High Diagnostic Agreement Research Articles

R-cVR, a two-step bedside algorithm for the differential diagnosis of acute dizziness and vertigo

BackgroundThe ability to quickly and accurately differentiate between peripheral and central dizziness or vertigo is vital. We developed the R-cVR algorithm for the early identification of central-type dizziness or vertigo. MethodsIn this single-center, retrospective cohort study, we assessed patients with isolated dizziness or vertigo between December 10, 2023, and February 28, 2024. Classification into central or peripheral types was based on magnetic resonance imaging (MRI)-diffusion-weighted imaging (DWI) results. We reevaluated the diagnostic value of the Romberg test for acute dizziness or vertigo by quantifying the duration of standing and created the R-cVR algorithm. The algorithm's accuracy was subsequently validated against the MRI-DWI results. ResultsAfter screening, 109 patients were recruited and divided into central (n = 25) and peripheral (n = 84) groups. The central group had a high incidence of cerebral infarction (88.0 %), whereas the peripheral group included patients with vestibular neuronitis, benign paroxysmal positional vertigo, and Meniere's disease (96.4 %). Significant disparities in the incidence of balance disorders were noted between the groups (92.0 % vs. 15.5 %, p < 0.001). Multivariate logistic regression revealed an odds ratio of 61.82 for balance disorders (p < 0.001). The R-cVR algorithm, which integrates the Romberg test and the V-shaped stance with closed-eyes protocol, was tested against MRI-DWI and yielded high diagnostic agreement (kappa = 0.80), with a sensitivity and specificity of 88.0 % and 94.0 %, respectively. There was no significant difference in the diagnostic efficacy of this algorithm for acute dizziness or vertigo with or without nystagmus. ConclusionThe R-cVR algorithm effectively identifies central-type dizziness or vertigo and is simple for general practitioners to use without specialized equipment, which may be valuable in various clinical settings.

Evaluation of the relationship between FDG-PET hypometabolism and retinal layer thickness in patients with Alzheimer's disease.

We aimed to investigate the diagnostic value of Optical coherence tomography (OCT) in Alzheimer's disease (AD) and to assess the correlation between OCT and fluorodeoxyglucose (FDG)-positron emission tomography (PET) which shows high diagnostic agreement with findings from postmortem histopathology-the gold standard method. Patients who were diagnosed with AD-related dementia were selected for the study. Patients with a mini mental test (MMT) score between 18 and 23 were included in the study (n = 31). Volunteers with MMT ≥ 28 and no cognitive impairment were included in the study as the control group (n = 31). OCT imaging was performed in the patient and control groups after detailed ophthalmological examinations including visual acuity and intraocular pressure measurements. Brain glucose metabolism measurement was performed using 18 F-FDG PET/computed tomography. When adjusted for age and sex, mean retinal nerve fiber layer thickness (RNFL) thickness showed a significant difference between groups and the RNFL thickness in the superior temporal and superior nasal quadrants in AD-related mild dementia group showed a significant difference (p < 0.05). Furthermore, only the RNFL thickness in the inferior nasal quadrant of the right eye showed a significant difference between the groups (p = 0.016). It is thought that OCT is a promising imaging method in the elderly population due to its low-cost, non-invasive and easily applicability, and therefore, it may contribute in the future as a tool in the periodic follow-up of patients diagnosed with AD.

Accuracy of a new rapid diagnostic test for urinary antigen detection and assessment of drug treatment in opisthorchiasis

BackgroundScreening for opisthorchiasis, a parasitic worm infection affecting many millions of people in Southeast Asia, has traditionally relied on faecal egg examination such as the formalin-ethyl acetate concentration technique (FECT) and Kato-Katz method. Although the urinary enzyme-linked immunosorbent assay (ELISA) has been used more recently, we developed a urinary antigen-based rapid diagnostic test (RDT) to simplify diagnosis and as a point-of-care testing (POCT) and field applications for surveillance and control of opisthorchiasis.MethodsA urinary Opisthorchis viverrini (OV)-RDT was developed using immunochromatographic methodology with a specific monoclonal antibody against OV. The diagnostic performance of the urinary OV-RDT was compared to that of quantitative faecal FECT and urinary antigen ELISA (n = 493). Cross-reactivities of urinary OV-RDT with other helminthiases coexisted with O. viverrini were determined (n = 96). A field trial in the application of urinary OV-RDT was compared with urinary antigen ELISA at baseline screening and assessment of drug treatment outcomes in opisthorchiasis (n = 1629). The McNemar chi-square, Kruskal–Wallis and Cohen’s kappa coefficient (κ-value) tests were used for statistical analyses.ResultsUrinary OV-RDT had sensitivity of 94.2% and specificity of 93.2%, compared to faecal FECT. Urinary OV-RDT had high diagnostic agreement (Kappa = 0.842–0.874, P < 0.001) and quantitative correlation with urinary antigen ELISA (Kruskal–Wallis tests = 316.2, P < 0.0001) and faecal FECT (Kruskal–Wallis tests = 362.3, P < 0.0001). The positive rates by OV-RDT, ELISA and FECT were 48.9%, 52.5% and 49.3%, respectively. Cross-reactions of urinary OV-RDT with other helminthiases were few (2%). Field trials of urinary OV-RDT yielded comparable prevalence of O. viverrini between urinary OV-RDT (53.2%) and urinary antigen ELISA (54.0%). OV screening showed high diagnostic agreement (kappa > 0.8, P < 0.0001) between urinary OV-RDT and urinary antigen ELISA. The cure rates of opisthorchiasis at 1 month post-praziquantel treatment determined by urinary OV-RDT (86.6%) and urinary antigen ELISA (80.5%) were similar (P > 0.05).ConclusionsThe urinary OV-RDT test has high potential as a new tool for screening and evaluating treatment outcomes in opisthorchiasis. The ease of sample collection and simplicity of urinary OV-RDT may facilitate mass screening, control and elimination of opisthorchiasis, thereby contributing to a reduction in the disease burden in Southeast Asia.Graphical

Introducing 3D modelling of MRI in the preoperative mapping of perianal fistula: How it could help the surgeons?

BackgroundSurgeons find treating perianal fistula difficult because insufficient drainage and failure to eradicate perianal sepsis could increase the risk of recurrence and postoperative complications. For better planning of the most suitable surgical technique, surgeons must consider the risk factors of recurrence with an accurate pre-operative assessment of perianal fistulae.The most common imaging method for grading primary perianal fistulas, identifying their complications, and locating occult extensions is magnetic resonance imaging (MRI). However, surgeons may find it challenging to read the lengthy reports of complex tracts, particularly for complicated patients. The creation of three-dimensional (3D) models has gained traction recently as a genuinely useful diagnostic tool for pre-operative planning. The authors evaluated the value of these surgical models. Inspecting the 3D models in addition to the routine two-dimensional study caused four out of five skilled colorectal surgeons to re-evaluate how far the fistulae extended. This made promise that 3D models would be helpful, simple to understand, and quick to interpret for colorectal surgeons. The purpose of the study is to assess the value of adding 3D modelling of MRI to standard two-dimensional MRI protocol for more accurate delineation of perianal fistula and its complications aiming at better surgical outcomes.ResultsRegarding 3D models, the highest degree of accuracy was in detecting supra-levator extension (100%) by both the third radiologist and the surgeon. There was a statistically high diagnostic inter-observer agreement between both, with a p-value < 0.0001. The highest inter-observer agreement was in the supra-levator extension (50/50, 100%), and the lowest agreement was in the side branches detection (44/50, 88%).ConclusionsPre-operative 3D MRI modelling provided the surgeon with a pre- and intra-operative road map that improved the surgeon’s orientation and ability to see complex perianal fistulas and their consequences, especially those with supra levator extension, thus helping the surgeon achieve better surgical results and decrease the preoperative risk factors of recurrence. Surgeons should utilise it in complex and recurrent cases reducing preoperative risk factors and improving outcomes. Although this technique is expensive, its cost–benefit ratio is low relative to recurrent hospitalisation and complications.

Diagnostic Accuracy of Perception Threshold Tracking in the Detection of Small Fiber Damage in Type 1 Diabetes.

An objective assessment of small nerve fibers is key to the early detection of diabetic peripheral neuropathy (DPN). This study investigates the diagnostic accuracy of a novel perception threshold tracking technique in detecting small nerve fiber damage. Participants with type 1 diabetes (T1DM) without DPN (n = 20), with DPN (n = 20), with painful DPN (n = 20) and 20 healthy controls (HCs) underwent perception threshold tracking on the foot and corneal confocal microscopy. Diagnostic accuracy of perception threshold tracking compared to corneal confocal microscopy was analyzed using logistic regression. The rheobase, corneal nerve fiber density (CNFD), corneal nerve branch density (CNBD), and corneal nerve fiber length (CNFL) (all P < .001) differed between groups. The diagnostic accuracy of perception threshold tracking (rheobase) was excellent for identifying small nerve fiber damage, especially for CNFL with a sensitivity of 94%, specificity 94%, positive predictive value 97%, and negative predictive value 89%. There was a significant correlation between rheobase with CNFD, CNBD, CNFL, and Michigan Neuropathy Screening Instrument (all P < .001). Perception threshold tracking had a very high diagnostic agreement with corneal confocal microscopy for detecting small nerve fiber loss and may have clinical utility for assessing small nerve fiber damage and hence early DPN. NCT04078516.

Accuracy Assessment of Outpatient Telemedicine Encounters at an Academic Ophthalmology Department

Abstract Purpose We assess the clinical accuracy of direct-to-patient real-time outpatient video visit encounters at our eye center. Design This was a retrospective longitudinal study. Subjects and Methods Patients who completed a video visit over a 3-week period between March and April 2020 were included. Accuracy assessment was determined by comparing diagnosis and management from the video visit with subsequent in-person follow-up over the next year. Results A total of 210 patients (mean age 55±18 years) were included, of whom 172 (82%) were recommended a scheduled in-person follow-up encounter after their video visit. Among the 141 total patients who completed in-person follow-up, 137 (97%) had a diagnostic agreement between telemedicine and in-person evaluation. Management plan agreed for 116 (82%), with the remainder of visits either escalating or deescalating treatment upon in-person follow-up with little substantive change. Compared with established patients, new patients had higher diagnostic disagreement following video visits (12 vs. 1%, p=0.014). Acute visits trended toward more diagnostic disagreement compared with routine visits (6 vs. 1%, p=0.28) but had a similar rate of management change on follow-up (21 vs. 16%, p=0.48). New patients were more likely to have early unplanned follow-up than established patients (17 vs. 5%, p=0.029), and acute video visits were associated with unplanned early in-person assessments compared with routine video visits (13 vs. 3%, p=0.027). There were no serious adverse events associated with the use of our telemedicine program in the outpatient setting. Conclusions Video visits had high diagnostic and management agreement with subsequent in-person follow-up encounters.

Risks and Benefits of Artificial Intelligence in Teledermatology

Background Recently, deep convolutional neural networks (DCNNs) became of interest as decision support systems for dermoscopic and clinical analysis of skin diseases. Application of artificial intelligence in teledermatology (TD) has been recently reported in several studies as a tool for augmented intelligence. Objective In this session, a critical discussion of the opportunities, limitations, and risks of AI in TD will be presented with special attention to recent published studies. Methods We reviewed the literature in PubMed and EMBASE databases in the period of January 2018 to November 2021 with the search terms of dermatology, skin cancer, deep learning, and AI (review of the Regulation of Medical Devices, EU 2017/745). Results A clear definition of the clinical use of AI in TD has to be considered: primary TD from patients to nurses, primary care physicians or general dermatologists; secondary TD from primary care physicians or nurses to dermatologists; or tertiary TD from dermatologists to hospital dermatologists. In some health models of TD for nurses or primary care physicians, AI assistance can lower the rates of recommending a biopsy or specialist referral, increase self-reported diagnostic confidence, and help to achieve higher diagnostic agreement rates (with dermatologists) in nonreferred cases. The main limitations of the use of AI in TD are the lack of large longitudinal studies, the lack of interpretability of the CNN, biases in the databases and unrepresented dermatological conditions for training, limited representation of different ethnicities, standardization of clinical information and of the images, liability, and privacy issues. How to implement the concept of augmented intelligence in clinical practice with referral TD consultations including structured clinical information and good-quality images will need further research and education among end users. Even if the interface is used for either store-and-forward or live TD, interactive TD is, in principle, straightforward for AI systems, and different TD modalities have particular technological requirements that can reduce their efficacy. Finally, AI systems in TD are under the umbrella of medical device regulatory frames, and specific certification is compulsory. This regulation has the benefit of assuring the quality of the new AI systems and diminishing their risks, but it can simultaneously delay the incorporation of AI tools in clinical practice. Conclusions AI has the potential to improve the results of the technology in different aspects in multiple modalities of TD. However, the evidence is weak, and several barriers and limitations have to be resolved for their integration in clinical practice. Conflicts of Interest None declared.

Research utility of a CAPS-IV and CAPS-5 hybrid interview: Posttraumatic stress symptom and diagnostic concordance in recent-era U.S. veterans.

The Clinician-Administered PTSD Scale (CAPS) is used to measure posttraumatic stress symptoms (PTSS) and diagnose posttraumatic stress disorder (PTSD). However, its use, particularly in settings involving longitudinal assessment, has been complicated by changes in the diagnostic criteria between the fourth and fifth editions of the Diagnostic and Statistical Manual of Mental Disorders (i.e., DSM-IV and DSM-5, respectively). The current sample included trauma-exposed U.S. veterans who were deployed in support of military operations following the September 11, 2001, terrorist attacks (N=371) and were enrolled in a longitudinal study focused on deployment-related stress and traumatic brain injury. A hybrid clinical interview using item wording from the CAPS for DSM-IV (CAPS-IV) with the addition of items unique to the CAPS for DSM-5 (CAPS-5) was used to assess both DSM-IV and DSM-5 PTSD diagnostic criteria, allowing for the calculation of separate total scores and diagnoses. Diagnostic agreement, sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and interrater reliability between CAPS-IV and CAPS-5 were evaluated for the entire sample and stratified by gender. We found high diagnostic agreement (92.9%-95.4%), sensitivity (94.4%-98.2%), specificity (91.7%-92.8%), PPV (89.5%-93.0%), NPV (95.7%-98.1%), and interrater reliability,κ=0.86-0.91,) for both men and women. The current study supports the use of a hybrid PTSD diagnostic interview assessing both DSM-IV and DSM-5 diagnostic criteria, particularly in situations such as longitudinal studies that may require a feasible method of incorporating changes in diagnostic criteria from the DSM-IV to the DSM-5.

Building Capacity for Community Pediatric Autism Diagnosis: A Systemic Review of Physician Training Programs.

Training primary care providers to provide diagnostic assessments for autism spectrum disorder (ASD) decreases wait times and improves diagnostic access. Outcomes related to the quality of these assessments and the impacts on system capacity have not been systematically examined. This systematic review identifies and summarizes published studies that included ASD diagnostic training for primary care providers (PCPs) and aims to guide future training and evaluation methods. Systematic searches of electronic databases, reference lists, and journals identified 6 studies that met 3 inclusion criteria: training for PCPs, community setting, and training outcome(s) reported. These studies were critically reviewed to characterize (1) study design, (2) training model, and (3) outcomes. All studies were either pre-post design or nonrandomized trials with a relatively small number of participants. There was considerable heterogeneity among studies regarding the training provided and the program evaluation process. The most evaluated outcomes were access to autism diagnosis and accuracy of diagnosis. Training PCPs to make ASD diagnoses can yield high diagnostic agreement with specialty teams' assessments and reduce diagnostic wait times. Current data are limited by small sample size, poor to fair quality study methodology, and heterogenous study designs and outcome evaluations. Evidence is insufficient to draw conclusions about the overall effects of training PCPs for ASD diagnostic assessments. Since further research is still needed, this review highlights which outcomes are relevant to consider when evaluating the quality of ASD assessments across the continuum of approaches.

Smartphone-enabled otoscopy: method evaluation in clinical practice

ObjectiveTo assess the diagnostic agreement between smartphone-enabled otoscopy and rigid otoendoscopy in tympanic membrane and middle ear diseases. MethodsA cross-sectional study was carried out to analyze otoscopies in patients seen at a general otorhinolaryngology (ORL) outpatient clinic, from June to December 2019. Eighty-three images of patients obtained from otoscopies performed through a smartphone device and a rigid endoscope were included, recorded, and stored for further analysis. The images were first analyzed by an experienced otologist, who assigned his diagnostic impression (defined as the gold standard) on each of the images. After this analysis, the images were displayed to a group of secondary raters (an experienced otorhinolaryngologist, a second-year resident in ORL, and a general practitioner). A questionnaire was applied related to each image. ResultsThere was high agreement between the smartphone device and the otoendoscopy images for all professionals, with a Kappa coefficient of 0.97 (p < 0.001). The smartphone device showed a diagnostic sensitivity of 81.1% and a specificity of 71.1%. As for the otoendoscopy, it showed a sensitivity of 84.7% and a specificity of 72.4%. The image classification as “2 = Good” was the most frequent one, with 34.9% for otoendoscopy and 31.6% for the smartphone device. ConclusionThere was a high diagnostic agreement between smartphone device-guided otoscopy and the rigid otoendoscopy, demonstrating the feasibility of using this device in clinical practice.Level of Evidence: 3

Reliability of 2 methods in maxillary transverse deficiency diagnosis

The objective of this research was to evaluate the reliability of 2 methods (Andrews' Element III analysis and Yonsei transverse analysis) in maxillary transverse deficiency diagnosis. Plaster casts and cone-beam computed tomography images of 80 outpatients with skeletal Class I malocclusion (29 males and 51 females, mean age, 20.16±8.22years) were selected. Maxillary and mandibular width were measured, respectively, and independently by 2 examiners at an interval of 2weeks, using Andrews' Element III analysis and Yonsei transverse analysis. Intraclass correlation coefficients and Bland-Altman plots of intraexaminer and interexaminer reliability were evaluated. After diagnosis, Cohen's kappa statistics were calculated to evaluate the diagnostic agreement. The intraclass correlation coefficients were all above 0.85, indicating good to excellent reliability. Compared with Andrews' Element III analysis, Yonsei transverse analysis had higher intraexaminer and interexaminer reliability in both maxillary and mandibular width measurements. Thirty-one to 42 of the patients were diagnosed with maxillary transverse deficiency by 2 examiners using 2 methods. The intraexaminer and interexaminer Cohen's kappa values of Yonsei transverse analysis were all higher than those of Andrews' Element III analysis. Both Andrews' Element III analysis and Yonsei transverse analysis had good to excellent reliability and substantial diagnostic agreement. Yonsei transverse analysis had higher reliability in maxillary and mandibular width measurements and higher diagnostic agreement, compared with Andrews' Element III analysis.

Quantification of intracranial arterial stenotic degree evaluated by high-resolution vessel wall imaging and time-of-flight MR angiography: reproducibility, and diagnostic agreement with DSA.

The purpose of this study was to compare the reproducibility and diagnostic agreement of high-resolution vessel wall imaging (HR-VWI) and time-of-flight magnetic resonance angiography (TOF-MRA) with digital subtraction angiography (DSA) to evaluate intracranial arterial stenosis. We retrospectively enrolled patients who underwent HR-VWI and TOF-MRA with suspected intracranial artery disease and had DSA results from our institutional imaging database. Two neuroradiologists separately and independently evaluated anonymous image data for the stenotic lesions. DSA was analyzed by two neurointerventionalists and it served as a standard criterion. The reproducibility of these two MR techniques was determined by the intraclass correlation coefficients (ICCs). The diagnostic agreement to DSA was assessed by the concordance correlation coefficients (CCCs). A total of 246 lesions from 106 individuals were analyzed for stenotic degrees. The total intra-observer and inter-observer reproducibility of HR-VWI was excellent for identifying stenosis and better than of TOF-MRA. The overall concordance of HR-VWI with DSA was excellent with CCC = 0.932, whereas TOF-MRA was 0.694. In addition, HR-VWI could provide additional vessel wall information. HR-VWI has more advantages over TOF-MRA, such as better reproducibilities and diagnostic agreements with DSA to analyze intracranial arterial stenosis. It provides additional information that helps in clinical diagnosis and management. • High-resolution vessel wall imaging can assess intracranial arterial stenosis with a better reproducibility than TOF-MRA and has a higher diagnostic agreement with DSA. • High-resolution vessel wall imaging had a higher diagnostic agreement with DSA compared with TOF-MRA. • Apart from evaluating vascular stenosis, HR-VWI provided additional vessel wall information to help in clinical diagnosis.

Telestroke consultation can accurately diagnose ischemic stroke mimics

Introduction Telestroke (TS) networks are standard in many areas of the US. Despite TS systems having approximately 33% mimic rates, it is unknown if TS can accurately diagnose patients with acute ischemic stroke (AIS) versus stroke mimics. Methods We performed a retrospective review of consecutive TS consults to 27 TS sites in six states during 2018. Clinical information and diagnosis were extracted from discharge records and compared to those from the TS consult. Discharge diagnoses were verified and coded into 12 categories. Cases without a clear discharge diagnosis and intracerebral haemorrhage were excluded. We report agreement and a Cohen’s kappa between TS and discharge diagnoses for the category of AIS/transient ischemic attack (TIA) versus stroke mimic. Results We included 404 cases in the analysis (mean age 66 years; 54% women). Of these, 225 had a TS diagnosis of AIS/TIA; 102 (45%) received intravenous tissue plasminogen activator. Our study demonstrated a high diagnostic agreement for AIS/TIA (88%) with a kappa of 0.75 for stroke and mimics. Of the 179 patients diagnosed with a stroke mimic on TS, 27 (15%) were diagnosed with AIS/TA by discharge. TS mimic diagnosis had a positive predictive value (PPV) of 85% and a negative predictive value (NPV) of 90%; TS diagnosis of stroke/TIA had PPV 90%, NPV 85%. Discussion We found excellent correlation between TS and discharge diagnoses for patients with both stroke and stroke mimics. This suggests that TS systems can accurately assess a wider variety of patients with acute neurologic syndromes other than AIS.

CT-like images based on T1 spoiled gradient-echo and ultra-short echo time MRI sequences for the assessment of vertebral fractures and degenerative bone changes of the spine

ObjectivesTo evaluate the performance of 3D T1w spoiled gradient-echo (T1SGRE) and ultra-short echo time (UTE) MRI sequences for the detection and assessment of vertebral fractures and degenerative bone changes compared with conventional CT.MethodsFractures (n = 44) and degenerative changes (n = 60 spinal segments) were evaluated in 30 patients (65 ± 14 years, 18 women) on CT and 3-T MRI, including CT-like images derived from T1SGRE and UTE. Two radiologists evaluated morphological features on both modalities: Genant and AO/Magerl classifications, anterior/posterior vertebral height, fracture age; disc height, neuroforaminal diameter, grades of spondylolisthesis, osteophytes, sclerosis, and facet joint degeneration. Diagnostic accuracy and agreement between MRI and CT and between radiologists were assessed using crosstabs, weighted κ, and intraclass correlation coefficients. Image quality was graded on a Likert scale.ResultsFor fracture detection, sensitivity, specificity, and accuracy were 0.95, 0.98, and 0.97 for T1SGRE and 0.91, 0.96, and 0.95 for UTE. Agreement between T1SGRE and CT was substantial to excellent (e.g., Genant: κ, 0.92 [95% confidence interval, 0.83–1.00]; AO/Magerl: κ, 0.90 [0.76–1.00]; osteophytes: κ, 0.91 [0.82–1.00]; sclerosis: κ, 0.68 [0.48–0.88]; spondylolisthesis: ICCs, 0.99 [0.99–1.00]). Agreement between UTE and CT was lower, ranging from moderate (e.g., sclerosis: κ, 0.43 [0.26–0.60]) to excellent (spondylolisthesis: ICC, 0.99 [0.99–1.00]). Inter-reader agreement was substantial to excellent (0.52–1.00), respectively, for all parameters. Median image quality of T1SGRE was rated significantly higher than that of UTE (p < 0.001).ConclusionsMorphologic assessment of bone pathologies of the spine using MRI was feasible and comparable to CT, with T1SGRE being more robust than UTE.Key Points• Vertebral fractures and degenerative bone changes can be assessed on CT-like MR images, with 3D T1w spoiled gradient-echo–based images showing a high diagnostic accuracy and agreement with CT.• This could enable MRI to precisely assess bone morphology, and 3D T1SGRE MRI sequences may substitute additional spinal CT examinations in the future.• Image quality and robustness of T1SGRE sequences are higher than those of UTE MRI for the assessment of bone structures.

Confocal Laser Endomicroscopy Interpretation and Differentiation of Pancreatic Cysts: A Randomized Trial of Teaching Modalities

ABSTRACT Background EUS-guided needle-based confocal laser endomicroscopy (nCLE) has not been widely adopted for the differentiation of pancreatic cystic lesions (PCLs), perhaps due to a perceived difficulty in learning novel CLE image patterns. Hence, we sought to investigate the optimal teaching modality for interpretation of nCLE imaging from PCLs. Methods Sixteen nCLE-naive observers blinded to clinical data were randomized into didactic (classroom-based) versus self-directed (computer-based) teaching groups to review nCLE videos and differentiate mucinous and non-mucinous PCLs. The study was conducted concurrently for both groups in 3 phases. Phase-1-Teaching: both groups received an overview of EUS-nCLE of PCLs. Phase-2-Training: assessment of 20 EUS-nCLE subject-videos; the didactic group had a feedback session with an nCLE expert while the self-directed group received this information via pre-recorded presentation. Phase-3-Testing: assessment of 50 EUS-nCLE subject-videos. Results For all observers (n = 16), the diagnostic accuracy for nCLE-based differentiation of mucinous from non-mucinous PCLs was higher (p=0.005) in the Phase-3-Testing (94.6%, 95%CI: 92-96%) than in Phase-2-Training (89.9%, 95%CI: 85-93%). During Phase-3-Testing, both the didactic and self-directed teaching groups achieved a comparable (p=0.48) diagnostic accuracy of 93.9% and 95.4%, respectively. The interobserver agreement (kappa, standard error) for the differentiation of mucinous from non-mucinous PCLs improved from Phase-2-Training to Phase-3-Testing stage, and was “substantial” for both the didactic (k=0.81, 0.03) and self-directed (k=0.79, 0.03) training groups. Conclusion Notwithstanding didactic and self-directed teaching, a ‘training’ and ‘test’ strategy accomplished high diagnostic accuracies and considerable interobserver agreement among naive observers for EUS-nCLE image differentiation of PCLs; Clinical trial NCT02516488 ( https://clinicaltrials.gov/ct2/show/NCT02516488 )

Cepheid Xpert® Flu/RSV and Seegene Allplex™ RP1 show high diagnostic agreement for the detection of influenza A/B and respiratory syncytial viruses in clinical practice

BackgroundMolecular assays based on reverse transcription‐polymerase chain reaction (RT‐PCR) provide reliable results for the detection of respiratory pathogens, although diagnostic agreement varies. This study determined the agreement between the RT‐PCR assays (Xpert® Flu/RSV vs Allplex™ RP1) in detecting influenza A, influenza B, and respiratory syncytial viruses (RSVs) in clinical practice.MethodsWe retrospectively identified 914 patient encounters where testing with both Xpert® Flu/RSV and Allplex™ RP1 was undertaken between October 2015 and September 2019 in seven hospitals across New South Wales, Australia. The diagnostic agreement of the two assays was evaluated using positive percent agreement, negative percent agreement, and prevalence and bias‐adjusted kappa.ResultsThe positive percent agreement was 95.1% for influenza A, 87.5% for influenza B, and 77.8% for RSV. The negative percent agreement was 99.4% for influenza A, 99.9% for influenza B, and 100% for RSV. The prevalence and bias‐adjusted kappa was 0.98 for influenza A, 0.99 for influenza B, and 0.97 for RSV. In a sensitivity analysis, the positive percent agreement values were significantly higher during the non‐influenza season than the influenza season for influenza B and RSV.ConclusionsThe Xpert® Flu/RSV and Allplex™ RP1 demonstrated a high diagnostic agreement for all three viruses assessed. The seasonal variation in the positive percent agreement of the two assays for influenza B and RSV may have been due to lower numbers assessed, variability in the virology of infections outside the peak season, or changes in the physiology of the infected host in different seasons.

CSF total tau/\u03b1-synuclein ratio improved the diagnostic performance for Alzheimer\u2019s disease as an indicator of tau phosphorylation

BackgroundRecently, several studies suggested potential involvements of α-synuclein in Alzheimer’s disease (AD) pathophysiology. Higher concentrations of α-synuclein were reported in cerebrospinal fluid (CSF) of AD patients with a positive correlation towards CSF tau, indicating its possible role in AD. We analyzed the CSF biomarkers to verify whether α-synuclein could be an additional supported biomarker in AD diagnosis.MethodsIn this cross-sectional study, CSF samples of 71 early-onset AD, 34 late-onset AD, 11 mild cognitive impairment, 17 subjective cognitive decline, 45 Parkinson’s disease, and 32 healthy control (HC) were collected. CSF amyloid-β1-42 (A), total tau (N), and phosphorylated tau181 (T) were measured by commercial ELISA kits, and in-house ELISA kit was developed to quantify α-synuclein. The cognitive assessments and amyloid-PET imaging were also performed.ResultsCSF α-synuclein manifested a tendency to increase in AD and to decreased in Parkinson’s disease compared to HC. The equilibrium states of total tau and α-synuclein concentrations were changed significantly in AD, and the ratio of total tau/α-synuclein (N/αS) was dramatically increased in AD than HC. Remarkably, N/αS revealed a strong positive correlation with tau phosphorylation rate. Also, the combination of N/αS with amyloid-β1-42/phosphorylated tau181 ratio had the best diagnosis performance (AUC = 0.956, sensitivity = 96%, specificity = 87%). In concordance analysis, N/αS showed the higher diagnostic agreement with amyloid-β1-42 and amyloid-PET. Analysis of biomarker profiling with N/αS had distinctive characteristics and clustering of each group. Especially, among the group of suspected non-Alzheimer’s disease pathophysiology, all A−T+N+ patients with N/αS+ were reintegrated into AD.ConclusionsThe high correlation of α-synuclein with tau and the elevated N/αS in AD supported the involvement of α-synuclein in AD pathophysiology. Importantly, N/αS improved the diagnostic performance, confirming the needs of incorporating α-synuclein as a biomarker for neurodegenerative disorders. The incorporation of a biomarker group [N/αS] could contribute to provide better understanding and diagnosis of neurodegenerative disorders.

Abstract WP301: Telestroke Consultation Can Accurately Diagnose Ischemic Stroke Mimics

Introduction: Telestroke (TS) networks have become standard in many areas of the US, increasing thrombolysis rates in patients with acute ischemic stroke (AIS). By providing an early, accurate diagnosis, patients with stroke mimics may also benefit from TS consultation and avoid unnecessary treatments and transfers. However, despite TS systems having up to 50% mimic rates, it is unknown if TS can accurately diagnose patients with stroke vs stroke mimics. Methods: This was a retrospective review of consecutive TS consults at the University of Utah Hospital to 27 TS sites in 6 states from Jan-Dec 2018. Clinical information and diagnosis were extracted from discharge records and compared to those from the TS consult. Discharge diagnosis was determined by the discharging physician, recorded by the TS coordinator, and verified and coded into 12 categories by 2 physicians. Cases without a clear discharge diagnosis were excluded. When multiple TS diagnoses were listed without priority, the first one was used as the diagnosis. We report agreement and a Cohen’s kappa between TS and discharge diagnoses for the category of AIS/TIA versus stroke mimic. Results: We reviewed 476 TS cases (mean age 66 years; 54% women); 71 were excluded for lack of discharge diagnosis leaving 405 cases for analysis. Of these, there were 225 TS diagnoses of AIS/TIA; 102 (45%) received IV tPA. Our study demonstrated high diagnostic agreement for AIS/TIA (88%) with a kappa of 0.75 for stroke and mimics. Of the 180 patients diagnosed with a stroke mimic on TS, 27 (15%) were diagnosed with AIS/TA by discharge . (Figure 1 ). TS mimic diagnosis had a PPV of 85% and NPV of 90%; TS diagnosis of stroke/TIA had PPV 90%, NPV 85%. Only 3% of stroke mimics were transferred. Conclusion: The Utah TS system has excellent correlation between TS and discharge diagnoses for patients with both stroke and stroke mimics. This suggests that TS systems can accurately assess a wider variety of patients with acute neurologic syndromes other than AIS.

Diagnostic validity and triage concordance of a physiotherapist compared to physicians\u2019 diagnoses for common knee disorders

BackgroundEmergence of more autonomous roles for physiotherapists warrants more evidence regarding their diagnostic capabilities. Therefore, we aimed to evaluate diagnostic and surgical triage concordance between a physiotherapist and expert physicians and to assess the diagnostic validity of the physiotherapist’s musculoskeletal examination (ME) without imaging.MethodsThis is a prospective diagnostic study where 179 consecutive participants consulting for any knee complaint were independently diagnosed and triaged by two evaluators: a physiotherapist and one expert physician (orthopaedic surgeons or sport medicine physicians). The physiotherapist completed only a ME, while the physicians also had access to imaging to make their diagnosis. Raw agreement proportions and Cohen’s kappa (k) were calculated to assess inter-rater agreement. Sensitivity (Se) and specificity (Sp), as well as positive and negative likelihood ratios (LR+/−) were calculated to assess the validity of the ME compared to the physicians’ composite diagnosis.ResultsPrimary knee diagnoses included anterior cruciate ligament injury (n = 8), meniscal injury (n = 36), patellofemoral pain (n = 45) and osteoarthritis (n = 79). Diagnostic inter-rater agreement between the physiotherapist and physicians was high (k = 0.89; 95% CI:0.83–0.94). Inter-rater agreement for triage recommendations of surgical candidates was good (k = 0.73; 95% CI:0.60–0.86). Se and Sp of the physiotherapist’s ME ranged from 82.0 to 100.0% and 96.0 to 100.0% respectively and LR+/− ranged from 23.2 to 30.5 and from 0.03 to 0.09 respectively.ConclusionsThere was high diagnostic agreement and good triage concordance between the physiotherapist and physicians. The ME without imaging may be sufficient to diagnose or exclude common knee disorders for a large proportion of patients. Replication in a larger study will be required as well as further assessment of innovative multidisciplinary care trajectories to improve care of patients with common musculoskeletal disorders.

Diagnostic agreement and interobserver concordance with teledermoscopy referrals.

Malignant melanoma and non-melanoma skin cancers are among the fastest increasing malignancies in many countries. With the help of new tools, such as teledermoscopy referrals between primary health care and dermatology clinics, the management of these patients could be made more efficient. To evaluate the diagnostic agreement and interobserver concordance achieved when assessing referrals sent through a mobile teledermoscopic referral system as compared to referrals sent via the current paper-based system without images. The referral information from 80 teledermoscopy referrals and 77 paper referrals were evaluated by six Swedish dermatologists. They were asked to answer questions about the probable diagnosis, the priority, and a management decision. Teledermoscopy generally resulted in higher diagnostic agreement, better triaging and more malignant tumours being booked directly to surgery. The largest difference between the referral methods was seen for invasive melanomas. Referrals for benign lesions were significantly more often correctly resent to primary health care with teledermoscopy. However, referrals for cases of melanoma in situ were also incorrectly resent five times. The interobserver concordance was moderate with both methods. By adding clinical and dermoscopic images to referrals, the triage process for both benign and dangerous skin tumours can be improved. With teledermoscopy, patients with melanoma especially can receive treatment more swiftly.