Search results for "Observer Variation"
showing 10 items of 156 documents
Reproducible coronary plaque quantification by multislice computed tomography
2007
BACKGROUND: The aim of this study was to investigate reproducibility and accuracy of computer-assisted coronary plaque measurements by multislice computed tomography coronary angiography (QMSCT-CA). METHODS AND RESULTS: Forty-eight patients undergoing MSCT-CA and coronary arteriography for symptomatic coronary artery disease and quantitative intravascular ultrasound (IVUS, QCU) were examined. Two investigators performed the QMSCT-CA twice and a third investigator performed the QCU, all blinded for each other's results. There was no difference found for the matched region of interest (ROI) lengths (QCU 29.4 +/- 13 mm vs. QMSCT-CA 29.6 +/- 13 mm, P = 0.6; total length = 1,400 mm). The compari…
Idiopathic infantile asymmetry, proposal of a measurement scale
2004
Abstract To evaluate the development of idiopathic infantile asymmetry and the efficacy of therapeutic interventions, spinal scoliosis can be quantified on the basis of radiographs. For obvious reasons, use of this technique is limited. Here we present a clinical method to describe and quantify infantile asymmetry. For item selection, spontaneous movements (SMs), reactive movements (RMs) and length differences were video recorded in 30 infants (median age 10 weeks, range 6–16) with variable degrees of asymmetry. Within these three categories, reactive movements elicited by head turns to the right and left side in the prone and supine position emerged as reliable parameters reflecting trunk …
Detection of Left Ventricular Systolic Dysfunction in Cardiac Amyloidosis with Strain Rate Echocardiography .
2006
Background We examined the potential role of Doppler myocardial imaging including tissue velocity imaging, strain imaging, and strain rate imaging for detection of left ventricular systolic dysfunction in cardiac amyloidosis (CA) and determined the minimum dataset required to make the diagnosis. Methods and Results Doppler myocardial imaging was performed in 103 patients with amyloidosis (AL). Peak longitudinal systolic tissue velocity, systolic strain rate (sSR), and systolic strain (sS) were determined for 16 left ventricular segments. Radial and circumferential sSR and sS were also measured. Patients with increased left ventricular wall thickness were classified with advanced-CA, and the…
Computer-Aided Detection and diagnosis for prostate cancer based on mono and multi-parametric MRI: A review
2015
Prostate cancer is the second most diagnosed cancer of men all over the world. In the last few decades, new imaging techniques based on Magnetic Resonance Imaging (MRI) have been developed to improve diagnosis. In practise, diagnosis can be affected by multiple factors such as observer variability and visibility and complexity of the lesions. In this regard, computer-aided detection and computer-aided diagnosis systems have been designed to help radiologists in their clinical practice. Research on computer-aided systems specifically focused for prostate cancer is a young technology and has been part of a dynamic field of research for the last 10years. This survey aims to provide a comprehen…
Analysis of left ventricular volumes and function: a multicenter comparison of cardiac magnetic resonance imaging, cine ventriculography, and unenhan…
2013
Background: Contrast echocardiography improves accuracy and reduces interreader variability on left ventricular (LV)functional analyses inthe settingof two-dimensional (2D) echocardiography. Theneedfor contrast imaging using three-dimensional (3D) echocardiography is less defined. The aim of this multicenter study was to define the accuracy and interreader agreement of unenhanced and contrast-enhanced 2D and 3D echocardiography for the assessment of LV volumes and ejection fraction (EF). Methods: A multicenter, open-label study was conducted including 63 patients, using intrasubject comparisons to assess the agreement of unenhanced and contrast-enhanced 2D and 3D echocardiography as well as…
In vitro carious lesion detection on D-, E-, and F-speed radiographic films
2004
Abstract Objectives To compare the accuracy in detection of interproximal natural carious lesions in vitro between Ultraspeed (D), Ektaspeed Plus (E), and Insight (F) radiographic films. Study design Ten observers indicated on a 5-point scale their confidence in detecting an interproximal lesion in 240 surfaces (120 extracted teeth) with noncavitated carious lesions. Truth was assessed microscopically from hemisections. The areas (Az) beneath receiver operating characteristic (ROC) curves were pairwise compared and used for a 2-way analysis of variance. Results Az values were significantly correlated with observers ( P = .002; Eta = 0.671) and film type ( P = .003; Eta = 0.412). E differe…
Effect of diode laser irradiation on the attachment rate of periodontal ligament cells: an in vitro study.
2001
The present study is part of a basic research program investigating the cellular effects of an 810 nm GaAlAs-diode laser on human periodontal tissues. The aim of the investigation was to evaluate the effects of laser treatment of root surface specimens on the attachment of periodontal ligament (PDL) cells in vitro.Root specimens were prepared from periodontally diseased teeth. PDL cells were obtained from human third molar ligaments. Cells were cultured under simple, standardized, and reproducible experimental conditions. One hundred fifty root specimens were scaled and root planed with curets followed by air-powder abrasive treatment; 75 were then lased and 75 served as controls. The irrad…
Evaluation of the agreement by examiners according to classifications of third molars
2011
Objectives. This study recorded and evaluated the intra- and inter-group agreement degree by different examiners for the classification of lower third molars according to both the Winter’s and Pell & Gregory’s systems. Study Design. An observational and cross-sectional study was realized with forty lower third molars analyzed from twenty digital panoramic radiographs. Four examiner groups (undergraduates, maxillofacial surgeons, oral radiologists and clinical dentists) from Aracaju, Sergipe, Brazil, classified them in relation to angulation, class and position. The variance test (ANOVA) was applied in the examiner findings with significance level of p<0.05 and confidence intervals of 95%. R…
Impact of Aortic Diameter Measurements at Three Anatomical Landmarks on Left Ventricular Output Calculation in Neonates
2021
OBJECTIVES To assess reproducibility and accuracy of left ventricular output (LVO) quantifications in neonates, when left ventricular outflow tract diameter (LVOTD) was measured at the hinges of the aortic valve (AV), at the aortic sinus (AS), and at the sinotubular junction (STJ). METHODS This was an observational study. In the first cohort of very preterm neonates, we assessed intraobserver and interobserver repeatability of LVOTD measured at the AV, AS, and STJ and of the corresponding LVO. In the second cohort of older neonates, we compared paired LVO measurements by echo and magnetic resonance imaging (MRI). RESULTS In the first cohort of 48 neonates, mean (standard deviation) weight a…
Effects of Interrater Reliability of Psychopathologic Assessment on Power and Sample Size Calculations in Clinical Trials
2002
Although rater training is increasingly used to improve the quality of the investigated outcome parameters, the reliability of assessments is not perfect. Thus, empirical reliability estimates should be used instead of theoretically assumed perfect reliability. Implications of the reliability of psychiatric assessments for sample size and power calculations in clinical trials are presented. The theoretical basis of sample size and power calculations using empirical reliability scores is delineated. Examples from contemporary research on schizophrenia and depression are used to illustrate several implications for study design and interpretation of results. The tremendous impact of the lack o…