Comparison of adrenal vein sampling value between aldosterone producing adrenal adenoma and non-functioning adrenal adenoma: evaluation using receiver operating characteristic analysis

2005 ◽  
Vol 46 (7) ◽  
pp. 750-755 ◽  
Author(s):  
Y. Baba ◽  
H. Hokotate ◽  
M. Nakajo
Keyword(s):  
Adrenal Adenoma ◽  
False Positive Rate ◽  
Laboratory Data ◽  
Contralateral Side ◽  
Adrenal Vein ◽  
Operating Characteristics ◽  
Characteristic Analysis ◽  
Adrenal Vein Sampling ◽  
Positive Rate ◽  
Receiver Operating

Purpose: To evaluate adequate criteria for adrenal vein sampling values in patients with aldosterone producing adrenal adenoma (APA), retrospectively. Material and Methods: Between 1988 and 2002, 59 hypertensive patients (15 M and 44 F, aged 47.58±9.45 years) were referred to our hospital and diagnosed with APA based on established criteria. During the same period, 23 patients with non-functioning adrenal adenoma (11 M and 12 F aged 53.56±11.76 years) were diagnosed based on computed tomography and laboratory data. Results: All 82 patients were enrolled in the present study. Bilateral adrenal vein sampling (AVS) for measurement of plasma aldosterone (A) and cortisol (C) was performed, and a receiver operating characteristics (ROC) analysis was conducted to establish the best criteria from the AVS-derived index in patients with APA. A (APA side)/A (contralateral side) was confirmed to provide the best diagnostic accuracy {(>2.5: right APA, sensitivity 83.3%, specificity 79.5%), (>3: left APA, sensitivity 84.2%, specificity 76.9)}. The Az values for A (APA side)/A (contralateral side) were 0.8948 and 0.9260 for right and left APA, respectively. Conclusion: The A (APA side)/A (contralateral side) value was the best compromise for sensitivity and false-positive rate for lateralization of APA.

scholarly journals Vision-Based Finger Tapping Detection Without Fingertip Observation

2021 ◽  
Vol 33 (3) ◽  
pp. 484-493
Author(s):  
Shotaro Narita ◽  
◽  
Shingo Kagami ◽  
Koichi Hashimoto
Keyword(s):  
High Speed ◽  
Feature Vector ◽  
False Positive Rate ◽  
Finger Tapping ◽  
Surface Patch ◽  
Operating Characteristics ◽  
Machine Learning Approach ◽  
History Information ◽  
Characteristics Analysis ◽  
Positive Rate

A machine learning approach is investigated in this study to detect a finger tapping on a handheld surface, where the movement of the surface is observed visually; however, the tapping finger is not directly visible. A feature vector extracted from consecutive frames captured by a high-speed camera that observes a surface patch is input to a convolutional neural network to provide a prediction label indicating whether the surface is tapped within the sequence of consecutive frames (“tap”), the surface is still (“still”), or the surface is moved by hand (“move”). Receiver operating characteristics analysis on a binary discrimination of “tap” from the other two labels shows that true positive rates exceeding 97% are achieved when the false positive rate is fixed at 3%, although the generalization performance against different tapped objects or different ways of tapping is not satisfactory. An informal test where a heuristic post-processing filter is introduced suggests that the use of temporal history information should be considered for further improvements.

Considerations on the region of interest in the ROC space

2021 ◽  
pp. 096228022110605
Author(s):  
Luigi Lavazza ◽  
Sandro Morasca
Keyword(s):  
Receiver Operating Characteristic ◽  
Operating Characteristic ◽  
False Positive Rate ◽  
Area Under The Curve ◽  
Region Of Interest ◽  
True Positive Rate ◽  
True Positive ◽  
Receiver Operating Characteristic Curves ◽  
Positive Rate ◽  
Receiver Operating

Receiver Operating Characteristic curves have been widely used to represent the performance of diagnostic tests. The corresponding area under the curve, widely used to evaluate their performance quantitatively, has been criticized in several respects. Several proposals have been introduced to improve area under the curve by taking into account only specific regions of the Receiver Operating Characteristic space, that is, the plane to which Receiver Operating Characteristic curves belong. For instance, a region of interest can be delimited by setting specific thresholds for the true positive rate or the false positive rate. Different ways of setting the borders of the region of interest may result in completely different, even opposing, evaluations. In this paper, we present a method to define a region of interest in a rigorous and objective way, and compute a partial area under the curve that can be used to evaluate the performance of diagnostic tests. The method was originally conceived in the Software Engineering domain to evaluate the performance of methods that estimate the defectiveness of software modules. We compare this method with previous proposals. Our method allows the definition of regions of interest by setting acceptability thresholds on any kind of performance metric, and not just false positive rate and true positive rate: for instance, the region of interest can be determined by imposing that [Formula: see text] (also known as the Matthews Correlation Coefficient) is above a given threshold. We also show how to delimit the region of interest corresponding to acceptable costs, whenever the individual cost of false positives and false negatives is known. Finally, we demonstrate the effectiveness of the method by applying it to the Wisconsin Breast Cancer Data. We provide Python and R packages supporting the presented method.

Abstract 277: Mutations in the KCNJ5 Gene Imply a Higher Lateralization Index at Adrenal Vein Sampling for Primary Aldosteronism

Hypertension ◽  
2012 ◽  
Vol 60 (suppl_1) ◽  
Author(s):  
Teresa M Seccia ◽  
Franco Mantero ◽  
Claudio Letizia ◽  
Maniselvan Kuppusamy ◽  
Marlena Barisa ◽  
...  
Keyword(s):  
Primary Aldosteronism ◽  
Somatic Mutations ◽  
Contralateral Side ◽  
Adrenal Vein ◽  
K Channel ◽  
Coding Region ◽  
Aldosterone Secretion ◽  
Adrenal Vein Sampling ◽  
Lateralization Index

Background. The mutations that affect the selectivity filter of the KCNJ5 K+ channel can play a role in triggering and/or maintaining aldosterone oversecretion in primary aldosteronism (PA). We therefore hypothesized that these somatic mutations can be associated with an increased aldosterone secretion from the APA, thus translating in raised plasma aldosterone concentrations (PAC) in the ipsilateral adrenal vein. Aim. To investigate if the lateralization index (LI) at adrenal vein sampling (AVS) is higher in the patients with an APA carrying the mutation (KCNJ5mut), as compared to those without the mutation (KCNJ5wt). Methods. Ninety-two consecutive PA patients who underwent AVS and received diagnosis of APA based on the four corners criteria were recruited. Unequivocal information on the presence or absence of the KCNJ5 mutations was available for each patient. The selectivity index (SI) was calculated as ratio between the right or left adrenal vein PCC (PCCside) and the infrarenal IVC PCC and a cutoff of 2.00 was used. The lateralization index (LI) was calculated in the bilaterally selective AVS as the ratio of PAC/PCC at the APA side to PAC/PCC at the contralateral side. We sequenced the KCNJ5 coding region spanning aminoacids 122 to 199, which include the selectivity filer. Results. The overall prevalence rate of KCNJ5 somatic mutations was 34%; G151R, L168R and T158A mutations were found in 19, 10 and 1 APA respectively. The G151E mutation was not found. The KCNJ5mut and KCNJ5wt groups were similar for gender, age, sK+ levels, while PAC and ARR were higher, and PRA lower (all p<0.05) in the KCNJ5 mut group. In the latter group the LI was higher than in the KCNJ5wt group (29.3± 6.7 vs 16.7±3.9, p< 0.02). This was due to a PAC/PCC ratio which was higher in the adrenal vein ipsilateral to the APA side and lower contralaterally in the KCNJ5mut group. Conclusions. These results provide direct in vivo evidence for a higher aldosterone secretion from APA carrying the KCNJ5 mutations, which translates into higher values of the LI, compared to the tumors without such mutations. Hence, the presence of these KCNJ5 mutations can affect the accuracy of the AVS-based diagnosis of the subtype of PA.

Use of the receiver operating characteristic curve to evaluate sensitivity, specificity, and accuracy of methods for detection of peaks in hormone time series

1991 ◽  
Vol 124 (3) ◽  
pp. 295-306 ◽  
Author(s):  
A. D. Genazzani ◽  
D. Rodbard
Keyword(s):  
Receiver Operating Characteristic ◽  
False Positive ◽  
Operating Characteristic ◽  
False Positive Rate ◽  
Peak Detection ◽  
Lower Sensitivity ◽  
Modest Improvement ◽  
Free Data ◽  
Positive Rate ◽  
Receiver Operating

Abstract. We utilize the "Receiver Operating Characteristic" to describe the relationship between sensitivity and specificity as the threshold for peak detection is varied systematically, to provide objective comparison of the performance of methods for detection of episodic hormonal secretion. A computer program was used to generate synthetic data with peaks with variable durations, with constant or variable height, shape and/or interpulse interval. This approach was used to compare the CLUSTER and DETECT programs. For both programs, the observed false positive rates estimated using signal-free data were in good agreement with the nominal rates, but in the presence of signal the observed false positive rates were systematically lower. Sensitivity increases with increasing signal/noise ratio, as expected. Program DETECT, using its standard options, provided excellent sensitivity (90-100%) with very low false positive rate under all conditions tested. Its performance could be further improved by the use of a more stringent definition of a peak requiring the presence of "UP" followed by a "DOWN". The CLUSTER program was found to have very poor sensitivity when using the "local variance" option. Use of the true fixed standard deviation or percent coefficient of variation resulted in a modest improvement. Optimal performance of program CLUSTER was obtained by the use of the best of 3 variance models, testing 12 different cluster sizes (from 1×1) to 4×4 and selecting the best among these: under these conditions it can achieve high sensitivity (90-100%) for very low observed false positive rate, such that its performance was comparable to that of DETECT. The methods developed and illustrated here should permit the definitive characterization and validation of the performance of any one method, the objective comparison of the relative performance of two or more methods for analysis of pulsatile hormone levels for episodic hormone secretion, and lead to the improvement of algorithms for peak detection.

scholarly journals Evaluation of an Epitope-Blocking Enzyme-Linked Immunosorbent Assay for the Diagnosis of West Nile Virus Infections in Humans

2009 ◽  
Vol 16 (5) ◽  
pp. 749-755 ◽  
Author(s):  
M. A. Loroño-Pino ◽  
J. A. Farfan-Ale ◽  
B. J. Blitvich ◽  
J. L. Beebe ◽  
R. G. Jarman ◽  
...  
Keyword(s):  
West Nile Virus ◽  
Dengue Virus ◽  
Immunosorbent Assay ◽  
False Positive ◽  
False Positive Rate ◽  
Enzyme Linked Immunosorbent Assay ◽  
Virus Infections ◽  
Characteristic Analysis ◽  
West Nile ◽  
Positive Rate

ABSTRACT An epitope-blocking enzyme-linked immunosorbent assay (b-ELISA) was evaluated for the diagnosis of West Nile virus (WNV) infections in humans. Sera from patients diagnosed with WNV infections from an outbreak in 2003 in Colorado and from patients diagnosed with dengue virus infections from Mexico and Thailand were tested with the b-ELISA. The b-ELISAs were performed using the WNV-specific monoclonal antibody (MAb) 3.1112G and the flavivirus-specific MAb 6B6C-1. Although the WNV-specific b-ELISA was effective in diagnosing WNV infections in humans from Colorado, it was not efficacious for diagnosing WNV infections in serum specimens from Mexico and Thailand. In serum specimens from patients from Colorado, the WNV b-ELISA and the WNV plaque reduction neutralization test showed an overall agreement of 91%. The sensitivity and specificity of the WNV b-ELISA were 89% and 92%, respectively, with a false-positive rate of 5%, based on receiver operating characteristic analysis. In contrast, false-positive rate results in specimens from the countries of Mexico and Thailand, where flaviviruses are endemic, were 79% and 80%, presumably due to the presence of antibodies resulting from previous dengue virus infections in Mexico and/or Japanese encephalitis virus infections or vaccination in Thailand. Thus, in regions where people have experienced previous or multiple flavivirus infections, the use of the b-ELISA for WNV diagnosis is contraindicated.

scholarly journals Pre-Operative Combination of Normal BMI with Elevated YKL-40 and Leptin but Lower Adiponectin Level Is Linked to a Higher Risk of Breast Cancer Relapse: A Report of Four-Year Follow-Up Study

2020 ◽  
Vol 9 (6) ◽  
pp. 1742
Author(s):  
Kornel Bielawski ◽  
Piotr Rhone ◽  
Marek Bulsa ◽  
Barbara Ruszkowska-Ciastek
Keyword(s):  
Breast Cancer ◽  
Body Mass Index ◽  
Body Mass ◽  
Metastatic Breast ◽  
Clinicopathological Parameters ◽  
Operating Characteristics ◽  
Characteristic Analysis ◽  
Increased Risk ◽  
Receiver Operating

Adipokines are powerful agents involved in the development of obesity-dependent cancers. This prospective study aimed to investigate the association between pre-treatment body mass index (BMI) and serum YKL-40, leptin, and adiponectin concentrations as well as the plasma activity of tissue factor (TF) and the future prognosis of early, non-metastatic breast cancer (BrC) subjects. The serum levels of YKL-40, leptin, and adiponectin as well as plasma TF activity, anthropometric parameters, and clinicopathological parameters were analysed in 81 treatment-naïve females with invasive BrC. The predictive value of YKL-40, BMI, leptin, adiponectin, and TF was determined with a 95% confidence interval (CI). Kaplan–Meier plots and log-rank and F Cox tests were used to determine the clinical outcomes of progression-free survival (PFS). The median follow-up duration was 44 months with complete follow-up for the first event. Follow-up revealed a significantly higher incidence of disease relapse in BrC patients with a high baseline concentration of YKL-40 (22.22%) and TF activity (21.43%). Body mass index was an independent predictor of survival, with women who were overweight/obese being less prone to relapse (hazard ratio (HR): 0.75; 95% CI: 0.59 to 0.95). The recurrence rates for normal-weight BrC cases was 21.05% versus 7.14% for their overweight counterparts. The receiver operating characteristic analysis showed the strong ability of the analysed biomarkers to predict disease progression, with an area under the receiver operating characteristics (ROC) curve of 0.84 (95% CI, 0.823 to 0.931). In a prospective cohort of invasive BrC patients, overweight/obesity was associated with improved future outcomes. The combination of a normal BMI with high leptin and low adiponectin levels and high TF activity was associated with an increased risk of recurrence and decreased survival.

scholarly journals An Empirical Study towards dealing with Noise and Class Imbalance issues in Software Defect Prediction

2021 ◽  
Author(s):  
SUSHANT KUMAR PANDEY ◽  
Anil Kumar Tripathi
Keyword(s):  
False Positive Rate ◽  
Class Imbalance ◽  
Prediction Method ◽  
Defect Prediction ◽  
Software Defect Prediction ◽  
Operating Characteristics ◽  
Software Defect ◽  
Positive Rate ◽  
The Impact

Abstract The quality of the defect datasets is a critical issue in the domain of software defect prediction (SDP). These datasets are obtained through the mining of software repositories. Resent studies claims over the quality of the defect dataset. It is because of inconsistency between bug/clean fix keyword in fault reports and the corresponding link in the change management logs. Class Imbalance (CI) problem is also a big challenging issue in SDP models. The defect prediction method trained using noisy and imbalanced data leads to inconsistent and unsatisfactory results. Combined analysis over noisy instances and CI problem needs to be required. To the best of our knowledge, there are insufficient studies that have been done over such aspects. In this paper, we deal with the impact of noise and CI problem on five baseline SDP models; we manually added the various noise level (0 to 80%) and identified its impact on the performance of those SDP models. Moreover, we further provide guidelines for the possible range of tolerable noise for baseline models. We have also suggested the SDP model, which has the highest noise tolerable ability and outperforms over other classical methods. The True Positive Rate (TPR) and False Positive Rate (FPR) values of the baseline models reduce between 20\% to 30\% after adding 10% to 40% noisy instances. Similarly, the ROC (Receiver Operating Characteristics) values of SDP models reduces to 40% to 50%. The suggested model leads to avoid noise between 40% to 60% as compared to other traditional models.

Temperature and Total White Blood Cell Count as Indicators of Bacteremia

PEDIATRICS ◽  
1991 ◽  
Vol 87 (5) ◽  
pp. 670-674 ◽  
Author(s):  
David M. Jaffe ◽  
Gary R. Fleisher
Keyword(s):  
Receiver Operating Characteristic ◽  
False Positive ◽  
Operating Characteristic ◽  
Characteristic Curve ◽  
False Positive Rate ◽  
Diagnostic Information ◽  
Receiver Operating Characteristic Curves ◽  
Positive Rate ◽  
Wbc Count ◽  
Receiver Operating

This study was designed to quantify more precisely the accuracy of magnitude of rectal temperature and total white blood cell (WBC) count as indicators of bacteremia in children with an obvious focal bacterial infection. A total of 955 children, aged 3 to 36 months, who had rectal temperature ≥39.0°C and were seeking care at either of two urban pediatric emergency departments had blood drawn for culture; 885 had blood drawn for WBC count. Twenty-seven had bacteremia. Various combinations of temperature and WBC count were selected to construct receiver-operating-characteristic curves by plotting sensitivity vs false-positive rate (1 - specificity). The receiver-operating-characteristic curve of WBC count provided significantly better diagnostic information than the curve for temperature increments above 39.0°C. Each increment of 0.5°C led to large decrements in sensitivity and false-positive rates. At a WBC count cutoff of 10 000/mm3, the sensitivity was 92% while the false-positive rate was 57%. Using this cutoff point, the clinician could have avoided performing 368 of 955 blood cultures and missed only 2 of 26 children with bacteremia. Receiver-operating-characteristic curves combining WBC count and temperature increments above 39.0°C provided no better diagnostic information than that of WBC count at a temperature cutoff of 39.0°C. It is concluded that increments in temperature above 39.0°C provided additional diagnostic specificity for bacteremia only at the expense of unacceptable decreases in sensitivity. Total WBC count provided better information. A WBC count cutoff of 10 000/mm3 increased specificity with minimal decrease in sensitivity. Receiver-operating-characteristic curve analysis allows selection of cutoff criteria by individual practitioners based on the prevalence of bacteremia in their communities and on the perceived risks of bacteremia.

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