• Clinical and Experimental Pediatrics
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• v.45 no.8
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• pp.973-979
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• 2002

Purpose : Recently, a number of rapid antigen detection tests have been available to diagnose group A streptococcal pharyngotonsillitis. The purpose of this study was to determine the sensitivity, specificity and consistency of the two rapid antigen detection tests. Methods : Among the patients who visited our clinic from November 2001 to February 2002, 61 patients who had clinical findings of pharyngeal erythema or edema, pharyngeal exudates and soft palatine petechiae were enrolled in our study. A total of 61 patients were tested with rapid antigen detection tests and throat culture. BD $LINK2^{TM}$ Strep A(Becton, Dickinson & Company, U.S.A.) and $QuickVue^{(R)}$ $In-Line^{TM}$(Quidel Corporation, U.S.A.) were selected for rapid antigen detection tests. Results : Of the 61 patients tested, 22 patients were confirmed as group A streptococcal pharyngotonsillitis by throat culture. The BD $LINK2^{TM}$ Strep A had a sensitivity of 81.8% and a specificity 89.7%. The positive and negative predictive values were 81.8% and 89.7%, respectively. The $QuickVue^{(R)}$ $In-Line^{TM}$ had a sensitivity of 77.3% and a specificity of 100%. The positive and negative predictive values were 100% and 88.6%, respectively. The kappa values of BD $LINK2^{TM}$ Strep A and $QuickVue^{(R)}$ $In-Line^{TM}$ were 0.72 and 0.81, respectively. Conclusion : In addition to high sensitivity, specificity and consistency, both kits are easy to use and simple to interpret, and therefore have the potential to be used with backup throat culture for diagnosis of acute pharyngotonsillitis.

• Tuberculosis and Respiratory Diseases
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• v.50 no.2
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• pp.213-221
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• 2001

Background : There is a well recognized interlaboratory variation in the results using the polymerase chain reaction(PCR) to detect the IS6110 sequence. The clinical utility of a commercially developed PCR test(Amplicor) in bronchial washings for detecting pulmonary tuberculosis in smear negative patients was evaluated. The sensitivity and specificity of Amplicor was compared with that of an in-house PCR test used for detecting the IS6110 sequence of Mycobacterium tuberculosis(M.tbc) in the bronchial washing fluid. Methods : 66 patients whose sputum smear for M. tbc were negative or who could not produce any sputum were recruited from January 1999 to July 1999. They all had a bronchoscopy performed to determine if there were signs of hemoptysis, patients who could not cough up sputum, lung lesion that exclude pulmonary tuberculosis. Pulmonary tuberculosis was diagnosed on the basis of a positive culture or a response to anti-tuberculosis therapy. Results : 19 patients with tuberculosis were identified and samples from 16 patients were later confirmed by culture. Bronchial washing for Amplicor PCR revealed a sensitivity, specificity, positive and negative predictive values of 94.7%, 97.9%, 94.7%, 97.9%, respectively. Using IS6110 based PCR, the sensitivity, specificity, positive and negative predictive values were of 73.7%, 87.2%, 70%, 89.1% respectively. Conclusion : Bronchial washing for Amplicor PCR proved to be more useful than IS6110 based PCR in rapidly diagnosing smear negative pulmonary pulmoary tuberculosis in patients where tuberculosis was likely to be differential and rapid diagnosis was essential for optimal treatment.

• Tuberculosis and Respiratory Diseases
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• v.50 no.2
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• pp.222-228
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• 2001

Backgrounds : Recent technological developments have introduced a new method to identifying M. tuberculosis complex DNA in clinical samples directly. The direct amplification test (DAT) is approved for identifying M. tuberculosis complex in respiratory specimens that are smear-positive for acid-fast bacilli (AFB). When there is a discrepancy between the AFB smear and DAT, no information on their clinical utility is currently available. In this study, the diagnostic reliability of DAT was investigated in suspected pulmonary tuberculosis patients whose sputum AFB smear was negative. Methods : From June 1, 1998 through May 30, 1999, 909 patients with presumed active pulmonary tuberculosis were enrolled. A sputum AFB stain, culture, DAT and/or biopsy were performed. Using the criteria of clinical tuberculosis or confirmed tuberculosis, the positive predictive value of DAT in diagnosing pulmonary tuberculosis was investigated. Results : The positive predictive value of DAT was 82.1% by the clinically active tuberculosis criteria. However, it decreased to 61.5% when diagnosis was restricted to only to culture positive or biopsy proven cases. The false positive rate of DAT was 18.0%. Conclusion : The DAT is a valuable diagnostic method in suspected patients whose sputum AFB is was negative.

• Tuberculosis and Respiratory Diseases
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• v.46 no.1
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• pp.17-24
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• 1999

Background : A sizable percentage of tuberculous pleurisy patients are known to have residual pleural thickening(RPT) despite adequate anti-tuberculous chemotherapy. But, the predictive factors related to the development of RPT is not well known. Therefore, we studied to determine which factors are related to the development of RPT after completion of therapy. Methods: By retrospective review of medical records, fifty-eight patients initially diagnosed as having tuberculous pleurisy between March 1995 and January 1998 were separated into two groups : 27 patients in group 1 had RPT on simple chest radiography, while 31 patients in group 2 had no RPT after 6 month of anti-tuberculous chemotherapy. The clinical characteristics, radiologic findings and pleural fluid findings of the two group were compared at the time of diagnosis and during the course of therapy. Results: 47% of patients had RPT after 6 month of chemotherapy, and RPT was more common in man than in women(54% vs 29%, p=0.092). In group 2 patients, complete resorption of pleural lesion occurred rather late stage of therapy(1-2 month: 26%, 3-4 month: 29%, 5-6 month: 45%). Group 1 patients had increased percentage of loculated pleural lesion(26 % vs 19%) and increased white blood cell and lymphocyte count, lactate dehydrogenase level in pleural fluid ($3527\pm5652$ vs $2467\pm2201$/ml, $2066\pm2022$ vs $1698\pm1835$/ml and $1636\pm1143$ vs $1441\pm923$IU/mL respectively) than group 2 at the time of diagnosis, but statistically insignificant. Duration of symptom prior to treatment, size of pleural effusion, presence of parenchymal lung lesion, level of total protein, glucose and adenosine deaminase(ADA)activity in pleural fluid were similar in both group. Conclusion: 53% of tuberculous pleurisy patients showed slow but complete resorption of pleural lesion after 6 month of chemotherapy. But, no clinical, radiological and pleural fluid findings are predictive for the development of RPT.

• 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 Gastric Cancer
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• v.8 no.4
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• pp.250-255
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• 2008

Purpose: The purpose of this study was to assess the diagnostic value of 18F-fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) for detecting the lymph node (LN) metastasis of gastric cancer. Materials and Methods: 119 patients (M : F=89 : 30; mean age: 64) with gastric cancer were referred for preoperative FDG-PET/CT scanning and spiral enhanced abdominal pelvic CT from June 2006 to July 2008, and these were the subjects of our study. All the patients underwent curative radical gastrectomy and lymph node dissection. A final diagnosis was made for all the patients by the histology of the surgical specimens. Results: Both PET/CT and enhanced CT showed similar sensitivity for detecting regional lymph node metastasis (32.6% vs 39.5%, respectively). PET/CT was more accurate than enhanced CT for detecting regional lymph node metastasis (67.2% vs 63.0%, respectively), and PET/CT showed better specificity (86.8% vs 76.3, respectively) and a better positive predictive value (PPV) (58.3% vs 48.6%, respectively). PET/CT showed better specificity (98.0% vs 88.2%, respectively) and accuracy (79.4% vs 73.9%, respectively) than enhanced CT for detecting early gastric cancer. PET/CT showed better specificity (64.0% vs 52.0%, respectively), a better PPV (60.9% vs 57.1%), a better negative predictive value (NPV) (48.5% vs 46.4%, respectively) and better accuracy (53.6% vs 51.8%, respectively) than enhanced CT for detecting advanced gastric cancer. Conclusion: FDG-PET/CT is more usefulness than enhanced CT for making the preoperative diagnosis of regional LN metastases from gastric cancers.

• Clinics in Shoulder and Elbow
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• v.12 no.2
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• pp.115-125
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• 2009

Purpose: The purpose of the study is to evaluate the usefulness of CT arthrography (CTA) by conducting a comparative study of CTA and MR arthrography (MRA) with the arthroscopic findings in the same patients. Materials and methods: Forty nine patients who suffered from shoulder disease underwent MRA and CTA concurrently. The sensitivity and specificity of CTA was evaluated, as compared to MRA, in the case of four types of shoulder pathological lesions. The accuracy of CTA was evaluated by analyzing the arthroscopic findings of thirty four patients. Results: Compared to MRA, CTA showed a sensitivity of 90% and a specificity of 100% for diagnosing supraspinatus tendon (SST) full thickness tear, and CTA showed a sensitivity of 100% and a specificity of 97.5% for making the diagnosis of superior labrum anterior to posterior (SLAP) lesion. For diagnosing partial articular side supraspinatus avulsion (PASTA) lesion, some studies have shown the usefulness of CTA with a sensitivity of 71.4% and a specificity of 97.7%. However, for diagnosing SST bursal side partial tear, the sensitivity of CTA was as low as 10%. CTA has been shown to be relatively accurate when the diagnoses were verified with the arthroscopic findings; diagnosing SST full thickness tear and SLAP lesion with CTA has shown an accuracy of 100% and87.5% respectively, and CTA showed 71.4% diagnostic accuracy for PASTA lesion. Conclusion: CTA was a useful tool and it was equivalent to MRA for the assessment of SST full thickness tear, SLAP lesion and PASTA lesion, but not bursal side partial tear. Thus, it may be used preferably to diagnose shoulder pathology and for follow up as an inexpensive tool after operation.

• Journal of the Korean Society of Radiology
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• v.81 no.1
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• pp.147-156
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• 2020

Purpose The objective of this study was to evaluate the diagnostic value and threshold levels of cytokeratin fragment 21-1 (CYFRA 21-1) in fine-needle aspiration (FNA) washouts for detection of lymph node (LN) recurrence in postoperative breast cancer patients. Materials and Methods FNA cytological assessments and CYFRA 21-1 measurement in FNA washouts were performed for 64 axillary LNs suspicious for recurrence in 64 post-operative breast cancer patients. Final diagnosis was made on the basis of FNA cytology and follow-up data over at least 2 years. The concentration of CYFRA 21-1 was compared between recurrent LNs and benign LNs. Diagnostic performance and cut-off value were evaluated using a receiver operating characteristic curve. Results Regardless of the non-diagnostic results, the median concentration of CYFRA 21-1 in recurrent LNs was significantly higher than that in benign LNs (p < 0.001). The optimal diagnostic cut-off value was 1.6 ng/mL. The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of CYFRA 21-1 for LN recurrence were 90.9%, 100%, 100%, 98.1%, and 98.4%, respectively. Conclusion Measurement of CYFRA 21-1 concentration from ultrasound-guided FNA biopsy aspirates showed excellent diagnostic performance with a cut-off value of 1.6 ng/mL. These results indicate that measurement of CYFRA 21-1 concentration in FNA washouts is useful for the diagnosis of axillary LN recurrence in post-operative breast cancer patients.

• Nuclear Medicine and Molecular Imaging
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• v.42 no.6
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• pp.444-450
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• 2008

Purpose: The aim of this study was to evaluate the usefulness of whole body positron emission tomography (PET) using $^{18}F-fluorodeoxyglucose$ ($^{18}F-FDG$) for cancer screening in asymptomatic subjects. Materials and Methods: The subjects were 1,762 men and 259 women who voluntarily underwent $^{18}F-FDG$ PET for cancer screening as a part of a routine health examination. Final diagnosis was decided by other diagnostic studies, pathological results or clinical follow-up for 1 year. Results: Of 2,021 subjects, 40 (2.0%) were finally proved to have cancer. Abnormal focal $^{18}F-FDG$ uptake suggesting malignancy was found in 102 subjects (5.0%). Among them, 21 subjects (1.0%) were proved to have cancer. Other tests in the routine health examination could not find 9 of 21 cancers (42.9%) detected by PET. The sensitivity, specificity, positive predictive value, and negative predictive value of PET for cancer screening were 52.5%, 95.9%, 20.6%, and 99.0%, respectively. Pathologies of cancers missed on PET were adenocarcinoma (n = 9; 3 colon cancers, 3 prostate cancers, 2 stomach cancers, and 1 rectal cancer), differentiated thyroid carcinoma (n = 6), bronchioalveolar cell carcinoma (n = 2), urinary bladder cancer (n = 1), and melanoma (n = 1). More than half of cancers which were not detected by PET were smaller than 1 cm in diameter. Conclusion: $^{18}F-FDG$ PET might be useful for cancer screening in asymptomatic subjects due to its high specificity and negative predictive value and playa supplementary role to the conventional health check-up, but it could not replace due to limited sensitivity for urological cancers, small-sized tumors and some hypometaboic cancers.

• Journal of Chest Surgery
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• v.35 no.1
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• pp.27-35
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• 2002

Background: A perioperative myocardial infarction(PMI) is one of the major complications after CABG. Among diagnostic methods of PMI, CK-MB activity assays have been increasingly replaced by CK-MB mass assays, which have more sensitive, simple measurement. Also, new cardiac-specific and -sensitive marker, cardiac troponin I(cTnl), has been shown to be a marker of myocardial infarction. We report our evaluation of clinical significance of CK-MB mass and cTnl as a marker of PMI after CABG. Material and Method: We studied 32 patients who underwent CABG at Kangdong Sacred Hospital between April 2000 and April 2001. Postoperative serum CK-MB activity level, serum CK-MB mass, cTnl, electrocardiogram, echocardiogram, and clinical data were recorded prospectively The diagnosis of PMI was defined as positive 2 among 3 or all of the following , by a new Q wave on the electrocardiogram, by serum CK-MB activity higher than 200 lU/L within 72 hours after operation, and by new regional wall motion abnormality on the echocardiogram. Result: After CABG, 3 patients had sustained a PMI according to current diagnostic criteria. As serum CK-MB activity time course, a level of CK-MB activity 12 hours after CABG had very linear correlated significance with serum CK-MB mass 24hours(R=0.946) and cTnl 48 hours(R=0.933) after CABG(p=0.000). As we used a receiver operating characteristics curve(ROC curve) for a diagnostic cutoff value in patients with PMI, serum CK-MB mass levels higher than 30.05 ug/L 24 hours after CABG detected the presence of PMI with an area under the ROC curve of 1.0, a sensitivity of 100%, a specificity of 100%, a positive predictive value of 100%, and a negative predictive value of 100%. Also serum cTnl levels higher than 17.15 ug/L 48 hours after CABG detected the presence of PMI with an area under the ROC curve of 0.98, a sensitivity of 100%, a specificity of 96.6%, a positive preclictive value of 75%, and a negative predictive value of 100% Conclusion: We concluded that both the measurement of CK-MB mass and cTnl are the easier, accurate methods as a diagnostic marker of PMT after CABG, also as a proposal of diagnostic cutoff value enables to an early detection of PMI. However, a 1arger number of patient will be needed because of statistic limitation that a small number of participating patients, a small number of PMI.