• 제목/요약/키워드: Sensitivity and specificity

검색결과 2,269건 처리시간 0.038초

흰쥐의 출혈성 쇼크에서 관류와 젖산 농도 비를 이용한 새로운 생존 예측 지표 개발 (A New Shock Index for Predicting Survival of Rats with Hemorrhagic Shock Using Perfusion and Lactate Concentration Ratio)

  • 최재림;남기창;권민경;장경환;김덕원
    • 전자공학회논문지SC
    • /
    • 제48권4호
    • /
    • pp.1-9
    • /
    • 2011
  • 쇼크(shock)란 조직에 필요한 산소 요구량과 공급 간의 불균형에 의해 유발되는 임상증후군을 말한다. 환자의 치료효과와 생존율 향상을 위해서 쇼크의 조기 진단은 매우 중요하다. 그러나 현재 쇼크 진단에 사용되는 맥박, 혈압 등 생체 징후의 경우 출혈 정도를 제대로 반영하지 못하여 환자에 대한 처치가 늦어질 수 있다. 따라서 쇼크의 조기 진단을 위한 많은 연구들이 진행되어 왔으며, 조직의 저산소증, 대사성 산증을 반영해주는 지표인 젖산 농도와 관류 측정의 유용성이 입증된 바 있다. 본 연구에서는 흰쥐를 대상으로 정량적 출혈을 유도한 후, 젖산 농도 측정과 laser Doppler flowmeter를 통해 관류를 측정하였으며, 지혈 후 젖산 농도/관류의 비(ratio)를 생존 예측을 위한 새로운 지표로써 제안하였다. 새로 제안된 지표를 통한 생존예측을 ROC 커브 방법에 적용한 결과, 민감도 90.0%, 특이도 96.7%, 정확도 94.0%를 보였으며, 생존군과 사망군 간 새로운 지표의 유의한 차이도 가장 조기에 보여주었다. 향후 임상 적용 연구를 통해 새롭게 제안한 지표의 임상 적용이 가능하다면, 쇼크 환자를 조기 진단하고 치료효과를 높일 수 있을 것으로 생각된다.

약물중독 환자에서 Neutrophil Lymphocyte Ratio의 흡인성폐렴 발생 예측인자로서의 고찰 (Neutrophil-to-lymphocyte Ratio as A Predictor of Aspiration Pneumonia in Drug Intoxication Patients)

  • 이정범;이선화;윤성종;류석용;최승운;김혜진;강태경;오성찬;조석진;서범석
    • 대한임상독성학회지
    • /
    • 제16권2호
    • /
    • pp.61-67
    • /
    • 2018
  • Purpose: To evaluate the association between neutrophil-to-lymphocyte ratio (NLR) and occurrence of aspiration pneumonia in drug intoxication (DI) patients in the emergency department (ED) and to evaluate the relationship between NLR and length of hospital admission/intensive care unit (ICU) admission Methods: A total of 466 patients diagnosed with DI in the ED from January 2016 to December 2017 were included in the analysis. The clinical and laboratory results, including NLR, were evaluated as variables. NLR was calculated as the absolute neutrophil count/absolute lymphocyte count. To evaluate the prognosis of DI, data on the development of aspiration pneumonia were obtained. Also, we evaluated the relationship between NLR and length of hospital admission and between NLR and length of ICU admission. Statistically, multivariate logistic regression analyses, receiver-operating characteristic (ROC) curve analysis, and Pearson's correlation (${\rho}$) were performed. Results: Among the 466 DI patients, 86 (18.5%) developed aspiration pneumonia. Multivariate logistic regression analysis revealed NLR as an independent factor in predicting aspiration pneumonia (odds ratio, 1.7; p=0.001). NLR showed excellent predictive performance for aspiration pneumonia (areas under the ROC curves, 0.815; cut-off value, 3.47; p<0.001) with a sensitivity of 86.0% and a specificity of 72.6%. No correlations between NLR and length of hospital admission (${\rho}=0.195$) and between NLR and length of ICU admission (${\rho}=0.092$) were observed. Conclusion: The NLR is a simple and effective marker for predicting the occurrence of aspiration pneumonia in DI patients. Emergency physicians should be alert for aspiration pneumonia in DI patients with high NLR value (>3.47).

Added Value of Contrast Leakage Information over the CBV Value of DSC Perfusion MRI to Differentiate between Pseudoprogression and True Progression after Concurrent Chemoradiotherapy in Glioblastoma Patients

  • Pak, Elena;Choi, Seung Hong;Park, Chul-Kee;Kim, Tae Min;Park, Sung-Hye;Won, Jae-Kyung;Lee, Joo Ho;Lee, Soon-Tae;Hwang, Inpyeong;Yoo, Roh-Eul;Kang, Koung Mi;Yun, Tae Jin
    • Investigative Magnetic Resonance Imaging
    • /
    • 제26권1호
    • /
    • pp.10-19
    • /
    • 2022
  • Purpose: To evaluate whether the added value of contrast leakage information from dynamic susceptibility contrast magnetic resonance imaging (DSC MRI) is a better prognostic imaging biomarker than the cerebral blood volume (CBV) value in distinguishing true progression from pseudoprogression in glioblastoma patients. Materials and Methods: Forty-nine glioblastoma patients who had undergone MRI after concurrent chemoradiotherapy with temozolomide were enrolled in this retrospective study. Twenty features were extracted from the normalized relative CBV (nCBV) and extraction fraction (EF) map of the contrast-enhancing region in each patient. After univariable analysis, we used multivariable stepwise logistic regression analysis to identify significant predictors for differentiating between pseudoprogression and true progression. Receiver operating characteristic (ROC) analysis was employed to determine the best cutoff values for the nCBV and EF features. Finally, leave-one-out cross-validation was used to validate the best predictor in differentiating between true progression and pseudoprogression. Results: Multivariable stepwise logistic regression analysis showed that MGMT (O6-methylguanine-DNA methyltransferase) and EF max were independent differentiating variables (P = 0.004 and P = 0.02, respectively). ROC analysis yielded the best cutoff value of 95.75 for the EF max value for differentiating the two groups (sensitivity, 61%; specificity, 84.6%; AUC, 0.681 ± 0.08; 95% CI, 0.524-0.837; P = 0.03). In the leave-one-out cross-validation of the EF max value, the cross-validated values for predicting true progression and pseudoprogression accuracies were 69.4% and 71.4%, respectively. Conclusion: We demonstrated that contrast leakage information parameter from DSC MRI showed significance in differentiating true progression from pseudoprogression in glioblastoma patients.

Diagnostic Performance of Spin-Echo Echo-Planar Imaging Magnetic Resonance Elastography in 3T System for Noninvasive Assessment of Hepatic Fibrosis

  • Se Woo Kim;Jeong Min Lee;Sungeun Park;Ijin Joo;Jeong Hee Yoon;Won Chang;Haeryoung Kim
    • Korean Journal of Radiology
    • /
    • 제23권2호
    • /
    • pp.180-188
    • /
    • 2022
  • Objective: To validate the performance of 3T spin-echo echo-planar imaging (SE-EPI) magnetic resonance elastography (MRE) for staging hepatic fibrosis in a large population, using surgical specimens as the reference standard. Materials and Methods: This retrospective study initially included 310 adults (155 undergoing hepatic resection and 155 undergoing donor hepatectomy) with histopathologic results from surgical liver specimens. They underwent 3T SE-EPI MRE ≤ 3 months prior to surgery. Demographic findings, underlying liver disease, and hepatic fibrosis pathologic stage according to METAVIR were recorded. Liver stiffness (LS) was measured by two radiologists, and inter-reader reproducibility was evaluated using the intraclass correlation coefficient (ICC). The mean LS of each fibrosis stage (F0-F4) was calculated in total and for each etiologic subgroup. Comparisons among subgroups were performed using the Kruskal-Wallis test and Conover post-hoc test. The cutoff values for fibrosis staging were estimated using receiver operating characteristic (ROC) curve analysis. Results: Inter-reader reproducibility was excellent (ICC, 0.98; 95% confidence interval, 0.97-0.99). The mean LS values were 1.91, 2.41, 3.24, and 5.41 kPa in F0-F1 (n = 171), F2 (n = 26), F3 (n = 38), and F4 (n = 72), respectively. The discriminating cutoff values for diagnosing ≥ F2, ≥ F3, and F4 were 2.18, 2.71, and 3.15 kPa, respectively, with the ROC curve areas of 0.97-0.98 (sensitivity 91.2%-95.9%, specificity 90.7%-99.0%). The mean LS was significantly higher in patients with cirrhosis (F4) of nonviral causes, such as primary biliary cirrhosis (9.56 kPa) and alcoholic liver disease (7.17 kPa) than in those with hepatitis B or C cirrhosis (4.28 and 4.92 kPa, respectively). There were no statistically significant differences in LS among the different etiologic subgroups in the F0-F3 stages. Conclusion: The 3T SE-EPI MRE demonstrated high interobserver reproducibility, and our criteria for staging hepatic fibrosis showed high diagnostic performance. LS was significantly higher in patients with non-viral cirrhosis than in those with viral cirrhosis.

추락 후 사망 예측인자로서의 추락 높이 (The Height of Fall as a Predictor of Fatality of Fall)

  • 서주현;어은경;정구영
    • Journal of Trauma and Injury
    • /
    • 제18권2호
    • /
    • pp.101-106
    • /
    • 2005
  • Purpose: The number of the deceased from free-fall is increasing nowadays. Free-fall comes to a great social problem in that even the survivor will be suffering for cord injury or brain injury, and so on. We analyzed the cases of free-fall patients to find out whether the injury severity is mainly correlated with the height of fall. Methods: We retrospectively investigated the characteristics of patients, who fall from the height above 2m from January 2000 to August 2004. We excluded the patients who transferred to other hospital, transferred from other hospital, and not known the height of fall. 145 patients were evaluated. Variables included in data analysis were age, height of fall, injury severity score (ISS), the being of barrier, and the survival or not. To find out the correlation between height of fall and death, we used receive operating characteristics (ROC) curve analysis. Results: The mean age of patients was $36.5{\pm}19.4$ years old. 110 were male and 35 were female. Mean height of fall was $11.1{\pm}8.5m$. 51 patients (35.2%) were died and 30 patients of them (58.9%) got emergency room on dead body. The mean height of fall is $8.9{\pm}5.8m$ for 94 survivors and $15.2{\pm}11.0m$ for the 51 deceased (p<0.001). The area under the ROC curve was 0.646, which means the height of fall was not adequate factor for predicting for death. At 13.5m, as cut?off value, sensitivity is 52.9%, specificity is 86.2%, positive predictive value is 67.5% and negative predictive value is 77.1%. There were statistical differences in mortality rate and ISS between 'below 13.5m group' and 'above 13.5m group', but there was not statistical difference in head and neck AIS. Conclusion: The height of fall is not adequate factor for prediction of death. So other factors like intoxication or not, the being of barrier or protection device need to be evaluated for predicting of free-fall patient's death.

피로와 우울.불안증 환자에서 Fatigue Severity Scale의 임상적 유용성 (Clinical Usefulness of Fatigue Severity Scale for Patients with Fatigue, and Anxiety or Depression)

  • 정규인;송찬희
    • 정신신체의학
    • /
    • 제9권2호
    • /
    • pp.164-173
    • /
    • 2001
  • 연구목적: 피로는 일차 진료에서 흔한 증상이지만 비특이적 주관적 특성상 명확한 정의와 객관적 평가가 어렵고, 특히 기질적 질환이 없는 피로의 평가는 더욱 힘들다. 이에 저자들은 기질적 질환이 없는 피로 환자에게 Fatigue severity scale (FSS) 을 적용하여 그 유용성을 알아보고자 하였다. 방법: 피로환자 44명, 우울 또는 불안증의 정신과 환자 43명과 대조군 45명에게 피로도, 스트레스, 우울 불안 척도를 이용하여 FSS의 신뢰도와 타당도를 조사하였다. 결과: FSS의 신뢰도 계수는 0.935이었고 재검사의 상관관계 계수는 0.916이었다 (p<0.01). FSS 점수는 피로 군에서 유의하게 가장 높았고 대조군에서 가장 낮았다 (p<0.01). FSS와 Chalder fatigue scale의 상관관계 계수는 0.782로 높았다 (p<0.01). 피로군과 대조군에 대한 FSS index의 최적의 절단점은 민감도 84.1%. 특이도 85.7%인 3.22로 조사되었다. 결론: FSS는 일차진료에서 기질적 질환이 없는 피로환자와 우울 또는 불안증 환자에서 피로도를 평가할 수 있는 유용한 도구이며, 향후 보다 많은 환자를 대상으로 한 연구가 필요하리라 생각된다.

  • PDF

ROC(receiver operating characteristics) 해석 (Interpretation of Receiver Operating Characteristics (ROC))

  • 김재덕
    • Imaging Science in Dentistry
    • /
    • 제30권3호
    • /
    • pp.155-158
    • /
    • 2000
  • 1. 일반방사선사진과 칼라화한 방사선사진의 비교에서 각각 필름에서 진단을 시행할 때 ROC해석법에서는 true positive fraction (TPF), false positive fraction (FPF)를 매개변수로 하고 있으므로 우선 두가지 필름형태에 대해 각각 따로 다음과 같이 평가한다. 2. 판정기준 병변없다 A, 거의 없다 B, 모르겠다 C, 거의 있다 D, 있다 E 먼저 일반방사선사진에서 실제로 병소가 총있는 것이 50, 총없는 것이 50인데 위 판정기준 각각에 대해(equation omitted) 3. 곡선만들기 a.횡축은 FPF 종축은 TPF로 한 그래프를 plot를 한다. sensitivity 17/50 specificity 26/50 accuracy 43/100 b. 곡선만들기 프로그램을 이용하여 곡선을 만들시에는 TPF를 a에 입력하고 PFP를 b에 입력한다. 이 plot을 그릴 수 있는 프로그램은 http://www.members.tripod.co.kr/jdakim 또는 http://www.chosun.ac.kr/∼jdakim의 홈페이지내 공개자료실에서 다운 받으실 수 있습니다. (equation omitted) 이 프로그램에서 입력할 a, b의 값은 (equation omitted) 위와같이 입력하여 얻어진 일반방사선사진에서의 판독 결과 얻어진 곡선이 그래프에서 곡선이 된다. 이와 같은 커브를 컬러화한 사진 판독에서 똑같이 시행하여 ROC곡선(윗곡선)을 만든 다음 두 곡선을 비교하여 아래면적이 더 큰 쪽이 병소 판독에 우수하다고 결론짓는다.

  • PDF

The Value of X-ray Compared with Magnetic Resonance Imaging in the Diagnosis of Traumatic Vertebral Fractures

  • Lee, Yang Woo;Jang, Jae Ho;Kim, Jin Joo;Lim, Yong Su;Hyun, Sung Youl;Yang, Hyuk Jun
    • Journal of Trauma and Injury
    • /
    • 제30권4호
    • /
    • pp.158-165
    • /
    • 2017
  • Purpose: The purpose of this study was to evaluate the diagnostic accuracy of X-rays in patients with acute traumatic vertebral fractures visiting the emergency department and to analyze the diagnostic value of X-rays for each spine level. Methods: We retrospectively analyzed basal characteristics by reviewing medical records of 363 patients with adult traumatic vertebral fractures, admitted to the emergency center from March 1, 2014 to February 28, 2017. We analyzed spine X-rays and magnetic resonance imaging (MRI) scans to determine distribution according to the vertebral level, and we evaluated the efficacy of X-rays by comparing discrepancies between X-rays and MRI scans. Results: For a total of 363 patients, the mean age was 56.65 (20-93) and 214 (59%) were males. On the basis of X-rays, 67 cases (15.1%) were of the cervical spine, 133 cases (30.0%) were of the thoracic spine, and 243 cases (54.9%) were of the lumbar spine. In particular, the thoracolumbar region (T11-L2) was the most common, with 260 cases (58.7%). In X-rays, fractures were the least in the upper thoracic region (T1-T3), whereas MRI scans revealed fairly uniform distribution across the thoracic spine. Sensitivity of X-rays was lowest in the upper thoracic spine and specificity was almost always greater than 98%, except for 94.7% in L1. Positive predictive value was lower in the mid-thoracic region (T4-T9) and negative predictive value was slightly lower in C6, T2, and T3 than at other sites. Diagnostic accuracy of X-rays by vertebral body, transverse process, and spinous process according to fractured vertebral structures was significantly different according to vertebral level. Conclusions: Diagnostic accuracy of X-rays was lower in the upper thoracic region than in other parts. Further studies are needed to identify better methods for diagnosis considering cost and neurological prognosis.

Extracorporeal Cardiopulmonary Resuscitation: Predictors of Survival

  • Kim, Dong Hee;Kim, Joon Bum;Jung, Sung-Ho;Choo, Suk Jung;Chung, Cheol Hyun;Lee, Jae Won
    • Journal of Chest Surgery
    • /
    • 제49권4호
    • /
    • pp.273-279
    • /
    • 2016
  • Background: The use of extracorporeal life support (ECLS) in the setting of cardiopulmonary resuscitation (CPR) has shown improved outcomes compared with conventional CPR. The aim of this study was to determine factors predictive of survival in extracorporeal CPR (E-CPR). Methods: Consecutive 85 adult patients (median age, 59 years; range, 18 to 85 years; 56 males) who underwent E-CPR from May 2005 to December 2012 were evaluated. Results: Causes of arrest were cardiogenic in 62 patients (72.9%), septic in 18 patients (21.2%), and hypovolemic in 3 patients (3.5%), while the etiology was not specified in 2 patients (2.4%). The survival rate in patients with septic etiology was significantly poorer compared with those with another etiology (0% vs. 24.6%, p=0.008). Septic etiology (hazard ratio [HR], 2.84; 95% confidence interval [CI], 1.49 to 5.44; p=0.002) and the interval between arrest and ECLS initiation (HR, 1.05 by 10 minutes increment; 95% CI, 1.02 to 1.09; p=0.005) were independent risk factors for mortality. When the predictive value of the E-CPR timing for in-hospital mortality was assessed using the receiver operating characteristic curve method, the greatest accuracy was obtained at a cutoff of 60.5 minutes (area under the curve, 0.67; 95% CI, 0.54 to 0.80; p=0.032) with 47.8% sensitivity and 88.9% specificity. The survival rate was significantly different according to the cutoff of 60.5 minutes (p=0.001). Conclusion: These results indicate that efforts should be made to minimize the time between arrest and ECLS application, optimally within 60 minutes. In addition, E-CPR in patients with septic etiology showed grave outcomes, suggesting it to be of questionable benefit in these patients.

인증표준물질(CRM)을 이용한 방사면역측정법의 회수율 평가 (The Evaluation of Recovery Rate of Radioimmunoassay Using Certified Reference Material (CRM))

  • 최성희;신선영;임소희;홍미경;노경운;김진의
    • 핵의학기술
    • /
    • 제18권1호
    • /
    • pp.158-162
    • /
    • 2014
  • 공인된 기구에 의해 발급된 문서를 동반하는 인증표준물질은 특성값과 추정값의 신뢰정도를 나타내는 연계 불확도, 그리고 측정한 결과가 명시된 불확정 정도의 범위 내에서 국가 측정 또는 국제측정표준에 일치되도록 연속적으로 비교하고 교정하는 소급성을 제공하는 표준물질이다. 회수율 검사는 검체를 측정하여 얻은 값이 참값에서 얼마만큼 벗어났는지의 차이를 말하며 키트의 정확도를 반영한다. 이러한 인증표준물질을 가지고 회수율 검사를 하는 것은 체외 방사면역진단키트의 정확성을 보여주며 이러한 평가는 매우 중요하다. 인증표준물질은 NIBSC (National Institute for biological standard and control, United Kingdom)와 IRMM (Institute for Reference Materials and Measurements, Belgium)에서 구입하였고 검사 종목은 T4, Ferritin, PSA, Prolactin, AFP 그리고 TSH으로 총 6종목이다. T4는 IRMM의 표준물질을 사용하였고 나머지 종목은 NIBSC의 표준물질을 사용하였다. C-1 (저농도), C-2 (중농도), C-3 (고농도) 3 level로 제조하여 본원에서 사용하는 키트를 이용하여 4회 측정하였다. WHO 인증표준물질을 이용한 회수율 측정에서 T4 90%, Ferritin 88%, PSA 94%, Prolactin 99%, AFP 94%, TSH 93%였다. 6개 종목의 회수율 측정에서 88-99%로 양호한 결과를 보였다. 핵의학 체외진단키트의 정확성을 높이기 위해서 이 연구가 다른 검사실의 키트로 확장되어 검사가 되어야 하고 검사실간에도 교류가 필요하다. 인증표준물질을 이용한 체외진단키트의 회수율 평가가 앞으로도 지속되어야 하며 결과의 정확성은 환자의 만족의 증가로 이어질 것으로 기대한다.

  • PDF