Search results for "Receiver operating characteristic"
showing 10 items of 262 documents
MRI radiomics-based machine-learning classification of bone chondrosarcoma.
2019
Abstract Purpose To evaluate the diagnostic performance of machine learning for discrimination between low-grade and high-grade cartilaginous bone tumors based on radiomic parameters extracted from unenhanced magnetic resonance imaging (MRI). Methods We retrospectively enrolled 58 patients with histologically-proven low-grade/atypical cartilaginous tumor of the appendicular skeleton (n = 26) or higher-grade chondrosarcoma (n = 32, including 16 appendicular and 16 axial lesions). They were randomly divided into training (n = 42) and test (n = 16) groups for model tuning and testing, respectively. All tumors were manually segmented on T1-weighted and T2-weighted images by drawing bidimensiona…
Evaluation of esophagogastric junction relaxation by 4-second Integrated Relaxation Pressure in achalasia using High Resolution Manometry with water-…
2014
Background Relaxation of the esophagogastric junction (EGJ) is now evaluated calculating 4-second integrated relaxation pressure (4-s IRP) by high resolution manometry (HREPT). Solid-state catheters have been used to define abnormal values. Our aim was to evaluate 4-s IRP in esophageal achalasia using HREPT with perfused catheters. Methods From June 2009 to June 2013, 936 HREPT studies have been performed in our unit. Of these, 194 patients having treated achalasia were excluded. Control group was constituted by 695 patients without achalasia, and 47 patients with untreated achalasia constituted the study group. HREPT was performed with water-perfused catheters. To establish the cut-off val…
Resovist enhanced MR imaging of the liver: Does quantitative assessment help in focal lesion classification and characterization?
2009
Purpose: To improve characterization of focal liver lesions by a prospective quantitative analysis of percentage signal intensity change, in dynamic and late phases after slow (0.5 mL/s) Resovist administration. Materials and Methods: Seventy-three patients were submitted on clinical indication to MR examination with Resovist. Signal intensity of 92 detected focal lesions (5–80 mm) were measured with regions of interest and normalized to paravertebral muscle in arterial, portal, equilibrium and T1/T2 late phases, by two observers in conference. Five values of percentage variations per patient were obtained and statistically evaluated. Results: The enhancement obtained on dynamic study is mo…
Serum Concentrations of Fluvoxamine and Clinical Effects: A prospective open clinical trial
1998
This pilot study examined prospectively blood serum concentrations of fluvoxamine, side effects and therapeutic response after a fixed dosage of 100 mg fluvoxamine/day for 14 days. Twenty male and female patients who met the DSM-IV criteria of a major depression received 50 mg fluvoxamine b.i.d. for two weeks. On days 7 and 14 side effects and therapeutic response were registered and serum concentrations of fluvoxamine were determined. A Receiver Operating Characteristic (ROC) curve was constructed to determine a possible relationship between serum concentrations and clinical effects. The serum concentrations of fluvoxamine were highly variable, even when dosages were corrected for body wei…
Therapeutic drug monitoring for optimizing amisulpride therapy in patients with schizophrenia.
2005
Amisulpride is a clinically effective antipsychotic drug in a broad dose range with low propensity for extrapyramidal symptoms (EPS). Daily doses and plasma levels of amisulpride were analyzed within a large-scale therapeutic drug monitoring (TDM) survey to find plasma level ranges for optimized treatment under naturalistic conditions. Data of 378 schizophrenic patients treated with amisulpride (100-1550 mg) were included (40% female). Amisulpride plasma levels were analyzed at steady state; assessment comprised improvement (CGI-I) and side-effects, particularly EPS. For detection of cut-off values regarding non-response or EPS, receiver operating characteristics (ROC) curves were applied a…
Sex-related differences in D-dimer levels for venous thromboembolism screening.
2021
Background D-dimer is generally considered positive above 0.5 mg/L irrespective of sex. However, women have been shown to be more likely to have a positive D-dimer after controlling for other factors. Thus, differences may exist between males and females for using D-dimer as a marker of venous thromboembolic (VTE) disease. We hypothesized that the accuracy of D-dimer tests may be enhanced by using appropriate cutoff values that reflect sex-related differences in D-dimer levels. Methods This research is a secondary analysis of a multicenter, international, prospective, observational study of adult (18+ years) patients suspected of VTE, with low-to-intermediate pretest probability based on We…
Predictive biomarkers for complicated acute appendicitis: A prospective Ecuadorian study.
2020
The aim of the study was to determine the usefulness of known biomarkers as pre-operative predictors of complicated acute appendicitis (CAA) and perforated appendicitis (PA).This was an observational, analytic, cross-sectional, and prospective study at Hospital Teodoro Maldonado Carbo (August 2016-December 2017). Evaluated biomarkers: white blood cells count, neutrophil percentage (N%), neutrophil-to-lymphocyte ratio, glucose, total bilirubin, C-reactive protein, and procalcitonin (PCT). The statistical analysis was performed by means of the area under the receiver operating characteristics (AUROC) curve estimation. Biomarkers' cutoff point was identified using Youden's index. Sensitivity, …
Kinetics of plasma biomarkers of inflammation and lung injury in surgical patients with or without postoperative pulmonary complications
2017
Background Postoperative pulmonary complications (PPCs) are common after major abdominal surgery. The kinetics of plasma biomarkers could improve identification of patients developing PPCs, but the kinetics may depend on intraoperative ventilator settings. Objective To test whether the kinetics of plasma biomarkers are capable of identifying patients who will develop PPCs, and whether the kinetics depend on the intraoperative level of positive end-expiratory pressure (PEEP). Design A preplanned substudy of a randomised controlled trial. Setting Operation room of five centres. Patients Two hundred and forty-two adult patients scheduled for abdominal surgery at risk of developing PPCs. Interv…
Diagnostic performance of reformatted isotropic thin-section helical CT images in the detection of superior semicircular canal dehiscence
2017
Purpose The purpose of this article is to assess the diagnostic performance of computed tomography (CT) reformatted images for detection of superior semicircular canal (SSC) dehiscence. Material and methods Forty-two patients, with sound- and/or pressure-induced vestibular symptoms, and 42 control participants underwent helical CT examination with a highly collimated beam (0.5 mm). Reformatted images of the vestibular labyrinth were obtained in the standard axial and coronal planes (group A images), and in a plane parallel and perpendicular to the SSC (group B images). Diagnostic performance obtained by evaluating the group A images alone and the group B images alone was analyzed by using t…
Stratification for Identification of Prognostic Categories In the Acute RESpiratory Distress Syndrome (SPIRES) Score.
2021
OBJECTIVES: To develop a scoring model for stratifying patients with acute respiratory distress syndrome into risk categories (Stratification for identification of Prognostic categories In the acute RESpiratory distress syndrome score) for early prediction of death in the ICU, independent of the underlying disease and cause of death. DESIGN: A development and validation study using clinical data from four prospective, multicenter, observational cohorts. SETTING: A network of multidisciplinary ICUs. PATIENTS: One-thousand three-hundred one patients with moderate-to-severe acute respiratory distress syndrome managed with lung-protective ventilation. INTERVENTIONS: None. MEASUREMENTS AND MAIN …