• Title/Summary/Keyword: ROC AUC

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Study on Standardization of Korean Version of Psychiatric Diagnostic Screening Questionnaire(K-PDSQ) (한국판 정신장애 진단 선별 질문지의 표준화 연구)

  • Choi, Hyeong-Keun;Jung, Sung-Won;Jo, Hyun-Ju;Kim, Jeong-Bum;Jung, Chul-Ho
    • Anxiety and mood
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    • v.9 no.1
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    • pp.31-37
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    • 2013
  • Objective : The PDSQ is a brief and psychometrically strong self-report scale designed to screen for common DSM-IV Axis I disorders in clinical settings. In this study, the K-PDSQ was compared with the M.I.N.I.-Plus (Mini-International Neuropsychiatric Interview-Plus) for diagnostic validity and availability of the K-PDSQ as a part of standardization of the K-PDSQ. Methods : The 640 patients were evaluated with the K-PDSQ and the M.I.N.I.-Plus. Diagnosing with the M.I.N.I.-Plus, the diagnostic correspondence, administering time, sensitivity, specificity, ROC curve, and AUC of the K-PDSQ were evaluated. Results : For the diagnostic correspondence of the K-PDSQ, Cohen's kappa coefficient was .66 between the K-PDSQ and the M.I.N.I.-Plus. The administering time of the K-PDSQ was $18.2{\pm}11.80$ minutes. Both sensitivity and specificity of the K-PDSQ were higher: the mean sensitivity across 10 subscales of K-PDSQ was 86%; the mean specificity was 84%. All AUCs of each subscale were above .80, which were statistically significant. Conclusion : The K-PDSQ is valid and available as a diagnostic screening tool. It will be widely used in clinical settings for screening DSM-IV Axis I diagnosis because of its simplicity and high reliability.

Forensic Decision of Median Filtering Image Using a Coefficient of Variation of Fourier Transform (Fourier 변환 변이계수를 이용한 미디언 필터링 영상의 포렌식 판정)

  • RHEE, Kang Hyeon
    • Journal of the Institute of Electronics and Information Engineers
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    • v.52 no.8
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    • pp.67-73
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    • 2015
  • In a distribution of digital image, there is a serious problem that is the image alteration by a forger. For the problem solution, this paper proposes the forensic decision algorithm of a median filtering (MF) image using the feature vector based on a coefficient of variation (c.v.) of Fourier transform. In the proposed algorithm, we compute Fourier transform (FT) coefficients of row and column line respectively of an image first, then c.v. between neighboring lines is computed. Subsquently, 10 Dim. feature vector is defined for the MF detection. On the experiment of MF detection, the proposed scheme is compared to MFR (Median Filter Residual) and Rhee's MF detection schemes that have the same 10 Dim. feature vector both. As a result, the performance is excellent at Unaltered, JPEG (QF=90), Down scaling (0.9) and Up scaling (1.1) images, and it showed good performance at Gaussian filtering ($3{\times}3$) image. However, in the performance evaluation of all measured items of the proposed scheme, AUC (Area Under ROC (Receiver Operating Characteristic) Curve) by the sensitivity and 1-specificity approached to 1 thus, it is confirmed that the grade of the performance evaluation is rated as 'Excellent (A)'.

Performance of the R-way Colposcopic Evaluation System in Cervical Cancer Screening

  • Zhao, Jian;Zhang, Xi;Chen, Rui;Zhao, Yu-Qian;Wang, Ting-Ting;He, Shan;Qiao, You-Lin
    • Asian Pacific Journal of Cancer Prevention
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    • v.16 no.10
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    • pp.4223-4228
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    • 2015
  • Objective: To investigate the diagnostic value of the R-way colposcopic evaluation system (R-way system) in cervical cancer screening. Materials and Methods: Between August 2013 and August 2014, a total of 1,059 cases referred to colposcopy in Peking University First Hospital were studied using both the R-way system and conventional colposcopy. Our study evaluated and compared the diagnostic ability of the two methods in detecting high-grade lesions and cervical cancer (hereinafter called CIN2+). Evaluation indicators including sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), Youden index and the area under the curve (AUC) of the receiver operating characteristic (ROC) were calculated. Results: The R-way system had a slightly lower specificity (94.5%) than conventional colposcopy (96.0%) for CIN2+ detection (P=0.181). However, the sensitivity (77.8%) was significantly higher than with the conventional colposcopic method (46.6%) (${\chi}^2=64.351$, P<0.001). In addition, the AUC of the ROC for CIN2+ detection using the R-way system (0.839) was larger than that with conventional colposcopy (0.731) (Z=4.348, P<0.001). If preliminary result had been drawn from cervical exfoliated cytology before colposcopy referral, combination of the R-way system with cytology could increase the sensitivity to 93.9% for CIN2+ detection (excluding ASCUS\LSIL), confirmed by multipoint biopsy or ECC. Conclusions: The diagnostic value of the R-way evaluation system is higher than that of conventional colposcopic evaluation in cervical cancer screening. Moreover, taking the ease of use and standardized quality control management into account, the R-way system is highly preferable.

VRIFA: A Prediction and Nonlinear SVM Visualization Tool using LRBF kernel and Nomogram (VRIFA: LRBF 커널과 Nomogram을 이용한 예측 및 비선형 SVM 시각화도구)

  • Kim, Sung-Chul;Yu, Hwan-Jo
    • Journal of Korea Multimedia Society
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    • v.13 no.5
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    • pp.722-729
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    • 2010
  • Prediction problems are widely used in medical domains. For example, computer aided diagnosis or prognosis is a key component in a CDSS (Clinical Decision Support System). SVMs with nonlinear kernels like RBF kernels, have shown superior accuracy in prediction problems. However, they are not preferred by physicians for medical prediction problems because nonlinear SVMs are difficult to visualize, thus it is hard to provide intuitive interpretation of prediction results to physicians. Nomogram was proposed to visualize SVM classification models. However, it cannot visualize nonlinear SVM models. Localized Radial Basis Function (LRBF) was proposed which shows comparable accuracy as the RBF kernel while the LRBF kernel is easier to interpret since it can be linearly decomposed. This paper presents a new tool named VRIFA, which integrates the nomogram and LRBF kernel to provide users with an interactive visualization of nonlinear SVM models, VRIFA visualizes the internal structure of nonlinear SVM models showing the effect of each feature, the magnitude of the effect, and the change at the prediction output. VRIFA also performs nomogram-based feature selection while training a model in order to remove noise or redundant features and improve the prediction accuracy. The area under the ROC curve (AUC) can be used to evaluate the prediction result when the data set is highly imbalanced. The tool can be used by biomedical researchers for computer-aided diagnosis and risk factor analysis for diseases.

Evaluation of Gestational Diabetes Mellitus Risk Factors Using Abdominal Subcutaneous Fat Thickness for Early Pregnancy in the US Imaging (초음파영상에서의 임신초기 복부피하지방두께를 이용한 임신성당뇨 위험인자 평가)

  • Kim, Changsoo;Yang, Sung-Hee;Kim, Jung-Hoon
    • Journal of radiological science and technology
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    • v.40 no.1
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    • pp.35-40
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    • 2017
  • The purpose of this study was to investigate the relationship between abdominal subcutaneous fat thickness(ASFT) and maternal gestational diabetes mellitus(GDM) measured by ultrasound at period of pregnancy. We compared maternal age, pre-pregnancy body mass index, and weight gain during pregnancy in 286 pregnant women who were diagnosed with early pregnancy ASFT and high GDM screening test(50 g OGTT) of more than 140 mg/dL. ROC curve analysis was used to determine the cut-off value of ASFT for GDM prediction. Maternal age and weight gain during pregnancy were not related to GDM in the mid-trimester and pre-pregnancy body mass index and earely pregnancy ASFT were significantly different between normal and GDM high risk groups. The cut-off value of ASFT for GDM prediction was 2.23 cm(AUC 0.913. Sensitivity 76.19%, Specificity 93.72%). ASFT measured by ultrasound in early pregnancy was useful as an important index for predicting mid-trimester GDM prediction. Therefore, ASFT can be used as an auxiliary diagnostic index for early recognition of GDM.

Guideliness of the Parameters Using Integrated Test in Down Syndrome Risk Prediction (다운증후군위험도 예측에서 통합선별검사를 이용한 파라미터의 유의성)

  • Lee, Jin-Won;Go, Sung-Jin;Kang, Se-Sik;Kim, Chang-Soo
    • Journal of radiological science and technology
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    • v.39 no.4
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    • pp.549-555
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    • 2016
  • This study was an evaluation of the significance of each parameter through aimed at pregnant women subjected to screening test(integrated test) in predicting risk of Down syndrome. We retrospectively analysed the correlation of risk of Down's syndrome with Nuchal Translucency(NT) images measured by ultrasound, Pregnancy Associated Plasma Protein A(PAPP-A), alpha-fetoprotein(AFP), unconjugated estriol(uE3), human chorionic gonadotrophin(hCG) and Inhibin A by maternal serum. As a result, a significant correlation with NT, uE3, hCG, Inhibin A is revealed with Down's syndrome risk(P<.001). In ROC analysis, AUC of Inhibin A is analysed as the biggest predictor of Down's syndrome(0.859). And the criterion for cut-off was inhibin A 1.4 MoM(sensitivity 81.8%, specificity 75.9%). In conclusion, Inhibin A was the most useful in parameters to predict Down's syndrome in the integrated test. If we make up for the weakness based on the cut-off value of parameters they will be able to be used as an independent indicator in the risk of Down's syndrome screening.

THE CHANGES OF SERUM C-REACTIVE PROTEIN IN THE HEAD AND NECK INFECTION (두경부 감염 환자에서 혈청 내 C-Reactive Protein의 변화)

  • Lee, Ju-Hyun;Kim, Chin-Soo;Lee, Sang-Han;Kim, Chul-Hwan
    • Journal of the Korean Association of Oral and Maxillofacial Surgeons
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    • v.29 no.1
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    • pp.5-13
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    • 2003
  • The purpose of this study is to determine the value of serum concentration of C-reactive protein(CRP) in comparison with ESR and leukocyte as the tools for diagnosis and follow-up study of infection. For this study, thirty-one patients with head and neck infection and thirty-two patients performed the orthognathic surgery were selected for experimental and control groups each other. we analyzed the blood sample daily to measure CRP, ESR and leukocytosis. The results of this study are as the following : 1. Serum C-Reactive Protein levels in the experimental group were higher than control group and the pattern of CRP changes continued to decline in both groups(P<0.001). 2. ESR changes in both groups were scattered without any special pattern. 3. Correlation between CRP and Leukocyte was higher than others(r=0.664, P<0.01). 4. In the Receiver Operating Characteristic(ROC) Curve of experimental group, rapid increase of CRP curve and Area under the curve(AUC) value, 0.774, indicate the high accuracy of estimation. 5. In experimental group, sensitivity of CRP, ESR, and Leukocytosis on recovery day were 83%, 17% and 71%. Based on the results of this study, we could conclude that determination of CRP is more useful method to diagnosis and follow-up study of infection than other commonly used variables in oral and maxillofacial region.

Serum Uric Acid to Creatinine Ratio as a Predictor of Metabolic Syndrome in Healthy Adults Men (건강한 성인 남성의 대사증후군 위험 예측인자로서 혈청 요산/크레아티닌 비율)

  • Kim, Myong Soo;Shin, Kyung A
    • Korean Journal of Clinical Laboratory Science
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    • v.51 no.1
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    • pp.42-49
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    • 2019
  • This study compared the utility of the serum uric acid/creatinine ratio with that of uric acid as a risk predictor of metabolic syndrome. From November 2016 to October 2018, 14,190 adult men under the age of 20 years, who underwent a comprehensive health checkup at a general hospital in their metropolitan area, were included. Metabolic syndrome was assessed according to the American Heart Association/National Heart Lung and Blood Institute (AHA/NHLBI) criteria. Abdominal obesity was based on the WHO criteria in the Western Pacific region. The serum uric acid/creatinine ratio was found to be higher in the fourth quartile than in the first quartile, with a high incidence of metabolic syndrome and metabolic syndrome components. On the other hand, ROC analysis revealed the serum uric acid/creatinine ratio to be a similar indicator of the metabolic syndrome risk to serum uric acid (AUC, 0.554 vs 0.566). The serum uric acid/creatinine ratio showed lower sensitivity and higher specificity than uric acid. In conclusion, the utility of the serum uric acid/creatinine ratio as an independent indicator to predict the risk of metabolic syndrome is limited, and should be used only as an auxiliary marker.

Differences in Static Lower Extremity Alignment according to the History of Lateral Ankle Sprain: Efficacy and Limitation of Static Lower Limb Alignment Measurement as a Predictor of Lateral Ankle Sprain (외측 발목 염좌 병력에 따른 정적 하지 정렬 차이: 외측 발목 염좌의 예측인자로서 정적 하지 정렬 검사의 효용성과 한계점)

  • Jeon, Hyung Gyu;Ha, Sunghe;Lee, Inje;Kang, Tae Kyu;Kim, Eun Sung;Lee, Sae Yong
    • Korean Journal of Applied Biomechanics
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    • v.31 no.1
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    • pp.1-15
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    • 2021
  • Objective: The aim of this study was to investigate 1) the difference in static lower extremity alignment (SLEA) according to a history of lateral ankle sprain (LAS), 2) to identify SLEA factors affecting LAS, and 3) to present the cut-off value and 4) the usefulness and limitations of the SLEA measurement. Method: This case-control study recruited 88 men (age: 27.78±4.69 yrs) and 39 women (age: 24.62±4.20 yrs) subjects with and without LAS. SLEA measurement protocol included Q angle, tibiofemoral angle, genu recurvatum, rear foot (RF) angle, tibal varum and torsion, navicular drop, ankle dorsiflexion range of motion (DF ROM). Independent t-test, logistic regression and receiver operating characteristic (ROC) curve were used for statistical analysis. Results: Men with a history of LAS had significantly smaller Q angles both in standing and in supine position, while women with a history of LAS had significantly greater DF ROM in non-weight bearing (NWB; p < 0.05). Logistic regression model suggests tibial varum (OR = 0.779, p = 0.021) and WB DF ROM (OR = 1.067, p = 0.045) were associated with LAS in men. In case of women, there were no significant SLEA factors for LAS, however, ROC curve analysis revealed standing RF angle (AUC = 0.647, p = 0.028) and NWB DF ROM (AUC = 0.648, p = 0.026) could be affecting factors for LAS. Conclusion: There are differences in SLEA according to the history of LAS, furthermore, the identified items were different by sex. In case of men, tibial varum and WB DF ROM affect LAS occurrence. Standing RF angle and NWB DF ROM of women could be a predictor for LAS. However, since the sensitivity and specificity in most of the SLEA measurements are low, kinematic in dynamic tasks should be considered together for a more accurate evaluation of LAS risk.

The Effect of Hounsfield Unit Value with Conventional Computed Tomography and Intraoperative Distraction on Postoperative Intervertebral Height Reduction in Patients Following Stand-Alone Anterior Cervical Discectomy and Fusion

  • Lee, Jun Seok;Son, Dong Wuk;Lee, Su Hun;Ki, Sung Soon;Lee, Sang Weon;Song, Geun Sung;Woo, Joon Bum;Kim, Young Ha
    • Journal of Korean Neurosurgical Society
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    • v.65 no.1
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    • pp.96-106
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    • 2022
  • Objective : The most common complication of anterior cervical discectomy and fusion (ACDF) is cage subsidence and maintenance of disc height affects postoperative clinical outcomes. We considered cage subsidence as an inappropriate indicator for evaluating preservation of disc height. Thus, this study aimed to consider patients with complications such as reduced total disc height compared to that before surgery and evaluate the relevance of several factors before ACDF. Methods : We retrospectively reviewed the medical records of 40 patients who underwent stand-alone single-level ACDF using a polyetheretherketone (PEEK) cage at our institution between January 2012 and December 2018. Our study population comprised 19 male and 21 female patients aged 24-70 years. The minimum follow-up period was 1 year. Twenty-seven patients had preoperative bone mineral density (BMD) data on dual-energy X-ray absorptiometry. Clinical parameters included sex, age, body mass index, smoking history, and prior medical history. Radiologic parameters included the C2-7 cobb angle, segmental angle, sagittal vertical axis, disc height, and total intervertebral height (TIH) at the preoperative and postoperative periods. Cage decrement was defined as the reduction in TIH at the 6-month follow-up compared to preoperative TIH. To evaluate the bone quality, Hounsfield unit (HU) value was calculated in the axial and sagittal images of conventional computed tomography. Results : Lumbar BMD values and cervical HU values were significantly correlated (r=0.733, p<0.001). We divided the patients into two groups based on cage decrement, and 47.5% of the total patients were regarded as cage decrement. There were statistically significant differences in the parameters of measuring the HU value of the vertebra and intraoperative distraction between the two groups. Using these identified factors, we performed a receiver operating characteristic (ROC) curve analysis. Based on the ROC curve, the cut-off point was 530 at the HU value of the upper cortical and cancellous vertebrae (p=0.014; area under the curve [AUC], 0.727; sensitivity, 94.7%; specificity, 42.9%) and 22.41 at intraoperative distraction (p=0.017; AUC, 0.722; sensitivity, 85.7%; specificity, 57.9%). Using this value, we converted these parameters into a bifurcated variable and assessed the multinomial regression analysis to evaluate the risk factors for cage decrement in ACDF. Intraoperative distraction and HU value of the upper vertebral body were independent factors of postoperative subsidence. Conclusion : Insufficient intraoperative distraction and low HU value showed a strong relationship with postoperative intervertebral height reduction following single stand-alone PEEK cage ACDF.