Inter- and intra-observer variability of ultrasonographic arm muscle thickness measurement by critical care physicians.
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ABSTRACT:
SUBMITTER: Hadda V
PROVIDER: S-EPMC5525479 | biostudies-other | 2017 Jul-Sep
REPOSITORIES: biostudies-other
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Project description:Muscle wasting is common among critically ill patients with sepsis and has a significant effect on clinical outcome. However, appropriate tool for measurement of muscle loss is debatable. Ultrasonography (USG) has been used for objective assessment of quadriceps muscle thickness among these patients; however, there is limited data on its reliability.This study was aimed to assess the reliability of quadriceps muscle thickness as measured by critical care physicians.This cross-sectional study included twenty patients with sepsis. Quadriceps muscle thickness was measured on right mid-thigh at a predefined point by two critical care fellows using bedside USG. Intra- and inter-observer reliability of the measurements was assessed by intra-class correlation coefficient (ICC).Hundred and twenty quadriceps muscle thickness measurements, three by each of the two critical care fellows, were done in twenty patients with sepsis. First, second, and third measurements (mean ± standard deviation) taken by the first observer (RK) were 35.030 ± 3.546 mm, 35.055 ± 3.307 mm, and 35.245 ± 3.027 mm, respectively. The three values recorded by the second observer (AD) were 35.585 ± 3.746 mm, 35.1 ± 3.006 mm, and 34.89 ± 2.556 mm, respectively. ICC for observer 1 and 2 was 0.925 (95% confidence interval [CI]: 0.851-0.967) and 0.835 (95% CI: 0.689-0.925), respectively. The mean difference of measurement between two observers was 0.082 mm (95% CI: -1.194-1.031). The mean ICC (95% CI) for inter-observer reliability was 0.992 (0.979-0.997); P < 0.001.This study shows that ultrasound is a reliable tool for the measurement of quadriceps muscle thickness by critical care physicians with excellent inter- and intra-class reliability.
| S-EPMC5538093 | biostudies-other
Project description:BackgroundTear lipid morphology is important for normal tear function. Recently, there have been clinical studies using interferometry to assess lipid layer thickness (LLT). The aim of the study is to examine the repeatability of a commercially available interferometer.MethodsTwo observers measured LLT in twenty Asian subjects (20 eyes) using an interferometer (LipiView® ocular surface interferometer, TearScience Inc, Morrisville, NC). Dry eye symptoms, tear break up time (TBUT) and corneal fluorescein staining were also prospectively evaluated.ResultsData for 20 participants are presented for either right or left eye (randomly selected). The mean LLT ± standard deviation of these participants was 53.53 ± 14.59 nm. When a single observer repeated the imaging on the same day, the coefficient of repeatability was 16 nm and the 95% limits of agreement were between -11 nm and 18 nm. When a different observer repeated the scan, the coefficient of repeatability was 13 nm and limits of agreement were -9 nm and 16 nm. LLT was not significantly associated with TBUT, presence of any corneal staining in any corneal zones, or symptomatic status.ConclusionWith the repeatability of measurements being known, the significance of LLT changes measured by this interferometer may be better interpreted. In this small Asian study, the LLT was lower than previously reported studies.
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Project description:The NIMO TEMPO (Lambda-X, Nivelles, Belgium) is a novel, user-friendly and compact device designed for in vitro optical analysis of refractive and diffractive intraocular lenses (IOLs). This device analyzes the IOL wavefront and generates a synthetic eye model for numerical computation. The objective of this study was to evaluate the precision of this innovative device. Intra- and inter-observer variability were calculated using a two-way analysis of variance (ANOVA) after conducting ten measurements of eight different IOL models, with each measurement being repeated by three distinct operators (resulting in a total of 30 measurements for each IOL). The device demonstrated satisfactory intra- and inter-observer variability in evaluating IOL power and modulation transfer function (MTF) profiles, with values of 0.066 and 0.078 diopters for IOL power and 0.018 and 0.019 for MTF measurements, respectively. Furthermore, this hybrid optical and numerical in vitro IOL wavefront analyzer appears to have several advantages over conventional optical bench devices. It reduces the need for operator manipulation, and allows for numerical modeling of various optical environments, including cornea models and apertures. In conclusion, this novel metrology device designed for refractive and diffractive IOLs appears to provide a satisfactory precision, making it a promising tool in the field of IOL metrology.
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Project description:Background and purposeThe delineation of the gross tumor volume (GTV) is a critical step for radiation therapy treatment planning. The delineation procedure is typically performed manually which exposes two major issues: cost and reproducibility. Delineation is a time-consuming process that is subject to inter- and intra-observer variability. While methods have been proposed to predict GTV contours, typical approaches ignore variability and therefore fail to utilize the valuable confidence information offered by multiple contours.Materials and methodsIn this work we propose an automatic GTV contouring method for soft-tissue sarcomas from X-ray computed tomography (CT) images, using deep learning by integrating inter- and intra-observer variability in the learned model. Sixty-eight patients with soft tissue and bone sarcomas were considered in this evaluation, all underwent pre-operative CT imaging used to perform GTV delineation. Four radiation oncologists and radiologists performed three contouring trials each for all patients. We quantify variability by defining confidence levels based on the frequency of inclusion of a given voxel into the GTV and use a deep convolutional neural network to learn GTV confidence maps.ResultsResults were compared to confidence maps from the four readers as well as ground-truth consensus contours established jointly by all readers. The resulting continuous Dice score between predicted and true confidence maps was 87% and the Hausdorff distance was 14 mm.ConclusionResults demonstrate the ability of the proposed method to predict accurate contours while utilizing variability and as such it can be used to improve clinical workflow.
| S-EPMC8934266 | biostudies-literature
Project description:BackgroundSeveral radiographic measurements of the humerus can be used to evaluate the treatment outcome of supracondylar fractures in children. Because of the cartilaginous nature of the immature elbow, interpretation of radiographs around this area is sometimes challenging and can be unreliable. This study was conducted to determine the inter-observer and intra-observer reliability of the six commonly used radiographic measurements of the distal humerus.MethodThe Baumann angle, humero-ulna angle, metaphyseal-diaphyseal angle, radial epiphyseal angle, shaft-condylar angle and lateral capitellohumeral angle of the humerus were measured by two observers on the radiographs of uninjured elbows from 58 children. The values between each measurement were compared and correlated using a Pearson coefficient of correlation to determine the inter-observer and intra-observer reliability.ResultsAll of the radiographic parameters showed excellent intra-observer reliability with the correlation coefficient values of the Baumann angle, humero-ulna angle, metaphyseal-diaphyseal angle, radial epiphyseal angle, shaft-condylar angle, lateral capitellohumeral angle as 0.945, 0.95, 0.909, 0.888, 0.961 and 0.975 (p < 0.001), respectively. The inter-observer reliability of the Baumann and humero-ulna angles were also found to be highly correlated at r = 0.843 (p < 0.001) and 0.878 (p < 0.001), respectively. The metaphyseal-diaphyseal angle had poor reliability with r = 0.136 (p = 0.291) while the radial epiphyseal angle, shaft-condylar angle, and lateral capitellohumeral angle demonstrated good reliability with r = 0.675 (p < 0.001), 0.747 (p < 0.001), and 0.686 (p < 0.001), respectively.ConclusionThe Baumann angle and humero-ulna angle measurements of distal humerus showed excellent inter- and intra-observer reliability. Both parameters represent repeatable and reliable methods for determining the outcome of supracondylar humeral fractures in pediatric population.
| S-EPMC6612040 | biostudies-literature
Project description:BackgroundRadial probe endobronchial ultrasound (R-EBUS) is often utilized in guided bronchoscopy for the diagnosis of peripheral pulmonary lesions. R-EBUS probe positioning has been shown to correlate with diagnostic yield, but overall diagnostic yield with this technology has been inconsistent across the published literature. Currently there is no standardization for R-EBUS image interpretation, which may result in variability in grading concentricity of lesions and subsequently procedure performance. This was a survey-based study evaluating variability among practicing pulmonologists in R-EBUS image interpretation.MethodsR-EBUS images from peripheral bronchoscopy cases were sent to 10 practicing Interventional Pulmonologists at two different time points (baseline and 3 months). Participants were asked to grade the images as concentric, eccentric, or no image. Cohen's Kappa-coefficient was calculated for inter- and intra-observer variability.ResultsA total of 100 R-EBUS images were included in the survey. There was 100% participation with complete survey responses from all 10 participants. Overall kappa-statistic for inter-observer variability for Survey 1 and 2 was 0.496 and 0.477 respectively. Overall kappa-statistic for intra-observer variability between the two surveys was 0.803.ConclusionsThere is significant variability between pulmonologists when characterizing R-EBUS images. However, there is strong intra-rater agreement from each participant between surveys. A standardized approach and grading system for radial EBUS patterns may improve inter-observer variability in order to optimize our clinical use and research efforts in the field.
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Project description:Cine-MRI for adhesion detection is a promising novel modality that can help the large group of patients developing pain after abdominal surgery. Few studies into its diagnostic accuracy are available, and none address observer variability. This retrospective study explores the inter- and intra-observer variability, diagnostic accuracy, and the effect of experience. A total of 15 observers with a variety of experience reviewed 61 sagittal cine-MRI slices, placing box annotations with a confidence score at locations suspect for adhesions. Five observers reviewed the slices again one year later. Inter- and intra-observer variability are quantified using Fleiss' (inter) and Cohen's (intra) κ and percentage agreement. Diagnostic accuracy is quantified with receiver operating characteristic (ROC) analysis based on a consensus standard. Inter-observer Fleiss' κ values range from 0.04 to 0.34, showing poor to fair agreement. High general and cine-MRI experience led to significantly (p < 0.001) better agreement among observers. The intra-observer results show Cohen's κ values between 0.37 and 0.53 for all observers, except one with a low κ of -0.11. Group AUC scores lie between 0.66 and 0.72, with individual observers reaching 0.78. This study confirms that cine-MRI can diagnose adhesions, with respect to a radiologist consensus panel and shows that experience improves reading cine-MRI. Observers without specific experience adapt to this modality quickly after a short online tutorial. Observer agreement is fair at best and area under the receiver operating characteristic curve (AUC) scores leave room for improvement. Consistently interpreting this novel modality needs further research, for instance, by developing reporting guidelines or artificial intelligence-based methods.
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Project description:Discern inter- and intra-observer variability in the classification of extracapsular extension (ECE) in p16+ oropharyngeal (OP) SCC comparing pathologists' own criteria versus those of a well-defined classification system.Five pathologists reviewed 50 digitally scanned nodal metastasis slides in three Rounds. Round One was by their own criteria as ECE present or absent, and Rounds Two and Three were with a defined ECE system: Grade 0 (no ECE), 0c (no ECE - thick capsule; no infiltration), 1 (ECE - cells beyond capsule), and 2 (soft tissue metastasis - cells in soft tissue without residual node). Round Three assessed intra-observer variability after an 8 month washout period.In Round One, all five agreed on only 48% of cases (n=24). Fleiss's Kappa value was 0.508 (95% CI: 0.357-0.644). For Rounds Two and Three, Grades 0 and 0c and Grades 1 and 2 were separately grouped as ECE absent or present. In Round Two, all five agreed on 68% of cases (n=34). Fleiss' Kappa was 0.635 (95% CI: 0.472-0.783), indicating statistically significantly better agreement. In Round Three, all five agreed on 64% of cases (n=32) giving a Fleiss's Kappa of 0.639. Pathologists agreed with their prior reads in approximately 90% of cases (average n=45.4, range n=42-49), an average intra-observer Cohen's Kappa of 0.8 (range: 0.68-0.95). Inter- and intra-observer variability rates for classification of soft tissue metastasis (ECE2) were substantially worse.There is substantial inter-, and modest intra-, observer variability among head and neck pathologists for ECE in p16+ OPSCC, which is modestly improved by a defined system.
| S-EPMC4875754 | biostudies-literature
Project description:BackgroundMusculoskeletal disorders particularly in the back and lower extremities are common among marines. Here, movement-control tests are considered clinically useful for screening and follow-up evaluation. However, few studies have addressed the reliability of clinical tests, and no such published data exists for marines. The present aim was therefore to determine the inter- and intra-observer reliability of clinically convenient tests emphasizing movement control of the back and hip among marines. A secondary aim was to investigate the sensitivity and specificity of these clinical tests for discriminating musculoskeletal pain disorders in this group of military personnel.MethodsThis inter- and intra-observer reliability study used a test-retest approach with six standardized clinical tests focusing on movement control for back and hip. Thirty-three marines (age 28.7 yrs, SD 5.9) on active duty volunteered and were recruited. They followed an in-vivo observation test procedure that covered both low- and high-load (threshold) tasks relevant for marines on operational duty. Two independent observers simultaneously rated performance as "correct" or "incorrect" following a standardized assessment protocol. Re-testing followed 7-10 days thereafter. Reliability was analysed using kappa (κ) coefficients, while discriminative power of the best-fitting tests for back- and lower-extremity pain was assessed using a multiple-variable regression model.ResultsInter-observer reliability for the six tests was moderate to almost perfect with κ-coefficients ranging between 0.56-0.95. Three tests reached almost perfect inter-observer reliability with mean κ-coefficients > 0.81. However, intra-observer reliability was fair-to-moderate with mean κ-coefficients between 0.22-0.58. Three tests achieved moderate intra-observer reliability with κ-coefficients > 0.41. Combinations of one low- and one high-threshold test best discriminated prior back pain, but results were inconsistent for lower-extremity pain.ConclusionsOur results suggest that clinical tests of movement control of back and hip are reliable for use in screening protocols using several observers with marines. However, test-retest reproducibility was less accurate, which should be considered in follow-up evaluations. The results also indicate that combinations of low- and high-threshold tests have discriminative validity for prior back pain, but were inconclusive for lower-extremity pain.
| S-EPMC3552977 | biostudies-literature
Project description:ObjectiveTo determine inter-observer and inter-examination variability of manual attenuation measurements of the vertebrae in low-dose unenhanced chest computed tomography (CT).MethodsThree hundred and sixty-seven lung cancer screening trial participants who underwent baseline and repeat unenhanced low-dose CT after 3 months because of an indeterminate lung nodule were included. The CT attenuation value of the first lumbar vertebrae (L1) was measured in all CTs by one observer to obtain inter-examination reliability. Six observers performed measurements in 100 randomly selected CTs to determine agreement with limits of agreement and Bland-Altman plots and reliability with intraclass correlation coefficients (ICCs). Reclassification analyses were performed using a threshold of 110 HU to define osteoporosis.ResultsInter-examination reliability was excellent with an ICC of 0.92 (p < 0.001). Inter-examination limits of agreement ranged from -26 to 28 HU with a mean difference of 1 ± 14 HU. Inter-observer reliability ICCs ranged from 0.70 to 0.91. Inter-examination variability led to 11.2 % reclassification of participants and inter-observer variability led to 22.1 % reclassification.ConclusionsVertebral attenuation values can be manually quantified with good to excellent inter-examination and inter-observer reliability on unenhanced low-dose chest CT. This information is valuable for early detection of osteoporosis on low-dose chest CT.Key points• Vertebral attenuation values can be manually quantified on low-dose unenhanced CT reliably. • Vertebral attenuation measurements may be helpful in detecting subclinical low bone density. • This could become of importance in the detection of osteoporosis.
| S-EPMC4972882 | biostudies-literature