes. This study analyzes the subjects' general characteristics, thyroid ultrasounds, and fine needle aspiration cytology in order to find out the relationship between male and female thyroid nodules and thyroid cancer frequency. An ultrasound examination of the thyroid was performed for 32,973 individuals who visited the K Hospital of Health Examination. Subjects have no history of thyroid disease and are 20 years old or over. Data of general characteristics, diabetes) was collected by a written survey completed by the subject, and the ultrasound of the thyroid(thyroid nodules existence, size, number) and FNAC was used to find out the malignancy rate. Frequency of patients with thyroid nodule was 4,611(26.1%) in men and 5,341(34.9%) in women between 32,973 individuals. Women's prevalence rate is significantly higher than men, and the prevalence rate significantly increased with age in men and women(p < 0.05). The prevalence of multiple nodules was significantly higher in women(43.5%) than in men(35.6%), and significantly increased with age in men and women(p < 0.05). The fine needle aspiration cytology was performed in 692(men 342, women 350) subjects who showed signs of malignancy through ultrasound. Prevalence of malignancy of the nodules was higher in men(33.3%) than in women(29.4%) although it is not statistically significant. It is known that thyroid nodule prevalence in women is much higher than in men. But this study shows the men's prevalence rate was not too low compared with women, and the men showed a rather higher malignancy rate in nodules than women. It is considered that the role of thyroid ultrasound is both important in men and women.

• Nuclear Medicine and Molecular Imaging
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• v.43 no.6
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• pp.543-556
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• 2009

Purpose: We studied the patterns of FDG uptake of primary papillary thyroid microcarcinoma (PTMCa) lesions and benign thyroid nodules in dual time point $^{18}F$-FDG PET/CT imaging. Materials and Methods: Consecutive 134 patients (154 lesions) with PTMCa and 49 patients (61 nodules) with benign thyroid nodules equal to or less than 1.0 cm who underwent dual time point $^{18}F$-FDG PET/CT study before surgery were enrolled. We calculated the maximum standardized uptake value of PTMCa and benign nodules in both time points, and percent change of SUVmax (${\Delta}%SUVmax$) and lesion to background ratio of SUVmax (${\Delta}L:B$% ratio) between both time points. The mean time interval between scans was $23.4{\pm}4.4$ minutes (thyroid to thyroid interval: $10.7{\pm}4.4$ minutes). Results: The mean of SUVmax of PTMCa was increased from $4.9{\pm}4.3$ to $5.3{\pm}4.7$ (p<0.001) and ${\Delta}%SUVmax$ was $12.3{\pm}23.6%$. But, the mean of SUVmax of benign nodules was no definite change ($2.1{\pm}1.0$ to $2.1{\pm}1.3$, p=0.686) and ${\Delta}%SUVmax$ was $-0.3{\pm}20.5%$. Of the 154 PTMCa, 100 nodules (64.9%) showed an increase in SUVmax over time, while 19 (31.1%) of the 61 benign thyroid nodules showed an increase (p<0.001). The dual time point $^{18}F$-FDG PET/CT found more PTMCa in visual assessment (62.3% vs. 76.6%, p=0.006), even in smaller than 0.5 cm (38.6% vs. 60.0%, p=0.011). Conclusion: Dual time time $^{18}F$-FDG PET/CT imaging was more useful than single time point $^{18}F$-FDG PET/CT imaging for distinction between PTMCa and benign nodule, especially when nodule showed equivocal or negative findings in single time point $^{18}F$-FDG PET/CT imaging or was smaller than 0.5 cm.

• Proceedings of the KOR-BRONCHOESO Conference
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• 1983.05a
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• pp.11.2-11
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• 1983

Vocal nodules and polyps are much more frequent in singers, public speakers, teachers and actors. Voice trauma and voice misuse, at times associated with mild inflammatory reaction, appear to be important in their etiology. It is generally agreed that vocal cord nodules and polyps are inflammatory in nature and they arise in the subepithelial layer of loose connective tissue of the vocal cord. Since the junction of anterior and middle thirds of the membranous cord and has the greatest amplitude of vibration. This is the site of predilection for vocal cord nodules. The author performed laryngomicrosurgery for 70 cases of vocal nodules and polyps at Ewha Womans University Hospital during the period of 5 years. The result obtained were as follows ; 1) Surgical excision is not necessarily the best approach because vocal nodules in the early stages will resolve with the simplest voice therapy. 2) In children, surgery is rarely indicated because most nodules in children regress during adolescence. 3) For patients who use their voices professionally, voice therapy is indicated for three months. 4) If after three month of conservative treatment the cord lesion does not improve and the patient it still dissatisfied with his voice, laryngomicrosurgery can then be considered. 5) The small cuffed endotracheal tube in the interarytenoid space helps to keep the cords immobile and in an abducted position. 6) Removal of the nodule shoule be started by gentle retraction posteriorly and as soon as a tear appears anterior to the nodule. 7) On occasion it is preferable to start the dissection with a siccle knife while the nodule is held on the stretch. 8) Voice rest should be maintained for a week following which the free edges of the cords are usually healed.

• Korean Journal of Mineralogy and Petrology
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• v.34 no.4
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• pp.241-253
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• 2021

Manganese nodules have been found in the shallow water depth of the Arctic Ocean as well as in the abyssal plains of the Pacific and Indian Oceans, but detailed study for them were rarely investigated. Manganese nodules, collected from the East Siberian Sea through the Arctic Expedition using Araon ice braking vessel, have a high potential for Mn mineral resources because they have high Mn content with high Mn/Fe ratio. This study investigated the external form, size and weight, internal texture for the non-spherical manganese nodule, which has about 7 % of total nodule from the East Siberian Sea. This study also researched the relative Mn-oxide mineral composition using the peak area ratio of X-ray diffraction pattern and their chemical composition. All data obtained from non-spherical nodules were compared with the spherical ones. Ellipsoidal, platy and irregular types are common among 5 groups of non-spherical manganese nodule based on the external form, and major axis and weight have positive relationship. All non-spherical manganese nodules have core mainly composed of mud sediments. The average Mn oxide mineral contents in nodules are birnessite, buserite and todorokite in descending order. Although mineral composition does not show any correlation with the external form, kind of core or internal structure, todorokite and buserite contents tend to increase and birnessite content decrease from the surface to the core in the nodule. Non-spherical manganese nodules have higher Mn content and Mn/Fe ratio than those from the shallow water depth of the Arctic Sea and even in the deep-sea of the Pacific and Indian Ocean. Although non-spherical nodule is larger and heavier, and has lower Mn content and Mn/Fe ratio than spherical nodule, there are not any differences in mineral composition and internal structure between them. Almost all manganese nodules collected from the East Siberian Sea are attributed to diagenetic process, because they are higher than 5 in Mn/Fe ratio.

• Proceedings of the Petrological Society of Korea Conference
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• 1999.06a
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• pp.99-102
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• 1999

• Proceedings of the Petrological Society of Korea Conference
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• 1999.06a
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• pp.70-74
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• 1999

• Proceedings of the Petrological Society of Korea Conference
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• 1999.06a
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• pp.95-98
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• 1999

• Korean Journal of Radiology
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• v.22 no.2
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• pp.291-292
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• 2021