Experienced Observers Research Articles

Reliability of colour Doppler ultrasonography of the major salivary glands in Sjögren's disease.

To analyse intraobserver and interobserver reliability of colour Doppler (CD) ultrasonography of the major salivary glands (SGUS) in patients clinically suspected of Sjögren's disease (SjD). One hundred consecutive outpatients visiting the University Medical Center Groningen for a diagnostic trajectory because of a suspicion of SjD were evaluated using CD ultrasonography of the submandibular and parotid salivary glands. All images were independently assessed by four observers (two experienced observers, one lesser experienced resident, one inexperienced trainee) in two sessions using the Outcome Measures in Rheumatology (OMERACT) CD scoring system (scale 0-3). A total score was calculated as the sum of the scores of the 4 glands (scale 0-12). Intra- and interobserver reliability, and reliability of live versus static scores were determined. Factors influencing variability in scores were analysed. Intraobserver weighted Cohen's kappa's of individual glands ranged from 0.23 (inexperienced observer) to 0.81 (experienced observer). Intraclass Correlation Coefficients (ICCs) for intraobserver reliability of the total CD score ranged from 0.53 (inexperienced observer) to 0.90 (experienced observer). The ICC for intraobserver reliability of live scoring compared to static images was 0.72. ICCs for interobserver reliability of the total CD score were 0.81 for session 1 and 0.71 for session 2. Patient variance was 74.1%, whereas residual variance contributed 15.5% to the total variance. CD SGUS is a reliable imaging technique to visualise intraparenchymal vasculature in patients suspected of SjD, and therefore could be an asset in daily clinical practice. It requires, however, experience and prior training.

External Validation of Fully-Automated Infrarenal Maximum Aortic Aneurysm Diameter Measurements in Computed Tomography Angiography Scans Using Artificial Intelligence (PRAEVAorta 2).

This study investigates the accuracy of fully-automated maximum aortic diameter measurements in abdominal aortic aneurysm (AAA) patients using artificial intelligence software (PRAEVAorta 2, Nurea, Bordeaux, France). This is a multicenter, retrospective validation study using prospectively collected data from the Zenith alpha for aneurysm Repair Registry (ZEPHYR). Automated measurements of PRAEVAorta 2 are compared with measurements of an internationally recognized core laboratory (Syntactx, New York, New York State). The reviewers at the core laboratory were measurement technologists trained to and utilizing established measurement standards, overseen by vascular surgeons and radiologists. The data set comprised 871 computed tomography angiography scans from the ZEPHYR registry with 347 patients who underwent endovascular aneurysm repair (EVAR) with the Zenith Alpha Endovascular Abdominal Graft (Cook Medical, Bloomington, Indiana) in Germany, Belgium, and The Netherlands between 2016 and 2019. The analysis demonstrated excellent correlation of the measurements (r=0.97) with an intraclass correlation (ICC) of 0.972 (95% confidence interval [CI]=0.968-0.976) across all scans. For preoperative computed tomography (CT) scans, ICC was 0.953 (95% CI=0.941-0.963), and for postoperative scans, ICC was 0.979 (95% CI=0.975-0,983), respectively. In total, 95.4% of measurements were within the clinically acceptable range of 5 mm in absolute difference. In total, 10% of scans demonstrated obvious segmentation errors, mainly due to failure in detecting vessel segments (renal arteries, aortic bifurcation) or due to mis-detecting the outer border of the AAA (duodenum, inferior vena cava, aortic branches) and were excluded from the analysis. In this study, the maximum AAA diameter could be accurately measured fully-automatically by PRAEVAorta 2 (Nurea) in most cases demonstrating that artificial intelligence (AI) software could serve as an important adjunct for research and clinical practice. However, critical review of the generated reports by an experienced observer and cautious use is warranted to identify flawed segmentations. This multicenter, retrospective validation study assessed the accuracy of fully-automated maximum infrarenal aortic aneurysm diameter measurements. It was demonstrated, that 95.4% of measurements were within the clinically acceptable range of 5 mm in absolute difference, positioning the software as a potential adjunct for clinical practice and research. It is also highlighted however, that critical review of the measurements is obligatory, due to a 10% segmentation error rate.

In the eye and mind of the beholder: The effects of familiarisation on the perception of atypical infant facial configurations.

Perception of infant faces plays a crucial role in adult-infant caretaking behaviour, with adults being found to demonstrate a reliable attraction towards infant faces over other stimuli. When affected by a congenital facial malformation such as cleft lip and/or palate, however, adults' visual scanning patterns and subjective appraisal of these faces have been found to be adversely affected. Little past work has explored how an observer's prior experience with this specific malformation might play a role in the perception of cleft-affected infant faces. To this end, two groups of adult female participants were recruited and presented with 48 images of infant faces (24 typical, 24 cleft-affected) with one group subjected to novel, purpose-built familiarisation training, where participants were exposed to infant cleft lip/palate related visual and informational stimuli prior to testing (n = 43). Eye gaze patterns and subjective "cuteness" ratings from this group were compared with an age matched control group which received no training (n = 41). No between group differences were found for "cuteness" ratings or eye gaze patterns to the cleft-affected mouth area in isolation, however, a significant negative relationship was found between gaze duration to the mouth region of cleft-affected images and subjective "cuteness" ratings, for control participants only. Notably, this relationship was not observed for the familiarised participants, suggesting their modified prior experience attenuated the effect that visual processing had on subjective appraisal of cleft-affected faces, when these two factors were assessed in tandem. Our findings suggest it is possible to attenuate the typically observed aversive behaviour towards cleft-affected infant faces. This may have implications for clinical practice concerned with supporting adult caretaking of malformation-affected infants and policies related to increasing positive perception of congenital facial disfigurement.

Visualization of anatomical structures in the carpal region of the horse using cone beam computed tomography in comparison with conventional multidetector computed tomography.

In the diagnostics of orthopedic diseases in the horse, diagnostic imaging often plays a decisive role. Cone beam computed tomography (CBCT) imaging is used in both human and small animal medicine and becoming increasingly popular. To see whether CBCT imaging can be useful in the diagnosis of orthopedic diseases of the carpal region of the horse and to explore possible limitations we compared CBCT images with multidetector computed tomography (MDCT) images of the carpal region of equine cadaveric specimens. Twenty-eight forelimbs from fifteen horses, slaughtered for reasons unrelated to this study, were examined. Native and contrast enhanced CBCT and MDCT scans were performed. Anatomical structures were blindly evaluated by three independent experienced observers using a visual scoring system previously reported and adapted to the equine carpal region. A descriptive evaluation was carried out as well as Spearman's rank correlation and interobserver agreement was shown by percent agreement (PA). Visualization of osseous structures was excellent in both MDCT and CBCT. Articular cartilage could only be assessed in contrast enhanced scans whereby MDCT showed a slightly better visualization than CBCT. Soft tissue structures were generally difficult to assess. An exception were the medial and lateral palmar intercarpal ligament, which could not be visualized in native but were well visualized in contrast enhanced scans in both MDCT and CBCT images. For the evaluation of osseous structures and some intraarticular ligaments after contrast enhancement, CBCT serves as a reliable diagnostic imaging modality for the equine carpal region. However, soft tissue structures and cartilage are imaged more reliably using MDCT.

Comparison of tooth shade determination using two methods: visual and spectrophotometric

Introduction: Dental color determination is a crucial procedure in oral rehabilitation treatments, since with precision, aesthetically correct results will be achieved that fit the naturalness of the patient's teeth. Thanks to technological advances, new tools have emerged, such as spectrophotometers, intraoral scanners, among others, which have significantly improved the way of carrying out this process.Objective: To evaluate the effectiveness of dental color determination with the visual method compared to the spectrophotometer.Methods: A descriptive and documentary study was carried out following a systematic bibliographic search of articles in the last 10 years, which were selected according to the inclusion and exclusion criteria.Results: The study compared the effectiveness of two methods to determine the color of teeth: visual and instrumental (with a spectrophotometer). The visual method, although traditional, presents high variability due to factors such as lighting, the observer's experience and the individual perception of color. The spectrophotometer offers a more objective and reproducible measurement of color, as it is not influenced by external factors. Although both methods can achieve similar results in some cases, significant differences were generally observed in the selection of the dental shade. The spectrophotometer allows for the detection of more subtle color differences and offers greater consistency in the results.Conclusion: Dental shade measurement is more effective with a spectrophotometer, however, the authors recommend using the two methodologies together.

Deep learning improves test-retest reproducibility of regional strain in echocardiography.

The clinical utility of regional strain measurements in echocardiography is challenged by suboptimal reproducibility. In this study, we aimed to evaluate the test-retest reproducibility of regional longitudinal strain (RLS) per coronary artery perfusion territory (RLSTerritory) and basal-to-apical level of the left ventricle (RLSLevel), measured by a novel fully automated deep learning (DL) method based on point tracking. We measured strain in a dual-centre test-retest data set that included 40 controls and 40 patients with suspected non-ST elevation acute coronary syndrome. Two consecutive echocardiograms per subject were recorded by different operators. The reproducibility of RLSTerritory and RLSLevel measured by the DL method and by three experienced observers using semi-automatic software (2D Strain, EchoPAC, GE HealthCare) was evaluated as minimal detectable change (MDC). The DL method had MDC for RLSTerritory and RLSLevel ranging from 3.6 to 4.3%, corresponding to a 33-35% improved reproducibility compared with the inter- and intraobserver scenarios (MDC 5.5-6.4% and 4.9-5.4%). Furthermore, the DL method had a lower variance of test-retest differences for both RLSTerritory and RLSLevel compared with inter- and intraobserver scenarios (all P < 0.001). Bland-Altman analyses demonstrated superior reproducibility by the DL method for the whole range of strain values compared with the best observer scenarios. The feasibility of the DL method was 93% and measurement time was only 1 s per echocardiogram. The novel DL method provided fully automated measurements of RLS, with improved test-retest reproducibility compared with semi-automatic measurements by experienced observers. RLS measured by the DL method has the potential to advance patient care through a more detailed, more efficient, and less user-dependent clinical assessment of myocardial function.

Oral behaviour during riding is associated with oral lesions in dressage horses – A field study

The welfare of sports horses is debated both within and outside the horse community. One welfare concern is the frequent occurrence of oral lesions. Lesions may be caused by inappropriate training and ill-fitting equipment. Increased knowledge of behavioural signs of pain, discomfort and frustration (often jointly labelled ‘conflict behaviour’) in horses can increase awareness by riders, trainers, officials, and competition judges, which is a first step towards reducing the occurrence. This study included 11 warmblood dressage horses competing at upper national level (Intermediaire I). The horses were randomly selected (from a total of 22 horses) for an unannounced inspection for oral lesions immediately after leaving the dressage arena. Five of the 11 horses had abrasion of the skin and/or mucosa at one or both commissures of the lips and were eliminated from the competition according to the rules of the national equestrian federation. An experienced observer who was blind regarding the outcome of the inspection, scored behaviour in the 11 horses from official video recordings available online from the event. The frequency of mouth opening ranged from 5 to 59 times in the 11 horses. Horses with oral lesions had a significantly higher frequency of mouth opening compared to horses without oral lesions (t-test, mean ±SEM; lesions: 34.6 ±6.7 vs. no lesions: 12.2 ±2.4, t(9) = 3.4, P = 0.008). The frequency of other conflict behaviours did not differ significantly between the groups (e.g. tail swishing: MWU-test, median [25;75 %]; lesions: 25 [14;27] vs. no lesions: 10 [6,24], U = 7.0, P = 0.18). It is concluded that oral behaviour may be a useful indicator of oral lesions. Further studies are needed to investigate behavioural signs of discomfort and pain in riding horses, as behaviour can be an early predictor of compromised welfare. Increased awareness of subtle behavioural signs is therefore an important first step towards improved sports horse welfare.

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.

LONG-TERM VISUAL OUTCOMES AND OPTICAL COHERENCE TOMOGRAPHY BIOMARKERS IN EYES WITH MACULAR EDEMA SECONDARY TO RETINAL VEIN OCCLUSION FOLLOWING ANTI-VASCULAR ENDOTHELIAL GROWTH FACTOR THERAPY.

To evaluate the structural characteristics and long-term visual outcomes in eyes impacted by macular edema as a consequence of retinal vein occlusion that has undergone effective treatment with anti-vascular endothelial growth factor therapy. Inclusion criteria comprised 42 eyes of 41 patients, subjected to long-term follow-up, displaying resolved macular edema after a minimum of 5 years since the commencement of anti-vascular endothelial growth factor therapy. During the final visit, two experienced observers evaluated several qualitative parameters using spectral-domain optical coherence tomography, such as the integrity of the external limiting membrane, the state of the ellipsoid zone and retinal pigment epithelium, and the presence of disorganization of the retinal inner layers. In addition, a quantitative evaluation of the inner and outer retinal thicknesses was conducted for the purpose of topographical analysis. The most prominent qualitative correlation identified with best-corrected visual acuity during the final visit was connected to the presence of disorganization of the retinal inner layers ( P = 0.004) and the integrity of the external limiting membrane ( P = 0.015). In relation to quantitative aspects, a noteworthy correlation was noted between the visual acuity during the last visit and the parafoveal thickness in both the inner ( P = 0.003) and outer retina ( P = 0.018). In eyes where macular edema resulting from retinal vein occlusion has been successfully resolved with anti-vascular endothelial growth factor therapy, changes in the status of the external limiting membrane and the presence of disorganization of the retinal inner layers serve as valuable optical coherence tomography biomarkers, indicating prolonged visual outcomes.

Comparison of different radiographic methods to measure the slip angle in children with slipped capital femoral epiphysis (SCFE).

The management of patients with slipped capital femoral epiphysis (SCFE) requires imaging diagnostics of good quality and accurate measurement of the degree of slippage. In Sweden, three different radiological methods are commonly used: the calcar femorale method; the Billing method; and the Head-shaft angle described by Southwick. To evaluate whether any of the three most common methods used in Sweden to measure the slip angle was more useful and reproducible than the others. Two experienced orthopaedists measured the slip angle in preoperative hip radiographs. Intra- and inter-observer variability between the two experienced observers and the reported value by clinicians who treated the child with SCFE was evaluated. The intraclass correlation coefficient (ICC) confidence interval (CI) between the two experienced observers and the reporting clinicians overlapped for the three methods. In 37% of the cases, the difference was more than 5° between the experienced observers' measurement and the reported value by clinicians. The two experienced orthopaedists' intra- and inter-observer variability was low. The observer's experience is more important than the method of choice when measuring the slip angle in SCFE. The research group recommends the calcar femorale method due to its feasibility on the versatile and commonly used frog leg lateral view.

Exploring the CIEDE2000 thresholds for lightness, chroma, and hue differences in dentistry

ObjectiveTo evaluate the perceptibility and acceptability CIEDE2000 (KL:KC:KH) thresholds for lightness, chroma and hue differences in dentistry. MethodA Python-based program was developed to conduct a psychophysical experiment based on visual assessments of computer-simulated images of human teeth. The experiment was performed on a calibrated display. A 40-observer panel: dentists and laypersons (male and female; n=10), evalu- ated three subsets of simulated human teeth: the lightness subset (%∆L00 ≥ 98 %), the chroma subset (%∆C00 ≥ 98 %) and the hue subset (%∆H00 ≥ 98 %), using ∆E00 ≥ 5 units. A Takagi-Sugeno-Kang Fuzzy Approximation model was used as fitting procedure, and 50:50 % lightness, chroma and hue CIEDE2000 (1:1:1) and CIEDE2000 (2:1:1) perceptibility (PT00) and accept- ability (AT00) thresholds were calculated. Data was statistically analyzed using t-test (p < 0.05). ResultsThe 50:50 % PT00 for KL=1 were ∆L00=1.04, ∆C00=1.58 and ∆E00=1.01; and for KL=2 were ∆L00=0.51, ∆C00=1.58 and ∆E00=0.71. The 50:50 % AT00 for KL=1 were ∆L00=2.82, ∆C00=3.04 and ∆E00=2.66; and for KL=2 were ∆L00=1.40, ∆C00=3.04 and ∆E00=1.78. PT00 and AT00 ∆H00 may be considered no computable. A significant difference was found between CIEDE2000(1:1:1) and CIEDE2000(2:1:1), between lightness and chroma metrics, and between observer groups. No differences for lightness and chroma PT00 were found between male and female groups. ConclusionsIt is important to use PT00 and AT00 for lightness, chroma and hue specific to evaluate perceptual sensitivity for color changes in the tooth color space. AT00 for lightness and chroma are influenced by the observer's experience and gender. Males and laypersons show more tolerance for changes in chroma (∆C00) and in lightness (∆L00). SignificanceHue and chroma mismatch are more difficult to be accepted in dental color space.

Evaluation of Mis-Selection of End Vertebrae and Its Effect on Measuring Cobb Angle and Curve Length in Adolescent Idiopathic Scoliosis.

Background: The Cobb angle is critical in assessing adolescent idiopathic scoliosis (AIS) patients. This study aimed to evaluate the error in selecting the upper- and lower-end vertebrae on AIS digital X-rays by experienced and novice observers and its correlation with the error in measuring the Cobb angle and determining the length of the scoliotic curves. Methods: Using the TraumaMeter v.873 software, eight raters independently evaluated 68 scoliotic curves. Results: The error percentage in the upper-end vertebra selection was higher than for the lower-end vertebra (44.7%, CI95% 41.05-48.3 compared to 35%, CI95% 29.7-40.4). The mean bias error (MBE) was 0.45 (CI95% 0.38-0.52) for the upper-end vertebra and 0.35 (CI% 0.69-0.91) for the lower-end vertebra. The percentage of errors in the choice of the end vertebrae was lower for the experienced than for the novices. There was a positive correlation (r = 0.673, p = 0.000) between the error in selecting the end vertebrae and determining the length of the scoliotic curves. Conclusions: We can conclude that errors in selecting end vertebrae are common among experienced and novice observers, with a greater error frequency for the upper-end vertebrae. Contrary to the consensus, the accuracy of determining the length of the scoliotic curve is limited by the Cobb method's reliance on the correct selection of the end vertebrae.

Interobserver Agreement Rates on CXCR4-Directed PET/CT in Patients with Marginal Zone Lymphoma

C-X-C motif chemokine receptor 4 (CXCR4)-directed molecular imaging provides excellent read-out capabilities in patients with marginal zone lymphoma (MZL). We aimed to determine the interobserver agreement rate of CXCR4-targeted PET/CT among readers with different levels of experience.Methods50 subjects with MZL underwent CXCR4-targeted PET/CT, which were reviewed by four readers (including two experienced and two less experienced observers). The following 8 parameters were investigated: overall scan result, CXCR4 density in lymphoma tissue, extranodal organ involvement, No. of affected extranodal organs and extranodal organ metastases, lymph node (LN) involvement and No. of affected LN areas and LN metastases. We applied intraclass correlation coefficients (ICC; < 0.4, poor; 0.4–0.59, fair; 0.6–0.74, good and > 0.74 excellent agreement rates).ResultsAmong all readers, fair agreement was recorded for No. of affected extranodal organs (ICC, 0.40; 95% confidence interval [CI], 0.25–0.68), overall scan result (ICC, 0.42; 95%CI, 0.28–0.57), CXCR4 density in lymphoma tissue (ICC, 0.52; 95%CI, 0.38–0.66), and No. of extranodal organ metastases (ICC, 0.55; 95%CI, 0.41–0.61) and LN involvement (ICC, 0.59; 95%CI, 0.46–0.71). Good agreement rates were observed for No. of LN metastases (ICC, 0.71; 95%CI, 0.60–0.81) and No. of LN areas (ICC, 0.73; 95%CI, 0.63–0.82), while extranodal organ involvement (ICC, 0.35; 95%CI, 0.21–0.51) achieved poor concordance. On a reader-by-reader comparison, the experienced readers achieved significantly higher agreement rates in 4/8 (50%) investigated scan items (ICC, range, 0.21–0.90, P < / = 0.04). In the remaining 4/8 (50%), a similar trend with higher ICCs for the experienced readers was recorded (n.s.).ConclusionCXCR4-directed PET/CT mainly provided fair to good agreement rates for scan assessment, while a relevant level of experience seems to be required for an accurate imaging read-out.

Development of an initial training and evaluation programme for manual lower limb muscle MRI segmentation

BackgroundMagnetic resonance imaging (MRI) quantification of intramuscular fat accumulation is a responsive biomarker in neuromuscular diseases. Despite emergence of automated methods, manual muscle segmentation remains an essential foundation. We aimed to develop a training programme for new observers to demonstrate competence in lower limb muscle segmentation and establish reliability benchmarks for future human observers and machine learning segmentation packages.MethodsThe learning phase of the training programme comprised a training manual, direct instruction, and eight lower limb MRI scans with reference standard large and small regions of interest (ROIs). The assessment phase used test–retest scans from two patients and two healthy controls. Interscan and interobserver reliability metrics were calculated to identify underperforming outliers and to determine competency benchmarks.ResultsThree experienced observers undertook the assessment phase, whilst eight new observers completed the full training programme. Two of the new observers were identified as underperforming outliers, relating to variation in size or consistency of segmentations; six had interscan and interobserver reliability equivalent to those of experienced observers. The calculated benchmark for the Sørensen-Dice similarity coefficient between observers was greater than 0.87 and 0.92 for individual thigh and calf muscles, respectively. Interscan and interobserver reliability were significantly higher for large than small ROIs (all p < 0.001).ConclusionsWe developed, implemented, and analysed the first formal training programme for manual lower limb muscle segmentation. Large ROI showed superior reliability to small ROI for fat fraction assessment.Relevance statementObservers competent in lower limb muscle segmentation are critical to application of quantitative muscle MRI biomarkers in neuromuscular diseases. This study has established competency benchmarks for future human observers or automated segmentation methods.Key points• Observers competent in muscle segmentation are critical for quantitative muscle MRI biomarkers.• A training programme for muscle segmentation was undertaken by eight new observers.• We established competency benchmarks for future human observers or automated segmentation methods.Graphical

Real-time quantification of laser speckle contrast imaging during intestinal laparoscopic surgery: successful demonstration in a porcine intestinal ischemia model

BackgroundAnastomotic leakage (AL) is a dreaded complication following colorectal cancer surgery, impacting patient outcome and leads to increasing healthcare consumption as well as economic burden. Bowel perfusion is a significant modifiable factor for anastomotic healing and thus crucial for reducing AL.AimsThe study aimed to calculate a cut-off value for quantified laser speckle perfusion units (LSPUs) in order to differentiate between ischemic and well-perfused tissue and to assess inter-observer reliability.MethodsLSCI was performed using a porcine ischemic small bowel loop model with the PerfusiX-Imaging® system. An ischemic area, a well-perfused area, and watershed areas, were selected based on the LSCI colormap. Subsequently, local capillary lactate (LCL) levels were measured. A logarithmic curve estimation tested the correlation between LSPU and LCL levels. A cut-off value for LSPU and lactate was calculated, based on anatomically ischemic and well-perfused tissue. Inter-observer variability analysis was performed with 10 observers.ResultsDirectly after ligation of the mesenteric arteries, differences in LSPU values between ischemic and well-perfused tissue were significant (p < 0.001) and increased significantly throughout all following measurements. LCL levels were significantly different (p < 0.001) at both 60 and 120 min. Logarithmic curve estimation showed an R2 value of 0.56 between LSPU and LCL values. A LSPU cut-off value was determined at 69, with a sensitivity of 0.94 and specificity of 0.87. A LCL cut-off value of 3.8 mmol/L was found, with a sensitivity and specificity of 0.97 and 1.0, respectively. There was no difference in assessment between experienced and unexperienced observers. Cohen’s Kappa values were moderate to good (0.52–0.66).ConclusionReal-time quantification of LSPUs may be a feasible intraoperative method to assess tissue perfusion and a cut-off value could be determined with high sensitivity and specificity. Inter-observer variability was moderate to good, irrespective of prior experience with the technique.

Training and assessing convolutional neural network performance in automatic vascular segmentation using Ga-68 DOTATATE PET/CT

To evaluate a convolutional neural network’s performance (nnU-Net) in the assessment of vascular contours, calcification and PET tracer activity using Ga-68 DOTATATE PET/CT. Patients who underwent Ga-68 DOTATATE PET/CT imaging over a 12-month period for neuroendocrine investigation were included. Manual cardiac and aortic segmentations were performed by an experienced observer. Scans were randomly allocated in ratio 64:16:20 for training, validation and testing of the nnU-Net model. PET tracer uptake and calcium scoring were compared between segmentation methods and different observers. 116 patients (53.5% female) with a median age of 64.5 years (range 23–79) were included. There were strong, positive correlations between all segmentations (mostly r > 0.98). There were no significant differences between manual and AI segmentation of SUVmean for global cardiac (mean ± SD 0.71 ± 0.22 vs. 0.71 ± 0.22; mean diff 0.001 ± 0.008, p > 0.05), ascending aorta (mean ± SD 0.44 ± 0.14 vs. 0.44 ± 0.14; mean diff 0.002 ± 0.01, p > 0.05), aortic arch (mean ± SD 0.44 ± 0.10 vs. 0.43 ± 0.10; mean diff 0.008 ± 0.16, p > 0.05) and descending aorta (mean ± SD < 0.001; 0.58 ± 0.12 vs. 0.57 ± 0.12; mean diff 0.01 ± 0.03, p > 0.05) contours. There was excellent agreement between the majority of manual and AI segmentation measures (r ≥ 0.80) and in all vascular contour calcium scores. Compared with the manual segmentation approach, the CNN required a significantly lower workflow time. AI segmentation of vascular contours using nnU-Net resulted in very similar measures of PET tracer uptake and vascular calcification when compared to an experienced observer and significantly reduced workflow time.

A spatiotemporal comparison of interobserver error in vegetation sampling

AbstractQuestionsWe asked how interobserver error in sampling vegetation (excluding trees) varied over time, space and habitat type; determined whether there were any obvious correlates of observer error; and evaluated evidence of bias among observers.LocationNine national park units in the Midwestern USA.MethodsWe quantified observer error in the context of a long‐term monitoring program employing three observers, evaluating interobserver error across 11 locations in the Midwestern USA over five years. The vegetation (excluding trees) was sampled independently by two teams of observers at prairie and woodland locations (n = 94 plots total).ResultsTotal pseudoturnover ranged between 20.2% and 22.1% at prairie locations, and between 16.8% and 28.6% at woodland locations. The overlooking component of pseudoturnover accounted for 75% or more of total pseudoturnover, with misidentification and cautious components each contributing 19% or less of the total, depending on location. The percentage of comparisons in which both observers recorded the same cover class ranged from 71.3% to 78.5% at the prairie locations and 56.9% to 85.6% at woodland locations. When observers did not agree on cover class, they were off by more than one class less than 6% of the time. Overlooking error was more likely to occur for species with less cover, while estimation error was more likely to occur for species with greater cover. A bias existed among observers, as the least experienced observer recorded 6.2%–11.8% more species than the other two observers. Interobserver bias also existed for rates of estimation error, as one observer consistently recorded higher cover classes.ConclusionsObserver error is a pervasive aspect of vegetation sampling. Continued training and experience yielded limited increases in precision. Elements of the sampling design probably reduced observer error to a certain degree, although some level of interobserver error in vegetation surveys is unavoidable.

Interobserver agreement during clinical magnetic resonance imaging of the equine foot

AbstractBackgroundAgreement between experienced observers for assessment of pathology and assessment confidence are poorly documented for magnetic resonance imaging (MRI) of the equine foot.ObjectivesTo report interobserver agreement for pathology assessment and observer confidence for key anatomical structures of the equine foot during MRI.Study designExploratory clinical study.MethodsTen experienced observers (diploma or associate level) assessed 15 equine foot MRI studies acquired from clinical databases of 3 MRI systems. Observers graded pathology in seven key anatomical structures (Grade 1: no pathology, Grade 2: mild pathology, Grade 3: moderate pathology, Grade 4: severe pathology) and provided a grade for their confidence for each pathology assessment (Grade 1: high confidence, Grade 2: moderate confidence, Grade 3: limited confidence, Grade 4: no confidence). Interobserver agreement for the presence/absence of pathology and agreement for individual grades of pathology were assessed with Fleiss' kappa (k). Overall interobserver agreement for pathology was determined using Fleiss' kappa and Kendall's coefficient of concordance (KCC). The distribution of grading was also visualised with bubble charts.ResultsInterobserver agreement for the presence/absence of pathology of individual anatomical structures was poor‐to‐fair, except for the navicular bone which had moderate agreement (k = 0.52). Relative agreement for pathology grading (accounting for the ranking of grades) ranged from KCC = 0.19 for the distal interphalangeal joint to KCC = 0.70 for the navicular bone. Agreement was generally greatest at the extremes of pathology. Observer confidence in pathology assessment was generally moderate to high.Main limitationsDistribution of pathology varied between anatomical structures due to random selection of clinical MRI studies. Observers had most experience with low‐field MRI.ConclusionsEven with experienced observers, there can be notable variation in the perceived severity of foot pathology on MRI for individual cases, which could be important in a clinical context.

Man versus machine: cost and carbon emission savings of 4G-connected Artificial Intelligence technology for classifying species in camera trap images

Timely and accurate detection and identification of species are crucial for monitoring wildlife for conservation and management. Technological advances, including connectivity of camera traps to mobile phone networks and artificial intelligence (AI) algorithms for automated species identification, can potentially improve the timeliness and accuracy of species detection and identification. Adoption of this new technology, however, is often seen as cost-prohibitive as it has been difficult to calculate the cost savings or qualitative benefits over the life of the program. We developed a decision tool to quantify potential cost savings associated with incorporating the use of mobile phone network connectivity and AI technologies into monitoring programs. Using a feral cat eradication program as a case study, we used our decision tool to quantify technology-related savings in costs and carbon emissions, and compared the accuracy of AI species identification to that of experienced human observers. Over the life of the program, AI technology yielded cost savings of $0.27 M and when coupled with mobile phone network connectivity, AI saved $2.15 M and 115,838 kg in carbon emissions, with AI algorithms outperforming human observers in both speed and accuracy. Our case study demonstrates how advanced technologies can improve accuracy and cost-effectiveness and improve monitoring program efficiencies.

Craniocervical Morphometry in Pomeranians-Part II: Associations with Chiari-like Malformation and Syringomyelia.

The aim of Part II of this two-part study is to describe and analyze the association of various aspects and measurements related to the morphometry of the skull and craniocervical region to CM/SM status of Pomeranians, by means of computed tomography (CT) and magnetic resonance imaging (MRI). Prospectively, Pomeranians were included that underwent both CT and MRI studies of the head and cervicothoracic vertebral column. For those cases where qualitative classifications differed between observers, the experienced observer re-evaluated the studies and decided on a final classification that was used for further analysis. For quantitative measurements, the means of the observers' measurements were used for analysis. Among statistically significant differences in measurements, we found that dogs with SM had a significantly shorter clivus length based on both MRI (p = 0.01) and CT measurements (p = 0.01), and a significantly smaller caudal cranial fossa area based on both MRI (p = 0.02) and CT measurements (p = 0.02). Significant morphometrical differences were identified between dogs with or without CM/SM. The findings in this study add to those already described in other breeds and provide further insight into factors that may play a role in the pathogenesis of CM/SM in Pomeranians.