Volume Scans Research Articles

Investigation of pulmonary artery dilation in the population of Moscow using automated analysis of radiological examination results

INTRODUCTION: In modern clinical practice, the diagnosis establishment and monitoring of pulmonary arteries are important components of care for patients with cardiovascular and respiratory diseases. However, in Russia, there remains a limited amount of epidemiological data on the prevalence of pulmonary artery dilation, especially at the population level.This study aims to fill this gap by providing population-based data on the prevalence of pulmonary artery dilation in the city of Moscow. With the help of advanced artificial intelligence technologies, this work seeks to offer a comprehensive assessment of the pathology, covering both its main characteristics and the effects of various factors such as age and gender.OBJECTIVE: To investigate the prevalence of pulmonary artery dilation in Moscow using the data from computed tomography (CT) scans of the chest analysed by means of an automatic artificial intelligence technology.MATERIALS AND METHODS: The study involved the analysis of a large volume of chest CT scans acquired from September 2022 to February 2023. The total study sample comprised 134,218 patients. Artificial intelligence technologies were applied for the automatic detection of signs of pulmonary artery dilation.RESULTS: An analysis of 125,878 CT scans, including 57,913 men and 67,965 women, revealed that 34.4% of patients (43,242 individuals) showed signs of pulmonary artery dilation. Among them, the proportion of men with this pathology was 35.6% (20,630 individuals), while for women it was 33.3% (22,612 individuals). The prevalence of the pathology increased with age, starting at 14.8% among younger patients and reaching 62.7% among the elderly. The prevalence of pulmonary artery dilation among the population of Moscow was 794.7 cases per 100,000 people.DISCUSSION: The results of this research allowed us to draw conclusions regarding the meaning of pulmonary artery dilation as a predictor of pulmonary hypertension. The results demonstrated a correlation between the frequency of pathology occurrence and gender and age groups, with a more pronounced association observed in women. Detailed analysis also revealed corellations of pulmonary artery diameter with age and gender.CONCLUSION: The study provided the first population-based data on the prevalence of pulmonary artery dilation in Moscow. The importance of early diagnosis to prevent severe complications, especially in patients with chronic lung diseases, is emphasized. The study results can provide a basis for screening strategies and treatment approaches for this pathology.

Catheterizations Reduced Following a Protocol Change for Postoperative Urinary Retention Following Total Joint Arthroplasty With Spinal Anesthesia.

Postoperative urinary retention (POUR) is a common concern after total joint arthroplasty (TJA). However, overdiagnosis of POUR by bladder scans may lead to unnecessary interventions and associated complications. The purpose of this study was to determine the viability of a selective bladder scanning protocol to reduce overdiagnosis of POUR following TJA. A study of 500 consecutive patients operated on by 13 surgeons underwent a novel bladder scanning protocol designed to reduce overdiagnosis of POUR (selective protocol) through selective bladder scanning of only patients symptomatic for urinary retention. The protocol was then compared with the previous bladder scanning protocol under which 500 patients received routine bladder scans following TJA regardless of symptoms. The primary outcome of interest was the catheterization rate. Chi-squared and Student t-tests were used for analyses. Catheterization rates were markedly reduced when following the novel protocol (46.6% standard versus 38.2% selective; P = 0.009). Prevoid bladder scan volumes were markedly higher in the selective protocol cohort (459 ± 278 mL, 746 ± 226 mL; P ≤ 0.001), whereas postvoid bladder scan volumes were the same (247 ± 250 mL, 243 ± 271 mL; P = 0.859). Preoperative evaluation of urinary problems, intraoperative urinary complications, postoperative urinary symptoms, and spinal medication type were similar in each cohort. Length of service, rate of same-day discharge, total surgical time, and readmission rate were also similar. The selective protocol led to a notable reduction in catheterizations when compared with the standard protocol. This was done safely, without increased rates of urinary-related complications during or following surgery. These findings suggest that the selective protocol should be considered as a viable alternative to reduce overdiagnosis of POUR in TJA patients.

A multi-centre, randomised trial for diagnostic efficacy of the automatic breast volume scanner ultrasound for breast cancer screening in China.

The US plays a crucial role in screening Asian women for breast disease. ABUS offers several advantages over traditional HHUS, including quicker examination, objectivity, and the ability to store and reconstruct images. This study marks the first large-scale opportunistic screening of ABUS in the population. Between January 1, 2016, and December 31, 2019, 10,537 women aged 35-75 years from nine districts were randomly assigned to either HHUS or ABUS groups. Diagnostic methods were quantified, and comparisons were made using the Chi-square test. The screening groups consisted of 5,445 participants for HHUS and 4,936 for ABUS. The HHUS and ABUS groups identified 90 carcinomas and 292 benign lesions or 71 carcinomas and 178 benign lesions, respectively. SE), SP, AC, PPV, and NPV for HHUS were 51.11%, 93.84%, 93.13%, 12.23%, and 99.13%, respectively, while for ABUS, they were 66.20%, 93.77%, 93.38%, 13.43%, and 98.98%. The area under the curve (AUC) values for HHUS and ABUS were 0.72 (95% CI: 0.67-0.78) and 0.86 (95% CI: 0.82-0.91), respectively, indicating superior diagnostic performance of ABUS over HHUS (Delong test p < 0.05). ABUS is user-friendly, requires minimal training, reduces reliance on examiner experience, and demonstrates potential for superior sensitivity compared to HHUS in breast cancer screening.

Rapid Sampling and Polarimetric Statistics of Lightning With a Phased Array Radar

AbstractPrevious studies of lightning detection by radar mostly consisted of observations with reflector‐antenna systems yielding slow volume scan times. Phased array radars offer much faster scan times that are likely to capture echoes from propagating lightning channels. Rapidly updated range‐height indicator scans were used to observe severe storms that occurred in central Oklahoma with the fully digital S‐band Horus PAR to examine echoes from lightning plasma. Numerous lightning echoes were observed during the sampling period in good spatial and temporal agreement with lightning mapping array detections of very high frequency radiation sources. Statistically, they result in increased horizontal reflectivity factor, deviations in radial velocity and spectrum width, highly variable differential reflectivity and differential phase, and decreases in correlation coefficient. Results presented also highlight the capability of phased array radars to better observe lightning compared to current radars, and aid in the study of storm electrification and lightning physics.

Are we systematically overdosing women? Revisiting standardized contrast protocols for thoracoabdominal CT scans.

The purpose of this study was to evaluate whether the iodine contrast in blood and solid organs differs between men and women and to evaluate the effect of BMI, height, weight, and blood volume (BV) on sex-specific contrast in staging CT. Patients receiving a venous-phase thoracoabdominal Photon-Counting Detector CT (PCD-CT) scan with 100- or 120-mL CM between 08/2021 and 01/2022 were retrospectively included in this single-center study. Image analysis was performed by measuring iodine contrast in the liver, portal vein, spleen, left atrium, left ventricle, pulmonary trunk, ascending and descending aorta on spectral PCD-CT datasets. Univariable and multivariable analyses were performed to assess the impact of sex, age, BMI, height, weight, and BV on the iodine contrast. A total of 274 patients were included (mean age 68 years ± 12 SD, 168 men). Iodine contrast in organs and blood attenuation was significantly higher in women when using the same volume of CM. Sex, age, BMI, height, weight, and BV significantly influenced iodine contrast. After adjusting for confounding variables, sex remained a significant factor, with women having higher parenchymal and vascular iodine contrast. Standardized or weight-adapted use of CM in venous-phase thoracoabdominal CT scans results in significantly higher contrast in women compared to men. Customizing the CM dose to the patient's BV could result in a similar contrast between sexes. This approach has the potential to reduce the amount of CM, resulting in cost savings, and to decrease the risks associated with CM, particularly for the female sex. Question This study addresses whether current standardized iodinated contrast media protocols lead to systematically higher iodine enhancement in women than in men during thoracoabdominal CT. Findings Women consistently show greater iodine enhancement in blood and abdominal organs compared to BMI-matched men when receiving identical volumes of contrast media. Clinical relevance Adjusting contrast media dosage based on blood volume in venous-phase CT scans could equalize parenchymal and intravascular iodine enhancement across sexes. This approach may reduce unnecessary contrast exposure in women, lower associated risks, and optimize healthcare resource allocation.

Comparison of epicardial adipose tissue volume of normal and coronary artery disease patients during diastolic and systolic phases of retrospective electrocardiogram-gated volume scan

IntroductionThe abundance of epicardial adipose tissue (EAT) correlates with the extent and severity of coronary artery disease (CAD). If the quantity of EAT varies between diastole and systole during an ECG-synchronized volume scan, it can potentially affect the diagnostic accuracy of CAD. The aim of this study was to compare the EAT volume between the diastolic and systolic phases during an ECG-gated volume scan of patients with or without CAD. MethodsIn this study, 47 patients (11 with and 36 without CAD) underwent coronary computed tomography (CT) angiography between September 2022 and August 2023. All patients underwent a second-generation 320-row computed tomography (CT) scan with a retrospective ECG-triggered volume scan. The data volumes obtained at 5 % steps of the R–R interval were automatically analyzed on a Ziostation2 Plus workstation using a CT coronary artery analysis application. Myocardial fat components ranging from −160 to −70 in CT value were extracted to determine fat content. EAT volumes between R–R intervals were compared for 40 % diastolic and 75 % systolic phases in the scans of patients with and without CAD. ResultsThe median and interquartile range (IQR) of the EAT volumes were 130 (112–183) mL and 98 (67–129) mL for the groups with and without CAD, respectively, indicating a significant difference (p < 0.05). For the ECG-gated scan without CAD, the median and IQR of the EAT volumes were 98 (66–129) and 94 (68–134) mL in the diastolic and systolic phases (p = 0.82), respectively, and for CAD, 166 (129–191) and 158 (113–178) mL (p = 0.56), respectively. Thus, the differences in the EAT volume were not significant between diastolic and systolic phases (p > 0.05). ConclusionDifferences in EAT volume between patients with and without CAD were significant. However, the EAT volume differences between the diastolic and systolic phases were not significant, irrespective of CAD, during the ECG-gated volume scans. Implications for practiceThe diastolic and systolic cardiac phases did not significantly influence EAT volume measurements.

3D ophthalmic ultrasonography at the slit lamp using existing ultrasound systems.

This study aims to explore the feasibility and performance of three-dimensional ultrasound (3DUS) imaging in ophthalmology using commercially available ultrasound probes adapted to a slit lamp. Despite ultrasound's long-standing application in eye care for visualizing ocular components, the evolution of 3DUS technology has remained inactive, with limited development and commercial availability. This study introduces a novel method that could potentially enhance ophthalmic diagnostics and treatment planning by providing comprehensive 3D views of ocular structures using existing ultrasound probes adapted to the conventional slit lamp. A custom system was designed for mounting a linear actuator to a slit lamp and enabling the horizontal actuation of any ultrasound probe. Ophthalmic and non-ophthalmic ultrasound probes were tested for their ability to reconstruct 3DUS images of the posterior pole. The study involved designing and evaluating three US phantoms ex vivo and performing in vivo imaging on human subjects to assess the system's applicability. The system successfully acquired 3D volume scans of phantoms and live human eyes, demonstrating the system's potential for detailed ocular imaging. The adaptability of the device allowed for compatibility with various ultrasound probes. In vivo imaging revealed the system's capability to produce high-resolution 3D reconstructions of ocular structures, including eyes with pathological conditions. The introduction of a slit lamp-mounted 3DUS system represents a significant advancement in ophthalmic ultrasonography, offering a practical and accessible solution for comprehensive 3D ocular assessments. The device's modularity and compatibility with existing ultrasound probes make it a versatile tool for a wide range of ophthalmic applications. Further research and clinical trials are needed to optimize the system's performance and validate its clinical utility.

Volumetric assessment of the soft tissue envelope in unilateral closed ankle fractures using a portable 3D scanner.

Management of ankle fractures necessitating surgery is impacted by soft tissue swelling, often delaying open reduction and internal fixation (ORIF). Subjective evaluations are inconsistent, and traditional measurement methods are often inaccurate or impractical. This prospective observational study included 17 adults with unilateral closed ankle fractures requiring surgical fixation. A measurement protocol on regions of interest (ROI) was utilized, employing a handheld 3D scanner for daily volume scans of the fractured ankle, comparing these measurements with subjective assessments of swelling using a numerical scale. The 3D scanner detected significant soft tissue volume reductions of the ROI over 14 days, with reductions of 25 ± 25 % in the lower limb and 16 ± 9 % in the ankle. Significant swelling reduction was noted from day 8, preceding surgeons' assessments (days 11-14). The scanner exhibited high reproducibility, providing an objective tool for comparative studies on decongestive measures in perioperative soft tissue management. LEVEL OF EVIDENCE: 2 - Diagnostic Level 1 - Prognostic Level 1 - Prospective comparative study Level 2.

MACULAR VOLUME SCAN AS A MARKER OF ANGIOGRAPHIC UVEITIC RETINAL VASCULITIS: A Retrospective Longitudinal Study.

To determine whether optical coherence tomography thickness values from macular volume scans can be used to detect uveitic retinal vasculitis. Retrospective study of patients with noninfectious retinal vasculitis. Fluorescein angiogram and 61-line optical coherence tomography macular volume scans with an overlying Early Treatment Diabetic Retinopathy study grid were obtained. Correlation between 1 mm and 6 mm Early Treatment Diabetic Retinopathy study ring values and posterior pole vasculitis was analyzed. A linear longitudinal model was used to assess the relationship between global retinal vasculitis scores and optical coherence tomography macular thickness parameters. Ninety-nine eyes of 54 patients were included. A total of 460 optical coherence tomography and fluorescein angiogram pairs were analyzed. Central (1 mm) macular thickness was weakly correlated with posterior pole vasculitis (correlation coefficient [rho] = 0.09, P = 0.06). Both the mean 6 mm ring (rho = 0.11, P = 0.018) and the average of the superior and inferior (S/I) 6 mm ring values (rho = 0.13, P = 0.006) were strongly correlated with posterior pole leakage. The longitudinal model showed that S/I 6 mm ring values are associated with vasculitis in the posterior pole, mid, and far periphery ( P < 0.0001). Optical coherence tomography-based macular volume thickness can detect uveitic retinal vasculitis and aid in monitoring disease activity.

A Systematic Review of the Applications of Deep Learning for the Interpretation of Positron Emission Tomography Images of Patients with Lymphoma.

Background: Positron emission tomography (PET) is a valuable tool for the assessment of lymphoma, while artificial intelligence (AI) holds promise as a reliable resource for the analysis of medical images. In this context, we systematically reviewed the applications of deep learning (DL) for the interpretation of lymphoma PET images. Methods: We searched PubMed until 11 September 2024 for studies developing DL models for the evaluation of PET images of patients with lymphoma. The risk of bias and applicability concerns were assessed using the prediction model risk of bias assessment tool (PROBAST). The articles included were categorized and presented based on the task performed by the proposed models. Our study was registered with the international prospective register of systematic reviews, PROSPERO, as CRD42024600026. Results: From 71 papers initially retrieved, 21 studies with a total of 9402 participants were ultimately included in our review. The proposed models achieved a promising performance in diverse medical tasks, namely, the detection and histological classification of lesions, the differential diagnosis of lymphoma from other conditions, the quantification of metabolic tumor volume, and the prediction of treatment response and survival with areas under the curve, F1-scores, and R2 values of up to 0.963, 87.49%, and 0.94, respectively. Discussion: The primary limitations of several studies were the small number of participants and the absence of external validation. In conclusion, the interpretation of lymphoma PET images can reliably be aided by DL models, which are not designed to replace physicians but to assist them in managing large volumes of scans through rapid and accurate calculations, alleviate their workload, and provide them with decision support tools for precise care and improved outcomes.

Prognostic Relevance of Relative Ellipsoid Zone Reflectivity for Ellipsoid Zone Loss in Macular Telangiectasia Type 2.

The relative ellipsoid zone reflectivity (rEZR) is an innovative biomarker for photoreceptor alterations and showed association with disease staging in macular telangiectasia type 2 (MacTel). However, its prognostic relevance for the ellipsoid zone (EZ) loss is unclear. Longitudinal spectral-domain optical coherence tomography (SD-OCT) imaging of patients with MacTel from an observational natural history study was used for en face determination of manifest EZ loss. The rEZR was assessed globally (mean rEZR/SD-OCT volume scan) and topographically (spatially refined). Logistic and linear-mixed effect models were used to investigate the rEZR's association with EZ loss onset and the (square-root transformed) progression rate of existing EZ loss. A total of 97 eyes of 70 patients (39 women, mean age = 60.3 ± 8.9years) were included and reviewed in a median observational period of 28.7 months (range = 20.3-49.9 months). Whereas 65 eyes of 44 patients showed manifest EZ loss (mean ± SD area = 0.44 ± 0.57mm2) at baseline, 14 eyes of 14 patients developed EZ loss over time. Significant associations of the rEZR were only found in the topographical analyses indicated by lower rEZR values and a higher risk for EZ loss onset (odds ratio [OR] = 0.34, 95% confidence interval [CI] = 0.29 to 0.39, P < 0.001) as well as a faster EZ loss progression (coefficient estimate = -0.002, 95% CI = -0.0046 to 0.0001, P = 0.038). This study demonstrates the prognostic relevance of spatially refined rEZR changes before and beyond already existing EZ loss for both its onset and progression over time in MacTel. Further analyses of the rEZR are warranted to achieve both a more tailored patient selection and a novel end point identification for clinical trials in MacTel.

Hyperreflective material evolution patterns during long term anti-VEGF therapy in neovascular age-related macular degeneration.

This retrospective, real-life cohort was analyzed to detect the frequency of different HRM evolution patterns and their correlation with MNV types, morphological and functional changes in exudative nAMD under long-term anti-VEGF therapy.We evaluated optical coherence tomography (OCT) volume scans in 143 eyes of 94 nAMD patients (start of anti-VEGF therapy 2009-2018, therapy until the last visit) and recorded the VA at all visits. HRM evolution patterns were differentiated: pattern 1 = no HRM, pattern 2 = subretinal HRM resolved during follow-up, pattern 3 = persistent subretinal HRM with new HRM-boundary remodeling [BR], pattern 4 = persistent subretinal HRM without HRM-BR. Pattern 1 was observed in 58 eyes (40.6%), 33 eyes (23.1%) showed pattern 2, 39 eyes (27.3%) pattern 3 and 13 eyes (9.1%) pattern 4. HRM pattern correlated with type 1-3 MNV (p = 0.02), especially pattern 1 with type 1 MNV and pattern 3 with type 2 MNV. Over time, a change of MNV types could be observed only from type 2 into type 1 MNV (p = 0.0001). Some eyes with HRM pattern 3 changed during follow-up into pattern 4, which was often associated with the presence of macular atrophy (p = 0.0001) and demonstrated a reduced mean VA compared to pattern 1-3 at baseline (p = 0.0001), year 1 (p = 0.0001) and final visit (p = 0.02).In this study, we characterized different HRM evolution patterns in a real-world dataset and demonstrated their associations with MNV transformation during long term anti-VEGF therapy. The HRM patterns may provide prognostic value with morphological and functional implications.

Improving Tornado Intensity Prediction by Assimilating Radar-Retrieved Vortex Winds After Vortex Relocation

A time–space shift method was recently developed for relocating the best ensemble member predicted tornado vortex to the radar-observed location, aiming to improve the model’s initial condition and subsequent prediction of tornadoes. To further improve tornado prediction, a variational method for analyzing vortex flows, referred to as VF-Var, is used in this paper to retrieve high-resolution vortex winds from the earliest radar volume scan of tornado and the retrieved vortex winds are then assimilated as “observations” after the vortex relocation. The previous three-step method is also adaptively modified to estimate the tornado vortex center location, denoted by xc ≡ (xc, yc) as a continuous function of height z and time t, from the earliest two consecutive radar volume scans of the tornado, so the estimated xc(z, t) can have the VF-Var required accuracy for retrieving high-resolution vortex winds and the retrieved vortex winds can be assimilated as “observations” with a minimized observation latency. This approach, combined with vortex relocation, is applied to the 20 May 2013 Oklahoma Newcastle–Moore tornado, and is shown to be very effective in further improving the tornado intensity prediction and the continuity of predicted tornado track. Although assimilating the retrieved high-resolution vortex winds after the vortex relocation does not greatly affect the overall trajectory of the predicted tornado track, it proves highly beneficial.

Local OCT Structural Correlates of Deep Visual Sensitivity Defects in Early Atrophic Age-Related Macular Degeneration.

To determine local OCT structural correlates of deep visual sensitivity defects (threshold of ≤10 decibels on microperimetry) in early atrophic age-related macular degeneration (AMD). Prospective observational study. Forty eyes from 40 participants, with at least incomplete retinal pigment epithelium (RPE) and outer retinal atrophy (iRORA), or more advanced atrophic lesion(s). Participants underwent at least two targeted, high-density microperimetry tests of atrophic lesions of interest in one eye, and high-density 3×3 mm volume scans of that region on a swept-source OCT angiography device, all at a single visit. Seven OCT-defined features of atrophy were manually annotated: hypertransmission, RPE attenuation/disruption, complete RPE loss, ellipsoid zone (EZ) disruption, external limiting membrane (ELM) disruption, subsidence of the outer plexiform layer (OPL) and inner nuclear layer (INL), and/or hyporeflective wedge-shaped band, and outer nuclear layer (ONL) thickness. Association between OCT-defined features of atrophy and presence of a deep visual sensitivity defect at a local, pointwise level. All OCT-defined features of atrophy were individually associated with the presence of a deep visual sensitivity defect at a pointwise level in univariable mixed-effects logistic regression analyses (P < 0.001 for all). However, only hypertransmission, complete RPE loss, ELM disruption, and ONL thickness remained significantly and independently associated with deep visual sensitivity defects in a multivariable analysis (P ≤ 0.011). A prediction model incorporating these four OCT features (partial area under the curve [pAUC] at ≥90% specificity = 0.80) outperformed models using any single feature alone in predicting the presence of deep visual sensitivity defects (pAUC = 0.65 to 0.78 respectively; P ≥ 0.040). The study identified hypertransmission, complete RPE loss, ELM disruption, and ONL thickness as key OCT-defined features of atrophy independently associated with deep visual sensitivity defects. These findings are important when considering anatomical outcome measures for evaluating interventions for early atrophic AMD that are most likely to capture beneficial treatment effects that will be accompanied by evidence of functional preservation if measured directly.

Development of an Evaluation Method for Precipitation Particle Types by Using Disdrometer Data

Abstract A method for evaluating precipitation particle types from the size–fall velocity data observed by disdrometers by combining an expectation–maximization (EM) algorithm and a self-organizing map (SOM) was developed. An EM algorithm was used to estimate the particle size–fall velocity relationships according to previous work, and the SOM map was used to classify the relationships into graupel or snow categories. The method was applied for snowfall data observed by the volume scanning video disdrometer at a site in Sapporo, Japan, and the daily graupel-to-solid precipitation ratio (G/S ratio) from 1 December 2017 to 28 February 2018 was obtained. The sensitivity of the results to different SOM configurations, SOM node groupings, and training datasets was also tested. The G/S ratio obtained from the simulation data of a meteorological model was compared as an example of the application of the product created by the new method. Significance Statement A method using machine learning for evaluating the precipitation particle types from size and fall velocity data observed by a disdrometer was developed. This method was applied to classify data observed in Sapporo, Japan, in a single winter into graupel and snow, and the daily graupel-to-solid precipitation ratio was obtained. The daily graupel-to-solid precipitation ratio was compared with that simulated by a meteorological model as an example of the application of disdrometer data.

Neuroanatomical alterations in young boys and adolescents with Klinefelter syndrome

Klinefelter syndrome (KS, 47,XXY) is a common sex chromosome aneuploidy in males that is characterized by pubertal developmental delays and a wide range of alterations in cognitive, social and emotional functioning. The neural bases of these behavioral symptoms, however, are unclear. A total of 130 boys and adolescents, including 67 males with KS (11.5 ± 2.8 years) and 63 typically developing (TD; control) males (10.6 ± 2.8 years) underwent MRI scanning and pubertal assessment. Group differences in regional gray matter volume was examined using voxel-based morphometry while controlling for age at scan and total gray matter volume. Thresholded statistical significance maps indicated widespread reductions in frontal and temporal and cerebellar gray matter in males with KS relative to TD males, as well as increases in parietal and occipital gray matter. Secondary analyses explored potential associations between GMV in these regions and pubertal development. Lower testicular volume was a significant predictor of reduced GMV in frontal, temporal and cerebellar subregions, even after accounting for group status (KS, TD). Taken together, these findings add support for a neuroanatomical phenotype of KS and provide initial evidence for a role of pubertal development in KS-associated differences in gray matter structure. Future studies that examine the influence of testosterone supplementation on GMV in males with KS are warranted.

Effects of Anatomical Variation on Ganglion Cell and Nerve Fibre Layer Evaluation by Optical Coherence Tomography.

Background/Objectives: The automated analyses of optical coherence tomography (OCT) scans of the retina occasionally suggest the presence of tissue deficits when no visual field defects can be detected. This study was made to find the sources of such alerts. Methods: Data from a population-based cohort of 360 participants aged 30-80 years was analysed for the anatomical sources of alerts after the extensive exclusion of participants where any suspicion of abnormality could be raised. An analysis was made of 12 × 9 mm volume scans centred between the disc and the fovea. The exclusions comprised 107 eyes with definite or borderline abnormal visual fields or other potentially confounding characteristics. A statistical analysis of the thickness patterns was made using the manufacturer's proprietary algorithm. The analysis comprised alerts corresponding to local layer thickness values in the lower 5th percentile of an independent reference population. Results: Of the 613 eligible healthy eyes, thickness deficit alerts were seen in 391. They were related to the angle between the temporal nerve fibre ridges being wider, narrower, or rotated compared to the reference template in 174 eyes and to the variations in the size of the macula in 207 eyes. The source was unidentifiable in 28 eyes. The common sources were a thin papillomacular nerve fibre layer accompanied by arcuate nerve fibre ridges spaced far apart and a thinly, but wider than the normal macular ganglion cell layer. Conclusions: Anatomical variation in the retinal nerve fibre and ganglion cell layers was the source of more than 90% of the thickness deficit alerts in the eyes with normal visual fields.

Optical Attenuation Coefficient-Based En Face Optical Coherence Tomography Imaging for the Reliable Assessment of the Ellipsoid Zone.

Objective: This study used optical attenuation coefficient (OAC)-based optical coherence tomography (OCT) en face images to assess the ellipsoid zone (EZ) in the foveal region. Methods: This retrospective, observational, cross-sectional study of 41 healthy volunteers and 34 patients with retinal diseases included imaging data acquired using a prototype swept-source OCT system. EZ en face images were generated from OCT raster scan volumes based on OAC, followed by denoising and binarization to quantify the percentage of EZ structural normality or abnormality relative to the total imaging area. We evaluated the reliability of the OAC-based method compared with the OCT signal intensity-based method in healthy and diseased eyes. In addition, the validated program was applied to patients with various retinal conditions. Results: The estimated normal EZ area in healthy eyes was 96.2 ± 5.6% using the OAC-based method versus 89.3 ± 18.8% for the intensity-based method. The OAC-based method effectively mitigated various artifacts caused by retinal blood vessels and other factors in both healthy and diseased eyes. In a pilot study involving six diseased eyes, the area exhibiting EZ structural abnormalities was 27.5-99.6%. Conclusions: The OAC-based EZ assessment robustly suppressed image artifacts and reliably characterized structural abnormalities in the EZ from OCT volumes.

Progression to complete retinal pigment epithelium and outer retinal atrophy (cRORA): post hoc analysis of the GATHER1 trial.

Determine rates of progression of incomplete retinal pigment epithelium and outer retinal atrophy (iRORA) to complete retinal pigment epithelium and outer retinal atrophy (cRORA) and rates of progression of drusen to iRORA/cRORA in eyes with geographic atrophy (GA) treated with avacincaptad pegol (ACP). Post hoc analysis of the GATHER1 prospective, randomized, double-masked Phase II/III study that evaluated ACP 2mg vs. sham. Optical coherence tomography (OCT) data from GATHER1 were transferred to the Doheny Image Reading and Research Lab for masked analysis by readers experienced with Classification of Atrophy Meeting (CAM) grading features. Regions of OCT volume scans more than 500µm from the border of GA lesions were evaluated at baseline and at months 6, 12, and 18. Participants with iRORA and/or drusen (≥ 40µm height on OCT) at baseline were included in the analysis. The proportion of eyes progressing from iRORA to cRORA in the ACP 2mg group was 5.0%, 15.0%, and 20.0% at months 6, 12, and 18 respectively, as compared with 11.8%, 30.2%, and 41.8% of eyes in the sham group. The proportion of ACP 2mg-treated eyes progressing from drusen to iRORA or cRORA was 3.8%, 7.6%, and 7.6% at months 6, 12, and 18 compared with 15.9%, 18.1%, and 27.2% of sham-treated eyes. Rates of progression from iRORA to cRORA and drusen to iRORA/cRORA were reduced in eyes treated with ACP 2mg vs. sham, with increasing separation between groups over time, suggesting early intervention may slow disease progression. ClinicalTrials.gov identifier: NCT02686658. Date of registration: February 16, 2016. What is known Geographic atrophy is an advanced form of age-related maculardegeneration (AMD) that leads to irreversible vision loss, presenting a significant public health unmet need. The Classification of Atrophy Meeting (CAM) group recommended a new nomenclature for advanced AMD lesions, based on the affected anatomical layers on optical coherence tomography. Accordingly, the terms incomplete retinal pigment epithelium and outer retinal atrophy (iRORA) and complete retinal pigment epithelium and outer retinal atrophy (cRORA) were introduced (Guymer et al., Ophthalmology 127:394-409, 2020; Sadda et al., Ophthalmology 125:537-548, 2018). What is new GATHER1 post hoc analysis shows that treatment with avacincaptad pegol (ACP) 2mg decreases the proportion of eyes that progress from iRORA to cRORA, and from drusen to iRORA or cRORA, compared with sham, over 6, 12, and 18months. These findings suggest a potential role for ACP in delaying the progression of existing pre-atrophic AMD lesions.

Repeatability of Microperimetry in areas of RPE and Photoreceptor loss in Geographic Atrophy supported by AI-based OCT biomarker quantification

PurposeGrowing interest in microperimetry (MP) or fundus-controlled perimetry (FCP) as targeted psychometric testing method in geographic atrophy (GA) is warranted due to the disease subclinical/extra-foveal appearance or preexisting foveal loss with visual acuity becoming unreliable. We provide comprehensive pointwise test-retest repeatability reference values on the most widely used MP devices and combine them with targeted testing in areas of retinal pigment epithelium (RPE) as well as photoreceptor (PR) integrity loss, guiding the interpretation of sensitivity loss during the long-term follow-up of GA patients. DesignProspective reliability study MethodsPatients with GA underwent consecutive testing on CenterVue (iCare) MAIA and NIDEK MP3 devices. Obtained PWS measurements were spatially co-registered to an optical coherence tomography (OCT) volume scan acquired during the same visit. Areas with RPE and PR integrity loss, drusen and PR thickness as well as the volume of hyperreflective foci (HRF) where identified and quantified using a set of validated deep learning-based algorithms. Test-retest repeatability was assessed according to areas defined by biomarker-specific morphologic changes using Bland-Altmann coefficients of repeatability (CoR). Furthermore, the inter-device correlation, the repeatability of scotoma point detection as well as any potential effects on fixation stability were assessed. Results900 stimuli per device from twenty subjects were included. Identical overall PWS test-retest variance could be detected for MAIA (±6.57) and MP3 (±6.59). PR integrity loss was associated with a higher test-retest variance on both devices (MAIA: p=0.002; MP3: p<0.001). Higher CoR for stimuli in areas presenting RPE loss (±10.99 vs ±5.34) or HRF (±9.21 vs ±6.25) could only be detected on MP3 examinations (p<0.001 and p=0.01, respectively). An excellent intra-device correlation (MAIA: 0.94[0.93-0.95] MP3: 0.94[0.94-0.95]) and a good mean inter-device correlation (0.84[0.53-0.92]) could be demonstrated. The chosen device, run order or absence of foveal sparing had no significant effect on fixation stability. ConclusionAreas presenting automatically quantified PR integrity loss with and without underlying RPE loss are associated with higher test-retest variance for both MAIA and MP3. These findings are crucial for an accurate interpretation of GA progression during long-term follow-up and the planning of future trials with microperimetry testing as functional study endpoint.