• 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.

• Tuberculosis and Respiratory Diseases
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• v.53 no.6
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• pp.644-649
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• 2002

Background : Pulmonary hamartomas are the most common form of benign tumors, occurring in approximately 0.2% of routine autopsies. However, only a few reports on the clinical characteristics of pulmonary hamartoma in Korea have been published. Materials and Methods : The charts, X-rays and pathological specimens of 29 pulmonary hamartoma patients who were diagnosed by a pathological examination from 1990 to 1999 at the Catholic Medical Center were retrospectively reviewed. Results : The peak incidence of the tumor occurred in the sixth decade of life (37.5%). Seventeen patients (58.6%) were asymptomatic and 12 patients (41.4%) had symptoms. Chest discomfort was the most common symptom (31.0%). A total of 25 tumors (86.2%) were parenchymal, and 4 (13.8%) were endobronchial. Twenty cases were in the right lung and 9 cases were in the left lung (approximately 1:2.2). The RLL was the most commonly involved lobe (31.0%). Calcification was noted in 5 cases(19.2%) on a plain X-ray and in 5 cases (29.4%) on chest CT. Accompanied neoplasms were observed in 2 cases. Twenty-four hamartomas (82.8%) were diagnosed by a surgical resection and 4 cases(13.8%) were diagnosed by a fine needle aspiration biopsy. Twenty-six hamartomas (89.7%) were managed by a surgical resection. The follow up ranged from 4 to 55 months (mean, 19.6 months) and no recurrent pulmonary hamartomas were noted. Conclusion : Pulmonary hamartoma is more common in females and more commonly in the right lung. Calcification was noted only in 19.2% on a plain chest X-ray and 29.4% on a chest CT. No recurrent hamartomas had developed during the follow up period.

• 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.