• 제목/요약/키워드: Sensitivity and specificity

검색결과 2,269건 처리시간 0.038초

ED-XRF (Energy Dispersive X-ray Fluorescence spectrometer)를 이용한 콩 원산지 판별 (Discrimination of geographical origin for soybeans using ED-XRF)

  • 이지혜;강동진;장은희;허설혜;신병곤;한국탁;이성훈
    • 한국식품과학회지
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    • 제52권2호
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    • pp.125-129
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    • 2020
  • 본 연구는 무기성분을 활용하여 국산 콩과 외국산 콩의 원산지 판별법을 개발하기 위해 수행하였다. 2018년도에 수집한 국산 100점, 미국, 중국, 베트남, 태국으로 구성된 외국산 97점에 대하여 ED-XRF를 이용하여 총 26종 무기성분의 농도를 산출하였다. T-test, ANOVA, CDA 분석을 통해 원산지판별에 영향을 주는 주요 변수로 5종(P, Ni, Br, Zn, Mn)의 무기성분을 선발하였다. 원산지 판별식을 설정한 결과 감응도 91.0%, 선택성 95.9%, 효율성 93.4%를 나타냈다. 2019년도에 수집한 국산 30점, 외국산 30점으로 원산지 판별식을 검증한 결과 국산 예측률 93.3%, 외국산 예측률 100.0%를 나타냈다. 복잡한 전처리 없이 ED-XRF와 통계처리를 통해 국산 콩과 외국산 콩을 판별할 수 있는 실용적인 판별 체계를 구축하였으며 부정유통 단속을 위한 과학적인 근거자료로서 활용이 가능할 것으로 판단된다.

임베디드 기반의 휴대용 A-ABR 시스템 개발 및 평가 (Development and Assesment of an Embedded Portable A-ABR System)

  • 노형욱;남기창;장경환;차은종;김덕원
    • 전자공학회논문지SC
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    • 제47권3호
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    • pp.48-55
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    • 2010
  • 신생아 난청은 신생아들에게 있어서 흔한 선천성 질환 중의 하나로 알려져 있다. 이를 방치할 경우 언어장애와 학습장애를 불러 오는 결과를 초래하게 되지만 조기에 발견하여 치료를 한다면 예방 할 수 있다. 신생아 청력장애를 조기에 선별하기 위해 사용되는 방법으로 청성뇌간반응검사(auditory brainstem response; ABR)가 유용하게 쓰이고 있다. 하지만 기존의 수동 ABR 시스템은 시간이 오래 걸리며 숙련된 검사자가 매번 파형을 분석해야 하는 번거로움이 있다는 단점이 있다. 이와 같은 이유로 최근 청력을 자동으로 판독하는 A-ABR(Automated-ABR)의 필요성이 인식되어 연구가 활발하지만, 국내에서는 아직 관련된 연구가 미미한 실정이다. 본 연구에서는 선행 연구를 통하여 구현된 A-ABR 시스템을 휴대용으로 개발하여 신생아를 포함한 정상 성인과 난청을 가진 성인을 대상으로 시스템에 대한 성능 평가를 수행하였다. 임상 진단 결과와 A-ABR의 결과를 비교한 결과 94.4%의 민감도, 92.2%의 특이도, 93.0%의 정확도를 보임으로서 우수한 진단 성능을 확인할 수 있었다.

소 결핵 진단을 위한 인터페론감마 검사 키트의 성능 비교 평가 (Performance comparison and evaluation of interferon-gamma assay kit for bovine tuberculosis diagnosis)

  • 홍이곤;최우재;노영혜;안선민;김은경;최은희;김단일
    • 한국동물위생학회지
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    • 제43권4호
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    • pp.201-209
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    • 2020
  • In Korea, bovine tuberculosis (bTB) is a representative zoonotic disease that causes considerable economic loss. In determining the positive bTB, the ELISA method for examining the amount of interferon-gamma (IFN-γ) is included in Korea's diagnostic standard method. Recently, commercially available BIONOTE TB-Feron ELISA Plus (TB-Feron Plus) that detects IFN-γ has been introduced. However, since the scientific basis for the performance is limited, we evaluated performance by comparing it with the results of another IFN-γ ELISA assay kit (BOVIGAM®) certified by Office International des Epizooties. In our research, 42 positive blood samples preliminarily tested with a tuberculin skin test and/or BOVIGAM® and 54 negative blood samples collected from three bTB free farms were subjected to IFN-γ assay using the TB-Feron Plus and the BOVIGAM®, respectively. The result shows that the sensitivity, specificity and accuracy were 81.0% (34/42), 100% (54/54), 91.7% (88/96) in TB-Feron Plus kit and 78.6% (33/42), 100% (54/54), 90.6% (87/96) in BOVIGAM® kit, respectively. Moreover, the overall accordance percentage of the two kits was 99.0% (95/96) and there was almost perfect agreement between two assays (Kappa=0.977, P<0.0001). Furthermore, additional studies confirmed that elevated lymphocyte numbers in blood did not interfere with the results of the TB-Feron Plus kit. And, delayed time from sampling to culture decreased the optical density (OD) value. Therefore, we concluded that the TB-Feron Plus kit was not inferior to BOVIGAM® in performance. High lymphocyte numbers in blood did not impact on TB-Feron Plus results, while delayed time before culture interfered with OD value.

성별에 따른 경동맥 내중막두께와 사지근육량지수와의 관련성 (Relationship between Carotid Intima Media Thickness and Appendicular Skeletal Muscle Index according to Gender)

  • 양성희;이희정
    • 한국방사선학회논문지
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    • 제16권3호
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    • pp.309-317
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    • 2022
  • 본 연구는 코로나 펜데믹에 의한 사회적 거리두기는 신체활동 감소를 가져왔고 이로 인한 근육량 감소는 혈관질환의 위험도가 높아진다고 보고되고 있다. 이에 본 연구는 경동맥 내중막두께 측정을 통해 두께 증가에 따른 여러 변수들의 차이를 분석하였으며 사지근육량지수가 경동맥 내중막두께 위험도 예측을 위한 효과적 표지자로서의 유용성을 알아보고자 하였다. 2022년 1월부터 2022년 5월까지 부산지역 H병원 건강검진센터에 검진을 목적으로 방문하여 혈청학적 검사, 경동맥초음파, 체성분검사를 시행한 남자 121명, 여자 99명 총 220명을 연구대상으로 하였다. 성별에 따른 위험인자의 유의미한 차이는 카이제곱검정을 통해 분석하였다. 동맥경화를 예측할 수 있는 변수의 Cut-off value를 구하였으며 곡선하면적, 민감도, 특이도를 산출하여 정확도를 평가하였다. 그 결과 남자는 총콜레스테롤이 높을수록 여자는 사지근육량지수가 낮을수록 경동맥 내중막두께 위험도가 높게 나타났다. 경동맥 내중막두께 위험도를 예측할 수 있는 Cut-off value는 남성그룹에서 총콜레스테롤 199 mg/dL 이상, 여성그룹에서 사지근육량지수 5.9 kg/m2 이하로 산출되었다. 따라서 사지근육량지수는 쉽게 접근이 가능한 비침습적인 검사로 성인여성의 경우 혈관변화를 조기 예측하고 예방할 수 있는 표지자 역할이 가능할 것으로 기대된다.

지역 재가 노인의 낙상위험평가 (Fall Risk Assessment (FRA) of Korean community-dwelling elderly)

  • 신소희
    • 한국노년학
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    • 제39권4호
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    • pp.895-902
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    • 2019
  • 이 연구에서는 요인분석을 통해 타당성이 입증된 낙상위험평가 설문항목의 진단 정도와 평가기준을 검토하여 지역 재가 노인의 낙상고위험군을 진단하고 개인별 낙상리스크 프로파일을 제안하는데 목적이 있다. 연구대상자는 S시, U시, B시, Y시 거주 우리나라 지역 재가 노인 439명을 대상으로 하였다(평균연령 75.0±5.7세). FRA의 낙상위험진단정도와 평가기준을 검토하기 위해 ROC분석을 실시하였다. 분석결과 FRA의 하위요인인 '낙상잠재성', '질병과 신체증상', '환경' 및 '신체기능'의 4가지 하위 요인은 지역재가노인의 낙상 위험을 효율적으로 진단할 수 있는 것으로 나타났으며, 민감도와 특이도 결과를 바탕으로 요인별 평가기준을 제시하였다. 또한 낙상하위요인별 패턴을 분석한 결과 낙상 고위험군의 경우 두 가지 요인 이상에 문제를 가지고 있는 노인이 전체의 80%를 차지하는 것으로 나타났다. 이상으로, FRA의 4가지 하위 요인은 낙상위험정도를 효율적으로 진단할 수 있으며, 평가기준을 바탕으로 개인별 낙상위험프로파일을 제시할 수 있어 우리나라 지역 재가 노인의 낙상예방프로그램 구축을 위한 기초자료로 활용할 수 있을 것이다.

Two-Dimensional-Shear Wave Elastography with a Propagation Map: Prospective Evaluation of Liver Fibrosis Using Histopathology as the Reference Standard

  • Dong Ho Lee;Eun Sun Lee;Jae Young Lee;Jae Seok Bae;Haeryoung Kim;Kyung Bun Lee;Su Jong Yu;Eun Ju Cho;Jeong-Hoon Lee;Young Youn Cho;Joon Koo Han;Byung Ihn Choi
    • Korean Journal of Radiology
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    • 제21권12호
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    • pp.1317-1325
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    • 2020
  • Objective: The aim of this study was to prospectively evaluate whether liver stiffness (LS) assessments, obtained by two-dimensional (2D)-shear wave elastography (SWE) with a propagation map, can evaluate liver fibrosis stage using histopathology as the reference standard. Materials and Methods: We prospectively enrolled 123 patients who had undergone percutaneous liver biopsy from two tertiary referral hospitals. All patients underwent 2D-SWE examination prior to biopsy, and LS values (kilopascal [kPa]) were obtained. On histopathologic examination, fibrosis stage (F0-F4) and necroinflammatory activity grade (A0-A4) were assessed. Multivariate linear regression analysis was performed to determine the significant factors affecting the LS value. The diagnostic performance of the LS value for staging fibrosis was assessed using receiver operating characteristic (ROC) analysis, and the optimal cut-off value was determined by the Youden index. Results: Reliable measurements of LS values were obtained in 114 patients (92.7%, 114/123). LS values obtained from 2D-SWE with the propagation map positively correlated with the progression of liver fibrosis reported from histopathology (p < 0.001). According to the multivariate linear regression analysis, fibrosis stage was the only factor significantly associated with LS (p < 0.001). The area under the ROC curve of LS from 2D-SWE with the propagation map was 0.773, 0.865, 0.946, and 0.950 for detecting F ≥ 1, F ≥ 2, F ≥ 3, and F = 4, respectively. The optimal cut-off LS values were 5.4, 7.8, 9.4, and 12.2 kPa for F ≥ 1, F ≥ 2, F ≥ 3, and F = 4, respectively. The corresponding sensitivity and specificity of the LS value for detecting cirrhosis were 90.9% and 88.4%, respectively. Conclusion: The LS value obtained from 2D-SWE with a propagation map provides excellent diagnostic performance in evaluating liver fibrosis stage, determined by histopathology.

The Value of Adding Ductography to Ultrasonography for the Evaluation of Pathologic Nipple Discharge in Women with Negative Mammography

  • Younjung Choi;Sun Mi Kim;Mijung Jang;Bo La Yun;Eunyoung Kang;Eun-Kyu Kim;So Yeon Park;Bohyoung Kim;Nariya Cho;Woo Kyung Moon
    • Korean Journal of Radiology
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    • 제23권9호
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    • pp.866-877
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    • 2022
  • Objective: The optimal imaging approach for evaluating pathological nipple discharge remains unclear. We investigated the value of adding ductography to ultrasound (US) for evaluating pathologic nipple discharge in patients with negative mammography findings. Materials and Methods: From July 2003 to December 2018, 101 women (mean age, 46.3 ± 12.2 years; range, 23-75 years) with pathologic nipple discharge were evaluated using pre-ductography (initial) US, ductography, and post-ductography US. The imaging findings were reviewed retrospectively. The standard reference was surgery (70 patients) or > 2 years of follow-up with US (31 patients). The diagnostic performances of initial US, ductography, and post-ductography US for detecting malignancy were compared using the McNemar's test or a generalized estimating equation. Results: In total, 47 papillomas, 30 other benign lesions, seven high-risk lesions, and 17 malignant lesions were identified as underlying causes of pathologic nipple discharge. Only eight of the 17 malignancies were detected on the initial US, while the remaining nine malignancies were detected by ductography. Among the nine malignancies detected by ductography, eight were detected on post-ductography US and could be localized for US-guided intervention. The sensitivities of ductography (94.1% [16/17]) and post-ductography US (94.1% [16/17]) were significantly higher than those of initial US (47.1% [8/17]; p = 0.027 and 0.013, respectively). The negative predictive value of post-ductography US (96.9% [31/32]) was significantly higher than that of the initial US (83.3% [45/54]; p = 0.006). Specificity was significantly higher for initial US than for ductography and post-ductography US (p = 0.001 for all). Conclusion: The combined use of ductography and US has a high sensitivity for detecting malignancy in patients with pathologic nipple discharge and negative mammography. Ductography findings enable lesion localization on second-look post-ductography US, thus facilitating the selection of optimal treatment plans.

Usefulness of Bone SPECT/CT for Predicting Avascular Necrosis of the Femoral Head in Children with Slipped Capital Femoral Epiphysis or Femoral Neck Fracture

  • Yoo Sung Song;Won Woo Lee;Moon Seok Park;Nak Tscheol Kim;Ki Hyuk Sung
    • Korean Journal of Radiology
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    • 제23권2호
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    • pp.264-270
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    • 2022
  • Objective: This study aimed to investigate the usefulness of bone single-positron emission tomography/computed tomography (SPECT/CT) of the hip in predicting the later occurrence of avascular necrosis (AVN) after slipped capital femoral epiphysis (SCFE) or femoral neck fracture in pediatric patients. The quantitative parameters of SPECT/CT useful in predicting AVN were identified. Materials and Methods: Twenty-one (male:female, 10:11) consecutive patients aged < 18 years (mean age ± standard deviation [SD], 11.0 ± 2.7 years) who underwent surgery for SCFE or femoral neck fracture and postoperative bone SPECT/CT were included. The maximum standardized uptake value (SUV), mean SUV, and minimum SUV of the femoral head were measured. The ratios of the maximum SUV, mean SUV, and minimum SUV of the affected femoral head to the contralateral side were determined. Patients were followed up for > 1 year after the surgery. The SPECT/CT parameters were compared between patients who developed AVN and those who did not. The accuracy of SPECT/CT parameters for predicting AVN was assessed. Results: Six patients developed AVN. There was a significant difference in the ratio of the mean SUV among patients who developed AVN (mean ± SD, 0.8 ± 0.3) and those who did not (1.1 ± 0.2, p = 0.018). However, there were no significant differences in the ratios of the maximum and minimum SUV between the groups (all p = 0.205). For the maximum, mean, and minimum SUVs, no significant differences were observed between the groups (p = 0.519, 0.733, and 0.470, respectively). The cutoff mean SUV ratio of 0.87 yielded a 66.7% sensitivity and 93.2% specificity for predicting AVN. Conclusion: Quantitative bone SPECT/CT is useful for evaluating femoral head viability in pediatric patients with SCFE or femoral neck fractures. Clinicians should consider the high possibility of later AVN development in patients with a decreased mean SUV ratio.

유방 탄성초음파의 Color overlay pattern에 대한 유용성 (Usefulness of Color-overlay Pattern of Breast Elastic Ultrasonography)

  • 안현;임인철
    • 한국방사선학회논문지
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    • 제11권5호
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    • pp.401-406
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    • 2017
  • 유방암 발생률이 해마다 증가하여 그에 따라 유방 종양을 진단하는 검사인 조직검사의 횟수도 같이 증가하고 있다. 조직검사는 침습적 검사로써 환자들의 불안감과 감염, 출혈 등의 부작용이 발생하고 있다. 본 연구에서는 유방 병변 환자를 대상으로 회색조 초음파와 탄성초음파검사 모두 실시한 69명을 대상으로 회색조 초음파는 BI-RADS Category에 따라 분류하고, 탄성초음파검사는 횡파의 전파 속도를 환산하여 나타낸 kPa값을 Color overlay pattern으로 분류하였다. 민감도와 특이도의 합이 가장 높은 최적의 Cut-off value는 54.70 kPa로 나타났다. Color overlay pattern에서 Dark Blue 42명, Light blue ~ Red 27명으로 분류된 결과와 BI-RADS Category 분류 결과인 양성 40명, 악성 29명으로 분류된 결과가 유사하다. 따라서 Color overlay pattern에서 Dark Blue에 분류될 경우에는 양성, Light blue ~ Red에 분류될 경우에는 악성으로 의심할 수 있을 것으로 판단된다. 결론적으로 유방 탄성초음파는 무분별한 유방 조직검사의 횟수를 줄이고 양성종양과 악성종양을 구분하는데 획기적인 역할을 할 것으로 사료된다.

Asthma predictive index as a useful diagnostic tool in preschool children: a cross-sectional study in Korea

  • Lee, Dong Hyeon;Kwon, Ji-Won;Kim, Hyung Young;Seo, Ju-Hee;Kim, Hyo-Bin;Lee, So-Yeon;Jang, Gwang-Cheon;Song, Dae-Jin;Kim, Woo Kyung;Jung, Young-Ho;Hong, Soo-Jong;Shim, Jung Yeon
    • Clinical and Experimental Pediatrics
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    • 제63권3호
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    • pp.104-109
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    • 2020
  • Background: It is challenging to diagnose asthma in preschool children. The asthma predictive index (API) has been used to predict asthma and decide whether to initiate treatment in preschool children. Purpose: This study aimed to investigate the association between questionnaire-based current asthma with API, pulmonary function, airway hyperreactivity (AHR), fractional expiratory nitric oxide (FeNO), and atopic sensitization in preschool children. Methods: We performed a population-based cross-sectional study in 916 preschool children aged 4-6 years. We defined current asthma as the presence of both physician-diagnosed asthma and at least one wheezing episode within the previous 12 months using a modified International Study of Asthma and Allergies in Childhood questionnaire. Clinical and laboratory parameters were compared between groups according to the presence of current asthma. Results: The prevalence of current asthma was 3.9% in the study population. Children with current asthma showed a higher rate of positive bronchodilator response and loose and stringent API scores than children without current asthma. The stringent API was associated with current asthma with 72.2% sensitivity and 82.0% specificity. The diagnostic accuracy of the stringent API for current asthma was 0.771. However, no intergroup differences in spirometry results, methacholine provocation test results, FeNO level, or atopic sensitization rate were observed. Conclusion: The questionnaire-based diagnosis of current asthma is associated with API, but not with spirometry, AHR, FeNO, or atopic sensitization in preschool children.