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Purpose There remain uncertainties due to inter‐ and intraobserver variability in soft‐tissue‐based patient positioning even with the use of image‐guided radiation therapy (IGRT). This study aimed to reveal observer uncertainties of soft‐tissue‐based patient positioning on cone‐beam computed tomography (CBCT) images for prostate cancer IGRT. Methods Twenty‐six patients (7–8 fractions/patient, total number of 204 fractions) who underwent IGRT for prostate cancer were selected. Six radiation therapists retrospectively measured prostate cancer location errors (PCLEs) of soft‐tissue‐based patient positioning between planning CT (pCT) and pretreatment CBCT (pre‐CBCT) images after automatic bone‐based registration. Observer uncertainties were evaluated based on residual errors, which denoted the differences between soft‐tissue and reference positioning errors. Reference positioning errors were obtained as PCLEs of contour‐based patient positioning between pCT and pre‐CBCT images. Intraobserver variations were obtained from the difference between the first and second soft‐tissue‐based patient positioning repeated by the same observer for each fraction. Systematic and random errors of inter‐ and intraobserver variations were calculated in anterior–posterior (AP), superior–inferior (SI), and left–right (LR) directions. Finally, clinical target volume (CTV)‐to‐planning target volume (PTV) margins were obtained from systematic and random errors of inter‐ and intraobserver variations in AP, SI, and LR directions. Results Interobserver variations in AP, SI, and LR directions were 0.9, 0.9, and 0.5 mm, respectively, for the systematic error, and 1.8, 2.2, and 1.1 mm, respectively, for random error. Intraobserver variations were

A good classification system is important for clinical handoffs, research, and clinical treatment guidelines. A reliable classification system shows good interobserver and intraobserver agreement. This study analyzed the interobserver and intraobserver agreement of a descriptive system for ankle fractures and the Lauge-Hansen classification. Three groups of observers (experts, semiexperts, and novices) scored a total of 20 ankle radiographs. All ankle radiographs were classified according to the Lauge-Hansen and Danis-Weber classifications. The ankle fractures were subsequently reviewed in a descriptive manner for the following features: number of affected malleoli, type of fracture of the lateral and medial malleolus, and congruence of the ankle joint. After 2 weeks, the same set of radiographs were reviewed. For interobserver and intraobserver variability, the separate groups were used for analysis, and the Fleiss (multirater) κ values were calculated. The interobserver agreement for the Lauge-Hansen classification was moderate for the experts, fair for semiexperts, and slight for novices (κ = 0.45, κ = 0.37, and κ = 0.16). All factors of the descriptive system had better interobserver agreement than the Lauge-Hansen classification, except for the agreement on the type of fracture of the lateral malleolus. The intraobserver agreement of the Lauge-Hansen classification was substantial for the experts, moderate for the semiexperts, and fair for the novice observers (κ = 0.70, κ = 0.49, and κ = 0.26). The intraobserver agreement was better for all factors of the descriptive system compared with the Lauge-Hansen classification. The descriptive system presented in this study shows less variability between observers than the Lauge-Hansen classification. This system has clinical implications and is easy to use for clinicians with mixed levels of experience. It has the potential to improve clinical and research handoffs and overcome the limitations of current classification systems.

Introduction: Universal screening for preterm delivery by adding transvaginal ultrasound measurement of cervical length to routine second trimester ultrasound has been proposed. The aim is to estimate inter- and intraobserver agreement and reliability of second trimester transvaginal ultrasound measurements of cervical length performed by specially trained midwife sonographers. Material and methods: This is a prospective reliability and agreement study performed in seven Swedish ultrasound centers. In total, 18 midwife sonographers specially trained to perform ultrasound measurements of cervical length and 286 women in the second trimester were included. In each center, two midwife sonographers measured cervical length a few minutes apart in the same woman, the number of women examined per examiner pair varying between 24 and 30 (LIVE study). Sixteen midwife sonographers measured cervical length twice >= 2 months apart on 93 video clips (CLIPS study). The main outcome measures were mean difference, limits of agreement, intraclass correlation coefficient, intra-individual standard deviation, repeatability, Cohen's kappa and Fleiss kappa. Results: The limits of agreement and intraclass correlation coefficient of the best examiner pair in the LIVE study were -4.06 to 4.72 mm and 0.91, and those of the poorest were -11.11 to 11.39 mm and 0.31. In the CLIPS study, median (range) intra-individual standard deviation was 2.14 mm (1.40-3.46), repeatability 5.93 mm (3.88-9.58), intraclass correlation coefficient 0.84 (0.66-0.94). Median (range) interobserver agreement for cervical length

BACKGROUND: QRS narrowing after CRT is a predictor of patient outcome. Further narrowing can be obtained by interventricular pacing delay (VVd) optimization, raising interest to inter and intraobserver variation in manual measurements of QRS duration.METHODS: (a) Variation in intrinsic rhythm QRS duration in CRT patients with LBBB: In 40 intrinsic 12-lead ECGs, six observers measured QRS duration defined as widest QRS in any lead. In 20 of these ECGs, two observers repeated the measurements. (b) Variation in paced QRS duration at different VVd settings and agreement in selecting the narrowest QRS: In 20 CRT patients, five paced ECGs were recorded at different VVds. The most frequently selected VVd(s) estimated to cause the narrowest QRS in each patient defined the optimal VVd. Two observers repeated the measurements and VVd selections.RESULTS: Absolute interobserver difference in measured QRS duration in intrinsic rhythm ECGs was mean 2 ms, range (-40; 40 ms), mean limits of agreement (LoA): -21; 25 ms. Absolute interobserver difference in measured QRS duration in paced ECGs was mean 3 ms, range (-50; 60 ms), mean LoA: -20; 27 ms. There was no difference in LoA between intrinsic and paced QRS duration (lower limit p = 0.68; upper limit p = 0.44). The optimal VVd was included in 17/20 (85%) of the VVd selections by six observers. Interobserver variation was comparable with the intraobserver variation.CONCLUSIONS: Interobserver variation and intraobserver variation in manually measured paced and intrinsic rhythm QRS duration are clinically acceptable and comparable in a cohort of CRT patients. Inter and intraobserver reproducibility for selecting the optimal VVd is good and warrants manual VVd optimization for QRS narrowing in CRT.

OBJECTIVE Measurement of brown adipose tissue (BAT) activity is the focus of intensive research, among others as a potential target for weight-lowering strategies. In this, BAT activity is visualized and quantified using F-fluorodeoxyglucose (F-FDG) PET-CT. The aim of this study was to determine the interobserver and intraobserver variability for detecting and quantifying BAT on F-FDG PET-CTs. METHODS Three observers retrospectively independently assessed 55 F-FDG PET-CTs (performed between April 2013 and January 2014) for BAT activity parameters: BAT volume, the maximal and mean standardized uptake value (SUVmax and SUVmean) obtained in healthy male controls. One observer reassessed the scans after 2 months for the intraobserver variability. Interobserver and intraobserver variability were expressed using Lin's concordance coefficient (LCC) and Bland-Altman plots. Correlations between the three parameters were assessed using Spearman's correlation. RESULTS The LCCs for the interobserver and intraobserver concordance for SUVmax were the highest (LCC SUVmax varied between 0.998 and 0.999, for SUVmean between 0.989 and 0.991 and for volume between 0.947 and 0.972). The Bland-Altman analysis showed a small absolute mean difference between all observers for both SUVmax and SUVmean, but the differences for volume were markedly higher. All parameters correlated statistically strongly and positively. CONCLUSION The SUVmax showed the lowest interobserver and intraobserver variation. Although SUVmean and BAT volume had a higher interobserver and intraobserver variation, the variation is still within acceptable limits. Therefore, all parameters can be used to describe BAT activity. However, for an adequate comparison between studies, we recommend the use of SUVmax.

To evaluate the current diagnostic criteria in reporting nuclear features of noninvasive follicular thyroid neoplasm with papillary-like nuclear features (NIFTP), nine Asian pathologists with expertise in thyroid reviewed virtual slides of 30 noninvasive follicular patterned thyroid lesions according to the nuclear scoring system originally proposed by an international expert and a more detailed scoring system proposed by the Asian Working Group. The interobserver agreement for nuclear grading score was generally moderate (kappa value = 0.452). The best consistency fell on the chromatin features (kappa value = 0.658-1.000). A fair to moderate interobserver agreement was demonstrated in the evaluation of nuclear elongation, nuclear overlapping, membrane irregularities and distribution of papillary thyroid carcinoma (PTC) type nuclear features. A slight agreement was rendered for the evaluation of the nuclear enlargement. Intraobserver agreement was substantial to perfect when comparing results of both scoring systems. However, both scoring systems were not able to reliably separate NIFTP from an encapsulated follicular variant PTC with minimal lymph node metastasis or BRAFV600E mutation. Although the three-point nuclear scoring system for the diagnosis of NIFTP is widely used in Asian practice, interobserver variation was considerable. Ancillary immunohistochemical or molecular testing might be helpful in differentiating NIFTP from true PTC.

Introduction Peripheral blood smear (PBS) review is a routine laboratory test which requires pathologist's interpretation when abnormal indices, atypical cells, or critical findings are identified. Real-time remote digital microscopy (DM) can potentially facilitate rapid review when an on-site pathologist is not available. Herein, we assess intraobserver concordance of PBS evaluation with light microscopy (LM) and DM using VisionTek M6 robotic DM and TeamViewer imaging software. Methods Thirty-seven de-identified PBS slides were evaluated by five reviewers. Slides were loaded on a VisionTek M6 robotic microscope at an off-site laboratory and evaluated remotely via TeamViewer software. Reviewers recorded interpretation, time required for interpretation (in minutes), imaging quality (score 0-3), and confidence of interpretation (score 0-3). Other relevant information associated with DM evaluation was also documented. Slides were subsequently evaluated using LM after washout interval. The intraobserver variation of results for impression, digital slide quality, minutes to interpretation, and confidence of interpretation was compared between DM and LM. Results The intraobserver concordance between LM and DM was 93%, with nine discordant interpretations among 135 evaluations under each review modality, respectively. Although reviewers spent more time under DM mode (5 min/slide) than LM mode (2.5 min/slide), the reviewers felt the DM provided sufficient image quality and the confidence levels of reviewers on slide interpretation were comparable between DM (2.6/3) and LM (2.8/3). Conclusion There was a high level of intraobserver concordance and comparable interpretation confidence between DM and LM. DM can be a useful methodology for off-site pathologist's review of PBS.

Introduction The aim of this study was to evaluate observer variations and observer reproducibility in the interpretation of periapical health using the Strindberg system, the periapical index (PAI), and the probability index for radiologic assessment of periapical health. Methods Four observers read digital periapical images to evaluate the periapical health of 200 root-filled teeth. Each observer evaluated a tooth twice by using the Strindberg system, twice by using the PAI, and twice by using the probability index. Each observation session was held at 1-month intervals. Three scores were used for the evaluations conducted by using the Strindberg system. Both the PAI and the probability index were considered on 5-point scales and were also dichotomized. SPSS for Windows 15.0 software (SPSS Inc, Chicago, IL) was used for data analysis, and intra- and interobserver agreements were described by using kappa statistics. Results The average kappa values of intra- and interobserver agreement calculated for the Strindberg system were 0.53 and 0.36, respectively. The corresponding average kappa values were calculated as 0.48 and 0.39 for the PAI and 0.45 and 0.30 for the probability index. The highest mean proportion values of intra- and interobserver agreement were observed for the dichotomization of the PAI (88.9% and 87.0%, respectively) followed by the dichotomization of the probability index (86.8% and 82.9%, respectively). Conclusions The Strindberg system has lower intraobserver variation compared with the PAI and the probability index, whereas PAI has lower interobserver variation compared with the Strindberg system and the probability index. The dichotomization of the PAI and the probability index provided higher intra- and interobserver agreement values in the radiologic assessment of periapical health.

Visual assessment of immunohistochemically detected estrogen receptor protein is prone to interobserver and intraobserver variation due to its subjective evaluation. The aim of this study was to validate a new image analysis system based on virtual double staining (VDS) by comparing visual and automated scorings of ER in tissue microarrays of breast carcinomas. Tissue microarrays were constructed of 112 consecutive resection specimens of breast carcinomas. Immunohistochemistry assays for ER and pancytokeratin was applied on separate serial sections. ER scoring was visually performed by 5 observers using the histoscore (H-score) method. The Visiopharm ER image analysis protocol (APP) software application using VDS technique was applied separating stromal cells from carcinoma and other epithelial cells based on the pancytokeratin reaction. Using color deconvolution, polynomial filters, and nuclear segmentation the APP determined the percentage of positive cells and their intensity, and calculated the resulting H-score. On the basis of 1% cutoff VDS was perfectly correlated with visual assessment (κ=1). Using H-score, a very high agreement between VDS and visual ER assessment was seen (R=0.950). Image analysis has the attributes to eliminate the shortcomings of visual ER evaluation by generating automated, reproducible, and objective results of ER assessment.

Purpose To assess whether an education program on CT and MRI prostate anatomy would reduce inter- and intraobserver prostate contouring variation among experienced radiation oncologists. Methods and Materials Three patient CT and MRI datasets were selected. Five radiation oncologists contoured the prostate for each patient on CT first, then MRI, and again between 2 and 4 weeks later. Three education sessions were then conducted. The same contouring process was then repeated with the same datasets and oncologists. The observer variation was assessed according to changes in the ratio of the encompassing volume to intersecting volume (volume ratio [VR]), across sets of target volumes. Results For interobserver variation, there was a 15% reduction in mean VR with CT, from 2.74 to 2.33, and a 40% reduction in mean VR with MRI, from 2.38 to 1.41 after education. A similar trend was found for intraobserver variation, with a mean VR reduction for CT and MRI of 9% (from 1.51 to 1.38) and 16% (from 1.37 to 1.15), respectively. Conclusion A well-structured education program has reduced both inter- and intraobserver prostate contouring variations. The impact was greater on MRI than on CT. With the ongoing incorporation of new technologies into routine practice, education programs for target contouring should be incorporated as part of the continuing medical education of radiation oncologists.

Objectives: To determine the inter- and intra-observer variation of volume calculations of human fetuses at a gestational age of 11 +0-13 +6 weeks by three-dimensional ultrasound (3DUS). Methods: 3DUS datasets were acquired during nuchal translucency measurements. The fetal volume (FV) was measured in 65 cases by two independent investigators. The Virtual Organ Computer aided AnaLysis (VOCAL™) imaging software was used to manually calculate the FV (rotational angle 9°). Inter- and intra-observer variation were assessed by Bland-Altman plots and intraclass correlation coefficients (ICC). Results: Both inter- and intraobserver reproducibility were highly reliable as shown by the Bland-Altman plots and an ICC of respectively 0.934 and 0.994. Conclusion: FV calculation by 3DUS with VOCAL and a rotational angle of 9° is feasible and has a high inter- and intraobserver reliability in the first trimester of pregnancy.

Background and Objectives : Radiological and histological evaluations are affected by subjective interpretation. This study determined the level of inter- and intraobserver variation among radiologists for detection of abnormal parenchymal lung changes on high resolution computed tomography (HRCT). Methods : HRCT images of 65 patients known to have systemic lupus erythematosus (with clinical pulmonary involvement) were retrospectively reviewed by four nonthoracic radiologists (two with expertise in magnetic resonance [MR] and two general radiologists). Each radiologist read the scans twice, with an interval between readings of at least 6 months. The interobserver variation among the first and second readings of the four radiologists and the intraobserver variation of each radiologist′s two readings were assessed by the kappa statistic. Results : There was good agreement between the first and second readings of each radiologist. There was moderate agreement between the two readings of one MR radiologist (kappa=0.482); the other three radiologists had kappa values that were good to excellent (0.716, 0.691, and 0.829). There was a clinically acceptable level of interobserver variability between all radiologists. The agreement was fair to moderate between the MR radiologist and the other observers (kappa range: 0.362-0.519) and moderate to good between the other three radiologists (0.508-0.730). Conclusion : The interpretation of imaging findings of abnormal parenchymal lung changes on HRCT is reproducible and the agreement between general radiologists is clinically acceptable. There is reduced agreement when the radiologist is not involved on a regular basis with thoracic imaging. Difficult or indeterminate cases may benefit from review by a chest radiologist.

Aims According to the classification established by the Japanese Society for Oesophageal Disease, early oesophageal cancer can be subdivided into six successive layers of the mucosa or submucosa, which influences the treatment strategy and prognosis of the individual patient. However, the reproducibility of this classification in terms of inter-and intraobserver variability is unclear. Methods Histological slides from 105 surgical resection specimens of patients who had undergone oesophagectomy for early oesophageal adenocarcinoma were reviewed independently by three gastrointestinal pathologists, and were classified according to the Japanese criteria (m1/m2/m3/sm1/sm2/sm3 tumours). Inter-and intraobserver variation was determined by k-statistics. Results The interobserver reproducibility was good between pathologist 1 and 2 (kappa=0.61, 95% CI 0.55 to 0.67), and moderate between pathologist 1 and 3 (kappa-0.51, 95% CI 0.45 to 0.57) and between pathologist 2 and 3 (kappa=0.50, 95% CI 0.38 to 0.61). The intraobserver agreement as assessed by the expert pathologist was good (kappa=0.76), with a 95% CI that was interpreted as good to very good (0.67 to 0.85). Most agreement was achieved at the lower (m1) and upper site (sm2, sm3) of the spectrum, whereas the m2 tumours reflected the most discrepant stage. The majority of the observed discrepancy included the variation in one substage only. Conclusions The reproducibility of the Japanese classification is good in terms of inter- and intraobserver variability when grading early oesophageal adenocarcinoma on surgical resection specimens. The present data confirm that dedicated gastrointestinal pathologists with broad experience are preferred when grading the resection specimens of patients with early oesophageal adenocarcinoma.

BACKGROUND: Atypia of undetermined significance is a controversial category in thyroid fine-needle aspiration (FNA), not only for its questioned clinical utility, but also for its very existence as an expression of uncertainty. The current study was performed to investigate the potential impact of eliminating this category on the sensitivity and specificity for detecting thyroid neoplasms by FNA. METHODS: Forty cases originally diagnosed as atypia of undetermined significance with histologic follow-up were selected for the present study. These cases were reinterpreted blindly by 2 experienced reviewers, who eliminated atypia of undetermined significance as a diagnostic possibility and reclassified these cases as either benign, follicular neoplasm, suspicious for malignancy, or malignant. Twenty-six cases of atypia of undetermined significance were randomly selected and reevaluated 6 months later to study intraobserver variation. RESULTS: After eliminating the atypia of undetermined significance category, the sensitivity for detecting papillary thyroid carcinoma (PTC) was reduced from 100% to 27% (P = .04). In those atypia of undetermined significance cases that were reclassified as benign, 37% had PTC. In those reclassified as follicular neoplasm or suspicious for malignancy, 38% were histologically proven to be benign lesions. Unanimous interobserver and intraobserver agreement was observed in only 60% of cases. CONCLUSIONS: Eliminating the diagnosis of atypia of undetermined significance substantially decreases the sensitivity of thyroid FNAs and increases both false-positive and false-negative rates. In addition, it increases interobserver and intraobserver variability. Therefore, the atypia of undetermined significance category should not be eliminated; but we advocate minimizing its use. Cancer (Cancer Cytopathol) 2009. © 2009 American Cancer Society.

Objective To compare the inter- and intraobserver variation of fetal biometric measurements utilizing two-dimensional (2D) and three-dimensional (3D) ultrasound imaging. Methods This prospective study, utilizing three pairs of doctors trained in sonography, evaluated singleton pregnancies in the mid-trimester. Measurements of the biparietal diameter (BPD), head circumference (HC), abdominal circumference (AC) and femur length (FL) were taken in duplicate by each doctor using 2D imaging and then again using 3D volume datasets. Each set of paired doctors evaluated 12 patients. Inter- and intraobserver variation were calculated as the SD of the difference between paired measurements performed by the doctor pairs and by the individual doctors, respectively. Bland–Altman plots were used to visually compare measurement bias and agreement by 2D and 3D methods. Results Inter- and intraobserver variation for 2D and 3D ultrasound were small. The intraobserver variation of HC, AC and FL was significantly lower for 3D compared with 2D ultrasound. Interobserver variation was not significantly different when measured with 2D and 3D ultrasound, with the exception of FL, which was lower when measured with 3D ultrasound. The Bland–Altman plots showed that in 95% of the measurements, the percentage difference between 2D and 3D ultrasound techniques was within 5.3%, 4.6%, 9.6% and 9.6% for BPD, HC, AC and FL, respectively. Conclusions 2D and 3D fetal biometric measurements are reproducible. The use of 3D ultrasound significantly reduces intraobserver variation for HC, AC and FL and reduces interobserver variation for FL. Copyright © 2009 ISUOG. Published by John Wiley & Sons, Ltd.

This study was designed to evaluate the interobserver and intraobserver agreement of two-dimensional (2-D) and three-dimensional (3-D) anal endosonography for the detection of local recurrence anal carcinoma.Thirty-six patients were treated for anal carcinoma, and seven had recurrent disease. They were investigated by using 3-D endosonography at Rigshospitalet from July 2001 to January 2005 because of suspected local recurrence. The 3-D endosonographic examinations were reviewed from the hard disc by two observers who twice reviewed all 2-D examinations (the axial projection) as well as all 3-D examinations (the axial, as well as the reconstructed coronal and sagittal projections). The observers scored each examination according to the following scale regarding presence of local recurrence: 1 = no finding/benign findings; 2 = properly benign findings; 3 = suspicious findings/malignant findings. Kappa statistic-statistic was used to evaluate interobserver and intraobserver variation.Three-dimensional endosonography achieved better interobserver agreement than 2-D endosonography: kappa 3-D 0.34-047 vs. kappa 2-D 0.15-0.28 and better intraobserver agreement: kappa 3-D 0.34-0.62 vs. kappa 2-D 0.22-0.28. These differences showed P0.05.Three-dimensional endosonography proved to have significantly better interobserver and intraobserver agreement than 2-D endosonography concerning detection of recurrent anal cancer. Three-dimensional endosonography seems to be less dependent of the individual examiner than 2-D endosonography.

Background: Open surgical or endovascular abdominal aortic aneurysm (AAA) relies on precise preprocedual imaging. Purpose of this study was to assess inter- and intraobserver variation of software-supported automated and manual multi row detector CT angiography (MDCTA) in aortoiliac diameter measurements before AAA repair. Patients and methods: Thirty original MDCTA data sets (4 times 2mm collimation) of patients scheduled for endovascular AAA repair were studied on a dedicated software capable of creating two-dimensional reformatted planes orthogonal to the aortoiliac center-line. Measurements were performed twice with a four-week interval between readings. Data were analysed by two blinded readers at random order. Two different measurement methods were performed: reader-assisted freehand wall-to-wall measurement and semi-automatic measurement. Results: Aortoiliac diameters were significantly underestimated by the semi-automatic method as compared to reader-assisted measurements (p < 0.0031). Intraobserver variability of AAA diameter calculation was not significant (p > 0.15) for reader-assisted measurements except for the diameter of the left common iliac artery in reader 2 (p = 0.0045) and it was not significant (p > 0.14) using the semi-automatic method. Interobserver variability was not significant for AAA diameter measurements using the reader-assisted method and for proximal neck analysis with the semi-automatic method (p > 0.27). Relevant interobserver variation was observed for semi-automatic measurement of maximum AAA (p = 0.0007) and iliac artery diameters (p = 0.024). Conclusions: Dedicated MDCTA software provides a useful tool to minimize aortoiliac diameter measurement variation and to improve imaging precision before AAA repair. For reliable AAA diameter analysis the reader-assisted freehand measurement method is recommended to be applied to a set of reformatted CT data as provided by the software used in this study.

Background: Crohn's disease is a heterogeneous disease, and several classification systems have been developed to classify the patients in more homogeneous groups. Our aim was to assess the intra- and interobserver variation when classifying patients according to the widely used Vifenna classification. Methods: Ten randomly selected Crohn's disease cases were presented to 11 Danish gastroenterologists with a special interest in inflammatory bowel diseases. Clinical details, together with endoscopic, radiologic, and pathologic reports, were presented to the participants as a PowerPoint slide show, sent by e-mail with a data collection form. The experts were asked to classify the cases according to the Vienna classification and to evaluate intraobserver variation; the participants classified the patients 3 times. The strength of agreement was calculated using κ statistics. Results: Classification of the patients according to age gave a κ value of 1.00. The intraobserver κ value was good, with an average κ value of 0.75 (range, 0.42-0.86) for location and 0.77 (range, 0.53-1.00) for behavior. The mean overall interobserver κ value was 0.64 (range, 0.12-1.00), which improved slightly between the first and third rounds. When classifying according to location and behavior, most patients were classified in 2 or 3 different ways, and in no patients was there full agreement among the observers for both location and behavior. Conclusions: In this study, we found an overall good interobserver agreement when using the Vienna classification, although when looking at individual cases, there was some disagreement.

The purpose of this study was to describe a largely observer-independent computer-assisted method for accurate quantitative analysis of bone marrow edema.Ten patients with bone marrow edema of the knee were included in the study. Coronal STIR images of the affected knees were obtained using a 1.0-T MR scanner. Size and signal intensity of the bone marrow edema were assessed on the basis of gray-scale value analysis and calculation of a threshold value for differentiating normal and edematous bone marrow. All measurements were carried out three times for statistical analysis.The intraobserver coefficient of variation was 0.89% for the volume and 0.94% for the signal intensity of the bone marrow edema, showing the small impact of manual interference on results produced with this method.A computer-assisted method for quantification of bone marrow edema has been described. Intraobserver variation was very low, indicating excellent reproducibility of results. Although the method is too time-consuming for clinical use, it is recommended for research purposes.

Objectives: Our aim was to validate 3-dimensional echocardiography (3DE) for assessment of left ventricular (LV) end-diastolic volume, end-systolic volume (ESV), stroke volume, and ejection fraction (EF) using the freehand-acquisition method. Furthermore, LV volumes by breath hold—versus free breathing—3DE acquisition were assessed and compared with magnetic resonance imaging (MRI). Methods: From the apical position, a fan-like 3DE image was acquired during free breathing and another, thereafter, during breath hold. In 27 patients, 28 breath hold— and 24 free breathing—3DE images were acquired. A total of 17 patients underwent both MRI and 3DE. MRI contours were traced along the outer endocardial contour, including trabeculae, and along the inner endocardial contour, excluding trabeculae, from the LV volume. Results: All 28 (100%) breath hold— and 86% of free breathing—3DE acquisitions could be analyzed. Intraobserver variation (percentual bias ± 2 SD) of end-diastolic volume, ESV, stroke volume, and EF for breath-hold 3DE was, respectively, 0.3 ± 10.2%, 0.3 ± 14.6%, 0.1 ± 18.4%, and −0.1 ± 5.8%. For free-breathing 3DE, findings were similar. A significantly better interobserver variability, however, was observed for breath-hold 3DE for ESV and EF. Comparison of breath-hold 3DE with MRI inner contour showed for end-diastolic volume, ESV, stroke volume, and EF, a percentual bias (± 2 SD) of, respectively, −13.5 ± 26.9%, −17.7 ± 47.8%, −10.6 ± 43.6%, and −1.8 ± 11.6%. Compared with the MRI outer contour, a significantly greater difference was observed, except for EF. Conclusions: 3DE using the freehand method is fast and highly reproducible for (serial) LV volume and EF measurement, and, hence, ideally suited for clinical decision making and trials. Breath-hold 3DE is superior to free-breathing 3DE regarding image quality and reproducibility. Compared with MRI, 3DE underestimates LV volumes, but not EF, which is mainly explained by differences in endocardial contour tracing by MRI (outer contour) and 3DE (inner contour) of the trabecularized endocardium. Underestimation is reduced when breath-hold 3DE is compared with inner contour analysis of the MRI dataset. (J Am Soc Echocardiogr 2003;16:101-9.)

This study identified the extent of inter- and intraobserver variation in assessing intrarenal Doppler waveform parameters.Optimized Doppler waveforms from the interlobar arteries of five healthy volunteers were recorded. The waveforms were digitized for off-line evaluation by six observers. Using the same set of waveforms, the observers initially selected three of six waveforms for each subject on the basis of their preference for clinical usefulness. The observers then were directed to evaluate three previously picked waveforms. The systolic acceleration time (SAT) and the resistive index were calculated from each waveform. The observers also characterized the shape of each waveform according to four categories.Significant interobserver (p.01) but not intraobserver variation occurred when measuring the SAT. Differences were caused by the observers' perceptions of waveform shapes (kappa = .12, p.01) as well as the observers choosing different systolic starting points. No significant inter- or intraobserver variation occurred in measuring the resistive index.Much variability among and within laboratories can be expected when observers of Doppler waveforms use SAT to evaluate patients for renal artery stenosis.

In a blinded, randomized design, six histopathologists with an interest in gynecological pathology examined the inter- and intraobserver variation of the histopathological diagnosis of endometrial hyperplasia according to the World Health Organization (WHO) classification of 1975 and the new WHO classification of 1994. On four occasions, the pathologists assessed hematoxylin/eosin-stained slides from 128 cases originally diagnosed and coded in the Snomed system as endometrial hyperplasia. In the first and third rounds, the slides were classified according to the 1975 classification and in the second and fourth rounds according to the 1994 classification. The overall interobserver agreement in the two rounds where the 1975 classification was used was 0.47 and 0.51, and the kappa values 0.24 [95% confidence interval (CI) 0.21-0.27] and 0.30 (95% CI 0.27-0.33). The overall interobserver agreement in the two rounds using the 1994 classification was 0.45 and 0.41 and the kappa values 0.25 (95% CI 0.23-0.28) and 0.20 (95% CI 0.17-0.22). Reducing the classification to two categories with clinical significance (atypical endometrial hyperplasia versus others in the 1975 classification, and atypical endometrial hyperplasia, complex versus others in the 1994 classification) increased the overall agreement of the 1975 classification in both rounds to 0.91 and of the 1994 classification to 0.92 and 0.90. The kappa values increased to 0.54 (95% CI 0.49-0.58) and 0.49 (95% CI 0.45-0.54) in the 1975 classification and to 0.59 (95% CI 0.54-0.63) and 0.42 (95% CI 0.37-0.46) in the 1994 classification. The intraobserver overall agreement for the 1975 classification ranged from 0.80 to 0.55 and the kappa values from 0.70 (95% CI 0.58-0.81) to 0.28 (95% CI 0.17-0.39). The intraobserver overall agreement for the 1994 classification ranged from 0.71 to 0.46 and the kappa values from 0.60 (95% CI 0.51-0.70) to 0.20 (95% CI 0.09-0.30). It is concluded that there is considerable inter- and intraobserver variation using both the 1975 and the 1994 classifications of endometrial hyperplasia. We propose that there is need for a specification and for a simplification of the classification.

PURPOSE To assess inter- and intraobserver variability in wireless resonance frequency analysis (RFA) stability measurements of palatal implants and to evaluate the influence of age, sex, time after implant insertion, and measurement direction on variability. MATERIALS AND METHODS Three observers conducted wireless RFA stability measurements of palatal implants from 16 patients. Measurements were taken in anteroposterior and laterolateral directions and were repeated after 1 hour. RESULTS Data showed a small interobserver variation (1.93) with intraobserver variation (1.77) as its largest component. Time after implantation showed a strong influence (P = .027) on the interobserver variation. CONCLUSIONS The tested wireless RFA device can be considered a reliable instrument for measuring the stability of palatal implants. Multiple readings and observers could further improve measurement reliability.

In this study, the observer variation and the influence of observer experience in diagnosing mitral valve prolapse in dogs was assessed by having three observers with different degrees of echocardiographic experience (10 years, 4 years, and no prior experience) analyze 303 mitral valve video recordings from 253 dogs, both with and without mitral regurgitation. To assess intraobserver variation, 16 recordings were analyzed twice, and 34 dogs were scanned twice at intervals of a few days. By consensus, 90 dogs had no mitral valve prolapse, 130 had mild and 33 had severe mitral valve prolapse. Intraobserver repeatabilities ranged from 88% to 100% and interobserver repeatabilities from 70% to 78%. In 79% to 94% of the dogs that were scanned twice, the observers diagnosed both recordings identically. All repeatabilities were reduced by approximately 10% when mitral valve prolapse was graded into mild and severe. The three observers differed significantly in diagnosing mitral valve prolapse when compared with each other in pairs (all p-values < 0.01). The unexperienced observer had the highest and most unsystematic occurrence of false diagnoses. It is possible that the interobserver repeatabilities would have been lower had each sonographer obtained his own echocardiograms. We conclude, that mitral valve prolapse in dogs can be diagnosed using two-dimensional echocardiography with the same degree of observer variation as reported in human studies, and that education and training of staff is mandatory to ensure proper ultrasonographic evaluation.

Purpose:The aim of this study was to assess the QUESTOR Precision Radiography system (QPR) and to compare it with the routine hip-knee-ankle (HKA) angle measurements. The aim was also to evaluate the robustness of the QPR system against the osseous changes of arthrotic disease.Material and Methods:Twenty-four patients, operated on with a high tibial osteotomy for medial gonarthrosis, were examined. The alignment of the leg was measured by the conventional technique and by the QPR method.Results and Conclusion:The 2 methods correlated well. The intraobserver variation in the QPR measurements was, with the exception of the capito-midcondylar-femoral shaft angle and the tibial plateau width, not affected by the osseous changes inflicted by the arthrotic process. The patients tolerated both systems well while the staff preferred the QPR system.

One hundred and ten cervical smears were circulated to five specialist consultant cytopathologists and five consultant histopathologists. Of these smears, 100 were randomized and re-circulated. The cytopathologists reported endocervical cells and wart virus infection more frequently than the histopathologists, although neither group showed good inter-observer agreement for either assessment. Apart from smear adequacy and the presence of endocervical cells, both groups showed good intra-observer agreement in all the parameters measured. This suggests that overall individuals were applying their own personal criteria with consistency over time, although a previous study had shown considerable lack of inter-observer agreement among the histopathologists on the grade of dyskaryosis and the management recommendation. The results indicate that specialist cytopathologists bring a different viewpoint to the reporting of cervical smears than histopathologists. They also show a lack of standardization in the reporting of smears despite the guidelines issued by the British Society for Clinical Cytology.

To assess the reliability of bone scintigraphy, a random sample of 100 bone scans was reviewed twice by each of two physicians. Observer variation in the description and interpretation of bone scintigrams varied by diagnosis. Good to excellent κ values were obtained for inter- and intraobserver variation in relation to metastasis or normal scans. For degenerative bone disease, as well as the specific agreement on major pathologies other than metastases, κ values were found to be moderate. The agreement on the need for further radiographic studies was poor to moderate. The interpretation of bone metastases or normal scintigrams was found to be more reliable in a research setting than in the usual clinical framework, and the latter requires improvement. The interpretation of bone scintigraphy as consistent with degenerative changes is not reliable. The diagnosis should be evaluated by radiography.

This study was undertaken with the aim of evaluating inter- and intraobserver variation on the pathophysiological interpretation of individual electromyographic (EMG) tests on muscles and nerve segments. Seven physicians from 6 European EMG laboratories independently interpreted 81 EMG studies comprising 735 muscle tests and 726 tests on nerve segments. Pathophysiological conclusions were inferred from findings of these tests without considering clinical information. For most combinations of findings, both the inter- and intraobserver variations on the interpretation were low, suggesting that common criteria for pathophysiological interpretations were used and that these were used consistently. For some combinations of findings, however, there was disagreement on whether these indicated specific or unspecific pathophysiological changes. In particular disagreement on whether findings indicated demyelination may be of clinical significance. A large part of the intraobserver variation may be explained by a change towards more cautious interpretations during the study for most of the physicians. It is concluded that there is a need to seek for consensus on the pathophysiological interpretation of individual findings and for incentives to ensure consistency in interpretations. The fact that experienced physicians changed their ways to interpret findings during the study suggests that agreement may be improved globally.

The purpose of this study was to compare mandibular linear distances measured from cone beam CT (CBCT) images produced by different radiographic parameter settings (peak kilovoltage and milliampere value).20 cadaver hemimandibles with edentulous ridges posterior to the mental foramen were embedded in clear resin blocks and scanned by a CBCT machine (CB MercuRay(TM); Hitachi Medico Technology Corp., Chiba-ken, Japan). The radiographic parameters comprised four peak kilovoltage settings (60 kVp, 80 kVp, 100 kVp and 120 kVp) and two milliampere settings (10 mA and 15 mA). A 102.4 mm field of view was chosen. Each hemimandible was scanned 8 times with 8 different parameter combinations resulting in 160 CBCT data sets. On the cross-sectional images, six linear distances were measured. To assess the intraobserver variation, the 160 data sets were remeasured after 2 weeks. The measurement precision was calculated using Dahlberg's formula. With the same peak kilovoltage, the measurements yielded by different milliampere values were compared using the paired t-test. With the same milliampere value, the measurements yielded by different peak kilovoltage were compared using analysis of variance. A significant difference was considered when p0.05.Measurement precision varied from 0.03 mm to 0.28 mm. No significant differences in the distances were found among the different radiographic parameter combinations.Based upon the specific machine in the present study, low peak kilovoltage and milliampere value might be used for linear measurements in the posterior mandible.

An acromiohumeral interval narrower than 6 mm measured on AP shoulder radiographs has been considered pathological and suggestive of rotator cuff tears. This prospective study was conducted to assess inter- and intraobserver variation in the radiographic assessment of the acromiohumeral interval and its critical value on routinely taken AP shoulder radiographs off-study use to evaluate the accuracy of this measurement method. The acromiohumeral distance from the inferior anterior acromial aspect to the humeral head was measured in millimeters. Thirty blinded, anteroposterior shoulder radiographs were independently reviewed by five board-certified orthopedic shoulder surgeons at two time points in random order. The results of three investigators showed significant intraobserver variation. Five investigator pairs showed significant interobserver variation at both examination time points. The maximum interobserver difference for the same radiograph was 8 mm (range 0 to 8 mm). Our results indicate that the assessment of the acromiohumeral interval using non-standardized anteroposterior radiographs off-study use cannot be seen as a reproducible and reliable method of measurement.

This audit analysed the Tanner and Whitehouse II twenty bone (TW2) method of bone age assessment which was used in our department, and compared it with the Greulich and Pyle (GP) method. 50 previous bone ages were independently re-calculated by each of three registrars using both techniques, with the time taken to perform each assessment being recorded. For each method the interobserver variation was analysed in terms of the spread of results. The intraobserver variation in TW2 was determined by comparing the bone age originally reported with that subsequently calculated on the same film by the same registrar. The average spread of results was 0.74 years for TW2 method, and 0.96 years for the GP method and this difference is not statistically significant at the 5% level. The average intraobserver variation to TW2 was 0.33 years, but with 95% confidence limits of -0.87 to +1.53 years. The average time taken was 7.9 min for TW2 and 1.4 min for GP assessments. It was concluded that the GP method gave similar reproducibility and was faster than the TW2 method. Following clinical discussion the routine departmental bone age assessment method was changed from the TW2 to the GP method.

The objective of this study was to compare the relative utility of tissue harmonic (H) and brightness (B) transrectal ultrasound (TRUS) images of the prostate by studying interobserver and intraobserver variation in prostate delineation.Ten patients with early-stage disease were randomly selected. TRUS images of prostates were acquired using B and H modes. The prostates on all images were contoured by an experienced radiation oncologist (RO) and five equally trained observers. The observers were blinded to information regarding patient and imaging mode. The volumes of prostate glands and areas of midgland slices were calculated. Volumes contoured were compared among the observers and between observer group and RO. Contours on one patient were repeated five times by four observers to evaluate the intraobserver variability.A one-sample Student t-test showed the volumes outlined by five observers are in agreement (p0.05) with the RO. Paired Student t-test showed prostate volumes (p = 0.008) and midgland areas (p = 0.006) with H mode were significantly smaller than that with B mode. Two-factor analysis of variances showed significant interobserver variability (p0.001) in prostate volumes and areas. Inter- and intraobserver consistency was quantified as the standard deviation of mean volumes and areas, and concordance indices. It was found that for small glands (≤35 cc) H mode provided greater interobserver consistency; however, for large glands (≥35 cc), B mode provided more consistent estimates.H mode provided superior inter- and intraobserver agreement in prostate volume definition for small to medium prostates. In large glands, H mode does not exhibit any additional advantage. Although harmonic imaging has not proven advantageous for all cases, its utilization seems to be judicious for small prostates.

PURPOSE: To evaluate intra- and interobserver agreement of target vessel measured from computed tomography (CT) scans with 2 measuring techniques used in planning fenestrated endovascular aneurysm repairs (FEVAR): multiplanar reconstruction (MPR) and semi-automated central lumen line (CLL). METHODS: CT datasets from 25 FEVAR patients were independently analyzed by 2 experienced observers according to a standardized protocol using the MPR (Leonardo workstation) and CLL (Aquarius workstation) techniques for each patient. Longitudinal vessel separation and clock-face position of the visceral aortic branches were measured twice. The repeatability coefficient (RC) was calculated using the Bland and Altman method to measure intra- and interobserver variability. Differences between groups were examined by paired t test (continuous data) or chi-squared analysis (categorical). Clock-face discrepancy >30 minutes was considered significant. RESULTS: Intraobserver mean difference was insignificant regardless of the measurement technique: the observer and workstation-specific RCs varied between 3.9 and 4.9 mm. Paired measurements differed by >3 mm in 8%. Interobserver variability was greater: observer and workstation-specific RC varied between 5.6 and 7.4 mm, with a tendency toward consistency using MPR, although the mean difference was insignificant. Paired measurements differed by >3 mm in 18%. There was no significant intraobserver variation in clock-face measurement, while interobserver variation was significant in 12% of measurements using the Aquarius workstation and 6% using the Leonardo workstation (p = 0.19). CONCLUSION: Subjective interpretation of anatomical landmarks is more important than measurement techniques or workstations used in the generation of measurement inconsistencies. Introduction of consensus regarding interpretation of anatomical detail and development of fenestrated stent-grafts tolerant of measurement errors might ameliorate some of the problems encountered in FEVAR.

Intra- and interobserver (n = 3) variability of sizing and counting microbubbles using optical microscopy (OM) was assessed. The system was calibrated using standardised mono-disperse and poly-disperse microspheres. Results of the calibration show intraobserver variations of number count (C) = 13.0% and arithmetic mean size (MS) = 0.2%, and interobserver variations of C = 18.4% and MS = 0.6%, for the mono-disperse microspheres. For the poly-disperse microspheres, intraobserver variations were: C = 6.9% and MS = 0.8%, and interobserver: C = 10.5% and MS = 0.3%. For SonoVue™ the intraobserver variations were: C = 23.3% and MS = 8.0%, and interobserver C = 6.8% and MS = 3.8%. The results suggest that the higher values of the intraobserver variation for SonoVue™ arise from the natural decay of microbubbles over time. This article presents a detailed protocol and outlines potential pitfalls in our approach. These results are in general agreement with those previously reported and compare well with known size distributions. (E-mail: c.sennoga@imperial.ac.uk )

This study evaluates the accuracy and reproducibility of an experimental flat-panel-detector-based CT scanner (fp-CT) in comparison with those of a 64-slice multidetector row CT (MDCT) in automated pulmonary nodule volumetry. An anthropomorphic chest phantom with 31 spherical nodules (nodule diameters of 2.94-10.01 mm; volumes of 13.24-524.97 mm(3)) was scanned both with an amorphous silicon-based fp-CT scanner, using various tube current and kilovoltage settings, and with a conventional MDCT scanner. Automated nodule volumetry was performed using dedicated software. CT image data were evaluated twice by two independent radiologists. Intra- and inter-observer variations of volumetric measurements were determined and tested using the Kruskal-Wallis test and analysis of variance (fn-ANOVA). The percentage measurement errors (PME) were calculated and differences tested using Wilcoxon signed ranks and Friedman tests. Intraobserver variation was significantly higher for MDCT than for fp-CT (range: p = 0.043-0.045). The measured nodule volumes were significantly greater on fp-CT than on MDCT scans (p0.001). The PME was significantly greater in fp-CT than in MDCT scans (PME range, 12.35-13.35% for fp-CT scan protocols and 16.87-19.02% for MDCT scan protocols; p0.0001). The PME increased significantly with reduction of nodule size, and this increase was significantly higher on MDCT than on fp-CT scans (p = 0.0001). The absolute PME was significantly different for nodules of less than 5 mm in diameter (p = 0.0001-0.0033) than for larger nodules. Flat-panel-detector-based CT has advantages over MDCT in accurately determining the volume of pulmonary nodules below 5 mm in diameter.

Objective Variations in pregnancy rates (PR) between IVF programs are due to multiple factors, including embryo quality. Standardized embryo grading systems have been developed to improve communication between embryologists and clinicians. However, these grading systems have not been validated. We sought to quantify both interobserver and intraobserver variability using a standardized day 3 embryo grading system (Veeck scale). Design Prospective, sample-randomized, controlled, blinded study. Setting University hospital. Patient(s) Twenty-six practicing embryologists. Intervention(s) Observation and grading of 35 video clips of day 3 embryos. Main Outcome Measure(s) Interobserver and intraobserver variability. Embryologists were also assessed by education level, years of experience, size of IVF program, and type of grading system used. Kappa scores and intraclass correlation coefficients were calculated. Result(s) Practicing embryologists differed from control (Lucinda Veeck) by as much as two grades, despite using the same grading system (Kappa = 0.24, interclass correlation coefficient=0.98). There was also variability in grading the same embryo (Kappa = 0.69, interclass correlation coefficient=0.88). Programs with higher cycle numbers per year had lower variability. Conclusion(s) There is substantial interobserver variability and moderate intraobserver variability among embryologists. Such variability could alter both the expected quality of embryos transferred, as well as the number transferred, both of which directly impact IVF program success.

Background and Aim: The clinical value of oesophageal histology in non-complicated gastro-oesophageal reflux disease (GORD) is controversial. Our aim was to explore the role of histology in preoperative diagnosis and postoperative follow-up in GORD. Methods: From 40 patients 2 histopathologists graded and scored 191 oesophageal biopsies in a blinded manner to evaluate inter- and intraobserver variation pre- and postoperatively. Correlation between preoperative histology and objective clinical findings (endoscopy, esophageal 24-hour pH monitoring, and manometry) was calculated as well. Results: Pathologist I interpreted 16 (50%) preoperative biopsies as normal, 5 (16%) with mild, 4 (12.5%) moderate, and 7 (21.9%) severe reflux changes. Pathologist II interpreted 11 (35.5%) preoperative biopsies as normal, 11 (35.5%) with mild, 6 (19.4%) moderate, and 3 (9.7%) severe reflux changes. In preoperative biopsies, interobserver variation was 33.8% and intraobserver variation 9.7%. A positive correlation was detectable between preoperative endoscopic and morphologic findings; no correlation existed between either acid reflux or LES pressure and oesophageal morphology. Normal pH monitoring and fundic wrap were noted postoperatively in all cases. In postoperative histology no significant differences according to pathologist I existed when compared with preoperative changes: 22 normal (69%), 7 mild (22%), 1 moderate (3.1%), and 2 severe (6.3%). Compared to preoperative analysis, pathologist II interpreted 24 (77%, p = 0.001) of the postoperative findings as normal, 1 (3%, p = 0.003) as mild, 4 (12.9%, n.s.) as moderate, and 2 (6.5% n.s.) as severe reflux changes. In postoperative biopsies interobserver variation was 21.1% and intraobserver variation 5.6%. Conclusion: The role of oesophageal histology in preoperative diagnosis and postoperative follow-up of GORD may be considered limited.

Summary Introduction: The aim of this study was to determine the reliability of currently used classification systems for intertrochanteric fractures of the proximal femur, and to determine the reliability of these systems in experienced orthopaedic surgeons. Materials and methods: Forty intertrochanteric fractures of the proximal femur were classified independently by five experienced observers using the AO, Evans, Kyle, and Boyd classification systems on two separate occasions 3 months apart. The interobserver and intraobserver variation was assessed using kappa statistics. Results: The level of agreement for classification into AO groups was almost perfect or substantial, and higher than other classification systems. When the fractures were further classified using the AO classification with subgroups, reliability became worse. Conclusions: The current study suggests that the AO classification system with groups can be used more reliably to measure intertrochanteric fractures of the proximal femur than Evans, Kyle, and Boyd classification systems. However, the reliability of the AO classification with subgroups is not satisfactory.

AIMS The development of imaging and measurement techniques has brought the prospect of greater objectivity in the measurement of optic disc features, and therefore better agreement between observers. The purpose of this study was to quantify and compare the variation between observers using two measurement devices. METHODS Optic disc photographs and images from the Heidelberg retina tomograph (HRT) of 30 eyes of 30 subjects were presented to six observers for analysis, and to one observer on five separate occasions. Agreement between observers was studied by comparing the analysis of each observer with the median result of the other five, and expressed as the mean difference and standard deviation of differences between the observer and the median. Inter- and intraobserver variation was calculated as a coefficient of variation (mean SD/mean × 100). RESULTS For planimetry, agreement between observers was dependent on observer experience, for the HRT it was independent. Agreement between observers (SD of differences as a percentage of the median) for optic disc area was 4.0% to 7.2% (planimetry) and 3.3% to 6.0% (HRT), for neuroretinal rim area it was 10.8% to 21.0% (planimetry) and 5.2% to 9.6% (HRT). The mean interobserver coefficient of variation for optic disc area was 8.1% (planimetry) and 4.4% (HRT), for neuroretinal rim area it was 16.3% (planimetry) and 8.1% (HRT), and (HRT only) for rim volume was 16.3%, and reference height 9.1%. HRT variability was greater for the software version 1.11 reference plane than for version 1.10. The intraobserver coefficient of variation for optic disc area was 1.5% (planimetry) and 2.4% (HRT), for neuroretinal rim area it was 4.0% (planimetry) and 4.5% (HRT). CONCLUSIONS Variation between observers is greatly reduced by the HRT when compared with planimetry. However, levels of variation, which may be clinically significant, remain for variables that depend on the subjective drawing of the disc margin.

Background: A new endoscopic classification of gastroesophageal reflux disease (GERD) has been proposed, and the term mucosal break has been introduced to describe mucosal damage. This new classification was evaluated by endoscopists with different levels of experience. Methods: Fifty endoscopic photographs for each of 20 randomly selected patients with GERD were assessed retrospectively by three groups of seven endoscopists classified by experience: group 1 (100 to 500 procedures), group 2 (500 to 3000), and group 3 (more than 3000). The new classification was modified by adding grade 0 to describe healed mucosal breaks, so that there were five grades. All photographs were assessed twice at an interval of more than 1 week, and κ statistics were used to determine observer variation. Results: Interobserver variation within group 3 (κ = 0.39, n = 21) and between groups 3 and 2 (κ = 0.36, n = 49) was significantly different (p < 0.01) from that between groups 3 and 1 (κ = 0.26, n = 49). Intraobserver variation in group 1 (κ = 0.39, n = 7) was significantly different (p < 0.01) from that in group 2 (κ = 0.51, n = 7) and group 3 (κ = 0.54, n = 7). Conclusions: Observer variation depends on level of endoscopic experience. Only experienced endoscopists should use the new classification for grading of GERD. (Gastrointest Endosc 1999;49:700-4.)

OBJECTIVE: To determine the interobserver and intraobserver variations in sonographic measurement of thyroid volume in children. DESIGN: Thyroid volumes of 30 healthy children were measured by three separate observers. Additionally each observer measured thyroid volumes of ten separate children three times. METHODS: The data were used to assess intraobserver and interobserver variations in measurement of thyroid volume. Interobserver and intraobserver variations in measuring each diameter of the thyroid gland were also determined. The effect of thyroid size on interobserver and intraobserver variations was analyzed. RESULTS: Intraobserver variation in measurement of thyroid volume was 8.4+/-6.7% (mean+/-s. d.). Interobserver variation was 13.3+/-8.2%. The widest interobserver variation was encountered in determining the craniocaudal diameter of the thyroid gland. No correlation was found between thyroid volume and interobserver variation (r=-0.12, P=0.27), whereas a slight but statistically significant correlation was found between thyroid volume and intraobserver variation (r=-0.26, P=0.012). CONCLUSION: Significant interobserver and intraobserver variation occurs in sonographic measurement of thyroid volume in children.

BACKGROUND To assess the interobserver and intraobserver variation of Papanicolaou (Pap) smear screening with the computer-assisted (neural network based) PAPNET Testing System in diagnosing cervical smear abnormalities, results of agreement were compared with the interobserver and intraobserver variation of conventional smear analysis. METHODS Cervical smears obtained from women in 1996 were reevaluated both by conventional light microscopy and with use of the PAPNET Testing System by the same four investigators, and results were compared with the original screening diagnoses obtained by both methods. RESULTS The interobserver results for epithelial abnormalities (the degree of agreement between the cytologists), characterized by weighted kappa statistics, were 0.71 (95% CI: 0.68–0.73) for PAPNET screening and 0.69 (95% CI: 0.66–0.72) for conventional screening. No significant differences were found among the individual results obtained by the four cytotechnologists (intraobserver variation) with conventional screening versus PAPNET reviewing. CONCLUSIONS Pap smear grading with the PAPNET Testing System has interobserver and intraobserver variation similar to that of conventional screening of Pap smears in routine use. Cancer (Cancer Cytopathol) 1999;87:178–83. © 1999 American Cancer Society.

We examined the reliability of the Seinsheimer classification of subtrochanteric fractures of the femur. 50 consecutive anteroposterior and lateral radiographs were assessed independently by 4 observers twice with a 6-week interval. The interobserver variation was large; only 13 of the 50 fractures were classified identically by all 4 observers. The intraobserver variation showed identical classification in 26-37 of 50 radiographs. When assessing only whether the fracture was subtype 3A or not, the 4 observers agreed in 31 of 50 radiographs. We conclude that the Seinsheimer classification has no value in clinical practice.

A new method of measuring the size of the thymus in infants less than 1 year of age is presented. The width of the thymus was measured in a transverse image while the area of the largest lobe was assessed in a longitudinal image. The thymic index was then defined as the product of these two values. Intra- and interobserver variation analysis were performed in 23 infants. Each infant was scanned alternately by both of two radiologists, and later the same day the measurements were repeated. The mean differences between the first and second measurements (intraobserver variation) were -0.25 (2 SD 7.56) and -1.13 (2 SD 10.80), respectively, for the two observers. The mean difference between the first measurements of the two observers (interobserver variation) was 1.47 (2 SD 9.39). In a postmortem study of 12 infants the thymic index measured by sonography showed an acceptable correlation to the actual volume (c = 0.80) and weight (c = 0.87) of the thymus. In conclusion, our sonographic estimate of the volume of the thymus, the thymic index, in infants under 8 months of age seems to be easy, reliable and reproducible.

Intraobserver variation associated with the non-invasive assessment of pulmonary artery pressure (PAP), using measurement of pulmonary artery Doppler derived systolic time intervals, was investigated. Forty pairs of independent ultrasound examinations of the pulmonary artery were performed by a single observer in 20 preterm infants, median gestation 27 weeks (range 24-31 weeks). Median age at study was 17 days (range 1-47 days). paired measurements of acceleration time (AT), ratio between acceleration time and right ventricular ejection time (AT:RVET), corrected AT, and corrected AT:RVET were compared to assess intraobserver agreement. For the corrected AT:RVET ratio, the mean percentage difference between observations was -0.9% (95% confidence intervals -5.0 to 3.1%). The limits of agreement for the two measurements were -26.3 to 24.5%. The coefficient of repeatability was 25.4%. Variation for other indices was similar. Non-invasive assessment of PAP using Doppler derived systolic time intervals is associated with considerable intraobserver variation.

The reproducibility of intraocular pressure (IOP) measurement with the Goldmann applanation tonometer was investigated as part of a population-based epidemiological study. Sixty-two subjects were examined in a first measurement session. The IOP was measured three times consecutively in both eyes according to a fixed protocol. The mean standard deviation (SD) of these measurements was 0.8 mmHg. The mean intraobserver variation for the first measurement was 1.64 (SD 2.07) mmHg. For the median of the three measurements the intra-observer variation was 1.50 (SD 1.96) mmHg. The mean inter-observer values were 1.79 (SD 2.41) mmHg for the first measurement and 1.60 (SD 2.15) mmHg for the median measurement. The correlation coefficient between the median values of the three measurements of both observers was 0.81. No systematic differences were found between the two observers. Using the median value of three consecutive measurements reduced the inter-observer variation by 11% and the intra-observer variation by 9% compared with a single measurement.

Purpose: This study was designed to evaluate inter and intraobserver concordance in gross tumor volume (GTV) delineation on megavoltage CT (MVCT) images in patients with postoperative vault recurrences. Materials and Methods: Three observers delineated GTV on MVCT and CECT and two observers recontoured on MVCT images. Tumor volumes were calculated and correlated using Spearman correlation. The standard deviation of centre of mass was averaged on per patient basis. The ratio of common volume and encompassing volume was used to determine intra and interobserver spatial concordance. Lack of difference in spatial concordance ratio between MVCT and CECT images was used as an index of usability of MVCT images. Results: Thirty six datasets were available for seven patients. High intraobserver GTV correlation was recorded for observer 1 and 2 (r = 0.93 and r = 0.98; P =0.03 and 0.0001). The average intraobserver spatial concordance ratio was 0.57 and 0.62 respectively. The mean GTV of observers 1, 2 and 3 were 31.6 (18.7-52.2); 28.2 (16.7-51.8) and 46.3 cc (29.1-90.5) respectively. Average standard deviation of centre of mass of all observers was less than 5 mm in either direction. Largest interobserver discordance was observed in anterior, inferior and lateral direction. The interobserver spatial concordance of GTV on MVCT and CECT images was 0.34 and 0.36 ( P =0.24) respectively. Conclusion: Moderate to good inter and intraobserver GTV correlation was observed on MVCT images, however, was associated with low interobserver spatial concordance on both MVCT and CECT images. Strategies to improve contouring reproducibility on MVCT and KVCT images are desirable.

Objective To determine the magnitude of intraobserver variation in dating endometrial biopsies and its impact on clinical management. Design Blinded histopathologic interpretation of endometrial biopsy specimens 1 year apart by five pathologists. Setting Large military tertiary care center. Patients Endometrial biopsy specimens from 51 patients undergoing evaluation for potential luteal phase defects. Interventions None. Main Outcome Measures Calculation of the magnitude of the individual and overall intraobserver variation in endometrial dating for the five pathologists and estimation of its potential impact on clinical management. Results The intraobserver variation was 0.69 ± 0.05 days (means ± SE). There was no significant difference in the magnitude of the variation for 1-day or 2-day dating ranges. The theoretical probability of altering clinical management by having the same pathologist redate a given specimen ranged from 15% to 28%. Conclusion Histologic dating of endometrial biopsies is subject to a small but highly clinically significant intraobserver variability that may have a major impact on clinical management.