• 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.

• Investigative Magnetic Resonance Imaging
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• v.6 no.1
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• pp.47-54
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• 2002

Purpose : Hippocampal atrophy is one of the characteristic pathologic findings of hippocampal sclerosis, for which MR imaging of the hippocampus is essential in the evaluation of hippocampal sclerosis. The purpose of this study is to present the normal MR volumetric data of the hippocampus in normal adult Korean and to compare those with MR volumetric data of hippocampus in patients with hippocampal s-clerosis, providing the diagnostic volume criteria of the hippocampal atrophy. Materials and methods : MR volumetry was performed in 30 normal adults and 28 patients with temporal lobe epilepsy whose final diagnosis was hippocampal sclerosis. The volumetric data were compared between sexes, right and left sides, and normal and abnormal hippocampus, and the volume criteria for the diagnosis of hippocampal atrophy was determined. Results : The mean $volumes({\pm}standard$ deviation) of normal Korean adult were $2.20{\pm}0.73\textrm{cm}^3$ (right) and $2.17{\pm}0.72\textrm{cm}^3$ (left) in male and $2.27{\pm}0.47{\;}\textrm{cm}^3$ (right) and $2.23{\pm}0.48\textrm{cm}^3$ (left) in female. The mean right-left differences were $0.14{\pm}0.11\textrm{cm}^3$ and $0.19{\pm}0.13\textrm{cm}^3$ in male and female, respectively. The MR volumetry showed no significant statistical differences between sexes and between right and left. The mean volume and standard deviation of the hippocampus in hippocampal sclerosis patients was $1.46{\pm}0.60{\;}\textrm{cm}^3$, and the right-left difference was $0.51{\pm}0.41\textrm{cm}^3$, In comparison of two volume distributions between normal adult group and hippocampal sclerosis patients group, the reasonable diagnostic volume criteria was $0.4{\;}\textrm{cm}^3$ as right-left volume difference, in which the sensitivity and specificity are 0.61 and 0.90. In all patients with right-left volume difference more than $0.4{\;}\textrm{cm}^3$, visual determination of unilateral hippocampal atrophy was possible. Conclusion : The MR-based hippocampal volumetry is a useful add-on of visual MR diagnosis, only when visual diagnosis of hippocampal sclerosis is difficult.

• Pediatric Infection and Vaccine
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• v.12 no.2
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• pp.124-134
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• 2005

Purpose : It has been known that the diagnostic confirmation of group A streptococcal pharyngitis is accompanied with the results of throat culture and/or rapid antigen detection test(RADT). This study was designed to evaluate the usefulness and cost benefits of the RADT in patients with a sore throat compared the empirical antibiotic treated group without using RADT or throat culture with the antibiotic treated group according to the results of RADT test and/or throat culture. Methods : From April 2003 to August 2003, total 369 patients were enrolled this study. They were redistributed into two groups. In one group, the RADT test and throat culture were used and the patients received antibiotic treatment according to the results of test and in the other group, no diagnostic examinations were used and the patients were treated with antibiotics which were chosen empirically. The flow sheet with questionnaire was drawing up and obtained the clinical symptoms, signs and the name of antibiotics that were administered. Results : A total of 244 patients were treated after the throat culture and/or RADT, and 125 patients were treated empirically. The prevalence of bacteriologically confirmed group A streptococcal pharyngitis was 20.1%. The sensitivity and specificity of RADT were 89.8% and 86.1%, respectively. Positive predictive value and negative predictive value were 62.0% and 97.1%, respectively. The rate of antibiotic use was high in both groups. Because the physician used the antibiotics even if the result of RADT was negative. So about 37% of reduction of antibiotics use might be possible if we used antibiotics according to the results of RADT. There were no cost differences between the RADT applied group and the empirically treated antibiotic group if we could reduce the price of RADT to 63% of the current price. Conclusion : The RADT could be applied for the easy and rapid diagnosis and prompt treatment for group A streptococcal pharyngitis, and RADT could reduced the number of antibiotics used if the price of RADT was reduced to 63% of current price. For accurate evaluation of efficacy and cost effect, further controlled study is needed.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.11 no.2
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• pp.103-109
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• 2008

Purpose: Children with esophagitis express a variety of nonspecific symptoms and signs depending on their age, and diagnosis is limited because gastrointestinal endoscopy (GFS) and biopsy are difficult to perform. The aim of this study was to examine the prevalence of esophagitis in children with upper abdominal pain, to determine the necessity of esophageal biopsy, and to evaluate the associated risk factors. Methods: We reviewed 266 pediatric patients with upper abdominal pain who underwent history-taking, physical examination, and GFS with esophageal and gastric biopsies between January 2006 and December 2007. Esophagitis was confirmed on biopsy. We analyzed the risk factors for histologic esophagitis and the necessity of esophageal biopsy. Results: The prevalence of esophagitis was 19.9% (53/266 patients). The sensitivity and specificity of endoscopic diagnosis were 41.5% and 77%. Of 53 patients with histologic esophagitis, reflux esophagitis was seen in 50 patients, eosinophilic esophagitis was seen in 2 patients, and esophageal candidiasis was seen in 1 patient. Vomiting was a significant factor in patients under 8 yr of age (p<0.05). H. pylori infection was documented in 41.5% of patients with histologic esophagitis, compared with 58.5% of patients not infected with H. pylori (p<0.05). The possibility of histologic esophagitis was higher in patients with H. pylori infection (OR 2.5, 95% CI 1.2544 to 4.8286) and in those who visited in the spring (OR 2.5, 95% CI 1.2544 to 4.8286). Conclusion: We believe esophageal tissue biopsy should be performed in pediatric patients with upper gastrointestinal symptoms who are undergoing GFS and stomach tissue biopsy, especially preschoolers and H. pylori-infected children in the spring.

• Tuberculosis and Respiratory Diseases
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• v.57 no.6
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• pp.528-534
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• 2004

Background : Microscopic examination of sputum smears for acid-fast bacilli (AFB) is the most important and rapid diagnostic test for pulmonary tuberculosis. However, the AFB observed on the smear may represent either M. tuberculosis or nontuberculous mycobacteria (NTM). This study examined the clinical usefulness of a polymerase chain reaction test for M. tuberculosis (TB-PCR) for the differentiation of pulmonary tuberculosis and NTM lung disease in patients with smear-positive sputums in a tertiary hospital in Korea. Material and Methods : From January, 2003 to December, 2003, 826 AFB smear-positive and culture-positive sputum specimens were collected from 299 patients. Results : NTM were recovered from 26.6% (220/826) of the smear-positive sputum specimens and 23.4% (70/299) of the patients with smear-positive sputum. All the patients with isolated NTM had clinically significant NTM lung disease; 38 patients (54.3%) had M. avium and 26 patients (37.1%). had M. abscessus. In the patients with pulmonary tuberculosis, 78.7% of the patients (74/94) showed TB-PCR positivity, and all the patients with NTM lung disease showed negative results on the TB-PCR test (p<0.001). A positive result of the TB-PCR test on the sputum or bronchial washing fluid specimens was able to predict pulmonary tuberculosis with 88.4% sensitivity, 100% specificity, a 100% positive predictive value and a 79.7% negative predictive value for the patients with smear-positive sputum. Conclusion : The TB-PCR test for sputum specimens or bronchial washing fluid specimens could be useful for differentiating pulmonary tuberculosis and NTM lung disease for the patients with smear-positive sputum in Korea.

• Nuclear Medicine and Molecular Imaging
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• v.43 no.5
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• pp.436-442
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• 2009

Purpose: We underwent this study to evaluate the diagnostic potential of I-123/I-131 metaiodobenzylguanidine (MIBG) scintigraphy alone in the initial diagnosis of pheochromocytoma, compared with biochemical test and anatomic imaging. Materials & Methods: Twenty two patients (M:F=13:9, Age: $44.3{\pm}\;19.3$ years) having the clinical evaluation due to suspicious pheochromocytoma received the biochemical test, anatomic imaging modality (CT and/or MRI) and I-123/I-131 MIBG scan for diagnosis of pheochromocytoma, prior to histopathological confirmation. MIBG scans were independently reviewed by 2 nuclear medicine physicians. Results: All patients were confirmed histopathologically by operation or biopsy (incisional or excisonal). In comparison of final diagnosis and findings of each diagnostic modality, the sensitivities of the biochemical test, anatomic imaging, and MIBG scan were 88.9%, 55.6%, and 88.9%, respectively. And the specificities of the biochemical test, anatomic imaging, and MIBG scan also were 69.2%, 69.2%, and 92.3%, respectively. MIBG scan showed one false positive (neuroblastoma) and one false negative finding. There was one patient with positive MIBG scan and negative findings of the biochemical test, anatomic imaging. Conclusion: Our data suggest that I-123/I-131 MIBG scan has higher sensitivity, specificity, positive predictive value, negative predictive value and accuracy than those of biochemical test and anatomic imaging. Thus, we expect that MIBG scan is e tectively used for initial diagnosis of pheochromocytoma alone as well as biochemical test and anatomic imaging.

• Tuberculosis and Respiratory Diseases
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• v.45 no.2
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• pp.280-289
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• 1998

Background: It is sometimes difficult to differentiate tuberculous pleural effusion from malignant pleural effusion by clinical symptoms, signs, by routine tests of pleural fluid, and by pathologic studies. And recently, it was discovered that cytokines such as IL-2, IFN-$\gamma$, TNF-$\alpha$ are elevated in tuberculous pleural fluid, and there have been several attempts to diagnose tuberculous pleural effusion by using these immunological mediators. There are several studies regarding the diagnostic value of IFN-$\gamma$, and there are two studies in Korea. But the diagnostic values of IFN-$\gamma$ in these studies were slightly lower than those in other countries. To compare the diagnostic value of IFN-$\gamma$ with those of CEA and ADA, and to determine the sensitivity and specificity of IFN-$\gamma$ in Korean, we mesured IFN-$\gamma$, CEA level and ADA activity in pleural effusions. Methods: ADA activity, IFN-$\gamma$ level and CEA level as well as cell count, differential count, and biochemical assays such as protein content and lactate dehydrogenase were measured in 40 cases of tuberculous pleuritis and 42 cases of malignant pleural effusion. Results: Tuberculous pleural fluid showed higher levels of IFN-$\gamma$ and ADA ($832.6{\pm}357.2$ pg/ml and $82.5{\pm}25.9$ U/L, respectively) than those of malignant pleural effusion ($2.6{\pm}8.0$ pg/ml and $19.2{\pm}10.9$ U/L, respectively) (p<0.01). Malignant pleural effusions showed higher median value (102.2 ng/ml) than tubercalous pleural effusions (1.8 ng/ml) (p<0.01). The sensitivities of IFN-$\gamma$, ADA, CEA were 0.97, 0.87, 0.67 and the specificities of IFN-$\gamma$, ADA, CEA were 1.0, 0.97, 1.0, respectively. There was no significant correlation between ADA activity and IFN-$\gamma$ level. Conclusion: This study showed that IFN-$\gamma$ test would be a very useful clinical test for differential diagnosis of tuberculous pleuritis and malignant pleural effusion because it is very sensitive and specific, although it is an expensive test.

• Tuberculosis and Respiratory Diseases
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• v.55 no.6
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• pp.589-596
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• 2003

Background : The solitary pulmonary nodule(SPN) presents a diagnostic dilemma to the physician and the patients in the our nation with high incidence of tuberculoma. We could not exclude whether the SPN was benign or malignant by the change of the size at chest radiograph and findings of chest CT. Recently, positron emission tomography(PET) have been tried as the differential diagnostic method of SPN. We evaluated the efficacy of PET for differentiating malignant from benign SPN and the relationship between standardized uptake values(SUV) of PET and serum glucose. Method : Between January 2001 and July 2002, sixty-one patients with pulmonary nodule were examined by the chest CT and PET. The SPN has been finally diagnosed by the transthorasic needle aspiration and biopsy, bronchoscopic biopsy, and open lung biopsy. Results : Forty eight patients had a malignant nodule(23 squamous cell lung carcinoma, 16 adenocarcinoma, 9 small cell lung cancer) and thirteen patients had a benign nodule(3 tuberculoma, 9 inflammatory granuloma, 1 cryptococcosis). The mean size of malignant and benign nodule was 40.6 mm and 20.0 mm, respectively. All malignant nodules showed a marked increase in 18 fluorodeoxyglucose (FDG) uptake. Mean SUV of malignant was $9.52{\pm}5.20$ and benign nodule was $1.61{\pm}3.60$. There were false positive cases with an increase in 18-FDG uptake (2 tuberculoma, 1 inflammatory granuloma). The SUV of malignant nodule in diabetes patients has no difference in non diabetes patients($9.10{\pm}4.51$ vs $9.65{\pm}5.46$). The sensitivity and specificity of the PET scan for SPN were 100%, 77%, respectively. The positive and negative predictive values were 94% and 100%. Conclusion : PET scanning showed highly accurate result in differentiating the malignant and benign SPN. There were no significant differences between the SUV and serum glucose in the patients with lung cancer.

• Clinical and Experimental Pediatrics
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• v.49 no.1
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• pp.87-92
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• 2006

Purpose : It is difficult to make a distinction between lower urinary tract infection(UTI) and acute pyelonephritis(APN) during the acute phase of febrile UTI due to nonspecific clinical symptoms and laboratory findings, especially among young children. We measured the serum procalcitonin(PCT) in children with UTI to distinguish between acute pyelonephritis and lower UTI, and to determine the accuracy of PCT measurement compared with other inflammatory markers. Methods : Serum samples were taken from children who admitted with unexplained fever or were suspected of having UTI. 51 children(mean $12.2{\pm}11.4$ months) were enrolled in this study. Leukocyte counts, erythrocyte sedimentation rates(ESR) and C-reactive protein(CRP) were also measured. Renal parenchymal involvement was assessed by $^{99m}Tc$ DMSA scintigraphy in the first 7 days after admission. PCT was measured by immunoluminometric assay. Results : PCT values were significantly correlated with the presence of renal defects in children with UTI(n=16)($5.06{\pm}12.97{\mu}g/L$, P<0.05). However, PCT values were not significantly different between children with UTI without renal damage(n=18) and children without UTI(n=17). Using a cutoff of $0.5{\mu}g/L$ for PCT and 20 mm/hr for ESR, 20 mg/L for CRP, sensitivity and specificity in distinguishing between UTI with and without renal involvement were 81.3 percent and 88.9 percent for PCT 87.5 percent and 72.2 percent for ESR, and 87.5 percent and 55.6 percent for CRP, respectively. Positive and negative predictive values were 86.7 percent and 84.2 percent for PCT and 60.9 percent and 81.8 percent for CRP, respectively. Conclusion : In febrile UTI, PCT values were more specific than CRP, ESR and leukocyte count for the identification of patients who might develop renal defects.

• Progress in Medical Physics
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• v.24 no.2
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• pp.99-107
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• 2013

The surgical resection was occurred mainly in liver metastasis before the development of radiation therapy techniques. Recently, Radiation therapy is increased gradually due to the development of radiation dose delivery techniques. 18F-FDG PET image showed better sensitivity and specificity in liver metastasis detection. This image modality is important in the radiation treatment with planning CT for tumor delineation. In this study, we applied automatic image segmentation methods on PET image of liver metastasis and examined the impact of image factors on these methods. We selected the patients who were received the radiation therapy and 18F-FDG PET/CT in Korea Cancer Center Hospital from 2009 to 2012. Then, three kinds of image segmentation methods had been applied; The relative threshold method, the Gradient method and the region growing method. Based on these results, we performed statistical analysis in two directions. 1. comparison of GTV and image segmentation results. 2. performance of regression analysis for relation between image factor affecting image segmentation techniques. The mean volume of GTV was $60.9{\pm}65.9$ cc and the $GTV_{40%}$ was $22.43{\pm}35.27$ cc, and the $GTV_{50%}$ was $10.11{\pm}17.92$ cc, the $GTV_{RG}$ was $32.89{\pm}36.8$4 cc, the $GTV_{GD}$ was $30.34{\pm}35.77$ cc, respectively. The most similar segmentation method with the GTV result was the region growing method. For the quantitative analysis of the image factors which influenced on the region growing method, we used the standardized coefficient ${\beta}$, factors affecting the region growing method show GTV, $TumorSUV_{MAX/MIN}$, $SUV_{max}$, TBR in order. The result of the region growing (automatic segmentation) method showed the most similar result with the CT based GTV and the region growing method was affected by image factors. If we define the tumor volume by the auto image segmentation method which reflect the PET image parameters, more accurate and consistent tumor contouring can be done. And we can irradiate the optimized radiation dose to the cancer, ultimately.