Intraobserver Agreement (intraobserver + agreement)

Distribution by Scientific Domains


Selected Abstracts


Fractal dimension can distinguish models and pharmacologic changes in liver fibrosis in rats

HEPATOLOGY, Issue 4 2002
Frédéric Moal
Fractal analysis measures the complexity of geometric structures. The aim of this study was to evaluate the feasibility and accuracy of fractal analysis in liver fibrosis. A total of 77 rats were included: 10 sham, 46 with fibrosis secondary to bile duct ligation (BDL), and 21 with fibrosis due to CCl4 intoxication. Measurements included the fractal dimension of Kolmogorov (Dk), histologic lesions, the area of fibrosis by image analysis, liver hydroxyproline content, messenger RNA fibronectin, serum hyaluronate level, and portal pressure. Fibrotic rats were given placebo, octreotide, or O2 -vinyl 1-(pyrrolidin-1-yl)diazen-1-ium-1,2-diolate (V-PYRRO/NO). Intraobserver agreement of Dk was excellent with the intraclass (ic) correlation coefficient ric = 0.91 (P < .0001) as well as the interobserver agreement with ric = 0.88 (P < .001). Dk was correlated with other measurements or markers of fibrosis: the area of fibrosis (r = 0.75; P < .0001), hydroxyproline content (r = 0.51; P < .001), serum hyaluronate level (r = 0.52; P < .001), and portal pressure (r = 0.52; P < .01). Dk was significantly different between the 2 models of fibrosis (P < .0001), unlike the area of fibrosis, and this relationship was independent of other histologic lesions. The significant decrease in fibrosis observed with octreotide or V-PYRRO/NO was similarly reflected by Dk or the area of fibrosis. The diagnostic accuracy for the fibrosis model was 97% with the 5 main measurements or markers of fibrosis studied, with Dk isolated at the first step by stepwise analysis. In conclusion, fractal analysis is suitable for analyzing liver fibrosis and has excellent reproducibility. This is the only quantitative morphometric method that can discriminate among the models of fibrosis and is sensitive enough to detect pharmacologically induced changes in liver fibrosis. [source]


Invasive front grading: reliability and usefulness in the management of oral squamous cell carcinoma

JOURNAL OF ORAL PATHOLOGY & MEDICINE, Issue 1 2003
Faleh A. Sawair
Abstract Background:, The value of histological grading was examined with emphasis on reliability of assessment in 102 cases of intraoral squamous cell carcinoma from Northern Ireland with known outcome. Methods:, Two pathologists independently graded the invasive tumour front blinded to the stage and outcome. Results:, Intraobserver agreement was acceptable but interobserver agreement was not satisfactory. The degree of keratinisation was assessed most consistently while nuclear polymorphism was the least reliable feature. Multivariate survival analysis showed that the total grading score was associated with overall survival while the pattern of tumour invasion was the most valuable feature in estimating regional lymph node involvement. The number of positive lymph nodes was strongly associated with regional relapse, while the treatment modality and status of the surgical margins correlated with local relapse. Conclusions:, Grading of selected features in OSCC is reliable and can facilitate treatment planning. [source]


Variation in identifying neonatal percutaneous central venous line position

JOURNAL OF PAEDIATRICS AND CHILD HEALTH, Issue 9-10 2004
DE Odd
Objective: The study objective was to obtain data on interpretation, including intra and interobserver variation and action taken for a given line tip location, for a series of radiographs demonstrating neonatal long lines. Methods: Nineteen radiographs taken to identify line tip position were digitized and published on an internet site. One film was included twice in order to assess intraobserver variation giving a total of 20 images. Fourteen used radio-opaque contrast and five no contrast. Australian and New Zealand Neonatal Network members and National Women's Hospital NICU staff were invited to participate in the study. For each radiograph, participants were asked to identify if long line tip could be identified, the likely anatomical position and desired action. Interobserver agreement was assessed by the maximum proportion of agreement per radiograph and by the number of different options selected. Intraobserver agreement was assessed by comparing the two reports from the duplicate radiograph. Results: Twenty-seven responses were received. Overall, 50% of the reports stated that the long line tips could be identified. The most commonly reported position was in the right atrium (31%) and most commonly reported action was to pull the line back (53%). The median agreement of whether the line was seen was 68%, agreement on position 62% and agreement on action 86%. On analysis of intraobserver variability, from the identical radiographs, 27% of respondents differed on whether the line tip could be visualized. Conclusion: Interobserver and intraobserver reliability was poor when using radiographs to assess long line tips. The major determinant of line repositioning was the perceived location. [source]


Interobserver and intraobserver reproducibility in focal cortical dysplasia (malformations of cortical development)

EPILEPSIA, Issue 12 2009
Wendy A. Chamberlain
Summary Purpose:, Malformations of cortical development (MCD) (cortical dysplasias) are well-recognized causes of intractable epilepsy. Although a histologic classification system for MCD has been proposed by Palmini et al. (Neurology; 2004; 62:S2), studies to date have not assessed reproducibility. The purpose of this study was to analyze inter- and intraobserver agreement among eight experienced neuropathologists (NPs) with respect to this classification system. Methods:, Sections from 26 epilepsy resections were selected to represent the range of pathologies described by Palmini et al. Recuts of single sections from each case were sent to the NPs to classify. The slides were resent at a later date for reclassification. Kappa analysis for both inter- and intraobserver concordance was performed. Results:, Interobserver agreement was moderate (, = 0.4968). There was ,62.5% (5 of 8 NPs) agreement for 19 of 26 cases. The greatest concordance was present when making focal cortical dysplasia (FCD) types IIA/B classifications (12 of the 14 cases with ,75% consensus). Mild MCD (types I/II) and FCD types IA/B classifications were the least reproducible, and used most frequently in cases without consensus. Intraobserver concordance was moderate to very good (range , = 0.4654,0.8504). The category with the fewest classification changes made on reevaluation was FCD type IIB (4.2%), whereas that with the most changes was mild MCD (types I/II) (52.9%). Discussion:, Interobserver concordance using this approach was moderate. The classification categories with the greatest concordance were FCD type IIA/B, and the least, mild MCD and FCD types IA/B. In addition, difficulty in differentiating Mild MCD/FCD type I lesions from normal and/or gliotic tissue was noted. [source]


A new magnetic resonance imaging scoring method for assessment of haemophilic arthropathy

HAEMOPHILIA, Issue 4 2004
B. Lundin
Summary., In a European multicentre study, 39 ankles in 28 haemophilic boys were investigated by magnetic resonance imaging (MRI). A new MRI score was developed in the format A(e:s:h) for evaluating haemophilic arthropathy. This scheme provides high resolution and allows separation of different pathological components. The factor A is calculated as the sum of scores for subchondral cysts (maximum value 6), irregularity/erosion of subchondral cortex (maximum 4) and chondral destruction (maximum 6); e, s and h, respectively, represent effusion/haemarthrosis, synovial hypertrophy and haemosiderin deposition, and they are separately evaluated on a scale of 0,4. Working independently, two radiologists scored the 39 ankles twice using both this new ,European' scoring method and a previously published ,Denver' scoring scheme. Final classification was achieved by consensus. The reproducibility of the readings was assessed, and for both scoring methods the results indicated good or moderate intraobserver agreement, and good, moderate or fair interobserver agreement. These findings suggest that MRI can be useful for semiquantitative evaluation of haemophilic arthropathy, providing the examination is performed according to an appropriate protocol, and the images are evaluated by specially trained radiologists. [source]


Differentiating Atrioventricular Nodal Reentrant Tachycardia from Junctional Tachycardia: Novel Application of the Delta H-A Interval

JOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY, Issue 1 2008
KOMANDOOR SRIVATHSAN M.D.
Introduction: Junctional tachycardia (JT) and atrioventricular nodal reentrant tachycardia (AVNRT) can be difficult to differentiate. Yet, the two arrhythmias require distinct diagnostic and therapeutic approaches. We explored the utility of the delta H-A interval as a novel technique to differentiate these two tachycardias. Methods: We included 35 patients undergoing electrophysiology study who had typical AVNRT, 31 of whom also had JT during slow pathway ablation, and four of whom had spontaneous JT during isoproterenol administration. We measured the H-A interval during tachycardia (H-AT) and during ventricular pacing (H-AP) from the basal right ventricle. Interobserver and intraobserver reliability of measurements was assessed. Ventricular pacing was performed at approximately the same rate as tachycardia. The delta H-A interval was calculated as the H-AP minus the H-AT. Results: There was excellent interobserver and intraobserver agreement for measurement of the H-A interval. The average delta H-A interval was ,10 ms during AVNRT and 9 ms during JT (P < 0.00001). For the diagnosis of JT, a delta H-A interval , 0 ms had the sensitivity of 89%, specificity of 83%, positive predictive value of 84%, and negative predictive value of 88%. The delta H-A interval was longer in men than in women with JT, but no gender-based differences were seen with AVNRT. There was no difference in the H-A interval based on age , 60 years. Conclusion: The delta H-A interval is a novel and reproducibly measurable interval that aids the differentiation of JT and AVNRT during electrophysiology studies. [source]


Observer variability in the sonographic evaluation of thyroid nodules

JOURNAL OF CLINICAL ULTRASOUND, Issue 6 2010
Chang Suk Park MD
Abstract Objective. Inter- and intraobserver variabilities in the description and diagnostic categorization of sonographic (US) features of thyroid nodules were evaluated. Methods. The current study was conducted on 72 malignant nodules and 61 benign nodules. The US findings for each thyroid nodule were analyzed twice at a 6-week interval by five radiologists. The analyses were in accordance with the guidelines proposed bythe Thyroid Study Group of the Korean Society of Neuroradiology and Head and Neck Radiology (TSGKSNRHNR). Inter- and intraobserver variabilities were calculated using Cohen's kappa statistics. The sensitivity, specificity, positive-predictive value, and negative-predictive value in the assessment of the diagnostic accuracy using these guidelines were calculated. Result. The interobserver agreement was fair to substantial for US features and categorization. Of the US features of the thyroid nodules, internal content (solid versus cystic) showed substantial agreement (k= 0.64). There was moderate agreement with regard to shape, echogenicity, calcification, and diagnostic categories (k = 0.42, 0.57, 0.55, and 0.55, respectively). There was fair agreement for margin, echotexture, and capsule invasion (k = 0.34, 0.26, and 0.32, respectively). With regard to intraobserver agreement, there was moderate to substantial agreement for all US features except for echotexture and capsule invasion, which showed fair agreement. In particular, there was moderate to almost perfect agreement for the diagnostic category. The sensitivity, specificity, positive-predictive value, and negative-predictive value were 65.3%,81.9%, 60.7%,68.9%, 69.7%,73.8%, and 66.6%,75.5%, respectively. Conclusion. There were high degrees of inter- and intraobserver agreement using the "Guidelines for diagnostic thyroid ultrasonography," of the TSGKSNRHNR in the description and categorization of thyroid nodules. © 2010 Wiley Periodicals, Inc. J Clin Ultrasound, 2010 [source]


Retrospective review of children presenting with non cystic fibrosis bronchiectasis: HRCT features and clinical relationships,

PEDIATRIC PULMONOLOGY, Issue 2 2003
E.A. Edwards FRACP
Abstract Non cystic fibrosis (CF) bronchiectasis in children presents with a spectrum of disease severity. Our aims were to document the extent and severity of disease in children with non-CF bronchiectasis, to review the inter- and intraobserver agreement for the high-resolution computed tomography (HRCT) features examined, and to assess correlations between HRCT features and clinical measures of severity. We performed a retrospective review of 56 children from the Starship Children's Hospital. HRCT scans were scored by a modified Bhalla system, and the chest X-rays using the Brasfield score. Scores were correlated with demographics, number of hospitalizations, disease duration, pulmonary function, clinical examination, and chronic sputum infection. The bronchiectasis seen was widespread and severe, particularly in Maori and Pacific Island children. The kappa coefficient for intraobserver agreement was better than that for interobserver agreement. Comparisons between HRCT scan and lung function parameters showed that the strongest relationships were between forced expiratory volume in 1 sec (FEV1) and forced expiratory flow between 25,75% of forced vital capacity (FEF25,75) with the extent of bronchiectasis, bronchial wall thickening, and air trapping. Children with digital clubbing and chest deformity showed significantly higher scores for extent of bronchiectasis, bronchial wall dilatation and thickness, and overall computed tomography (CT) score. No relationship was demonstrated between chronic sputum infection and CT score. The HRCT score demonstrated a stronger correlation between the extent and severity of bronchiectasis, and spirometry values, than the chest X-ray score. In conclusion, pediatric non-CF bronchiectasis in Auckland is extensive and severe. The good intraobserver ratings mean that consistency of scoring is possible on repeated scans. This study cannot comment on the relationships of CT and less severe disease. Pediatr Pulmonol. 2003; 36:87,93. © 2003 Wiley-Liss, Inc. [source]


Two Temporal Bone Computed Tomography Measurements Increase Recognition of Malformations and Predict Sensorineural Hearing Loss,

THE LARYNGOSCOPE, Issue 8 2006
Derk D. Purcell MD
Abstract Objectives/Hypothesis: The objectives of this prospective study were to assess the reproducibility of the measurements of the cochlea and lateral semicircular canal (LSCC) and to determine if abnormal measurements predict sensorineural hearing loss (SNHL). Methods: Two readers independently measured the cochlear height on coronal section and the LSCC bony island width on axial section on 109 temporal bone computed tomography scans; audiologic data on these patients were collected independently from medical records. Inter- and intrareader variability was evaluated using intraclass correlation coefficients (ICCs) based on a random-effects model. The positive and negative predictive values of abnormal measurement for hearing loss were determined. Results: There was excellent inter- and intraobserver agreement for both measurements (ICC >80%). The average cochlear height was 5.1 mm (normal range, 4.4,5.9 mm) and average LSCC bony island width was 3.7 mm (normal range, 2.6,4.8 mm). Review of the original radiology reports demonstrated that both cochlear hypoplasia and LSSC dysplasia were overlooked in >50% of patients with both abnormal measurements and SNHL. Cochlear hypoplasia (<4.4 mm) had a positive predictive value of 100% for SNHL, whereas cochlear hyperplasia and bony island dysplasia were less predictive. Conclusion: The measurements of coronal cochlear height and axial LSCC bony width have excellent reproducibility and identify bony labyrinth abnormalities missed by visual inspection alone. In addition, cochlear hypoplasia is highly predictive of SNHL. To reliably identify inner ear malformations, measurement of the cochlear height and LSCC bony island width, in addition to the vestibular aqueduct, should be routinely performed on all temporal bone studies. [source]