Inexperienced Observers Research Articles

Ultrasound Assessment of Pleural Effusions After Orthotopic Pig‐to‐Baboon Cardiac Xenotransplantation

ABSTRACTBackgroundPleural effusions develop frequently after cardiac surgery in humans. Lung ultrasound is an essential non‐invasive tool in the diagnosis and treatment of these effusions. Pleural effusions also develop regularly after preclinical cardiac xenotransplantation experiments. Unlike in the human setting, modern ultrasound devices lack pre‐installed tools for calculating the volume of pleural effusions in baboons. The aim of this study was to analyze ultrasound examinations of pleural effusions after orthotopic pig‐to‐baboon cardiac xenotransplantation experiments in order to develop a formula for calculating the effusion volume based on ultrasound measurements.MethodsHearts from seven genetically modified (GGTA1‐KO, hCD46/hTBM transgenic) juvenile pigs were orthotopically transplanted into male baboons. Postoperatively, the baboons were tested regularly for the development of pleural effusions using ultrasound. When thoracocentesis was required, the drained effusion volume (EV) was compared to ultrasound‐derived calculations using various formulas. These calculations were based on measuring the distance between lung and diaphragm at the effusions’ maximum height (Hmax). Subsequently, the most promising formula was used to describe the interobserver variability between trained and untrained staff members to predict effusion volumes based on ultrasound measurements.ResultsUltrasound measurement correlated very strongly with the absolute EV (r = 0.9156, p < 0.0001), with EV indexed to total body weight (r = 0.9344, p < 0.0001) and with EV indexed to body surface area (BSA) (r = 0.9394, p < 0.0001). The ratio between Hmax and EV increased with total body weight and BSA and also depended on the baboon species. The sonographic measurements taken by an experienced and an inexperienced observer showed only low interobserver variability. A Bland–Altman plot of both observers’ measurements showed an overall bias of –2.39%.ConclusionUltrasound imaging provides a simple and non‐invasive tool for measuring pleural effusion quantity in baboons. This facilitates simple and efficient monitoring even in the hands of untrained personnel and may guide the decision‐making to perform thoracocentesis.

A visual guide for the Brabant index to score dental macrowear quantity and direction

AbstractThis study aimed to reduce subjectivity bias in scoring dental macrowear quantity and direction using the Brabant index, which previously relied solely on written descriptions. To achieve this, we present a new, optimized visual guide incorporating buccal and lingual scores. The optimization process involved conceptualizing and illustrating a visual guide using Holocene southern African hunter‐gatherer and herder teeth, featuring both buccal and lingual scores for multicuspid teeth. The guide was hand‐drawn using a stippling technique and digitized to depict surface details for each wear stage and tooth type. We conducted intra‐ and inter‐observer assessments to evaluate the optimized method using both the original and optimized Brabant indices. Statistical analysis was performed in R using Cohen's kappa for direction and Cohen's weighted kappa for quantity. Intra‐observer results for the original method yielded kappa values of 0.84 for direction and 0.94 for quantity, while the optimized version both resulted in improved values of 0.99. Inter‐observer results revealed some differences between an inexperienced and an experienced observer. The inexperienced observer achieved kappa scores of 0.20 for direction and 0.86 for quantity with the original method, and 0.17 and 0.80, respectively, with the optimized version. The experienced observer's results using the original index were 0.66 for direction and 0.89 for quantity, and 0.75 and 0.96, respectively, with the optimized version. These findings demonstrate that the optimized method enhances data reliability for experienced observers, highlighting the value of a published visual guide and multicuspid scoring adjustments. However, reduced or unappreciable changes in accuracies for the inexperienced observer illustrate the need for dental expertise when scoring for dental wear, even with a modified method.

Validation of a new method for the radiological measurement of rod curvature in patients with spine deformity.

The relationship between rod curvature and postoperative radiographic results is a debated topic. One of the reasons of the heterogeneity of the observed results might reside in the lack of a validated and widely employed method to measure the curvature of the rods. Aim of this study was to present and validate a novel method for rod measurement, which is based on routine X-rays and utilizes a regression algorithm that limits manual measurements and the related errors. Data from 20 adolescent idiopathic scoliosis/Scheuermann kyphosis (AIS/SK) patients and 35 adult spine deformity (ASD) patients for analysis, with 112 rods in total. An orthogonal reference grid was overlaid on the lateral X-ray; sevenpoints were then marked along each rod and their coordinates recorded in a table. Using these coordinates, a third-order polynomial regression was applied to obtain the rod curvature equation (correlation coefficients > 0.97). Three observers (one surgeon, one experienced and one inexperienced observer) independently applied the developed method to measure the rod angulation of the included patients and performed the measurements twice. The reliability of the method was evaluated in terms of intraclass correlation coefficient (ICC), Bland-Altmann plot and 2SR. The intra-observer ICCs for all measurements exceed 0.85, indicating an excellent correlation. For the AIS/SK group, the surgeon showed a slightly lower reliability compared to the other two evaluators (0.93 vs 0.98 and 0.98). However, the surgeon showed a higher reliability in measurements of the rods at the lumbar level, both for L1-S1 and L4-S1 (0.98 vs 0.96 and 0.89; 0.97 vs. 0.85 and 0.91, respectively). The variability also showed excellent results, with a mean variability ranging from 1.09° to 3.76°. The inter-observer ICCs for the three measurement groups showed an excellent reliability for the AIS/SK group (0.98). The reliability was slightly lower but still excellent for the lumbar measurements in ASD patients at L1-S1 (0.89) and L4-S1 (0.83). The results of the 2SR for each measured segment were 4.4° for T5-T11, 5.4° for L1-S1 and 5.5° for L4-S1. The described method represents a reliable and reproducible way to measure rod curvature. This method is based on routine X-rays and utilizes a regression algorithm that limits manual measurements and the related errors.

Social norms and the dynamics of observers' education

The paper presents a dynamical extension of the well­known Bernheim— Cartwright—Patel model of conformism. In this model the signaling equilibrium is a result of the optimal choice of an individual when he/she maximizes his/ her utility by choosing a donation in the amount x. In doing this the individual takes into account the intrinsic utility based on the generosity type t, and social attitude expressed by two types of observers: rational and naïve. Such an attitude significantly depends on social norms in this society and affects the esteem of the individual. Social attitude toward generosity varies within the broad range and at its endpoints leads to either neglect of the society (I do not care what people think of me) or an ideal conformism when a person chooses the same x as the rest of the public. Cartwright and Patel have shown that the presence of the inexperienced observers greatly affects equilibrium. This paper explores the dynamics of the naïve observers when they are informed by the rational ones. The dynamic law in the form of the differential equation was set and the stable steady­state solutions were found. Besides, while working on the dynamic law some clarifications of the preceding results of the original model were done.

The sound of silence: Quantification of typical absence seizures by sonifying EEG signals from a custom-built wearable device.

To develop and validate a method for long-term (24-h) objective quantification of absence seizures in the EEG of patients with childhood absence epilepsy (CAE) in their real home environment using a wearable device (waEEG), comparing automatic detection methods with auditory recognition after seizure sonification. The waEEG recording was acquired with two scalp electrodes. Automatic analysis was performed using previously validated software (Persyst® 14) and then fully reviewed by an experienced clinical neurophysiologist. The EEG data were converted into an audio file in waveform format with a 60-fold time compression factor. The sonified EEG was listened to by three inexperienced observers and the number of seizures and the processing time required for each data set were recorded blind to other data. Quantification of seizures from the patient diary was also assessed. Eleven waEEG recordings from seven CAE patients with an average age of 8.18 ± 1.60 years were included. No differences in the number of seizures were found between the recordings using automated methods and expert audio assessment, with significant correlations between methods (ρ > .89, p < .001) and between observers (ρ > .96, p < .001). For the entire data set, the audio assessment yielded a sensitivity of .830 and a precision of .841, resulting in an F1 score of .835. Auditory waEEG seizure detection by lay medical personnel provided similar accuracy to post-processed automatic detection by an experienced clinical neurophysiologist, but in a less time-consuming procedure and without the need for specialized resources. Sonification of long-term EEG recordings in CAE provides a user-friendly and cost-effective clinical workflow for quantifying seizures in clinical practice, minimizing human and technical constraints.

Diagnostic accuracy of lumbar CT and MRI in the evaluation of chronic low back pain without red flag symptoms

BackgroundLow back pain (LBP) is one of the most frequent reasons for medical consultation. Most of the patients will have nonspecific LBP, which usually are self-limited episodes. It is unclear which of the diagnostic imaging pathways is most effective and costeffective and how the imaging impacts on patient treatment. Imaging techniques are usually indicated if symptoms remain after 6 weeks. Magnetic resonance imaging (MRI) is the diagnostic imaging examination of choice in lumbar spine evaluation of low back pain; however, availability of MRI is limited. ObjectivesTo evaluate the diagnostic accuracy of computed tomography (CT) with MRI (as standard of reference) in the evaluation of chronic low back pain (LBP) without red flags symptoms. To compare the results obtained by two radiologists with different grades of experience. Materials and methodsPatients with chronic low back pain without red flags symptoms were retrospectively reviewed by two observers with different level of experience. Patients included had undergone a lumbar or abdominal CT and an MRI within a year. Once the radiological information was collected, it was then statistically reviewed. The aim of the statistical analysis is to identify the equivalence between both diagnostic techniques. To this end, sensitivity, specificity and validity index were calculated. In addition, intra and inter-observer reliability were measured by Cohen’s kappa values and also using the McNemar test. Results340 lumbar levels were evaluated from 68 adult patients with chronic low back pain or sciatica. 63.2% of them were women, with an average age of 60.3 years (SD 14.7). CT shows high values of sensitivity and specificity (>80%) in most of the items evaluated, but sensitivity was low for the evaluation of density of the disc (40%) and for the detection of disc herniation (55%). Moreover, agreement between MRI and CT in most of these items was substantial or almost perfect (Cohen’s kappa-coefficient > 0’8), excluding Modic changes (kappa = 0.497), degenerative changes (kappa0.688), signal of the disc (kappa = 0.327) and disc herniation (kappa = 0.639). Finally, agreement between both observers is mostly high (kappa > 0.8). Foraminal stenosis, canal stenosis and the grade of the canal stenosis were overdiagnosed by the inexperienced observer in the evaluation of CT images. Conclusions and significanceCT is as sensitive as lumbar MRI in the evaluation of most of the items analysed, excluding Modic changes, degenerative changes, signal of the disc and disc herniation. In addition, these results are obtained regardless the experience of the radiologist. The rising use of diagnostic medical imaging and the improvement of image quality brings the opportunity of making a second look of abdominal CT in search of causes of LBP. Thereby, inappropriate medical imaging could be avoided (2). In addition, it would allow to reduce MRI waiting list and prioritize other patients with more severe pathology than LBP.

Influence of Perspective Distortion in Laryngoscopy.

An experiment with controllable boundaries was designed to assess the influence of the recording angle and distance on two-dimensional (2D) imaging in laryngoscopy and resulting 2D parameter calculation derived from the glottal area waveform (GAW). Two high-speed camera setups were used to synchronously record an oscillating synthetic vocal fold (VF) model, simulating a high-speed videoendoscopy. One camera recorded at variable lateral recording angles and a reference camera in superior perspective. This was performed at different physiological recording distances and for two oscillation modes (with/without contacting VFs). The GAW was derived from the segmented glottis, and two parameters each for the categories of symmetry, periodicity, and closure were calculated, as well as two derivative measures. The percentage difference between the variable and reference camera value pairs was calculated, and the angle and height dependencies were quantified using linear regression. The visual perception of a laryngoscopy was found to be influenced by the lateral recording angle, which may lead to misinterpretation of VF symmetry among inexperienced observers. The strongest influence of recording angle was observed for symmetry parameters, the strongest being the Amplitude Symmetry Index with up to 2.6%/° (p < .05). A dependence on the recording distance was only found for the Maximum Area Declination Rate. The recording angle in 2D laryngoscopy should be carefully considered during visual inspection of the VF dynamics. Most of the investigated objective parameters were unaffected by the examined perspective distortion. However, especially left-right symmetry measures should only be used under controlled boundary conditions to avoid misdiagnosis and misinterpretation. https://doi.org/10.23641/asha.23961183.

Are there jumps in evidence accumulation, and what, if anything, do they reflect psychologically? An analysis of Lévy Flights models of decision-making.

According to existing theories of simple decision-making, decisions are initiated by continuously sampling and accumulating perceptual evidence until a threshold value has been reached. Many models, such as the diffusion decision model, assume a noisy accumulation process, described mathematically as a stochastic Wiener process with Gaussian distributed noise. Recently, an alternative account of decision-making has been proposed in the Lévy Flights (LF) model, in which accumulation noise is characterized by a heavy-tailed power-law distribution, controlled by a parameter, [Formula: see text]. The LF model produces sudden large "jumps" in evidence accumulation that are not produced by the standard Wiener diffusion model, which some have argued provide better fits to data. It remains unclear, however, whether jumps in evidence accumulation have any real psychological meaning. Here, we investigate the conjecture by Voss et al. (Psychonomic Bulletin & Review, 26(3), 813-832, 2019) that jumps might reflect sudden shifts in the source of evidence people rely on to make decisions. We reason that if jumps are psychologically real, we should observe systematic reductions in jumps as people become more practiced with a task (i.e., as people converge on a stable decision strategy with experience). We fitted five versions of the LF model to behavioral data from a study by Evans and Brown (Psychonomic Bulletin & Review, 24(2), 597-606, 2017), using a five-layer deep inference neural network for parameter estimation. The analysis revealed systematic reductions in jumps as a function of practice, such that the LF model more closely approximated the standard Wiener model over time. This trend could not be attributed to other sources of parameter variability, speaking against the possibility of trade-offs with other model parameters. Our analysis suggests that jumps in the LF model might be capturing strategy instability exhibited by relatively inexperienced observers early on in task performance. We conclude that further investigation of a potential psychological interpretation of jumps in evidence accumulation is warranted.

Artificial Intelligence for Classifying the Relationship between Impacted Third Molar and Mandibular Canal on Panoramic Radiographs.

The purpose of this investigation was to evaluate the diagnostic performance of two convolutional neural networks (CNNs), namely ResNet-152 and VGG-19, in analyzing, on panoramic images, the rapport that exists between the lower third molar (MM3) and the mandibular canal (MC), and to compare this performance with that of an inexperienced observer (a sixth year dental student). Utilizing the k-fold cross-validation technique, 142 MM3 images, cropped from 83 panoramic images, were split into 80% as training and validation data and 20% as test data. They were subsequently labeled by an experienced radiologist as the gold standard. In order to compare the diagnostic capabilities of CNN algorithms and the inexperienced observer, the diagnostic accuracy, sensitivity, specificity, and positive predictive value (PPV) were determined. ResNet-152 achieved a mean sensitivity, specificity, PPV, and accuracy, of 84.09%, 94.11%, 92.11%, and 88.86%, respectively. VGG-19 achieved 71.82%, 93.33%, 92.26%, and 85.28% regarding the aforementioned characteristics. The dental student's diagnostic performance was respectively 69.60%, 53.00%, 64.85%, and 62.53%. This work demonstrated the potential use of deep CNN architecture for the identification and evaluation of the contact between MM3 and MC in panoramic pictures. In addition, CNNs could be a useful tool to assist inexperienced observers in more accurately identifying contact relationships between MM3 and MC on panoramic images.

Assessment of inter-observer agreement among experienced and inexperienced observers and an automated device for dipstick urinalysis in dogs and cats.

Standard visual urine dipstick analysis (UDA) is performed routinely in veterinary medicine; results can be influenced by both the operator and the method. We evaluated the agreement of results for canine and feline urine samples analyzed using a 10-patch dipstick (Multistix10SG; Siemens), both visually under double-anonymized conditions by students and a laboratory technician, and with an automated device (AD; Clinitek Status, Siemens). The mean concordance for semiquantitative urinalysis results between students and the technician and between students and the AD was fair (κ0.21-0.40) in dogs and cats; concordance was moderate between the technician and the AD (κ0.41-0.60) in dogs and good (κ0.61-0.80) in cats. For pH, the mean concordance between students and the technician and between the technician and the AD was good (ρ0.80-0.92) in dogs and cats; concordance was good between students and the AD (ρ0.80-0.92) in dogs and moderate (ρ0.59-0.79) in cats. Repeatability was higher (p < 0.001) for the technician and the AD than for a student. We found good agreement between UDA performed by an experienced operator and an AD in dogs and cats but found low reproducibility and low repeatability for urinalysis performed by an inexperienced operator.

Contributions of global and local processing on medical image perception.

The influential holistic processing hypothesis attributes expertise in medical image perception to cognitive processing of global gist information. However, it has remained unclear whether or how experts use rapid global impression of images for their subsequent diagnostic decisions based on the focal sign of cancer. We hypothesized that continuous-global and discrete-local processes jointly attribute to radiological experts' detection of mammogram, with different weights and temporal dynamics. We examined experienced versus inexperienced observers' performance at first (500ms) versus second (2500ms) mammogram image presentation in an abnormality detection task. We applied a dual-trace signal detection (DTSD) model of receiver operating characteristic (ROC) to assess the time-varying contributions of global and focal cancer signals on mammogram reading and medical expertise. The hierarchical Bayesian DTSD modeling of empirical ROCs revealed that mammogram expertise (experienced versus inexperienced observers) manifests largely in a continuous-global component for the detection of the gist of abnormality at the early phase of mammogram reading. For the second presentation of the same mammogram images, the experienced participants showed increased task performance that was largely driven by better processing of discrete-local information, whereas the global processing of abnormality remained saturated from the first exposure. Modeling of the mouse trajectory of the confidence rating responses further revealed the temporal dynamics of global and focal processing. These results suggest a joint contribution of continuous-global and discrete-local processes on medical expertise, and these processes could be analytically dissociated.

Validation of a Semiautomatic Optical Coherence Tomography Digital Image Processing Algorithm for Estimating the Tear Meniscus Height.

To design and validate a high-sensitivity semiautomated algorithm, based on adaptive contrast image, able to identify and quantify tear meniscus height (TMH) from optical coherence tomography (OCT) images by using digital image processing (DIP) techniques. OCT images of the lacrimal meniscus of healthy patients and with dry eye are analyzed by our algorithm, which is composed of two stages: (1) the region of interest and (2) TMH detection and measurement. The algorithm performs an adaptive contrast sequence based on morphologic operations and derivative image intensities. Trueness, repeatability, and reproducibility for TMH measurements are computed and the algorithm performance is statistically compared against the corresponding negative obtained manually by using a commercial software. The algorithm showed excellent repeatability supported by an intraclass correlation coefficient equal to 0.993, a within-subject standard deviation equal to 9.88, and a coefficient of variation equal to 2.96%, and for the reproducibility test, the results did not show a significant difference as the mean value was 244.4 ± 114.9 µm for an expert observer versus 242.4 ± 111.2 µm for the inexperienced observer (P = 0.999). The method strongly suggests the algorithm can predict measurements that are manually performed with commercial software. The presented algorithm possess high potential to identify and measure TMH from OCT images in a reproducible and repeatable way with minimal dependency on user. The presented work shows a methodology on how, by using DIP, it is possible to process OCT images to calculate TMH and aid ophthalmologists in the diagnosis of dry eye disease.

Validez de la TC lumbar frente a la RM lumbar en el estudio de la lumbalgia y la lumbociatalgia crónica sin criterios de alarma

BackgroundLow back pain (LBP) is one of the most frequent reasons for medical consultation. Most of the patients will have nonspecific LBP, which usually are self-limited episodes. It is unclear which of the diagnostic imaging pathways is most effective and costeffective and how the imaging impacts on patient treatment. Imaging techniques are usually indicated if symptoms remain after 6 weeks. Magnetic resonance imaging (MRI) is the diagnostic imaging examination of choice in lumbar spine evaluation of low back pain; however, availability of MRI is limited. ObjectivesTo evaluate the diagnostic accuracy of computed tomography (CT) with MRI (as standard of reference) in the evaluation of chronic low back pain (LBP) without red flags symptoms. To compare the results obtained by two radiologists with different grades of experience. Materials and methodsPatients with chronic low back pain without red flags symptoms were retrospectively reviewed by two observers with different level of experience. Patients included had undergone a lumbar or abdominal CT and an MRI within a year. Once the radiological information was collected, it was then statistically reviewed. The aim of the statistical analysis is to identify the equivalence between both diagnostic techniques. To this end, sensitivity, specificity and validity index were calculated. In addition, intra and inter-observer reliability were measured by Cohen's kappa values and also using the McNemar test. Results340 lumbar levels were evaluated from 68 adult patients with chronic low back pain or sciatica. 63.2% of them were women, with an average age of 60.3 years (SD 14.7). CT shows high values of sensitivity and specificity (>80%) in most of the items evaluated, but sensitivity was low for the evaluation of density of the disc (40%) and for the detection of disc herniation (55%). Moreover, agreement between MRI and CT in most of these items was substantial or almost perfect (Cohen's kappa-coefficient > 0’8), excluding Modic changes (kappa=0.497), degenerative changes (kappa0.688), signal of the disc (kappa=0.327) and disc herniation (kappa=0.639). Finally, agreement between both observers is mostly high (kappa>0.8). Foraminal stenosis, canal stenosis and the grade of the canal stenosis were overdiagnosed by the inexperienced observer in the evaluation of CT images. Conclusions and significanceCT is as sensitive as lumbar MRI in the evaluation of most of the items analysed, excluding Modic changes, degenerative changes, signal of the disc and disc herniation. In addition, these results are obtained regardless the experience of the radiologist. The rising use of diagnostic medical imaging and the improvement of image quality brings the opportunity of making a second look of abdominal CT in search of causes of LBP. Thereby, inappropriate medical imaging could be avoided (2). In addition, it would allow to reduce MRI waiting list and prioritize other patients with more severe pathology than LBP.

An improved method for line transect sampling in Antarctic minke whale surveys

The series of abundance estimates for Antarctic minke whales obtained using standard line transect methods from IWC/SOWER surveys imply drastic (and probably unrealistic) changes in true abundance. One possible factor is that the detection probability on the trackline, g(0), may have decreased with the introduction of inexperienced observers in the most recent surveys. Additionally, mean observed school size may have decreased in the third circumpolar survey in comparison with the second survey. This paper introduces an extended and generalised hazard probability model without the assumption that g(0)=1 to estimate true school size distribution in the population. The proposed method uses a survey design that combines the use of both passing mode with independent observers and closing mode in which the vessel turns off the trackline and closes with the sighting for confirmation of school size and species. The abundance estimate is based on the Horvitz-Thompson estimator in an unequal detectability sampling scheme. The method is applied to the IDCR/SOWER dataset of Antarctic minke whales for illustrative purposes.

Color appearance in rotational material jetting

Material jetting (MJT) is a recognized additive manufacturing (AM) method to combine various materials and create a wide range of designed appearances. However, the measured color of MJT objects is frequently different from the color provided in the printer software. As a result, estimating the color quality and the measured color attributes of an object before printing is vital for accurate color reproduction. This study investigates the color variation based on the texture in an object 3D-printed using the MJT method on a rotary tray. The novel radial shape of the rotary tray build platform and variation in the layers structure were targeted as the main factors that can increase the uncertainty in accurate color reproduction. The influence of the PolyJet printer setup has been examined by thickness variation of the colored layers, location on the tray (swath selection), ink color, and finish type between layers. Color quality was assessed by comparing the produced object color by calculating spectral and colorimetric differences. Spearman rank correlation coefficient and principal component analysis (PCA) methods were used to analyze the direct or indirect influence of independent categorical factors on the measured color variables. Based on the studied parameters, switching swathes did not fail printer objects for industrial color matching. In contrast, a thickness variation as small as 0.5 mm could cause CIEDE2000 above 5 for most models, resulting in unnatural color reproduction. Color differences in most objects might be discernible to inexperienced observers, depending on the 3D printing parameters.

Inclusion of curcumin in b-cyclodextrin: a promising prospective as food ingredient

In the present work, the inclusion complexes between curcumin (CC) and β-cyclodextrin (β-CD) were obtained through co-precipitation at different times of magnetic stirring and simple mixing. The stoichiometric ratio between CC and β-CD was ascertained to be 1:2. The samples prepared by co-precipitation (24 h magnetic stirring and 24 h cold static precipitation) and by simple mixing, showed the best performance in terms of powder recovery (72 and 97%, respectively), encapsulation efficiency (72 and 95%, respectively) and tinting power, while no significant differences were revealed in terms of loading capacity (about 14%). Using either inclusion method, the complexation of CC into β-CD make the colorant 20-fold more water soluble than pure CC. The pigment stability was also enhanced under different storage conditions (high temperature and light exposure), either when applied in liquid or gel state. However, after 30 days under natural light exposure, an appreciable colour change from yellow to orange was revealed to an extent probably perceptible by an inexperienced observer.

Largest diameter delineations can substitute 3D tumor volume delineations for radiomics prediction of human papillomavirus status on MRI’s of oropharyngeal cancer

PurposeLaborious and time-consuming tumor segmentations are one of the factors that impede adoption of radiomics in the clinical routine. This study investigates model performance using alternative tumor delineation strategies in models predictive of human papillomavirus (HPV) in oropharyngeal squamous cell carcinoma (OPSCC). MethodsOf 153 OPSCC patients, HPV status was determined using p16/p53 immunohistochemistry. MR-based radiomic features were extracted within 3D delineations by an inexperienced observer, experienced radiologist or radiation oncologist, and within a 2D delineation of the largest axial tumor diameter and 3D spheres within the tumor. First, logistic regression prediction models were constructed and tested separately for each of these six delineation strategies. Secondly, the model trained on experienced delineations was tested using these delineation strategies. The latter methodology was repeated with the omission of shape features. Model performance was evaluated using area under the curve (AUC), sensitivity and specificity. ResultsModels constructed and tested using single-slice delineations (AUC/Sensitivity/Specificity: 0.84/0.75/0.84) perform better compared to 3D experienced observer delineations (AUC/Sensitivity/Specificity: 0.76/0.76/0.71), where models based on 4 mm sphere delineations (AUC/Sensitivity/Specificity: 0.77/0.59/0.71) show similar performance. Similar performance was found when experienced and largest diameter delineations (AUC/Sens/Spec: 0.76/0.75/0.65 vs 0.76/0.69/0.69) was used to test the model constructed using experienced delineations without shape features. ConclusionAlternative delineations can substitute labor and time intensive full tumor delineations in a model that predicts HPV status in OPSCC. These faster delineations may improve adoption of radiomics in the clinical setting. Future research should evaluate whether these alternative delineations are valid in other radiomics models.

Intra- and Interobserver Variability of Shear Wave Elastography in Rectal Cancer.

Simple SummaryFor a diagnostic tool to be important, there must be a high level of agreement between different observers. If not, the reliability of the measurement can not be considered valid. Previous studies have evaluated the reproducibility of tissue stiffness measurements of rectal tumors, but only on previously obtained images. Therefore, we aimed to investigate the issue in a clinical setting and found a high level of agreement between observers.Background: Endorectal ultrasound (ERUS) is an important tool when evaluating complex rectal adenomas and rectal cancer, and the accuracy is improved by adding elastography measurements. A high interobserver agreement is imperative in clinical practice. Therefore, the aim of this study was to evaluate interobserver agreement assessed on real-time images. Additionally, we investigated the intra- and interobserver agreement between experienced and inexperienced observers. Materials and methods: We prospectively included patients referred to an ERUS at the Department of Radiology with a complex rectal polyp or suspected rectal malignancy. Two operators independently scanned each patient in turn. Furthermore, four observers assessed previously obtained images using three different methods for placing the region of interest (ROI). Three months later, the four observers reassessed the images to assess intraobserver variability. Results: A total of 19 patients were included for live assessment. Agreement of tumor classification was substantial for T stage (kappa: 0.86) and fair for N stage (kappa: 0.73), with an absolute agreement for T and N stages of 84% and 89%, respectively. Agreement of SWE was good for Emean (ICC 0.94, 95% CI 0.86–0.98) and fair for Emax (ICC 0.85, 95% CI 0.66–0.94). Intra- and interobserver agreement between inexperienced and experienced observers showed good to excellent agreement with all ROI methods. Conclusion: Interobserver agreement is high in SWE when performed in a clinical setting. We found the best agreement using the mean value of several ROIs. Intra- and interobserver agreement was high regardless of operator experience.

Interobserver and Intraobserver Agreements of the Detection of Demodex Infestation by in Vivo Confocal Microscopy.

Objectives:The purpose of the study was to determine interobserver and intraobserver agreement, repeatability, and intrasubject variation of the detection of Demodex infestation in eyelids of blepharitis patients using in vivo confocal microscopy (IVCM).Methods:Eighty-three eyes of 42 blepharitis patients were included in the study. All eyelids were evaluated from temporal to nasal with IVCM using section mode and 10 lashes with their follicles were imagined, and every image with suspicion of Demodex infestation was recorded. Two experienced and two inexperienced ophthalmologists were masked for the diagnosis and interpreted the IVCM images regarding the presence of Demodex infestation with a 3-week interval. Interobserver and intraobserver agreements were calculated with Cohen’s kappa and its variant statistics between and within experienced observers and between inexperienced observers.Results:While average sensitivity for the diagnosis of demodicosis in IVCM images was 83.35% for experienced and 51.35% for inexperienced observers, the average positive predictive value was 88.6% for experienced observers and 91.05% for inexperienced ones. Interobserver agreement between experienced observers was moderate (κ = 0.529) and intraobserver agreements within experienced observers were perfect (κ = 0.918 for observer-1; κ = 0.958 for observer-2). Interobserver agreement between inexperienced observers was poor (κ = 0.162) and intraobserver agreements within inexperienced observers were fair (κ = 0.427 for observer-3; κ = 0.475 for observer-4).Conclusion:The sensitivity, interobserver and intraobserver agreements in IVCM image analysis for the detection of Demodex infestation were highly associated with the clinical experience on IVCM imaging. In the hands of an experienced clinician, IVCM could be reliable for the diagnosis of ocular demodicosis.

Investigation and assessment of decorative plaster ceilings

Plaster ceilings are an intrinsic feature of historic buildings, from high-status palaces and public buildings with elaborate decorative ceilings to vernacular domestic interiors with plain flatwork. An appreciation of the stylistic development is the first visual evidence for assessing their cultural significance and intrinsic value. Periodic campaigns of decoration coupled with repair and restoration often serve to mask original materials, methods and condition, misleading the unwary and inexperienced observer. A comprehensive understanding of the materials and methods used for fabrication is essential in helping to form an appropriate conservation approach to minimise intervention and loss of original fabric in remedial works that may be necessitated by decay and deterioration, or even loss. The partial collapse of the Apollo Theatre auditorium ceiling in London in 2013 particularly highlighted and focused attention on the inspection and certification of historic plaster ceilings throughout the UK. This paper outlines some of the key materials, fabrication methods, agents of decay, investigation, and approaches to repair and conservation of historic plaster ceilings.