• Korean Journal of Radiology
• /
• 제23권4호
• /
• pp.466-478
• /
• 2022

Objective: ¹⁸F-fluorodeoxyglucose (FDG) PET/CT is often used for detecting malignancy in patients with newly diagnosed hemophagocytic lymphohistiocytosis (HLH), with acceptable sensitivity but relatively low specificity. The aim of this study was to improve the diagnostic ability of ¹⁸F-FDG PET/CT in identifying malignancy in patients with HLH by combining ¹⁸F-FDG PET/CT and clinical parameters. Materials and Methods: Ninety-seven patients (age ≥ 14 years) with secondary HLH were retrospectively reviewed and divided into the derivation (n = 71) and validation (n = 26) cohorts according to admission time. In the derivation cohort, 22 patients had malignancy-associated HLH (M-HLH) and 49 patients had non-malignancy-associated HLH (NM-HLH). Data on pretreatment ¹⁸F-FDG PET/CT and laboratory results were collected. The variables were analyzed using the Mann-Whitney U test or Pearson's chi-square test, and a nomogram for predicting M-HLH was constructed using multivariable binary logistic regression. The predictors were also ranked using decision-tree analysis. The nomogram and decision tree were validated in the validation cohort (10 patients with M-HLH and 16 patients with NM-HLH). Results: The ratio of the maximal standardized uptake value (SUVmax) of the lymph nodes to that of the mediastinum, the ratio of the SUVmax of bone lesions or bone marrow to that of the mediastinum, and age were selected for constructing the model. The nomogram showed good performance in predicting M-HLH in the validation cohort, with an area under the receiver operating characteristic curve of 0.875 (95% confidence interval, 0.686-0.971). At an appropriate cutoff value, the sensitivity and specificity for identifying M-HLH were 90% (9/10) and 68.8% (11/16), respectively. The decision tree integrating the same variables showed 70% (7/10) sensitivity and 93.8% (15/16) specificity for identifying M-HLH. In comparison, visual analysis of ¹⁸F-FDG PET/CT images demonstrated 100% (10/10) sensitivity and 12.5% (2/16) specificity. Conclusion: ¹⁸F-FDG PET/CT may be a practical technique for identifying M-HLH. The model constructed using ¹⁸F-FDG PET/CT features and age was able to detect malignancy with better accuracy than visual analysis of ¹⁸F-FDG PET/CT images.

• 대한소아치과학회지
• /
• 제27권1호
• /
• pp.169-179
• /
• 2000

초기 우식병소와 건전한 치질은 광학적 특성 이 다르다는 사실에 근거하여 치과 치료용으로 개발된 가시광선 영역의 아르곤 레이저의 형광현상, 즉 물체에 조사되어 반사된 및은 물체의 광학적 특성에 따라 파장이 달라지는 특성을 이용하여, 우식 치질과 건전한 치질간의 광학적 특성의 차이를 아르곤 레이저 빛을 통한 색조의 차이로 유도 전환하는 시스템을 개발하고 이를 이용하여 초기 치아우식 병소를 조기에 시각적으로 탐지하여 data화 하는 새로운 우식활성검사법을 개발하는데 본 연구의 목적이 있다. 연구는 3단계로 나누어 1단계는 아르곤 레이저 형광법의 초기 우식병소 탐지능력을 평가하였으며 2단계는 임상에서 아동들을 대상으로 아르곤 레이저 형광법을 이용하여 초기 우식병소가 있는 치아의 갯수를 집계하고 이 수치에 대한 우식활성검사법인 $Cariescreen^{(R)}$ test, 그리고 일종의 구강환경검사인 우식경험치아의 수(dDfFtT) 검사와의 상관성을 평가하였다. 3단계는 이와 같은 자료를 기준으로 하여 레이저 형광법을 이용하여 검사할 수 있는 새로운 우식활성검사 모델을 만들고 이와 같은 검사법의 민감도, 타당도, 진단력 등을 분석하여 진단학적 측면에서 활용 가능성을 평가하고자 하였으며 그 결과는 다음과 같다. 초기 우식병소의 조직학적 깊이가 증가될수록 레이저 형광법을 이용하여 측정한 광밀도가 증가하였으며 이들 사이에는 높은 상관관계 (=0.7015)가 있었다. 또한 통계학적으로 회귀분석을 시행한 결과 병소의 깊이와 광밀도와 사이에는 정비례 관계의 직선방정식 관계를 나타내었다. 레이저 형광법을 이용한 우식활성검사법은 $Cariescreen^{(R)}$ test 그리고 dDfFtT 검사 등과 높은 상관관계를 나타냈다. 또한 레이저 형광법을 이용한 우식활성 검사법은 dDfFtT검사를 기준으로 48%의 민감도, 52%의 특이도, 45%의 진단력을 보였으며 $Cariescreen^{(R)}$ test를 기준으로 48%의 민감도, 51%의 특이도, 36%의 진단력을 보였다. 이상의 결과를 종합하면 레이저 형광법을 이용하여 측정한 초기 우식병소의 광밀도는 실제 초기우식병소의 조직학적병소의 깊이를 평가하는데 높은 진단학적 신뢰성을 보여주고 있으며 레이저 형광법을 이용한 우식활성검사는 진단학적 지표를 기준으로 볼 때, 그리고 검사절차와 시간, 비용 등의 면으로 볼 때 향후 임상적으로 활용 가능성이 높은 것으로 사료된다.

• Journal of Preventive Medicine and Public Health
• /
• 제52권4호
• /
• pp.272-275
• /
• 2019

The 2018 National Guideline for Tuberculosis Control, which was published by the Korea Centers for Diseases Prevention and Control (KCDC), mandates conducting an epidemiological survey among close contacts of active tuberculosis patients at public institutions such as schools. In the procedure for these surveys, the tuberculin skin test (TST) is mandated as the screening test for latent tuberculosis infection in elementary school students. However, several guidelines recommend using the interferon-gamma releasing assay (IGRA) for contacts aged over 5 years with a Bacillus Calmette-$Gu{\acute{e}}rin$ vaccination history. The main reason for this is that IGRA has a higher specificity and lower false positive rate than TST. In addition, IGRA requires only a single visit to draw blood and the results are available within 24 hours. These advantages could promote cooperation from both parents and students in conducting these surveys. Thus, these findings regarding the benefits of IGRA for surveys of close contacts at elementary schools should be incorporated into the KCDC guideline.

• 대한수의학회지
• /
• 제37권2호
• /
• pp.349-358
• /
• 1997

Mycobacterium paratuberculosis is the etiologic agent of Johne's disease, a chronic inflammatory bowel syndrome in ruminants. The attempts to control or eradicate the disease were severely hampered by the inadequacies of present diagnostic methods. The first purpose of this study was to detect Johne's disease out of 577 cows in the province of Kyunggi, Chungchong, Gangweon and the second purpose was to compare the results of non-absorbed ELISA, absorbed ELISA, PCR, and conventional culture methods. The third purpose was to increase diagnostic specificity, accuracy and rapidity. When non-absorbed ELISA test was conducted with Mycobacterium paratuberculosis antigen, the prevalence of positive was 10.9%. To increase diagnostic specificity, absorbed ELISA test with Mycobacterium phlei was used. In this test, the positive prevalence was 1.7%. For the specific detection of Mycobacterium paratuberculosis, PCR was applied to bacterial culture obtained from fecal samples of cattle. The DNA sequences derived from IS900 were used to prepare DNA primers for detection and identification of Mycobacterium paratuberculosis by PCR. PCR for M paratuberculosis isolated from fecal cultures amplified specific target DNA. PCR was much more rapid than that obtained by conventional culture technique in diagnosis of Johne's disease.

• Journal of Preventive Medicine and Public Health
• /
• 제43권1호
• /
• pp.9-17
• /
• 2010

Objectives: Parkinson's disease is one of the most common neurodegenerative diseases in the elderly population. In order to estimate the prevalence of Parkinson's disease in the community, the application of a good screening tool is essential. We evaluated the validity and reliability of a Parkinson's disease screening questionnaire and propose an alternative measure to improve its validity for use in community surveys. Methods: We designed the study in a three-phase approach consisting of a screening questionnaire, neurologic examination, and confirmatory examination. A repeated survey was administered to patients with disease detected in the community and on 150 subjects. We examined internal consistency using Cronbach's alpha test, test-retest reliability using the kappa statistic, and validity using sensitivity, specificity, and ROC curves. Unadjusted odds ratios were utilized for the estimation of weights for each questionnaire item. Results: The Cronbach's alpha of the questionnaire was 0.708. The kappa statistic for test-retest reliability was good to generally fair in most of the items. When newly proposed weighting scores were used, the optimum cut-off value was 7/8. When cut-off value was 5/6 for surveying prevalence in a community, the sensitivity was 0.98, and the specificity was 0.61, with simultaneous improvement in reliability. Conclusions: We recommend 5/6 as the ideal cut-off value for the survey of PD prevalence in community. This questionnaire designed for the Korean community could help future epidemiologic studies of PD.

• 대한수의학회지
• /
• 제34권3호
• /
• pp.529-536
• /
• 1994

To establish more specific and simple diagnostic methods for detection of the antibodies and antigens of Aujeszky's disease virus(ADV), we designed indirect dot-immunoassay(IDI) and double sandwich dotimmunoassay(DSDI) using the solid phases of nitrocellolose paper and polystyrene plate. The diagnostic efficacy of these methods was investigated. As the sensitivity of IDI was tested by various virus concentration, the specimens with the virus titer above $10^{4.0}TCID_{50}/0.2ml$ showed positive reaction, but that below $10^{1.0}TCID_{50}/ml$ revealed negative. Tonsil emulsion at the virus titer of $10^{4.5}TCID_{50}/0.2ml$ showed the highest sensitivity as diluted by 1/100. In detection of ADV antigens from the various tissues of the rats and pigs infected with ADV, IDI using monoclonal antibody showed the higher specificity as compared with IDI using polyclonal antibody and virus isolation method. The efficacy of the DSDI for detection of ADV antibody was compared with other tests. The sensitivity of DSDI was higher than virus neutralization(VN) and agar gel immunodiffusion test(AGID). Meanwhile, specificity of DSDI was lower than AGID, but similar to IDEA. In comparison with VN test, DSDI showed 96.9% agreement to VN test that is the highest of three tests. In general, application of polyclonal antibody in both tests caused the higher sensitivity but the lower specificty.

• 대한물리의학회지
• /
• 제14권4호
• /
• pp.29-35
• /
• 2019

PURPOSE: The aim of this study was to provide the standard value of the Five Times Sit to Stand Test (FTSST) measurement on the daily life independence of the elderly in Korea and examine the effects of this test on their daily lives. METHODS: This study was conducted on elderly people over 65 years of age living in Gyeongsangbuk-do, Korea. FTSST was performed while sitting position on a chair. The subjects were classified into independent and dependent living groups according to their lifestyle, and their influence was then examined through logistic regression analysis. To determine the usefulness and cut-off value of the FTSST, the analysis was performed using the ROC curve. RESULTS: The elderly were more likely to live in a group rather than independently as the FTSST time increased (p<.05) (OR=1.098). The area of the lower part of the ROC curve was .707, and as the FTSST increased, a subject was more likely to live in a group rather than independently (p<.05). The cut-off value was assigned to the point where both the specificity and sensitivity were at the coordinates. The sensitivity and specificity were .626 and .753, respectively at 15.62 seconds. CONCLUSION: The elderly in Korea are more likely to live a group-dependent lifestyle than live independently; the likelihood of this outcome is increased further for every additional second beyond 15.62 seconds. The loss of independence of daily life could be predicted based on the status of a subject's lower leg strength using the FTSST.

• 전자공학회논문지SC
• /
• 제49권2호
• /
• pp.38-45
• /
• 2012

선천성 난청으로 태어난 아이를 조기에 진단하여 가능한 빨리 적절한 치료를 해줌으로써 치료 효과를 극대화하고, 이후에 발생되는 사회적 비용을 최소화할 수 있기 때문에 신생아로부터 난청 이상 유무를 객관적으로 판별하는 검사 장비가 필요하다. 대표적인 것으로 청성뇌간반응(auditory brainstem response, ABR) 검사가 있으나 클릭음(click sound)에 대한 반응으로 주파수 특이성이 없고 고주파수 대역에 대한 청력을 주로 반영하는 단점이 있다. 청성지속반응(auditory steady-state response, ASSR) 검사는 주파수 특이도는 좋으나 오진의 가능성이 조금 높다. 이러한 단점을 보완하여 청성뇌간반응 검사와 청성지속반응 검사를 하나의 시스템에서 측정하고, Fsp와 F-test 분석을 통하여 객관적 지표를 보여주는 시스템을 제안하였다. 하드웨어 구성요소를 최소화하고 소프트웨어 역할을 강화하여 추후 하드웨어 수정 없이 소프트웨어의 수정만으로 다양한 검사가 가능하도록 설계하였다. 제안한 시스템의 객관적 평가 기능은 정상인 10명을 대상으로 한 실험을 통하여 검증하였다.

• Asian Pacific Journal of Cancer Prevention
• /
• 제16권3호
• /
• pp.1289-1293
• /
• 2015

Background: Anal intraepithelial lesions (AIL) are likely to represent a precursor for anal cancer. Women infected with human immunodeficiency virus (HIV) may be at higher risk of anal cancer but a screening program for AIL still is not routinely recommended. We here studied the relationship of dysplastic cells from cervical and anal cytology in HIV-infected women. Materials and Methods: This prospective study was conducted in Prapokklao Hospital, Thailand during 2013-2014. Five hundred and ninety nine HIV-infected women were recruited. Participants who had cytological reports of equally or over "abnormal squamous/glandular cells of undetermined significance" (ASC-US) were classified as abnormal cervical or anal cytology. Descriptive statistics and logistic regression analysis were used to evaluate correlations between groups. Results: HIV-infected women with abnormal cervical cytology had 3.8 times more risk (adjusted odd ratio 3.846, 95% confidence interval 1.247-11.862, p-value. 019) for abnormal anal cytology. The major problem of the anal Pap test in this study was the inadequacy of the collected specimens for evaluation (34.4%, 206/599). Sensitivity, specificity, positive predictive value, negative predictive value and accuracy of cervical and anal Pap tests were 93.9/12.0, 87.3/96.9, 39.7/21.4, 99.4/94.1 and 88.1/91.4 percent, respectively. Conclusions: Abnormal cervical cytology in HIV-infected women indicates elevated risk for abnormal anal cytology. The sensitivity of the anal Pap test for detection of AIL 2/3 in HIV-infected women was quite low while specificity was excellent. Inadequacy of specimen collection for evaluation was a major limitation. Improvement of sample collection is recommended for future investigations.

• 분석과학
• /
• 제34권2호
• /
• pp.68-77
• /
• 2021

Cannabis is one of the most abused drugs in Korea. The main psychoactive component in cannabis, Δ9-tetrahydrocannabinol, is metabolized to 11-nor-9-carboxy-Δ9-tetrahydrocannabinol (THCCOOH) and THCCOOH-glucuronide (THCCOOH-glu) in the human liver, whereby the amount of THCCOOH-glu found in urine is twice as high as that of THCCOOH. The analytical process adapted by the majority of urine drug-testing programs involves a two-step method consisting of an initial immunoassay-based screening test followed by a confirmatory test if the screening test result is positive. In this study, a qualitative gas chromatography-mass spectrometry (GC-MS) method was developed and validated for the detection of THCCOOH in human urine, where THCCOOH-glu was converted into THCCOOH by alkaline hydrolysis. For purification of the urine extract prior to instrumental analysis, high-speed centrifugation was used to minimize interference. In addition, an injection-port derivatization method using ethyl acetate and N,O-bis(trimethylsilyl)-trifluoroacetamide containing 1 % trimethylchlorosilane was employed to reduce the time required for derivatization, and an aliquot of the final solution was injected into the GC-MS. The method was validated by measuring the selectivity, limit of detection (LOD), and repeatability. The sensitivity, specificity, precision, accuracy, Kappa, F-measure, false positive, and false negative rate were determined by comparing the GC-MS results with those obtained using the immunoassay. The LOD was determined to be 0.32 ng/mL, while the repeatability was within 9.1 % for THCCOOH. Furthermore, a comparison study was carried out, whereby the screening immunoassay exhibited a sensitivity of 86.4 % and a specificity of 100 % compared to GC-MS. The applicability of the developed method was examined by analyzing spiked urine and forensic urine samples obtained from suspected cannabis abusers (n = 221).