• Investigative Magnetic Resonance Imaging
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• v.13 no.1
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• pp.74-80
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• 2009

Purpose : To evaluate the characteristic MR imaging findings of Langerhans cell histiocytosis (LCH) in the skull and to compare them with those of plain radiography and computed tomography. Materials and Methods : A total of 10 lesions in 9 patients (Age range; 5-42 years, Mean age; 18, all women) with Langerhans cell histiocytosis in the skull were included in our study. Nine lesions in nine patients were histologically confirmed by surgery or fine needle aspiration biopsy. All patients performed with MRI, and plain radiography and CT scan were done in 7 patients (8 lesions). Two experienced neuroradiologists reviewed the radiological examinations independently with attention to location, size, shape and nature of the lesions in the skull and compared the extent and extension of the lesions to adjacent structures. Results : The lesions were distributed in all of the skulls without predilection site. On MRI, the masses were shown as well-enhancing soft tissue masses (10/10) mainly in diploic spaces (8/10) with extension to scalp (9/10) and dura mater (7/10). Dural enhancement (7/10) and thickening (4/10) were seen. The largest diameter of the soft tissue masses ranged 1.1 cm to 6.8 cm, shaped as round (5/10) or oval (5/10). On CT scans, the lesions were presented as soft tissue masses involving diploic space (6/8) and scalp extension (7/8) were also well visualized. Although bony erosion or destruction was more clearly seen on CT rather than those of MRI, enhancement of soft tissue masses and dura were not well visualized on CT. In contrast, all of the lesions in LCH were seen as punched out (4/8), beveled-edge appearance (4/8) osteolytic masses in plain radiography, but scalp and dural extension could not be seen. Conclusion : Characteristic MR findings in patients with LCH are soft tissue mass in diploic space with extension to dura and scalp, and MRI would be better imaging modality than plain radiography or CT.

• Tuberculosis and Respiratory Diseases
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• v.44 no.6
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• pp.1263-1270
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• 1997

Background : Differentiation of malignity and benignity is crucial for management of solitary pulmonary nodule(SPN). Clinical parameters such as patient's age, nodule size, smoking history, doubling time, typical calcification in X-ray and CT findings have been reported as helpful in this purpose. However, in most cases, these parameters are not conclusive. Glucose metabolism is increased in cancer tissues including lung cancer tissues. After uptake of 2-[F-18]-fluoro-2-deoxy-D-glucose(FDG), the glucose analogue, by cancer cell, FDG is trapped in the cell without further metabolism after phosphorylation. Thus, hypermetabolic focus in FDG-positron emission tomography (PET) imaging suggest malignancy. We evaluated the diagnostic efficacy of FDG-PET imaging in distinguishing malignant and benign SPN. Methods : We evaluated 28 patients with SPN from Jan. 1995 to Jan. 1997. CT scan of chest and whole-body FDG-PET imaging were performed in all patients. Histologic diagnosis was confirmed by transthoracic fine needle aspiration and biopsy, bronchoscopic biopsy and open thoracotomy. Results : Of the 28 SPN's, 22 nodules were malignant and 6 nodules were benign. FDG-PET imaging diagnosed all malignant nodules correctly as positive, and diagnosed 4 of 6 benign nodules correctly as negative. One tuberculous granuloma and one aspergilloma showed hypennetabolic focus and were diagnosed falsely positve with FDG-PET imaging. In the diagnosis of SPN with FDG-PET, sensitivity and specificity were 100% and 66.7%, positive predictive value and negative predictive value were 92% and 100%. Conclusion : FDG-PET imaging is highly useful noninvasive diagnostic tool in distinguishing between malignant SPN and benign SPN.

• Journal of radiological science and technology
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• v.36 no.2
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• pp.149-155
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• 2013

The Korean Thyroid Association recommends fine-needle aspiration biopsy (FNAB) for nodules more than 0.5 cm in diameter. But nodules, smaller than 0.5 cm have been found in papillary carcinomas of the thyroid (PTC) at the health promotion center at SMC. We wanted to evaluate the ultrasonographic findings according to size of nodule in proven PTCs by FNAB, especially less than 0.5 cm. All nodules were classified into three groups by their longest diameter : less than 0.5 cm, more than 0.5 cm but less than 1 cm, and more than 1 cm. Sonographic findings suggesting malignancy were analyzed according to their size groups. Of 288 malignant nodules, 21.5 % (62/288) were less than 0.5 cm, 54.9 % (158/288) were more than 0.5 cm but less than 1 cm, 23.6 % (68/288) exceeded 1 cm. A taller-than-wide shape was observed in 90.3 % (56/62) of nodules less than 0.5 cm, and 48.5 % (33/68) of nodules exceeding 1 cm (p<0.001). There were no well-defined smooth nodules among nodules less than 0.5 cm, and spiculated or irregular margin nodules increased as the size increased (p=0.024). Nodules of size less than 0.5 cm did not showed hyper or isoechogenicity. Hypoechogenicity was greater than the marked hypoechogenicity in each group (p=0.034). Micro- or macro-calcifications were not founded in 77.4 % (48/62) of the nodule group sized less than 0.5 cm. From the small size of the group, micro- or macrocalcifications were observed 21.0 % (13/62), 48.1 % (76/158), 64.7 % (44/68), so the number of nodules containing micro- or macro-calcification increased as size increased (p<0.001). PTCs less than 0.5 cm in size on ultrasonography had taller than-wide shape, spiculated or irregular and ill-defined margins, and exhibited hypo and markedly hypoechogenicity, but microor macro-calcifications were not common. These ultrasonographic features of nodules less than 0.5 cm can be useful in reporting and guiding FNABs or follow-up exams.

• Journal of Chest Surgery
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• v.34 no.10
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• pp.787-791
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• 2001

Coronary artery aneurysm is a rare disorder. It is defined as abnormal dilatation of coronary artery with diameter exceeding 1.5 times the adjacent normal segments. The incidence of coronary aneurysm is 2.6% in Caucasians and 0.25% in Asians. Over half of the former were associated with atherosclerotic coronary artery disease. However, 70 percents of the latter were nonobstructive coronary artery aneurysms. Coronary artery fistula is a rare disorder. It has been identified in only 0.2% of routine cardiac angiographic studies conducted over a 10-year period. The clinical spectrums are various, asymtomatic, asymptomatic murmur, dyspnea on exertion, fatigue, and congestive heart failure. The right coronary artery (56%) and left coronary artery(36%) are mainly involved in the origin site of congenital coronary artery fistula. The draining site of fistula are right ventricle(39%), right atrium(33%), and pulmonary artery(20%) and so on. This 54 years-old woman had intermittent chest tightness and an abnormal mediastinal shadow on chest roentgenogram and chest C-T examination, which was diagnosed as a mediastinal mass such as teratoma. We performed the operation under left anterolateral thoracotomy for mass excision. However, we knew the mass had the pulsating arterial blood flow through a fine needle puncture of the mass and that it was attached to the left ventricle. We believed the excision of mass on beating heart would be very dangerous. Therefore, we closed the wound without excising the mass. After several days, we performed an echocardiography and coronary angiography, We knew it was cardiac tumor. Incidentally, the patient had a tortuous coronary fistula from the right coronary artery to pulmonary trunk. Using cardiopulmonary bypass with moderate systemic hypothermia, the mass was resected and the fistula was clipped with surgical clips. Pathology of the specimen was a giant coronary arterial aneurysm.

• Korean Journal of Radiology
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• v.22 no.12
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• pp.2094-2123
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• 2021

Incidental thyroid nodules are commonly detected on ultrasonography (US). This has contributed to the rapidly rising incidence of low-risk papillary thyroid carcinoma over the last 20 years. The appropriate diagnosis and management of these patients is based on the risk factors related to the patients as well as the thyroid nodules. The Korean Society of Thyroid Radiology (KSThR) published consensus recommendations for US-based management of thyroid nodules in 2011 and revised them in 2016. These guidelines have been used as the standard guidelines in Korea. However, recent advances in the diagnosis and management of thyroid nodules have necessitated the revision of the original recommendations. The task force of the KSThR has revised the Korean Thyroid Imaging Reporting and Data System and recommendations for US lexicon, biopsy criteria, US criteria of extrathyroidal extension, optimal thyroid computed tomography protocol, and US follow-up of thyroid nodules before and after biopsy. The biopsy criteria were revised to reduce unnecessary biopsies for benign nodules while maintaining an appropriate sensitivity for the detection of malignant tumors in small (1-2 cm) thyroid nodules. The goal of these recommendations is to provide the optimal scientific evidence and expert opinion consensus regarding US-based diagnosis and management of thyroid nodules.