Search results for "Receiver operating characteristic"
showing 10 items of 262 documents
Establishing cut-points for physical activity classification using triaxial accelerometer in middle-aged recreational marathoners
2018
The purpose of this study was to establish GENEA (Gravity Estimator of Normal Everyday Activity) cut-points for discriminating between six relative-intensity activity levels in middle-aged recreational marathoners. Nighty-eight (83 males and 15 females) recreational marathoners, aged 30-45 years, completed a cardiopulmonary exercise test running on a treadmill while wearing a GENEA accelerometer on their non-dominant wrist. The breath-by-breath V̇O2 data was also collected for criterion measure of physical activity categories (sedentary, light, moderate, vigorous, very vigorous and extremely vigorous). GENEA cut-points for physical activity classification was performed via Receiver Operatin…
Evidence for a white matter lesion size threshold to support the diagnosis of relapsing remitting multiple sclerosis
2018
Abstract Background The number of white matter lesions (WML) in brain MRI is the most established paraclinical tool to support the diagnosis of multiple sclerosis (MS) and to monitor its course. Diagnostic criteria have stipulated a minimum detectable diameter of 3 mm per WML, although this threshold is not evidence-based. We aimed to provide a rationale for a WML size threshold for three-dimensional MRI sequences at 3 T by comparing patients with relapsing-remitting MS (RRMS) to control subjects (CS). Methods We analyzed MR images from two cohorts, obtained at scanners from two different vendors, each comprising patients with RRMS and CS. Both cohorts were examined with FLAIR and T1w seque…
Characterization of hypoechoic focal hepatic lesions in patients with fatty liver: diagnostic performance and confidence of contrast-enhanced ultraso…
2007
The objective of this study was to assess the diagnostic performance of contrast-enhanced ultrasound (CEUS) to characterize hypoechoic focal hepatic lesions (HFHL) in fatty liver (FL). A study group of 105 patients with FL and 105 HFHLs (52 malignant and 53 benign) underwent CEUS after SonoVue administration. Two blinded readers independently reviewed baseline ultrasound (US) and CEUS scans and classified each lesion as malignant or benign on a five-point scale of confidence, and recorded whether further imaging work-up was needed. Sensitivity, specificity, areas under the receiver operating characteristic (ROC) curve (A (z)), and interobserver agreement were calculated. We observed that th…
Texture analysis in susceptibility-weighted imaging may be useful to differentiate acute from chronic multiple sclerosis lesions.
2020
To evaluate the diagnostic performance of texture analysis (TA) applied on non-contrast-enhanced susceptibility-weighted imaging (SWI) to differentiate acute (enhancing) from chronic (non-enhancing) multiple sclerosis (MS) lesions. We analyzed 175 lesions from 58 patients with relapsing-remitting MS imaged on a 3.0 T MRI scanner and applied TA on T2-w and SWI images to extract texture features. We evaluated the presence or absence of lesion enhancement on T1-w post-contrast images and performed a computational statistical analysis to assess if there was any significant correlation between the texture features and the presence of lesion activity. ROC curves and leave-one-out cross-validation…
Blood pressure for outcome prediction and risk stratification in acute pulmonary embolism.
2015
Abstract Introduction Risk stratification of patients with acute pulmonary embolism (PE) is crucial in deciding appropriate therapy management. Blood pressure (BP) is rapidly available and a reliable parameter. We aimed to investigate BP for short-term outcome in acute PE. Materials and methods Data of 182 patients with acute PE were analyzed retrospectively. Logistic regression models were calculated to investigate associations between BP and in-hospital-death as well as myocardial necrosis. Moreover, receiver operating characteristic (ROC) curves and cutoff values for systolic and diastolic BPs predicting in-hospital death and myocardial necrosis were computed. Results A total of 182 pati…
Solid bone tumors of the spine: Diagnostic performance of apparent diffusion coefficient measured using diffusion-weighted MRI using histology as a r…
2017
Purpose To assess the diagnostic performance of mean apparent diffusion coefficient (mADC) in differentiating benign from malignant bone spine tumors, using histology as a reference standard. Conventional magnetic resonance imaging (MRI) sequences have good reliability in evaluating spinal bone tumors, although some features of benign and malignant cancers may overlap, making the differential diagnosis challenging. Materials and Methods In all, 116 patients (62 males, 54 females; mean age 59.5 ± 14.1) with biopsy-proven spinal bone tumors were studied. Field strength/sequences: 1.5T MR system; T1-weighted turbo spin-echo (repetition time / echo time [TR/TE], 500/13 msec; number of excitatio…
Amplification of human β-glucoronidase gene for appraising the accuracy of negative SARS-CoV-2 RT-PCR results in upper respiratory tract specimens
2020
Real-time reverse transcription polymerase-chain reaction (RT-PCR) is the mainstay of Covid-19 diagnosis. False-negative RT-PCR results may hamper clinical management of patients and hinder the adoption of epidemiological measures to control the pandemic. The current study was aimed at assessing whether amplification of β-glucoronidase (GUSB) gene would help estimate the accuracy of SARS-CoV-2 RT-PCR negative results in upper respiratory tract (URT) specimens. URT specimens that tested negative by SARS-CoV-2 RT-PCR displayed higher GUSB RT-PCR cycle thresholds (CT) (P=0.070) than those testing positive (median, 30.7; range, 27.0-40.0, and median 29.7; range 25.5-36.8, respectively), this re…
Screening for DSM-5 Somatic Symptom Disorder: Diagnostic Accuracy of Self-Report Measures Within a Population Sample.
2017
OBJECTIVE The new DSM-5 somatic symptom disorder was introduced to improve the diagnosis of persons experiencing what used to be called somatoform disorders. So far, it is unclear whether existing self-report measures are useful to detect the new somatic symptom disorder. This study investigates the diagnostic accuracy of three self-report questionnaires that measure somatic complaints (15 item Patient Health Questionnaire [PHQ-15]) and psychological features (7-item Whiteley Index [WI-7]; Scale for Assessing Illness Behavior [SAIB]), in detecting somatic symptom disorder. METHODS A nationally representative general population survey was performed resulting in 250 participants (minimum age …
A complication risk score to evaluate clinical severity of thalassaemia syndromes
2020
The thalassaemia syndromes (TS) show different phenotype severity. Developing a reliable, practical and global tool to determine disease severity and tailor treatment would be of great value. Overall, 7910 patients were analysed with the aim of constructing a complication risk score (CoRS) to evaluate the probability of developing one or more complications. Nine independent variables were included in the investigation as predictors. Logistic regression models were used for Group A [transfusion-dependent thalassaemia (TDT)], Group B [transfused non-TDT (NTDT)] and Group C (non-transfused NTDT). Statistically significant predictors included age (years), haemoglobin levels, hepatic transaminas…
Contrast-enhanced ultrasonography: usefulness in the assessment of postoperative recurrence of Crohn's disease.
2013
Abstract Aim The aim of this study was to assess whether the contrast-enhanced ultrasonography (CEUS) can increase the value of the ultrasonography in the study of postoperative recurrence of Crohn's disease (CD). Materials and methods 60 patients with CD who had previously undergone ileocolic resection underwent prospectively both CEUS and colonoscopy within a 3-day period. The sonographic examination included evaluation of bowel wall thickness, transmural complications, colour Doppler grade and contrast-enhanced US. In addition a sonographic score was established. The capacity of CEUS to diagnose endoscopic recurrence, as well as its severity, was assessed by calculating the sensitivity, …