Inter-rater Differences Research Articles

Quantitative and Radiological Assessment of Post-cardiac-Arrest Comatose Patients with Diffusion-Weighted Magnetic Resonance Imaging.

Although magnetic resonance imaging, particularly diffusion-weighted imaging, has increasingly been used as part of a multimodal approach to prognostication in patients who are comatose after cardiac arrest, the performance of quantitative analysis of apparent diffusion coefficient (ADC) maps, as compared to standard radiologist impression, has not been well characterized. This retrospective study evaluated quantitative ADC analysis to the identification of anoxic brain injury by diffusion abnormalities on standard clinical magnetic resonance imaging reports. The cohort included 204 previously described comatose patients after cardiac arrest. Clinical outcome was assessed by (1) 3-6 month post-cardiac-arrest cerebral performance category and (2) coma recovery to following commands. Radiological evaluation was obtained from clinical reports and characterized as diffuse, cortex only, deep gray matter structures only, or no anoxic injury. Quantitative analyses of ADC maps were obtained in specific regions of interest (ROIs), whole cortex, and whole brain. A subgroup analysis of 172 was performed after eliminating images with artifacts and preexisting lesions. Radiological assessment outperformed quantitative assessment over all evaluated regions (area under the curve [AUC] 0.80 for radiological interpretation and 0.70 for the occipital region, the best performing ROI, p = 0.011); agreement was substantial for all regions. Radiological assessment still outperformed quantitative analysis in the subgroup analysis, though by smaller margins and with substantial to near-perfect agreement. When assessing for coma recovery only, the difference was no longer significant (AUC 0.83 vs. 0.81 for the occipital region, p = 0.70). Although quantitative analysis eliminates interrater differences in the interpretation of abnormal diffusion imaging and avoids bias from other prediction modalities, clinical radiologist interpretation has a higher predictive value for outcome. Agreement between radiological and quantitative analysis improved when using high-quality scans and when assessing for coma recovery using following commands. Quantitative assessment may thus be more subject to variability in both clinical management and scan quality than radiological assessment.

OSABSS: An authentic examination for assessing basic surgical skills in surgical residents

ObjectivesThis study aimed to develop and validate the OSABSS (Objective Structured Assessment of Basic Surgical Skills), a modified Objective Structured Clinical Examination (OSCE), to assess basic surgical skills in residents. DesignA developmental study conducted in two phases. Basic skills were identified through literature review and gap analysis. The OSABSS was then designed as a modified OSCE. SettingThis study took place at Alborz University of Medical Sciences in Iran. InterventionsThe OSABSS was created using Harden's OSCE (Objective Structured Clinical Examination) methodology. Scenarios, checklists, and station configurations were developed through expert panels. The exam was piloted and implemented with residents as participants and faculty as evaluators. Participants32 surgical residents in gynecology, general surgery, orthopedics, and neurosurgery participated. 22 faculty members were evaluators. Primary and secondary outcome measuresThe primary outcome was OSABSS exam scores. Secondary outcomes were written exam scores, and national residency entrance ranks. Main resultsThe mean OSABSS score was 16.59 ± 0.19 across all stations. Criterion validity was demonstrated through correlations between OSABSS scores, written scores and entrance ranks. Reliability was high, with a Cronbach's alpha of 0.87. No significant inter-rater score differences were found. ConclusionsThe rigorous OSABSS development process produced an exam demonstrating strong validity and reliability for assessing basic surgical skills. The comprehensive station variety evaluates diverse technical and non-technical competencies. Further research should expand participant samples across surgical disciplines.

Technical challenges in REM sleep microstructure classification: A study of patients with REM sleep behaviour disorder.

While commonly treated as a uniform state in practice, rapid eye movement sleep contains two distinct microstructures-phasic (presence of rapid eye movement) and tonic (no rapid eye movement). This study aims to identify technical challenges during rapid eye movement sleep microstructure visual classification in patients with rapid eye movement sleep behaviour disorder, and to propose solutions to enhance reliability between scorers. Fifty-seven sleep recordings were randomly allocated into three subsequent batches (n = 10, 13 and 34) for scoring. To reduce single-centre bias, we recruited three raters/scorers, with each trained from a different institution. Two raters independently scored each 30-s rapid eye movement sleep into 10 × fSEM3-s phasic/tonic microstructures based on the AASM guidelines. The third rater acted as an "arbitrator" to resolve opposite opinions persisting during the revision between batches. Besides interrater differences in artefact rejection rate, interrater variance frequently occurred due to transitioning between microstructures and moderate-to-severe muscular/electrode artefact interference. To enhance interrater agreement, a rapid eye movement scoring schematic graph was developed, incorporating proxy electrode use, filters and cut-offs for microstructure transitioning. To assess potential effectiveness of the schematic graph proposed, raters were instructed to systematically apply it in scoring for the third batch. Of the 34 recordings, 27 reached a Cohen's kappa score above 0.8 (i.e. almost perfect agreement between raters), significantly improved from the prior batches (p = 0.0003, Kruskal-Wallis test). Our study illustrated potential solutions and guidance for challenges that may be encountered during rapid eye movement sleep microstructure classification.

Automatic estimation of hallux valgus angle using deep neural network with axis-based annotation

ObjectivesWe developed the deep neural network (DNN) model to automatically measure hallux valgus angle (HVA) and intermetatarsal angle (IMA) on foot radiographs. The objective is to assess the accuracy of the model by comparing to the manual measurement of foot and ankle surgeons.Materials and methodsA DNN was developed to predict the bone axes of the first proximal phalanx and all metatarsals from the first to the fifth in foot radiographs. The dataset used for model development consisted of 1798 radiographs collected from a population-based cohort and patients at our foot and ankle clinic. The retrospective validation cohort comprised of 92 radiographs obtained from 92 consecutive patients visiting our foot and ankle clinic. The mean absolute error (MAE) between automatic measurements by the model and the median of manual measurements by three foot and ankle surgeons was compared to 3° using one-tailed t-test and was also compared to the inter-rater difference in manual measurements among the three surgeons using two-tailed paired t-test.ResultsThe MAE for HVA was 1.3° (upper limit of 95% CI 1.6°), and this was significantly smaller than the inter-rater difference of 2.0 ± 0.2° among the surgeons, demonstrating the superior accuracy of the model. In contrast, the MAE for IMA was 0.8° (upper limit of 95% CI 1.0°) that showed no significant difference from the inter-rater difference of 1.0 ± 0.1° among the surgeons.ConclusionOur model demonstrated the ability to measure the HVA and IMA with an accuracy comparable to that of specialists.

Does early administration of denosumab delay bone healing after intertrochanteric femoral fractures?

IntroductionHip fractures are commonly associated with osteoporosis and pose a risk for secondary fractures. Although the administration of anti-osteoporotic drugs is recommended after fractures to mitigate this risk, the potential effect of strong anti-resorptive drugs (e.g., denosumab) on fracture healing processes have not been extensively studied. This prospective study aimed to evaluate the feasibility of early denosumab administration after femoral intertrochanteric fracture surgery and to compare its effect on fracture healing to that of bisphosphonate-treated patients. Materials and MethodsPatients who underwent surgery for intertrochanteric femoral fragility fractures between November 2018 and November 2020 were prospectively examined. Patients were randomized into two groups (denosumab [DSM] and ibandronate [IBN] groups) using a simple randomization procedure. Physical findings, plain radiographs, and computed tomography (CT) were used to evaluate fracture healing at 3 months postoperatively. ResultsPhysical findings showed no significant differences between the two groups in pain on loading, tenderness at fracture site, or walking ability. There were inter-rater differences in radiological fracture healing rate: plain radiographs, 57.5% to 81.8% in the DSM group and 51.5% to 90.9% in the IBN group; CT, 51.5% to 72.7% in the DSM group and 45.4% to 81.8% in the IBN group. Although there were variations, there were no significant differences in the fracture healing rate between groups on plain radiographs or CT among all three raters. ConclusionsEarly administration of denosumab after intertrochanteric femoral fracture surgery did not delay radiological or clinical fracture healing times when compared with ibandronate administration.

A comparison of visual and direct assessments of lumbar spine posture

BackgroundPosture is assessed clinically and used to guide treatment of low back pain. Collectively, the relevance of posture and clinical postural assessments have come under scrutiny. This study aimed to determine (a) the intra-rater and inter-rater reliability of visual assessments of lumbar lordosis, and (b) the agreement between visual and direct postural assessments. MethodsTen physiotherapists visually assessed the lumbar lordosis from 3D scans of 50 asymptomatic participants, and 15 duplicates, using a grading scale of deviations (range: 0 = normal to 3 = severe). Lumbar lordosis angle was directly assessed using the Vitus Smart 3D whole body scanner. Cohen's Kappa was used to determine the intra-rater and inter-rater reliability of visual assessments, with polyserial correlation (ps) used to determine the agreement between visual and direct assessments. ResultsOverall, 93% and 83% of all intra-rater and inter-rater differences in visual assessments were within a single grade point, respectively. The intra-rater and inter-rater reliability of visual assessments was moderate (κ (95%CI): 0.56 (0.45, 0.67)) and slight (κ (95%CI): 0.13 (0.08, 0.19)), respectively. The agreement between visual and direct assessments was moderate (ps = −0.41, p = 0.04). ConclusionVisual assessments of lumbar posture demonstrated moderate repeatability and agreement with quantitative assessments. While agreement between assessors was slight, 83% of the visual ratings were within a single grade point, suggesting greater coherence among clinicians than our statistics suggested. As with any clinical assessments involving uncertainty, postural assessment should not solely guide treatment.

Virtual Assistants' Response to Queries About Nicotine Replacement Therapy: A Mixed-Method Analysis.

This study focused on investigating the potential of Artificial Intelligent-powered Virtual Assistants (VAs) such as Amazon Alexa, Apple Siri, and Google Assistant as tools to help individuals seeking information about Nicotine Replacement Treatment (NRT) for smoking cessation. The researchers asked 40 NRT-related questions to each of the 3 VAs and evaluated the responses for voice recognition. The study used a cross-sectional mixed-method design with a total sample size of 360 responses. Inter-rater reliability and differences between VAs' responses were examined by SAS software, and qualitative assessments were conducted using NVivo software. Google Assistant achieved 100% voice recognition for NRT-related questions, followed by Apple Siri at 97.5%, and Amazon Alexa at 83.3%. Statistically significant differences were found between the responses of Amazon Alexa relative to both Google Assistant and Apple Siri. Researcher 1's ratings significantly differed from Researcher 2's (p = .001), but not from Researcher 3's (p = .11). Virtual Assistants occasionally struggled to understand the context or nuances of questions, lacked in-depth information in their responses, and provided generic or unrelated responses. Virtual Assistants have the potential to be incorporated into smoking cessation interventions and tobacco control initiatives, contingent upon improving their competencies.

Estimation of Cochlear Implant Insertion Depth Using 2D-3D Registration of Postoperative X-Ray and Preoperative CT Images.

To improve estimation of cochlear implant (CI) insertion depth in postoperative skull x-rays using synthesized information from preoperative CT scans. Retrospective cohort. Tertiary referral center. Ten adult cochlear implant recipients with preoperative and postoperative temporal bone computed tomography (CT)scans and postoperative skull x-ray imaging. Postoperative x-rays and digitally reconstructed radiographs (DRR) from preoperative CTs were registered using 3D Slicer and MATLAB to enhance localization of the round window and modiolus. Angular insertion depth (AID) was estimated in unmodified and registration-enhanced x-rays and DRRs in the cochlear view. Linear insertion depth (LID) was estimated in registered images by two methods that localized the proximal CI electrode or segmented the cochlea. Ground truth assessments were made in postoperative CTs. Errors of insertion depth estimates were calculated relative to ground truth measurements and compared with paired t t ests. Pearson correlation coefficient was used to assess inter-rater reliability of two reviewer's measurements of AID in unmodified x-rays. In postoperative x-rays, AID estimation errors were similar with and without registration enhancement (-1.3 ± 20.7° and -4.8 ± 24.9°, respectively; mean ± SD; p = 0.6). AID estimation in unmodified x-rays demonstrated strong interrater agreement (ρ = 0.79, p < 0.05) and interrater differences (-15.0 ± 35.3°) comparable to estimate errors. Registering images allowed measurement of AID in the cochlear view with estimation errors of 14.6 ± 30.6° and measurement of LID, with estimate errors that were similar between proximal electrode localization and cochlear segmentation methods (-0.9 ± 2.2 mm and -2.1 ± 2.7 mm, respectively; p = 0.3). 2D-3D image registration allows measurement of AID in the cochlear view and LID using postoperative x-rays and preoperative CT imaging. The use of this technique may reduce the need for postimplantation CT studies to assess these metrics of CI electrode position. Further work is needed to improve the accuracy of AID assessment in the postoperative x-ray view with registered images compared with established methods.

Evaluation of CI electrode position from imaging: comparison of an automated technique with the established manual method

BackgroundA manual evaluation of the CI electrode position from CT and DVT scans may be affected by diagnostic errors due to cognitive biases. The aim of this study was to compare the CI electrode localization using an automated method (image-guided cochlear implant programming, IGCIP) with the clinically established manual method.MethodsThis prospective experimental study was conducted on a dataset comprising N=50 subjects undergoing cochlear implantation with a Nucleus® CI532 or CI632 Slim Modiolar electrode. Scalar localization, electrode-to-modiolar axis distances (EMD) and angular insertion depth (aDOI) were compared between the automated IGCIP tool and the manual method. Two raters made the manual measurements, and the interrater reliability (±1.96·SD) was determined as the reference for the method comparison. The method comparison was performed using a correlation analysis and a Bland-Altman analysis.ResultsConcerning the scalar localization, all electrodes were localized both manually and automatically in the scala tympani. The interrater differences ranged between ±0.2 mm (EMD) and ±10° (aDOI). There was a bias between the automatic and manual method in measuring both localization parameters, which on the one hand was smaller than the interrater variations. On the other hand, this bias depended on the magnitude of the EMD respectively aDOI. A post-hoc analysis revealed that the deviations between the methods were likely due to a different selection of mid-modiolar axis.ConclusionsThe IGCIP is a promising tool for automated processing of CT and DVT scans and has useful functionality such as being able to segment the cochlear using post-operative scans. When measuring EMD, the IGCIP tool is superior to the manual method because the smallest possible distance to the axis is determined depending on the cochlear turn, whereas the manual method selects the helicotrema as the reference point rigidly. Functionality to deal with motion artifacts and measurements of aDOI according to the consensus approach are necessary, otherwise the IGCIP is not unrestrictedly ready for clinical use.

43697 A survey study to understand inter-rater differences in lesions counts for hidradenitis suppurativa clinical trials

43697 A survey study to understand inter-rater differences in lesions counts for hidradenitis suppurativa clinical trials

Cross-cultural validation of the Berg balance scale to assess balance among Hungarian institutionalised older adults

Purpose To translate the Berg Balance Scale (BBS) to Hungarian and to evaluate the psychometric characteristics of the Hungarian version (HU-BBS). Methods In total, 150 institutionalised older adults were recruited for the study. Eighty-one participants completed the retesting. Internal consistency, intra- and inter-rater reliability, and 95% limits of agreement of the HU-BBS were examined. Construct validity was assessed through convergent, discriminant, and known-group validity. Results The overall Cronbach’s alpha was 0.943. The intra- and inter-rater reliability was excellent (intraclass correlation coefficient > 0.92). The Bland–Altman analysis revealed a mean inter-rater difference of 0.284 [−2.193–2.744] and a mean intra-rater difference of 0.259 [−2.657–3.162]. Regarding convergent validity, the HU-BBS was correlated with the functional status (r = 0.833), Timed Up and Go test (r= −0.824), and age (r= −0.606). The HU-BBS scores of women were similar to those of men (p = 0.104), showing discriminant validity. Additionally, the HU-BBS scores were lower among faller than among non-faller participants (p ˂ 0.0001), establishing known-group validity. Conclusions Translation and cultural adaptation of the original scale was successful. The HU-BBS proved to be a reliable, valid tool confirming that it can be used in future clinical and scientific work on Hungarian older adults. Implications for rehabilitation Institutionalised older adults are vulnerable and at a high risk of developing further decline in postural control, contributing to an increase in limited functional mobility and risk for falls. The Berg Balance Scale is a widely used tool originally developed to measure postural control in older adults. The Hungarian version of the Berg Balance Scale tested on institutionalised older adults shows excellent test-retest reliability, good internal consistency, and acceptable convergent construct validity. The Hungarian version of the Berg Balance Scale is a valid and reliable tool for measuring postural control among Hungarian-speaking institutionalised older adults both in clinical practice and scientific studies.

Efficacy of customized crown-level position jig in measuring peri-implant crestal bone level on periapical radiographs: An in vitro study

Background/purposeAccuracy of using implant length on periapical radiographs as calibration reference for measurements has not been verified. This study aimed to verify the measurements of peri-implant crestal bone level (piCBL) on periapical radiographs taken by the paralleling technique and using the implant length for calibration; and to propose a customized crownlevel position (CLP) jig to improve the measurement accuracy of piCBL. Materials and methodsA typodont installed an implant and a screw-retained crown at maxillary central incisor was used. To simulate piCBL, a metal post was placed near the implant at the same height of implant platform. The CLP jig was designed and 3-dimensionally printed out to allow implant projected orthogonally on periapical film. Thirty periapical radiographs were taken using paralleling technique with and without the jig by three examiners. The implant axis and implant length on radiographs were acquired by image segmentation. The discrepancy of piCBL determination (ΔD) from these measurements were compared and further analyzed when using the implant length for calibration. ResultsThe piCBL measurement errors were smaller when the jig was used for all examiners (P < 0.001). The inter-rater differences were insignificant. After calibration, ΔD with and without jig were 0.09 (0.07–0.11) and 0.43 (0.38–0.49) mm, respectively. ConclusionConventional long-cone paralleling technique using true implant length for calibration demonstrated imprecise piCBL measurement on periapical radiographs. Transferring the implant axis to the CLP jig allowed orthogonal projection of radiography which provided reliable measurements of piCBL with an accuracy of less than 0.1 mm.

The influence of raters and scoring procedures on EIT outcomes: An exploratory study

This mixed-methods study examines the role of rating modality (aural vs. written) and rater characteristics (language background, linguistics training) on outcomes on a Spanish elicited imitation task (EIT) and provides insight into rater cognition during the scoring process. Thirty Spanish-English bilingual raters were divided into two conditions—one that scored test-takers’ audio-recorded oral EIT productions, the other that scored written transcriptions. Within each condition, raters varied according to their language background (native vs. nonnative Spanish speaker) and linguistics training (no training, minimal training, moderate training, extensive training). All raters scored the same six 30-item EITs using Ortega et al.’s (2002) rubric. Ten raters additionally completed a think-aloud protocol during their scoring. Ordinal logistic mixed-effects modelling was used to explore quantitative interrater differences in scoring (k = 5,400), and content analysis (Krippendorf, 2018) was employed to investigate patterns in the verbal reports. Results reveal significant differences in EIT outcomes according to rating modality and language background but not linguistics training. Raters scoring in the aural condition and native Spanish speakers rated test items higher than their written condition and nonnative Spanish-speaking counterparts. Analyses of the verbal reports suggest some systematic differences in rating considerations according to rating modality such as differences introduced by punctuation in the written modality or by the need to determine what language was produced in the aural modality. The findings contribute novel information for EIT validity arguments and have implications for rating procedures for future EIT studies.

Measurement of interspinous motion in dynamic cervical radiographs using a deep learning-based segmentation model.

Interspinous motion (ISM) is a representative method for evaluating the functional fusion status following anterior cervical discectomy and fusion (ACDF) surgery, but the associated measuring difficulty and potential errors in the clinical setting remain concerns. The aim of this study was to investigate the feasibility of a deep learning-based segmentation model for measuring ISM in patients who underwent ACDF surgery. This study is a retrospective analysis of flexion-extension dynamic cervical radiographs from a single institution and a validation of a convolutional neural network (CNN)-based artificial intelligence (AI) algorithm for measuring ISM. Data from 150 lateral cervical radiographs from the normal adult population were used to train the AI algorithm. A total of 106 pairs of dynamic flexion-extension radiographs from patients who underwent ACDF at a single institution were analyzed and validated for measuring ISM. To evaluate the agreement power between human experts and the AI algorithm, the authors assessed the interrater reliability using the intraclass correlation coefficient and root mean square error (RMSE) and performed a Bland-Altman plot analysis. They processed 106 pairs of radiographs from ACDF patients into the AI algorithm for autosegmenting the spinous process created using 150 normal population radiographs. The algorithm automatically segmented the spinous process and converted it to a binary large object (BLOB) image. The rightmost coordinate value of each spinous process from the BLOB image was extracted, and the pixel distance between the upper and lower spinous process coordinate value was calculated. The AI-measured ISM was calculated by multiplying the pixel distance by the pixel spacing value included in the DICOM tag of each radiograph. The AI algorithm showed a favorable prediction power for detecting spinous processes with an accuracy of 99.2% in the test set radiographs. The interrater reliability between the human and AI algorithm of ISM was 0.88 (95% CI 0.83-0.91), and its RMSE was 0.68. In the Bland-Altman plot analysis, the 95% limit of interrater differences ranged from 0.11 to 1.36 mm, and a few observations were outside the 95% limit. The mean difference between observers was 0.02 ± 0.68 mm. This novel CNN-based autosegmentation algorithm for measuring ISM in dynamic cervical radiographs showed strong agreement power to expert human raters and could help clinicians to evaluate segmental motion following ACDF surgery in clinical settings.

Reliability of the Modified Frenchay Scale for the Assessment of Upper Limb Function in Adults With Hemiparesis

ObjectivesTo investigate the reliability of the Modified Frenchay Scale (MFS) in adults with hemiparesis. DesignProspective analysis of videos. SettingStudy conducted in a Neurorehabilitation Unit of a University Hospital. ParticipantsFifty-one patients (17 women [33%], age 46±15, time since injury 5.2±6.7 years) with hemiparesis secondary to stroke (N=47), tumor (N=3), or spinal cord injury (N=1) were enrolled. InterventionThe MFS measures active upper limb function in spastic hemiparesis based on a video recording of 10 daily living tasks, each rated from 0 to 10. Six tasks are bimanual and 4 are unimanual with the paretic hand. MFS videos performed in routine care of patients with hemiparesis between 2015 and 2021 were collected. After a 3-hour group training session, each MFS video was assessed twice, 1 week apart by 4 rehabilitation professionals with various levels of experience in using the scale. Main Outcome MeasuresInternal consistency was determined using Cronbach's alpha. Intra- and inter-rater reliability was measured using intraclass correlation coefficients (ICC, mean [95% CI]), mean differences between ratings and minimal detectable change (MDC). Bland-Altman plots were also performed for inter-rater assessments. ResultsThe mean overall MFS score was 4.95±1.20 with no floor or ceiling effect. Cronbach's α was 0.97. For the overall MFS score, intra- and inter-rater ICCs were 0.99[0.99;1.00] and 0.97[0.95;0.98], respectively; mean intra- and inter-rater differences were 0.10±0.04 and 0.24±0.12, respectively; and MDC were 0.17 and 0.37, respectively. ConclusionsThe MFS is an internally consistent and reliable scale to assess upper limb function in adults with hemiparesis.

Intra- and Interrater Reliability of CT- versus MRI-Based Cochlear Duct Length Measurement in Pediatric Cochlear Implant Candidates and Its Impact on Personalized Electrode Array Selection.

Radiological high-resolution computed tomography-based evaluation of cochlear implant candidates' cochlear duct length (CDL) has become the method of choice for electrode array selection. The aim of the present study was to evaluate if MRI-based data match CT-based data and if this impacts on electrode array choice. Participants were 39 children. CDL, length at two turns, diameters, and height of the cochlea were determined via CT and MRI by three raters using tablet-based otosurgical planning software. Personalized electrode array length, angular insertion depth (AID), intra- and interrater differences, and reliability were calculated. Mean intrarater difference of CT- versus MRI-based CDL was 0.528 ± 0.483 mm without significant differences. Individual length at two turns differed between 28.0 mm and 36.6 mm. Intrarater reliability between CT versus MRI measurements was high (intra-class correlation coefficient (ICC): 0.929-0.938). Selection of the optimal electrode array based on CT and MRI matched in 90.1% of cases. Mean AID was 629.5° based on the CT and 634.6° based on the MRI; this is not a significant difference. ICC of the mean interrater reliability was 0.887 for the CT-based evaluation and 0.82 for the MRI-based evaluation. MRI-based CDL measurement shows a low intrarater difference and a high interrater reliability and is therefore suitable for personalized electrode array selection.

Results of training with a low-cost simulation model for endoscope-assisted scaphocephaly repair.

Endoscope-assisted repair of sagittal craniosynostosis is an effective technique that requires a learning curve. Surgical simulation models can be applied to acquire the necessary skills for this procedure. Several models with a wide range of costs have been described for training in this technique. The aim of this work was to present the results of training with a low-cost simulation model for endoscope-assisted sagittal craniosynostosis repair. A simulation model for sagittal craniosynostosis was developed using low-cost materials. The model is easily assembled and allows successive uses. Three neurosurgery residents, 3 fellows, and 2 neurosurgeons performed a 4-session training program in sagittal craniosynostosis repair. The Global Rating Scale (GRS) score, number of errors, and the time required to perform the task were reported by 2 independent evaluators using a checklist. Measurements were compared between the first and last training using the Wilcoxon signed-rank test. All participants completed a questionnaire (5-point Likert scale) regarding the realism of the simulation model. A model was developed to recreate the steps required to perform an endoscope-assisted scaphocephaly repair with the patient in a simulated sphinx position. All participants improved their GRS performance between the first and final training. The median time needed to perform the initial training was 47.5 minutes (interquartile range [IQR] 44.5-48 minutes, interrater difference [IRD] p = 0.77), and for the last training was 40.5 minutes (IQR 35.5-43 minutes, IRD p > 0.99). The median number of errors reported in the initial training was 5.5 (IQR 3-7.75 errors, IRD p = 0.8), and in the last training was 1 (IQR 0.75-2.25 errors, IRD p = 0.35). There was a statistically significant difference regarding the time and number of errors between the initial and final training (p < 0.001). More than 85% of the participants found that the surface anatomy, skull and anterior fontanel, fused sagittal suture, and epidural space of the model were realistic and had appropriate detail required to perform the surgery. All respondents agreed or strongly agreed that the endoscope handling was realistic, and that the steps and skills required to complete the task were representative of those required for the real procedure. A low-cost sagittal craniosynostosis simulation model was developed, allowing successive uses. The acquisition of skills within the simulation was demonstrated for all participants regarding the GRS score and the number of errors and time needed to perform the task. In addition, the model was found to be realistic in terms of anatomical references and the procedural steps required for this minimally invasive technique.

Accuracy of Medical Student Measurements of CT Right-to-Left Ventricular Diameter in Patients with Acute Pulmonary Embolism.

Objectives: Acute pulmonary embolism (PE) is a common disease, necessitating risk stratification to determine management. A right ventricle (RV) to left ventricle (LV) diameter ratio ≥1.0 on computed tomography pulmonary angiography (CTPA) suggests RV strain, which may indicate a worse prognosis. Two prior studies showed that residents with brief training by a radiologist could accurately measure RV/LV ratio. We assessed whether medical students could accurately measure RV dilatation. Methods: We conducted a post hoc analysis of a retrospective cohort study of adults undergoing management for acute PE at 21 community emergency departments across Kaiser Permanente Northern California from 2013 to 2015. We created a sample, stratified to contain an equal number of patients from each of the 5 PE Severity Index classes. Four medical students measured RV and LV diameter on CTPA after training from an emergency medicine physician and an interventional radiologist. We used Cohen's kappa statistics, Bland-Altman plots, and Pearson correlation coefficients to assess interrater reliability. Results: Of the 108 CTPAs reviewed, 79 (73%) showed RV dilatation and 29 (27%) did not. The kappa statistic for the presence of RV dilatation of the medical students compared to the radiologist showed moderate agreement for 3 medical students (kappa (95% CI): 0.46 (0.21-0.70), 0.49 (0.31-0.68), 0.50 (0.32-0.68)) and fair agreement for 1 medical student (kappa (95% CI): 0.29 (0.10-0.47)). The average interrater differences in RV/LV ratio between a radiologist and each of the 4 medical students were -0.04, -0.05, 0.04, and 0.24. Pearson correlation coefficients were 0.87, 0.80, 0.74, and 0.78, respectively, indicating moderate correlation (P < .001 for all). Conclusion: Medical students were able to identify RV dilatation on CTPA in moderate agreement with that of a radiologist. Further study is needed to determine whether medical student accuracy could improve with additional training.

Four-dimensional digital subtraction angiography for the vascular anatomical diagnosis of dural arteriovenous malformation: Comparison with the conventional method.

Two-dimensional digital subtraction angiography (2D-DSA) and conventional three-dimensional digital subtraction angiography (3D-DSA) are used for the detailed analysis of dural arteriovenous fistula (DAVF). Recently, four-dimensional digital subtraction angiography (4D-DSA), a novel technology, has been attracting attention. The current study aimed to evaluate the capability of 4D-DSA in assessing anatomical angioarchitecture in DAVF. In total, 10 consecutive patients with DAVF who underwent 3D-DSA and 4D-DSA at a single institution were included in the analysis. Initially, one-slice multiplanar reconstruction (MPR) images obtained via 4D-DSA and 3D-DSA were compared to investigate the visibility of the feeding artery, fistulous point, and draining vein. Next, 4D-DSA images alone were compared and evaluated with and the MPR images of conventional 3D-DSA in terms of diagnosis of the angioarchitecture. In total, six men and four women (with a mean age of 65.6 ± 10.0 years) were included in the study. The MPR image obtained via 3D-DSA had a significantly better visibility of the feeding artery and fistulous point than that acquired via 4D-DSA (p < 0.05). As for the draining vein, the score was equivalent and not significant. The diagnosis of the vascular architecture of only 4D-DSA images was nearly equivalent to that of MPR images of 3D-DSA. There were no inter-rater differences. The MPR images obtained via 4D-DSA may be slightly inferior to those acquired via 3D-DSA in identifying fine angioarchitecture in DAVF. However, they were comparable in terms of diagnostic accuracy.

Deep learning based markerless motion tracking as a clinical tool for movement disorders: Utility, feasibility and early experience

Clinical assessments of movement disorders currently rely on the administration of rating scales, which, while clinimetrically validated and reliable, depend on clinicians’ subjective analyses, resulting in interrater differences. Intraoperative microelectrode recording for deep brain stimulation targeting similarly relies on clinicians’ subjective evaluations of movement-related neural activity. Digital motion tracking can improve the diagnosis, assessment, and treatment of movement disorders by generating objective, standardized measures of patients’ kinematics. Motion tracking with concurrent neural recording also enables motor neuroscience studies to elucidate the neurophysiology underlying movements. Despite these promises, motion tracking has seen limited adoption in clinical settings due to the drawbacks of conventional motion tracking systems and practical limitations associated with clinical settings. However, recent advances in deep learning based computer vision algorithms have made accurate, robust markerless motion tracking viable in any setting where digital video can be captured. Here, we review and discuss the potential clinical applications and technical limitations of deep learning based markerless motion tracking methods with a focus on DeepLabCut (DLC), an open-source software package that has been extensively applied in animal neuroscience research. We first provide a general overview of DLC, discuss its present usage, and describe the advantages that DLC confers over other motion tracking methods for clinical use. We then present our preliminary results from three ongoing studies that demonstrate the use of DLC for 1) movement disorder patient assessment and diagnosis, 2) intraoperative motor mapping for deep brain stimulation targeting and 3) intraoperative neural and kinematic recording for basic human motor neuroscience.