Search results for "reference standards"
showing 10 items of 156 documents
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…
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…
Meniscal ramp lesions: diagnostic performance of MRI with arthroscopy as reference standard
2021
Abstract Background The posteromedial meniscal region is gaining interest among orthopedic surgeons, as lesions of this area has been reported to be significantly associated with anterior cruciate ligament tears. The current imaging literature is unclear. Purpose To evaluate the diagnostic performance of MR in the detection of meniscal ramp lesions having arthroscopy as reference standard. Materials and methods We retrospectively included 56 patients (mean age of 25 ± 7 years; 14 females) from January to November 2017 with a arthroscopically proved ACL tear and posterior meniscocapsular separation. On preoperative MRI, two radiologists with 13 and 2 years’ experience in musculoskeletal imag…
Psychometric properties of non-specific electrodermal response frequency for a sample of male students.
1990
In the present study data on the frequency of non-specific electrodermal responses (NSRs) are presented for a large and, with regard to sex, age and educational level, homogeneous sample of male students (n = 590). These data were obtained in 9 independent experiments in which NSRs were recorded under equivalent conditions. NSRs were scored as skin conductance changes greater than 0.02 muSiemens. A recording period of 5 min prior to experimental manipulations was chosen. A systematic comparison between the 9 studies, the distribution of NSRs for the total sample, as well as descriptive data for stabile and labile subgroups are presented. For 213 subjects NSR-frequency was recorded twice, wi…
Towards an international language for incontinence-associated dermatitis (IAD): design and evaluation of psychometric properties of the Ghent Global …
2018
Background Incontinence-associated dermatitis (IAD) is a specific type of irritant contact dermatitis with different levels of severity. An internationally accepted instrument to assess the severity of IAD in adults with established diagnostic accuracy, agreement, and reliability is needed to support clinical practice and research.Objectives To design and psychometrically evaluate the Ghent Global IAD Categorisation Tool (GLOBIAD).Methods The design was based on expert consultation using a three-round Delphi procedure with 34 experts from 13 countries. The instrument was tested using IAD photographs reflecting different severity levels in a sample of 823 health professionals in 30 countries…
Overview of ambulatory blood pressure monitoring in childhood and pregnancy.
2001
Despite the fact that the study and applicability of ambulatory blood pressure in children and pregnant women share characteristics which limit the potential development of knowledge for their use, advances produced in the last few years provided the present knowledge regarding the significance and the potential use of ambulatory blood pressure in children and in the pregnant women. In children ambulatory blood pressure monitoring is useful for the diagnosis of mild hypertensives, assessment of refractory hypertension, therapeutic trials with antihypertensive drugs, and clinical investigation when BP is one of the parameters to be taken into account and/or when subtle BP abnormalities are t…
Clinical evaluation of a wireless ECG sensor system for arrhythmia diagnostic purposes
2013
Accepted version of an article in the journal: Medical Engineering and Physics. Also available from the publisher at: http://dx.doi.org/10.1016/j.medengphy.2013.03.002 In a clinical study, a novel wireless electrocardiogram (ECG) recorder has been evaluated with regard to its ability to perform arrhythmia diagnostics. As the ECG recorder will detect a "non-standard" ECG signal, it has been necessary to compare those signals to "standard" ECG recording signals in order to evaluate the arrhythmia detection ability of the new system. Simultaneous recording of ECG signals from both the new wireless ECG recorder and a conventional Holter recorder was compared by two independent cardiology specia…
Blood flow velocity waveforms of the fetal middle cerebral artery in a normal population: reference values from 18 weeks to 42 weeks of gestation
2002
The aim of this prospective cross-sectional study was to establish new Doppler reference curves for peak blood flow velocities (Vmax, Vmean, Vmin) and impedance indices (PI, RI) of the middle cerebral artery at 18-42 weeks of gestation by an automatic wave form analysis integrated into the ultrasound device. In 962 low-risk pregnancies, blood flow velocities were derived from the middle cerebral artery with pulsed color Doppler ultrasonography. Reference curves were constructed for the individual parameters based on a growth function from a four-parameter class of monotonic continuous functions according to the smallest square principle for maximum blood flow velocities, as well as on a pol…
Comparison of high-pressure liquid chromatography (HPLC) and Griess reagent-spectroscopic methods for the measurement of nitrate in serum from health…
2008
Bioavailability of NO can be estimated by measuring the concentration of nitrate (NO(3)) in serum. However, the methods used for the measurement NO(3) in plasma or serum show a great degree of variation. Therefore, we compared two analytical methods for the measurement of NO(3) in serum.The concentration of NO(3) in 600 serum samples collected from healthy individuals was determined by the HPLC and by the Griess reagent-spectroscopic method.The concentration of NO(3) in the samples was 29.4+/-16.1 micromol/L and 26.2+/-14.0 micromol/L (mean+/-SD) measured by HPLC and Griess reagent-spectroscopic method respectively (p0.0001). We detected a significant correlation between the two methods (R=…
Reference Standards for Software Evaluation
1990
AbstractThe field of automated ECG analysis was one of the earliest topics in Medical Informatics and may be regarded as a model both for computer-assisted medical diagnosis and for evaluating medical diagnostic programs. The CSE project has set reference standards of two kinds: In a broad sense, a standard how to perform a comprehensive evaluation study, in a narrow sense, standards as specific references for evaluating computer ECG programs. The evaluation methodology used within the CSE project is described as a basis for presentation of results which are published elsewhere in this issue.