Interobserver Kappa Research Articles

Accuracy of routine fat-suppressed FLAIR and diffusion-weighted images in detecting clinically evident acute optic neuritis

Contrast-enhanced, fat-suppressed T1-weighted imaging (CET1WI) magnetic resonance imaging (MRI) is quite sensitive in detecting acute optic neuritis (ON), but ON remains a clinical diagnosis. MRI is indicated to evaluate demyelinating brain lesions rather than the optic nerves, while "routine" brain protocols typically include axial FLAIR and DWI. To evaluate the accuracy of axial, fat-suppressed FLAIR and DWI sequences used for our routine brain imaging in detecting acute ON, as compared to CET1WI and the clinical diagnosis. The clinical data and MRI examinations were retrospectively reviewed of 60 patients presenting to a neuro-ophthalmologist for various visual symptoms. Each patient underwent dedicated neuro-ophthalmologic examination, with axial 5 mm fat-suppressed FLAIR and DWI (part of "routine" brain MRI protocol), as well as 3 mm axial and coronal fat-suppressed CET1WI (part of dedicated orbit MRI protocol). Two neuroradiologists independently evaluated FLAIR and DWI, while CET1WI was reviewed by consensus. Thirty-one patients were clinically positive, 29 negative for ON (total = 34 positive and 86 negative nerves). The sensitivities of FLAIR, DWI, and CET1WI for ON were 75.7-77.3%, 77.3%, and 89.5%, respectively; the specificities were 90.5-93.5%, 80.4-82.7%, and 86.0%, respectively; the accuracies were 85.7-88.2%, 79.5-81.1%, and 87.0%, respectively. Inter-observer kappa was 0.783 for FLAIR, and 0.605 for DWI; intra-observer kappa was 0.746-0.816 for FLAIR, and 0.674-0.699 for DWI (each P < 0.0001). Being more specific, but not as sensitive, as dedicated CET1WI in acute ON, axial fat-suppressed FLAIR likely has additional value in evaluating for acute ON in "routine" brain MR protocols evaluating for demyelinating disease, while DWI may be hampered by artifacts.

Fístulas durales arteriovenosas intracraneales. Experiencia con 81 casos y revisión de la literatura

To analyse the clinical, radiological and therapeutic variables of intracranial dural arteriovenous fistulae (DAVF) treated at our institution, and to assess the validity of the Borden and Cognard classifications and their correlation with the presenting symptoms. The DAVF identified were retrospectively analysed. They were classified according to their location, drainage pattern and the Borden and Cognard classifications. We recorded the different treatments, their complications and efficacy. There were 81DAVF identified between 1975 and 2012. The cavernous sinus (CS) location was the most frequent one. The Borden and Cognard classifications showed an interobserver Kappa index of 0.72 and 0.76 respectively. The odds ratio of aggressive presentation in the presence of cortical venous drainage (CVD) was 19.3 (2.8-132.4). No location, once adjusted by venous drainage pattern, showed significant association with an aggressive presentation. Endovascular transarterial treatment of cavernous sinus DAVF achieved symptomatic improvement of 78%, with a complication rate of 5%. The DAVF of non-CS locations, with CVD, treated surgically were angiographically shown cured in 100% of the cases, with no treatment-related complications. The presence of CVD was significantly associated with aggressive presentations. The Borden and Cognard classifications showed little interobserver variability. Endovascular treatment for CS DAVF is safe and relatively effective. Surgical treatment of non-CS DAVF with CVD is safe, effective and the first choice treatment in our environment.

Graduação radiográfica da cimentação de hastes femorais na artroplastia do quadril

OBJECTIVE: To determine intra and interobserver agreement of the grading system for femoral cementation in hip arthroplasty proposed by Barrack. METHODS: Immediate anteroposterior and lateral postoperative radiographs of 55 primary total hip arthroplasties were assessed by two observers familiar with the use of this grading system. The assessments were performed on two separate occasions by each observer and independently. The statistical analysis measured the Kappa coefficient, which determines the degree of agreement between tests with categorical variables. RESULTS: Intraobserver Kappa coefficient varied from 0.43 to 0.68, demonstrating moderate to substantial strength of agreement; interobserver Kappa coefficient varied from 0.19 to 0.44, demonstrating slight to moderate strength of agreement. CONCLUSION: Intra and particularly interobserver agreement are limited in this grading system, even when used by trained individuals. Level of Evidence III, Study of nonconsecutive patients; without consistently applied reference "gold" standard.

Measuring the food and built environments in urban centres: Reliability and validity of the EURO-PREVOB Community Questionnaire

The authors designed an instrument to measure objectively aspects of the built and food environments in urban areas, the EURO-PREVOB Community Questionnaire, within the EU-funded project 'Tackling the social and economic determinants of nutrition and physical activity for the prevention of obesity across Europe' (EURO-PREVOB). This paper describes its development, reliability, validity, feasibility and relevance to public health and obesity research. The Community Questionnaire is designed to measure key aspects of the food and built environments in urban areas of varying levels of affluence or deprivation, within different countries. The questionnaire assesses (1) the food environment and (2) the built environment. Pilot tests of the EURO-PREVOB Community Questionnaire were conducted in five to 10 purposively sampled urban areas of different socio-economic status in each of Ankara, Brno, Marseille, Riga, and Sarajevo. Inter-rater reliability was compared between two pairs of fieldworkers in each city centre using three methods: inter-observer agreement (IOA), kappa statistics, and intraclass correlation coefficients (ICCs). Data were collected successfully in all five cities. Overall reliability of the EURO-PREVOB Community Questionnaire was excellent (inter-observer agreement (IOA) > 0.87; intraclass correlation coefficients (ICC)s > 0.91 and kappa statistics > 0.7. However, assessment of certain aspects of the quality of the built environment yielded slightly lower IOA coefficients than the quantitative aspects. The EURO-PREVOB Community Questionnaire was found to be a reliable and practical observational tool for measuring differences in community-level data on environmental factors that can impact on dietary intake and physical activity. The next step is to evaluate its predictive power by collecting behavioural and anthropometric data relevant to obesity and its determinants.

Optimizing statistical parametric mapping analysis of 18F-FDG PET in children

BackgroundStatistical parametric mapping (SPM) procedure is an objective tool to analyze 18F-fluoro-2-deoxy-d-glucose-positron-emission tomography (FDG-PET) images and a useful complement to visual analysis. However, SPM requires a comparison to control data set that cannot be obtained in healthy children for ethical reasons. Using adults as controls showed some limitations. The purpose of the present study was to generate and validate a group of pseudo-normal children as a control group for FDG-PET studies in pediatrics.MethodsFDG-PET images of 47 children (mean ± SD age 10.2 ± 3.1 years) with refractory symptomatic (MRI-positive, n = 20) and cryptogenic (MRI-negative, n = 27) focal epilepsy planned for surgery were analyzed using visual and SPM analysis. Performances of SPM analysis were compared using two different control groups: (1) an adult control group consisting of healthy young adults (n = 25, 30.5 ± 5.8 years, adult PET template) and (2) a pediatric pseudo-control group consisting of patients (n = 24, 10.6 ± 3.1 years, children PET template) with refractory focal epilepsy but with negative MRI and with PET considered normal not only on visual analysis but also on SPM.ResultsAmong the 47 children, visual analysis succeeded detecting at least one hypometabolic area in 87% of the cases (interobserver kappa = 0.81). Regarding SPM analysis, the best compromise between sensitivity and specificity was obtained with a threshold of p less than 0.001 as an extent of more than 40 voxels. There was a significant concordance to detect hypometabolic areas between both SPM analyses [kappa (K) = 0.59; p < 0.005] and between both SPM and visual analyses (K = 0.45; p < 0.005), in symptomatic (K = 0.74; p < 0.005) as in cryptogenic patients (K = 0.26; p < 0.01). The pediatric pseudo-control group dramatically improved specificity (97% vs. 89%; p < 0.0001) by increasing the positive predictive value (86% vs. 65%). Sensitivity remained acceptable although it was not better (79% vs. 87%, p = 0.039). The main impact was to reduce by 41% the number of hypometabolic cortical artifacts detected by SPM, especially in the younger epileptic patients, which is a key point in clinical practice.ConclusionsThis age-matched pseudo-control group is a way to optimize SPM analysis of FDG-PET in children with epilepsy. It might also be considered for other brain pathologies in pediatrics in the future.

Value of MR and CT Imaging for Assessment of Internal Carotid Artery Encasement in Head and Neck Squamous Cell Carcinoma

Objective. This study was conducted to assess the value of CT and MR imaging in the preoperative evaluation of ICA encasement. Methods. Based upon three patient groups this study was performed. Retrospective analysis of 260 neck dissection reports from 2001 to 2010 was performed to determine unexpected peroperative-diagnosed encasement. Two experienced head and neck radiologists reviewed 12 scans for encasement. Results. In four out of 260 (1.5%) patients undergoing neck dissection, preoperative imaging was false negative as there was peroperative encasement of the ICA. Of 380 patients undergoing preoperative imaging, the radiologist reported encasement of the ICA in 25 cases. In 342 cases no encasement was described, 125 of these underwent neck dissection, and 2 had encasement peroperatively. The interobserver variation kappa varied from 0.273 to 1 for the different characteristics studied. Conclusion. These retrospectively studied cohorts demonstrate that preoperative assessment of encasement of the ICA using MRI and/or CT was of value in evaluation of ICA encasement and therefore contributively in selecting operable patients (without ICA encasement), since in only 1.5% encasement was missed. However, observer variation affects the reliability of this feature.

Normal Glenoid Relationships Used for Unilateral Quantification of Glenoid Bone Loss in Glenohumeral Instability

Objectives:Current methods used to quantify glenoid bone loss following anterior shoulder instability rely on bilateral shoulder imaging to obtain normal linear and surface area parameters of the uninjured glenoid fossa. This method is based on the assumption that there is little side-side variability in these anatomical relationships. Previous reports have demonstrated differences in the morphology of the glenoid fossa based on the anterior glenoid notch. The purpose of this study was to determine the normal dimensions of height, width, surface area, and shape of the human glenoid fossa as function of glenoid notch, and to determine if side-to-side differences exist for these parameters. Due to notch variation, we hypothesize that the inferior glenoid fossa is better represented as an ellipse versus a perfect circle as previously described. We also hypothesize that side-to-side differences exist in glenoid surface area.Methods:The authors studied 58 human scapulae pairs between 18 and 35 years of age from the Hamann-Todd Osteological Collection. Age, sex, race, body height and weight were known for each specimen. Paired specimens were sorted into groups of 5 according to race, sex, and notch type. All specimens were digitized using a 3-D laser scanner, with a stated accuracy of 0.005 inches. Height, width, surface area, and notch angle measurements were calculated using software written in the MATLAB platform. A best fit ellipse was applied to the inferior glenoid based on the glenoid circumference below the notch. Differences in surface area of paired glenoids were assessed using a matched pairs T-test. Multiple stepwise linear regression models were created to select predictors of glenoid surface area. Lastly, the intra-rater and inter-rater reliability of the notch classification as reported by Merrill et al. was assessed among 13 raters.Results:The mean height (s.d.) of the glenoid fossae was 35.0 ± 2.8 mm. Inferior width was 24.8 ± 2.5 mm. The best-fit ellipse of the inferior glenoid had a mean eccentricity of 0.425 ± 0.099. The right glenoid, when compared to its left counterpart, had greater overall surface area (x̄right= 679.6 mm2, x̄left= 657.2 mm2, P< 0.0001*) and inferior surface area (x̄right= 548.2 mm2, x̄left= 533.1 mm2, P< 0.0076*). Patient height, sex, and glenoid height correlated with total and inferior glenoid surface area with r2= 0.902 and 0.779, respectively (P< 0.0001*). Analysis of intra-observer reliability showed a consistency of 0.56 (95% CI= 0.26- 0.77), while the inter-observer reliability kappa coefficient was 0.43 (95% CI= 0.41- 0.45).Conclusion:By considering unilateral anatomic relationships of the glenoid fossa, we were able to determine alternative methods of evaluating glenoid bone loss. Glenoid notch angle had moderate reliability and was not considered clinically useful to stratify glenoid morphology. Based on non-zero eccentricity values of the best-fit ellipse, the inferior glenoid fossa did not represent a perfect circle. In addition, side-to-side differences were found between glenoid surface area measurements. The latter two findings contradict assumptions made by current techniques used in clinical practice to calculate bone loss and raise concern as to their validity. Using easily obtainable patient (height and sex) and glenoid (height) parameters, glenoid surface area can be predicted by means of regression modeling, permitting unilateral measurements of glenoid bone loss to be made in clinical practice.

Image Quality of Thoracic 64-MDCT Angiography: Imaging of Infants and Young Children With or Without General Anesthesia

The purpose of this study was to compare the image quality of thoracic CT angiography (CTA) studies performed with two techniques--with general anesthesia and without general anesthesia--for infants and for children younger than 5 years. All consecutively registered infants and young children (age, ≤ 5 years) who underwent contrast-enhanced thoracic CTA from November 2005 to October 2010 were categorized into two groups: general anesthesia and awake (i.e., no general anesthesia). Two radiologists independently evaluated image quality by quantifying the degree of motion artifact at three anatomic levels (upper, middle, and lower lung zones). Motion artifacts were graded on an ordinal scale (0, no motion; 1, mild; 2, moderate; 3, severe), and the Pearson chi-square test was used to assess whether the degree of motion artifact differed between the general anesthesia and awake groups in the upper, middle, and lower lung zones. Logistic regression analysis was performed to determine whether image quality based on the presence or absence of motion artifact in any lobe was related to general anesthesia versus the awake state; age and sex were covariates. Interobserver agreement between two reviewers was evaluated with kappa statistics. There were a total of 135 patients (mean age 1.0 year), 95 in the awake group (70%) and 40 in the general anesthesia group (30%). No significant difference was found between the two groups in percentage of studies with motion artifact detected in each lung zone and the total motion artifact score. Results of multivariable logistic regression analysis indicated that image quality was not influenced by age (p = 0.52) or sex (p = 0.20). There was excellent interobserver kappa agreement between reviewers for detecting motion artifact in the upper, middle, and lower lung zones (all κ > 0.90, p < 0.001). There is no significant difference in image quality of thoracic CTA with 64-MDCT assessed by degree of motion artifact with and without general anesthesia. The results of this study support use of thoracic CTA without general anesthesia in the care of young pediatric patients who meet screening criteria for awake imaging studies.

Reproducibility of three classifications of proximal humeral fractures

To propose a new system for classifying proximal humeral neck fractures, and to evaluate intra- and interobserver agreement using the Neer system that is the most commonly used in the area and the Arbeit Gemeinschaft für Osteosynthesefragen system created by an European group, and a new classification system proposed by the authors of this study. A total of 56 patients with proximal humeral fractures were selected, and submitted to digitized simple radiography in antero-posterior shoulder and scapular profile. Radiographs were analyzed by three observers at time one, and then three and six weeks later. The kappa coefficient modified by Fleiss was used for the analysis. The mean intra-observer Kappa agreement index (k = 0.687) of the new classification, was higher than both the Neer classification (k = 0.362) and the Arbeit Gemeinschaft für Osteosynthesefragen (k = 0.46). The mean interobserver Kappa agreement index (0.446) of the new classification, also had better results than both the Neer classification (k = 0.063) and the Arbeit Gemeinschaft für Osteosynthesefragen (k = 0.028). the new classification considering bone compression had higher results for intra- and interobserver compared to the Neer system, and the Arbeit Gemeinschaft für Osteosynthesefragen system.

Reliability of injury grading systems for patients with blunt splenic trauma

ObjectivesThe most widely used grading system for blunt splenic injury is the American Association for the Surgery of Trauma (AAST) organ injury scale. In 2007 a new grading system was developed. This ‘Baltimore CT grading system’ is superior to the AAST classification system in predicting the need for angiography and embolization or surgery. The objective of this study was to assess inter- and intraobserver reliability between radiologists in classifying splenic injury according to both grading systems. MethodsCT scans of 83 patients with blunt splenic injury admitted between 1998 and 2008 to an academic Level 1 trauma centre were retrospectively reviewed. Inter and intrarater reliability were expressed in Cohen's or weighted Kappa values. ResultsOverall weighted interobserver Kappa coefficients for the AAST and ‘Baltimore CT grading system’ were respectively substantial (kappa=0.80) and almost perfect (kappa=0.85). Average weighted intraobserver Kappa's values were in the ‘almost perfect’ range (AAST: kappa=0.91, ‘Baltimore CT grading system’: kappa=0.81). ConclusionThe present study shows that overall the inter- and intraobserver reliability for grading splenic injury according to the AAST grading system and ‘Baltimore CT grading system’ are equally high. Because of the integration of vascular injury, the ‘Baltimore CT grading system’ supports clinical decision making. We therefore recommend use of this system in the classification of splenic injury.

VALIDATION OF TABLET-BASED EVALUATION OF COLOR FUNDUS IMAGES

To compare diabetic retinopathy (DR) referral recommendations made by viewing fundus images using a tablet computer with those made using a standard desktop display. A tablet computer (iPad) and a desktop computer with a high-definition color display were compared. For each platform, 2 retinal specialists independently rated 1,200 color fundus images from patients at risk for DR using an annotation program Truthseeker. The specialists determined whether each image had referable DR and also how urgently each patient should be referred for medical examination. Graders viewed and rated the randomly presented images independently and were masked to their ratings on the alternative platform. Tablet-based and desktop display-based referral ratings were compared using cross-platform intraobserver kappa as the primary outcome measure. Additionally, interobserver kappa, sensitivity, specificity, and area under the receiver operating characteristic were determined. A high level of cross-platform intraobserver agreement was found for the DR referral ratings between the platforms (κ = 0.778) and for the 2 graders (κ = 0.812). Interobserver agreement was similar for the 2 platforms (κ = 0.544 and κ = 0.625 for tablet and desktop, respectively). The tablet-based ratings achieved a sensitivity of 0.848, a specificity of 0.987, and an area under the receiver operating characteristic of 0.950 compared with desktop display-based ratings. In this pilot study, tablet-based rating of color fundus images for subjects at risk for DR was consistent with desktop display-based rating. These results indicate that tablet computers can be reliably used for clinical evaluation of fundus images for DR.

Proximal caries detection accuracy using intraoral bitewing radiography, extraoral bitewing radiography and panoramic radiography

To compare proximal caries detection using intraoral bitewing, extraoral bitewing and panoramic radiography. 80 extracted human premolar and molar teeth with and without proximal caries were used. Intraoral radiographs were taken with Kodak Insight film (Eastman Kodak Co., Rochester, NY) using the bitewing technique. Extraoral bitewing and panoramic images were obtained using a Planmeca Promax Digital Panoramic X-ray unit (Planmeca Inc., Helsinki, Finland). Images were evaluated by three observers twice. In total, 160 proximal surfaces were assessed. Intra- and interobserver kappa coefficients were calculated. Scores obtained from the three techniques were compared with the histological gold standard using receiver operating characteristic analysis. Az values for each image type, observer and reading were compared using z-tests, with a significance level of α = 0.05. Kappa coefficients ranged from 0.883 to 0.963 for the intraoral bitewing, from 0.715 to 0.893 for the extraoral bitewing, and from 0.659 to 0.884 for the panoramic radiography. Interobserver agreements for the first and second readings for the intraoral bitewing images were between 0.717 and 0.780, the extraoral bitewing readings were between 0.569 and 0.707, and the panoramic images were between 0.477 and 0.740. The Az values for both readings of all three observers were highest for the intraoral bitewing. Az values for the extraoral bitewing images were higher than those of the panoramic images without statistical significance (p > 0.05). Intraoral bitewing radiography was superior to extraoral bitewing and panoramic radiography in diagnosing proximal caries of premolar and molar teeth ex vivo. Similar intra- and interobserver coefficients were calculated for extraoral bitewing and panoramic radiography.

Crypt Apoptotic Count Reproducibility in Small Bowel Allograft Biopsies

Enumeration of crypt apoptotic bodies (AB) is used in the diagnosis of acute cellular rejection (ACR) in small bowel allografts. Due to differing definitions, there is a potential for variation in AB numbers between pathologists that may affect diagnosis. Thirty biopsies from allografts were obtained: 10 negative for ACR, 10 indeterminate, and 10 with mild ACR. Three pathologists blindly reviewed each case twice and counted the maximal AB number per 10 crypts. Intraobserver kappa ranged from 0.423 to 0.913 and interobserver kappa from 0.478 to 0.686 depending on AB definition. Intraobserver diagnosis agreement based on classical AB number occurred in 81 of 90 instances (90%) and in 77 of 90 using the liberal definition (85%), P < .01). There was substantial intraobserver and moderate to substantial interobserver agreement in crypt AB counts. However, both intraobserver and interobserver variability would have led to diagnostic discrepancies in a small subset of cases.

Fiabilité d’une classification de Garden simplifiée pour les fractures intracapsulaires du col fémoral

Summary Background The Garden classification is used to classify intracapsular proximal femur fractures. The reliability of this classification is poor and several authors advise a simplified classification of intracapsular hip fractures into non-displaced and displaced fractures. However, this proposed simplified classification has never been tested for its reliability. Hypothesis We estimate simplifying the classification of femoral neck fractures will lead to a higher inter-observer agreement. Materials and Methods Ten observers, trauma surgeons and residents, from two different institutes classified 100 intracapsular femoral neck fractures. The inter-observer agreements were calculated using the multi-rater Fleiss’ kappa. Results The inter-observer kappa for the Garden classification was 0.31. An agreement of κ0.52 was observed if the Garden classification was simplified and the fractures were classified by our observers as ‘non-displaced’ or ‘displaced’. No difference in reliability was seen for the use of the four-grade Garden classification as well as the simplified classification between trauma surgeons and residents. Discussion Classification of intracapsular hip fractures according to the four-grade Garden classification is unreliable. The reliability of classification improves when the Garden classification is simplified in a classification using the terms: ‘non-displaced’ or ‘displaced’. Level of evidence Level IV. Diagnostic retrospective study.

The impact on case findings by transferring clinical breast examination skills to female community health volunteers in limited resources country like Nepal.

e11094 Background: In limited resources countries, patients with breast cancer present to the hospital in the late stage because of lack of awareness, screening program. Clinical Breast Examination (CBE) may be the only means of detecting the breast cancer early in countries with limited resources since mammography is less likely to be cost effective approach and CBE by surgeons are also not possible because of limited health care facility. Hence CBE by FCHVs seems to be more feasible. This study was conducted to observe the skill transfer to FCHVs for detection of clinical abnormalities in breast by determining kappa agreement, sensitivity, specificity, positive predictive value and negative predictive value of CBE by FCHVs considering CBE by the Surgeon as gold standard. Methods: It is a cross-sectional study conducted in Eastern Nepal for period of one year from June 2008 to May 2009. Total 1238 women were examined by both a FCHV and the Surgeon. The results were analyzed to find out interobserver kappa agreement, sensitivity, specificity, positive predictive value and negative predictive value for detection of clinical abnormalities in breast following CBE by FCHVs considering CBE by the Surgeon as gold standard. Results: Total 1238 women received CBE by both a FCHV and the Surgeon. The interobserver kappa agreement for the detection of clinical abnormalities in breast was 67% indicating a good agreement exists between the FCHVs and the Surgeon’s CBE Sensitivity, specificity, positive predictive value and negative predictive values of “FCHVs’ CBE” to detect clinical abnormalities in breast in comparison to “the Surgeon’s CBE” as gold standard were 70%, 95%, 74% and 94% respectively. Conclusions: In view of good CBE skills transfer to FCHVs for detection of clinical abnormalities in breast, the effective training of FCHVs may diagnose and refer the women with clinical breast abnormalities to the hospital for further investigation and treatment.

The reliability of a simplified Garden classification for intracapsular hip fractures

The Garden classification is used to classify intracapsular proximal femur fractures. The reliability of this classification is poor and several authors advise a simplified classification of intracapsular hip fractures into non-displaced and displaced fractures. However, this proposed simplified classification has never been tested for its reliability. We estimate simplifying the classification of femoral neck fractures will lead to a higher inter-observer agreement. Ten observers, trauma surgeons and residents, from two different institutes classified 100 intracapsular femoral neck fractures. The inter-observer agreements were calculated using the multi-rater Fleiss' kappa. The inter-observer kappa for the Garden classification was 0.31. An agreement of κ0.52 was observed if the Garden classification was simplified and the fractures were classified by our observers as 'non-displaced' or 'displaced'. No difference in reliability was seen for the use of the four-grade Garden classification as well as the simplified classification between trauma surgeons and residents. Classification of intracapsular hip fractures according to the four-grade Garden classification is unreliable. The reliability of classification improves when the Garden classification is simplified in a classification using the terms: 'non-displaced' or 'displaced'. Level IV. Diagnostic retrospective study.

Inter‐observer variability in the histological assessment of colorectal polyps detected through the NHS Bowel Cancer Screening Programme

Although effective clinical management of colorectal polyps detected through the National Health Service (NHS) Bowel Cancer Screening Programme (BCSP) is dependent on the quality of pathological diagnosis, there have been few attempts to formally evaluate inter-observer variability in histological assessment. The aim of this study was to examine the impact of inter-observer variability on the reported prevalence of prognostic features in a large series of screen-detected colorectal polyps. A retrospective series of 1329 screen-detected polyps (2008-10) was identified from computerized records at two histopathology departments participating in the NHS BCSP. Slides from a sample of 239 polyps were exchanged between centres for independent review and measurement of inter-observer (kappa) agreement. There were significant between-centre differences in the prevalence of polyps with high-risk histological features. Diagnostic review demonstrated good reliability with respect to the assessment of adenomatous change (κ = 0.83), excision margin status (κ = 0.74), high-grade dysplasia (0.61) and invasive malignancy (κ = 0.84). By contrast, there were significant inter-observer differences in the classification of villous lesions (0.18) despite recent efforts to standardize reporting practice. Inter-observer variability in the assessment of screen-detected colorectal polyps limits the prognostic value of histological subtyping and highlights the need for clarification of existing diagnostic criteria.

Assessment of endodontically treated teeth by using different radiographic methods: an ex vivo comparison between CBCT and other radiographic techniques

PurposeTo compare different radiographic methods for assessing endodontically treated teeth.Materials and MethodsRoot canal treatments were applied in 120 extracted mandibular teeth, which were divided into four groups: (1) ideal root canal treatment (60 teeth), (2) insufficient lateral condensation (20 teeth), (3) root canals filled short of the apex (20 teeth), (4) overfilled root canal treatment (20 teeth). The teeth were imaged using intraoral film, panoramic film, digital intraoral systems (CCD and PSP), CCD obtained with portable X-ray source, digital panoramic, and CBCT images obtained at 0.3 mm3 and 0.2 mm3 voxel size. Images were evaluated separately by three observers, twice. Kappa coefficients were calculated. The percentage of correct readings obtained from each modality was calculated and compared using a t-test (p<0.05).ResultsThe intra-observer kappa for each observer ranged between 0.327 and 0.849. The inter-observer kappa for each observer for both readings ranged between 0.312 and 0.749. For the ideal root canal treatment group, CBCT with 0.2 mm3 voxel images revealed the best results. For insufficient lateral condensation, the best readings were found with periapical film followed by CCD and PSP. The assessment of teeth with root canals filled short of the apex showed the highest percentage of correct readings by CBCT and CCD. For the overfilled canal treatment group, PSP images and conventional periapical film radiographs had the best scores.ConclusionCBCT was found to be successful in the assessment of teeth with ideal root canal treatment and teeth with canals filled short of the apex.

Evaluation of the Diagnostic Performance of Tomosynthesis in Fractures of the Wrist

The purpose of our study was to define the diagnostic value of tomosynthesis compared with standard radiography and CT in wrist injuries. One hundred consecutive patients with acute wrist trauma were investigated with standard radiography, tomosynthesis, and CT. Reference results were those obtained with CT; follow-up monitoring of the patients; and, in some cases, MRI (n=13). Three readers interpreted the findings independently, each using a PACS workstation, and categorized the cases into four groups: fracture of the radius, fracture of the scaphoid, fracture of another bone, and absence of fracture. Fifty-seven percent of the patients had a fracture. The interobserver kappa value varied between 0.54 and 0.59 for standard radiography, between 0.66 and 0.69 for tomosynthesis, and between 0.84 and 0.89 for CT. The sensitivity of standard radiography varied between 61% and 80% and specificity between 65% and 83%. The sensitivity of tomosynthesis ranged between 77% and 87%, and specificity between 76% and 82%. Ranges of sensitivity and specificity for CT were 93-95%, and 86-95%, respectively. The diagnostic value of tomosynthesis is superior to that of standard radiography but inferior to that of CT.

Ex vivocomparison of Galileos cone beam CT and intraoral radiographs in detecting occlusal caries

The aim of this study was to compare the accuracy of cone beam CT (CBCT) with intraoral radiographs for detection of occlusal caries. A set of 60 extracted teeth were imaged using a Sirona Galileos CBCT system (Sirona Dental Systems, Bensheim, Germany) and an intraoral Planmeca® system (Planmeca OY, Helsinki, Finland). Six observers looked at both modalities and used a five-point confidence scale to evaluate presence or absence of occlusal caries. Histology was used as the gold standard. Receiver operating characteristic analysis and weighted kappa statistics were used for statistical analysis. Differences in the area under the curve (AUC) values between observers and modalities were analysed using analysis of variance (ANOVA). Differences in sensitivity and specificity were analysed using the Wilcoxon test. Interobserver and intraobserver reliability was assessed by weighted kappa scores. The mean value and standard deviation of AUC was 0.719 ± 0.038 for CBCT and 0.649 ± 0.062 for the intraoral radiographs. The ANOVA results demonstrated that there was no significant difference between the modalities and the observers. The interobserver kappa for pairs of observers ranged from fair to substantial for bitewings (0.244-0.543) and CBCT (0.152-0.401). Four out of six observers reported higher sensitivity but lower specificity with CBCT. The Wilcoxon exact p-value showed no difference in sensitivity (0.175) or specificity (0.573) between the two modalities. Based on the results we conclude that the Sirona CBCT unit cannot be used for the sole purpose of looking at occlusal caries.