• 제목/요약/키워드: receiver operating characteristics (ROC)

검색결과 99건 처리시간 0.022초

골반골절 환자의 골절위치와 출혈량간의 상관관계 분석을 통한 대량수혈 필요에 대한 간단한 예측도구 개발: 골반골 출혈 지수 (Development of Simple Prediction Method for Injury Severity and Amount of Traumatic Hemorrhage via Analysis of the Correlation between Site of Pelvic Bone Fracture and Amount of Transfusion: Pelvic Bleeding Score)

  • 이상식;배병관;한상균;박성욱;류지호;정진우;염석란
    • Journal of Trauma and Injury
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    • 제25권4호
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    • pp.139-144
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    • 2012
  • Purpose: Hypovolemic shock is the leading cause of death in multiple trauma patients with pelvic bone fracures. The purpose of this study was to develop a simple prediction method for injury severity and amount of hemorrhage via an analysis of the correlation between the site of pelvic bone fracture and the amount of transfusion and to verify the usefulness of the such a simple scoring system. Methods: We analyzed retrospectively the medical records and radiologic examination of 102 patients who had been diagnosed as having a pelvic bone fracture and who had visited the Emergency Department between January 2007 and December 2011. Fracture sites in the pelvis were confirmed and re-classified anatomically as pubis, ilium or sacrum. A multiple linear regression analysis was performed on the amount of transfusion, and a simplified scoring system was developed. The predictive value of the amount of transfusion for the scoring system as verified by using the receiver operating characteristics (ROC). The area under the curve of the ROC was compared with the injury severity score (ISS). Results: From among the 102 patients, 97 patients (M:F=68:29, mean $age=46.7{\pm}16.6years$) were enrolled for analysis. The average ISS of the patients was $16.2{\pm}7.9$, and the average amount of packed RBC transfusion for 24 hr was $3.9{\pm}4.6units$. The regression equation resulting from the multiple linear regression analysis was 'packed RBC units=1.40${\times}$(sacrum fracture)+1.72${\times}$(pubis fracture)+1.67${\times}$(ilium fracture)+0.36' and was found to be suitable (p=0.005). We simplified the regression equation to 'Pelvic Bleeding Score=sacrum+pubis+ilium.' Each fractured site was scored as 0(no fracture) point, 1(right or left) point, or 2(both) points. Sacrum had only 0 or 1 point. The score ranged from 0 to 5. The area under the curve (AUC) of the ROC was 0.718 (95% CI: 0.588-0.848, p=0.009). For an upper Pelvis Bleeding Score of 3 points, the sensitivity of the prediction for a massive transfusion was 71.4%, and the specificity was 69.9%. Conclusion: We developed a simplified scoring system for the anatomical fracture sites in the pelvis to predict the requirement for a transfusion (Pelvis Bleeding Score (PBS)). The PBS, compared with the ISS, is considered a useful predictor of the need for a transfusion during initial management.

Molybdenum 저지극을 이용한 X-ray의 미세병소 검출능력에 관한 연구 (A Study on the Detection Ability of Minute Lesions in X-ray Using the Molybdenum Target)

  • 양다래;동경래;박용순;지연상;김영근;김창복
    • Journal of Radiation Protection and Research
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    • 제35권1호
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    • pp.43-48
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    • 2010
  • 방사선의 선질은 X선관의 target에 따라 결정된다. 유방검사의 경우 Molybdenum target을 사용하는데 22~28 kV 범위에서 평균 17.9~19.5 keV의 Mo 특성에너지를 얻어 유방의 high contrast 영상을 얻을 수 있다. 따라서 본 연구에서는 최근 대부분의 유방 검사장치에 이용되는 Mo/Mo 조합 유방장치의 미세병변 탐지능력을 측정하기 위하여 ALVIM TRM 팬텀을 이용하여 그 기초적인 실험으로 획득한 영상을 ROC(receiver operating characteristic) curve를 통해 분석하였다. 유방의 평균 피사체 두께가 40 mm로 가정하고 kV와 mAs, 그리고 두께변화에 따른 질환 검출능력을 실험한 결과, kV 변화에서는 Speck과 Fiber의 병소 검출능력이 거의 차이를 보이지 않은 것으로 나타났으며, mAs와 피사체두께 변화에서는 많은 차이를 보이는 것으로 나타났다. 즉, 유방의 피사체 평균두께인 약 40 mm에서는 관전압 변화가 병소의 검출능력에 많은 영향을 끼치지 않으므로 평균 두께의 피사체에서는 관전압을 높여서는 안된다.

만성질환 이환율을 이용한 여자노인의 체질량지수에 대한 아시아-태평양지역 기준과 Entropy모델 기준 비교 (A Comparison between Asia-Pacific Region Criteria and Entropy Model Criteria about Body Mass Index of Elderly Females Using Morbidity of Chronic Disease)

  • 정구범;박진용;권세영;박경옥;박필숙;박미연
    • 대한지역사회영양학회지
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    • 제19권5호
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    • pp.490-498
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    • 2014
  • Objectives: This study was conducted to propose the need of re-establishing the criteria of the body weight classification in the elderly. We compared the Asia-Pacific Region Criteria (APR-C) with Entropy Model Criteria (ENT-C) using Morbidity rate of chronic diseases which correlates significantly with Body Mass Index (BMI). Methods: Subjects were 886 elderly female participating in the 2007-2009 Korea National Health and Nutrition Examination Survey (KNHANES). We compared APR-C with those of ENT-C using Receiver Operating Characteristics (ROC) curve and logistic regression analysis. Results: In the case of the morbidity of hypertension, the results were as follows: Where it was in the T-off point of APR-C, sensitivity was 67.5%, specificity was 43.1%, and Youden's index was 10.6. While in the cut-off point of ENT-C, it was 56.7%, 56.6%, and 13.3 respectively. In the case of the morbidity of diabetes, the results were as follows: In the cut-off point of APR-C, Youden's index was 14.2. While in the cut-off point of ENT-C, it was 17.2 respectively. The Area Under the ROC Curve (AUC) of the subjects who had more than 2 diseases among hypertension, diabetes, and dyslipidemia was 0.615 (95% CI: 0.578-0.652). Compared to the normal group, the odds ratio of the hypertension group which will belong to the overweight or obesity was 1.79 (95% CI: 1.30-2.47) in the APR-C, and 2.04 (95% CI: 1.49-2.80) in the ENT-C (p < 0.001). Conclusions: We conclude that the optimal cut-off point of BMI to distinguish between normal weight and overweight was $24kg/m^2$ (ENT-C) rather than $23kg/m^2$ (APR-C).

가뭄의 전이 현상을 고려한 수문학적 가뭄에 대한 베이지안 네트워크 기반 확률 예측 (Bayesian networks-based probabilistic forecasting of hydrological drought considering drought propagation)

  • 신지예;권현한;이주헌;김태웅
    • 한국수자원학회논문집
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    • 제50권11호
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    • pp.769-779
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    • 2017
  • 최근 우리나라에서 빈번하게 발생되는 가뭄으로 인하여 많은 피해가 발생하고 있으며, 이에 대한 사전대응의 필요성이 커지고 있다. 가뭄에 대한 효과적인 사전대응을 위해서는 신뢰성 있는 가뭄 예측 정보가 필수적이다. 본 연구에서는 수문학적 가뭄에 대한 확률론적 예측을 수행하기 위하여 가뭄의 전이현상을 베이지안 네트워크 모형에 반영하였다. 가뭄의 전이현상을 고려한 베이지안 네트워크 기반의 가뭄 예측 모형(PBNDF)은 과거, 현재, 미래에 대한 다중 모형 앙상블 예측결과와 가뭄전이 관계를 결합하여 새로운 수문학적 가뭄 예측 결과를 생산하도록 구축되었다. 본 연구에서 PBNDF 모형은 파머수문학적 가뭄지수를 활용하여 낙동강 유역의 10개 지점을 대상으로 가뭄을 확률적으로 예측하는데 적용되었다. PBNDF 모형의 ROC 분석 결과 ROC 점수가 0.5 이상의 유의한 결과를 나타내 실제 예측 모형으로 활용가능하다는 것을 확인할 수 있었다. 또한, 기존에 개발된 모형(지속성 예측, 베이지안 네트워크 예측 모형)과 평균제곱오차의 제곱근(RMSE), 기술 점수(SS)를 활용하여 비교를 수행하였으며, 그 결과 PBNDF 모형의 RMSE는 상대적으로 낮은 값을 가지며, SS는 약 0.1~0.15 정도 높은 것으로 나타나 예측성능이 향상되었다는 것을 확인할 수 있었다.

베이지안 네트워크 및 의사결정 모형을 이용한 위성 강수자료 기반 기상학적 가뭄 전망 (Meteorological drought outlook with satellite precipitation data using Bayesian networks and decision-making model)

  • 신지예;김지은;이주헌;김태웅
    • 한국수자원학회논문집
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    • 제52권4호
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    • pp.279-289
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    • 2019
  • 가뭄재해는 다른 재해와 다르게 광범위한 공간에 걸쳐서 충분한 강우가 발생하기 전까지 오랜 기간 동안 발생되는 특성이 있다. 위성 영상은 시공간적으로 지속적인 강수량 관측을 제공할 수 있다. 본 연구는 위성 영상 기반의 강수자료를 활용하여 기상학적 가뭄 전망 모형을 개발하였다. PERSIANN_CDR, TRMM 3B42와 GPM IMERG 영상을 활용하여 강수 자료를 구축한 뒤, 표준강수지수(SPI)를 기반으로 기상학적 가뭄을 정의하였다. 과거의 가뭄 정보와 물리적 예측 모형 기반의 가뭄 예측 결과를 결합할 수 있는 베이지안 네트워크 기반 가뭄 예측 기법을 이용하여 확률론적 가뭄 예측 결과를 생산하였으며, 가뭄 예측결과를 가뭄 전망 의사결정 모형에 적용하여 가뭄 전망 결과를 도출하였다. 가뭄 전망 정보는 가뭄 발생, 지속, 종결, 가뭄 없음의 4단계로 구분하였다. 본 연구의 가뭄 전망 결과는 ROC 분석을 통하여 물리적 예측 모형인 다중모형 앙상블(MME)을 활용한 가뭄 전망 결과와 전망 성능을 비교하였다. 그 결과, 2~3개월 가뭄 전망에 대한 가뭄 발생 및 지속의 단계에서는 MME 모형보다 높은 전망성능을 보여주었다.

Diffusion tensor imaging of the C1-C3 dorsal root ganglia and greater occipital nerve for cervicogenic headache

  • Wang, Lang;Shen, Jiang;Das, Sushant;Yang, Hanfeng
    • The Korean Journal of Pain
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    • 제33권3호
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    • pp.275-283
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    • 2020
  • Background: Previous studies showed neurography and tractography of the greater occipital nerve (GON). The purpose of this study was determining diffusion tensor imaging (DTI) parameters of bilateral GONs and dorsal root ganglia (DRG) in unilateral cervicogenic headache as well as the grading value of DTI for severe headache. The correlation between DTI parameters and clinical characteristics was evaluated. Methods: The fractional anisotropy (FA) and apparent diffusion coefficient (ADC) values in bilateral GONs and cervical DRG (C2 and C3) were measured. Grading values for headache severity was calculated using a receiver operating characteristics curve. The correlation was analyzed with Pearson's coefficient. Results: The FA values of the symptomatic side of GON and cervical DRG (C2 and C3) were significantly lower than that of the asymptomatic side (all the P < 0.001), while the ADC values were significantly higher (P = 0.003, P < 0.001, and P = 0.003, respectively). The FA value of 0.205 in C2 DRG was considered the grading parameter for headache severity with sensitivity of 0.743 and specificity of 0.999 (P < 0.001). A negative correlation and a positive correlation between the FA and ADC value of the GON and headache index (HI; r = -0.420, P = 0.037 and r = 0.531, P = 0.006, respectively) was found. Conclusions: DTI parameters in the symptomatic side of the C2 and C3 DRG and GON were significantly changed. The FA value of the C2 DRG can grade headache severity. DTI parameters of the GON significantly correlated with HI.

SWAT model과 기후변화 자료를 이용한 산사태 예측 기법 제안과 평가: 지리산 국립공원 중산리 일대 사례연구 (Suggestion and Evaluation for Prediction Method of Landslide Occurrence using SWAT Model and Climate Change Data: Case Study of Jungsan-ri Region in Mt. Jiri National Park)

  • 김지수;김민석;조용찬;오현주;이춘오
    • 한국지하수토양환경학회지:지하수토양환경
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    • 제26권6호
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    • pp.106-117
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    • 2021
  • The purpose of this study is prediction of landslide occurrence reflecting the subsurface flow characteristics within the soil layer in the future due to climate change in a large scale watershed. To do this, we considered the infinite slope stability theory to evaluate the landslide occurrence with predicted soil moisture content by SWAT model based on monitored data (rainfall-soil moisture-discharge). The correlation between the SWAT model and the monitoring data was performed using the coefficient of determination (R2) and the model's efficiency index (Nash and Sutcliffe model efficiency; NSE) and, an accuracy analysis of landslide prediction was performed using auROC (area under Receiver Operating Curve) analysis. In results comparing with the calculated discharge-soil moisture content by SWAT model vs. actual observation data, R2 was 0.9 and NSE was 0.91 in discharge and, R2 was 0.7 and NSE was 0.79 in soil moisture, respectively. As a result of performing infinite slope stability analysis in the area where landslides occurred in the past based on simulated data (SWAT analysis result of 0.7~0.8), AuROC showed 0.98, indicating that the suggested prediction method was resonable. Based on this, as a result of predicting the characteristics of landslide occurrence by 2050 using climate change scenario (RCP 8.5) data, it was calculated that four landslides could occur with a soil moisture content of more than 75% and rainfall over 250 mm/day during simulation. Although this study needs to be evaluated in various regions because of a case study, it was possible to determine the possibility of prediction through modeling of subsurface flow mechanism, one of the most important attributes in landslide occurrence.

T2 Mapping with and without Fat-Suppression to Predict Treatment Response to Intravenous Glucocorticoid Therapy for Thyroid-Associated Ophthalmopathy

  • Linhan Zhai;Qiuxia Wang;Ping Liu;Ban Luo;Gang Yuan;Jing Zhang
    • Korean Journal of Radiology
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    • 제23권6호
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    • pp.664-673
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    • 2022
  • Objective: To evaluate the performance of baseline clinical characteristics and pretherapeutic histogram parameters derived from T2 mapping of the extraocular muscles (EOMs) in the prediction of treatment response to intravenous glucocorticoid (IVGC) therapy for active and moderate-to-severe thyroid-associated ophthalmopathy (TAO) and to investigate the effect of fat-suppression (FS) in T2 mapping in this prediction. Materials and Methods: A total of 79 patients clinically diagnosed with active, moderate-to-severe TAO (47 female, 32 male; mean age ± standard deviation, 46.1 ± 10 years), including 43 patients with a total of 86 orbits in the responsive group and 36 patients with a total of 72 orbits in the unresponsive group, were enrolled. Baseline clinical characteristics and pretherapeutic histogram parameters derived from T2 mapping with FS (i.e., FS T2 mapping) or without FS (i.e., conventional T2 mapping) of EOMs were compared between the two groups. Independent predictors of treatment response to IVGC were identified using multivariable analysis. Receiver operating characteristic (ROC) curve analysis was performed to evaluate the predictive performance of the prediction models. Differences between the models were examined using the DeLong test. Results: Compared to the unresponsive group, the responsive group had a shorter disease duration, lower kurtosis (FS-kurtosis), lower standard deviation, larger 75th, 90th, and 95th (FS-95th) T2 relaxation times in FS mapping and lower kurtosis in conventional T2 mapping. Multivariable analysis revealed that disease duration, FS-95th percentile, and FS-kurtosis were independent predictors of treatment response. The combined model, integrating all identified predictors, had an optimized area under the ROC curve of 0.797, 88.4% sensitivity, and 62.5% specificity, which were significantly superior to those of the imaging model (p = 0.013). Conclusion: An integrated combination of disease duration, FS-95th percentile, and FS-kurtosis was a potential predictor of treatment response to IVGC in patients with active and moderate-to-severe TAO. FS T2 mapping was superior to conventional T2 mapping in terms of prediction.

Application of MMP-7 and MMP-10 in Assisting the Diagnosis of Malignant Pleural Effusion

  • Cheng, Daye;Liang, Bin;Li, Yun-Hui
    • Asian Pacific Journal of Cancer Prevention
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    • 제13권2호
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    • pp.505-509
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    • 2012
  • Background: Matrix metalloproteinases (MMP) are proteolytic enzymes that are essentially involved in turnover of the extracellular matrix (ECM). The aim was to investigate the diagnostic value of MMP-7 and MMP-10 as tumor markers in pleural effusion (PE) and evaluate the value of combining MMP-7, MMP-10 and carcinoembryonic antigen (CEA) assays as diagnostic aids for malignant cells. Materials and Methods: A total of 179 patients with PE (87 malignant and 92 benign) were included in this study. The levels of MMP-7 and MMP-10 were measured using ELISA. Results: Values for MMP-7 and MMP-10 were significantly higher in malignant PE than those in benign PE (P<0.01). Among all variables evaluated, logistic regression found that MMP-7 and MMP-10 were significantly correlated with the presence of malignant disease (P<0.01). Analysis of receiver operating characteristics (ROC) curves showed that the area under the curve of MMP-10 (0.806) was significantly larger than that of MMP-7 (0.771) and CEA (0.789) (P<0.01). With parallel interpretation, the combination of MMP-10 and CEA achieved the higher sensitivity of 94.6%. The combination of MMP-7 and CEA in serial interpretation was able to boost the specificity to 95.7%. The combination of MMP-7, MMP-10 and CEA produced better sensitivity, specificity, PPV and NPV than MMP-7 and MMP-10 alone. Conclusion: MMP-7 and MMP-10 in PE may represent helpful adjuncts to conventional diagnostic tools in ruling out malignancy as a probable diagnosis, thus guiding the selection of patients who might benefit from further invasive procedures.

A Breast Cancer Nomogram for Prediction of Non-Sentinel Node Metastasis - Validation of Fourteen Existing Models

  • Koca, Bulent;Kuru, Bekir;Ozen, Necati;Yoruker, Savas;Bek, Yuksel
    • Asian Pacific Journal of Cancer Prevention
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    • 제15권3호
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    • pp.1481-1488
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    • 2014
  • Background: To avoid performing axillary lymph node dissection (ALND) for non-sentinel lymph node (SLN)-negative patients with-SLN positive axilla, nomograms for predicting the status have been developed in many centers. We created a new nomogram predicting non-SLN metastasis in SLN-positive patients with invasive breast cancer and evaluated 14 existing breast cancer models in our patient group. Materials and Methods: Two hundred and thirty seven invasive breast cancer patients with SLN metastases who underwent ALND were included in the study. Based on independent predictive factors for non-SLN metastasis identified by logistic regression analysis, we developed a new nomogram. Receiver operating characteristics (ROC) curves for the models were created and the areas under the curves (AUC) were computed. Results: In a multivariate analysis, tumor size, presence of lymphovascular invasion, extranodal extension of SLN, large size of metastatic SLN, the number of negative SLNs, and multifocality were found to be independent predictive factors for non-SLN metastasis. The AUC was found to be 0.87, and calibration was good for the present Ondokuz Mayis nomogram. Among the 14 validated models, the MSKCC, Stanford, Turkish, MD Anderson, MOU (Masaryk), Ljubljana, and DEU models yielded excellent AUC values of > 0.80. Conclusions: We present a new model to predict the likelihood of non-SLN metastasis. Each clinic should determine and use the most suitable nomogram or should create their own nomograms for the prediction of non- SLN metastasis.