Revealing speckle obscured living human retinal cells with artificial intelligence assisted adaptive optics optical coherence tomography.

BACKGROUND: In vivo imaging of the human retina using adaptive optics optical coherence tomography (AO-OCT) has transformed medical imaging by enabling visualization of 3D retinal structures at cellular-scale resolution, including the retinal pigment epithelial (RPE) cells, which are essential for maintaining visual function. However, because noise inherent to the imaging process (e.g., speckle) makes it difficult to visualize RPE cells from a single volume acquisition, a large number of 3D volumes are typically averaged to improve contrast, substantially increasing the acquisition duration and reducing the overall imaging throughput. METHODS: Here, we introduce parallel discriminator generative adversarial network (P-GAN), an artificial intelligence (AI) method designed to recover speckle-obscured cellular features from a single AO-OCT volume, circumventing the need for acquiring a large number of volumes for averaging. The combination of two parallel discriminators in P-GAN provides additional feedback to the generator to more faithfully recover both local and global cellular structures. Imaging data from 8 eyes of 7 participants were used in this study. RESULTS: We show that P-GAN not only improves RPE cell contrast by 3.5-fold, but also improves the end-to-end time required to visualize RPE cells by 99-fold, thereby enabling large-scale imaging of cells in the living human eye. RPE cell spacing measured across a large set of AI recovered images from 3 participants were in agreement with expected normative ranges. CONCLUSIONS: The results demonstrate the potential of AI assisted imaging in overcoming a key limitation of RPE imaging and making it more accessible in a routine clinical setting.

The retinal pigment epithelium (RPE) is a single layer of cells within the eye that is crucial for vision. These cells are unhealthy in many eye diseases, and this can result in vision problems, including blindness. Imaging RPE cells in living human eyes is time consuming and difficult with the current technology. Our method substantially speeds up the process of RPE imaging by incorporating artificial intelligence. This enables larger areas of the eye to be imaged more efficiently. Our method could potentially be used in the future during routine eye tests. This could lead to earlier detection and treatment of eye diseases, and the prevention of some causes of blindness.

Identification and information management of cognitive impairment of patients in acute care hospitals: An integrative review.

Objectives: Recognition of the cognitive status of patients is important so that care can be tailored accordingly. The objective of this integrative review was to report on the current practices that acute care hospitals use to identify people with cognitive impairment and how information about cognition is managed within the healthcare record as well as the approaches required and recommended by policies. Methods: Following Whittemore & Knafl's five-step method, we systematically searched Medline, CINAHL, and Scopus databases and various grey literature sources. Articles relevant to the programs that have been implemented in acute care hospitals regarding the identification of cognitive impairment and management of cognition information were included. The Mixed Methods Appraisal Tool and AACODS (Authority, Accuracy, Coverage, Objectivity, Date, Significance) Checklist were used to evaluate the quality of the studies. Thematic analysis was used to present and synthesise results. This review was pre-registered on PROSPERO ( CRD42022343577). Results: Twenty-two primary studies and ten government/industry publications were included in the analysis. Findings included gaps between practice and policy. Although identification of cognitive impairment, transparency of cognition information, and interaction with patients, families, and carers (if appropriate) about this condition were highly valued at a policy level, sometimes in practice, cognitive assessments were informal, patient cognition information was not recorded, and interactions with patients, families, and carers were lacking. Discussion: By incorporating cognitive assessment, developing an integrated information management system using information technology, establishing relevant laws and regulations, providing education and training, and adopting a national approach, significant improvements can be made in the care provided to individuals with cognitive impairment.

The Case for Advocacy Curricula and Opportunities in Medical Education: Past Examples to Inform Future Instruction.

ABSTRACT: With recent advances in understanding racial, socioeconomic, and mental health issues in medicine and their relation to policy and legislation, medical professionals are increasingly involved in local and national advocacy efforts. At the frontlines of these initiatives are medical students who, in addition to completing required coursework and clinical training, devote themselves to serving patients through civic participation. The burgeoning evidence concerning health care disparities and inequity, along with greater awareness of racial and socioeconomic discrimination, have made advocacy an essential aspect of many students' medical training. Every year, thousands of medical students join national medical advocacy organizations, in addition to regional, state, and local groups. Despite the rich history of medical student involvement in advocacy, there remains much speculation and skepticism about the practice as an essential component of the medical profession. From early initiatives pushing for national health insurance after World War II to encouraging antidiscrimination policies and practices, medical students have been collectively working to create change for themselves and their patients. Through efforts such as banning smoking on airplanes, creating safe syringe programs, and protesting against police brutality, many medical students work tirelessly in advocacy despite minimal educational support or guidance about the advocacy process. Given that medical student advocacy continues to grow and has shown measurable successes in the past, the authors believe that these efforts should be rewarded and expanded upon. The authors examine historical examples of medical student advocacy to suggest ways in which advocacy can be integrated into core medical school curricula and activities. They call attention to opportunities to support students' development of knowledge and skills to facilitate legislative change, expansion of interprofessional collaborations and credit, and curricular updates to promote social and health equity.

Dose-Volume Predictors of Radiation Pneumonitis After Thoracic Hypofractionated Radiation Therapy.

PURPOSE: Hypofractionated radiation therapy (HFRT) is a common treatment for thoracic tumors, typically delivered as 60 Gy in 15 fractions. We aimed to identify dosimetric risk factors associated with radiation pneumonitis in patients receiving HFRT at 4 Gy per fraction, focusing on lung V20, mean lung dose (MLD), and lung V5 as potential predictors of grade ≥2 pneumonitis. METHODS AND MATERIALS: All patients were treated with thoracic HFRT to 60 Gy in 15 fractions or 72 Gy in 18 fractions at a single health care system from 2013 to 2020. Tumors near critical structures (trachea, proximal tracheobronchial tree, esophagus, spinal cord, or heart) were considered central (within 2 cm), and those closer were classified as ultracentral (within 1 cm). The primary endpoint was grade ≥2 pneumonitis. Logistic regression analyses, adjusting for target size and dosimetric variables, were used to establish a dose threshold associated with <20% risk of grade ≥2 pneumonitis. RESULTS: During a median 24.3-month follow-up, 18 patients (16.8%) developed grade ≥2 radiation pneumonitis, with no significant difference between the 2 dose regimens (17.3% vs 16.3%, P = .88). Four patients (3.7%) experienced grade ≥3 pneumonitis, including 2 grade 5 cases. Patients with grade ≥2 pneumonitis had significantly higher lung V20 (mean 23.4% vs 14.5%, P < .001), MLD (mean 13.0 Gy vs 9.5 Gy, P < .001), and lung V5 (mean 49.6% vs 40.6%, P = .01). Dose thresholds for a 20% risk of grade ≥2 pneumonitis were lung V20 <17.7%, MLD <10.6 Gy, and V5 <41.3%. Multivariable analysis revealed a significant association between lung V20 and grade ≥2 pneumonitis (adjusted odds ratio, 1.48, P = .03). CONCLUSIONS: To minimize the risk of grade ≥2 radiation pneumonitis when delivering 4 Gy per fraction at either 60 Gy or 72 Gy, it is advisable to maintain lung V20<17.7%. MLD <10.6 Gy and V5<41.3% can also be considered as lower-priority constraints. However, additional validation is necessary before incorporating these constraints into clinical practice or trial planning guidelines.

Stereotactic ablative radiotherapy for primary renal cell carcinoma.

Stereotactic ablative radiotherapy (SAbR) is an emerging non-invasive definitive treatment option for primary renal cell carcinoma (RCC), particularly when surgery is not ideal. Employing ablative doses, SAbR delivered in one to five fractions to the primary tumor has been shown to achieve high local control rates with favorable toxicity profile in multiple retrospective and prospective series, and has dispelled previous notions of RCC radio-resistance. Moreover, emerging evidence suggests possible immunomodulatory effects, leading to clinical investigations of SAbR in combination with systemic and surgical management in patients with metastatic disease. In this review, we summarize key evidence supporting SAbR delivered to the primary tumor including preclinical rationale, dose escalation studies, recent prospective trials, and outcomes from ongoing multi-institutional registries. We also discuss areas of active clinical investigation including the use of primary SAbR in combination with systemic therapies in patients with metastatic disease. The accumulated body of evidence supports SAbR as promising indication being increasingly incorporated into the multi-disciplinary management of primary RCC.

Cellular-Level Visualization of Retinal Pathology in Multiple Sclerosis With Adaptive Optics.

Purpose: To apply adaptive optics-optical coherence tomography (AO-OCT) to quantify multiple sclerosis (MS)-induced changes in axonal bundles in the macular nerve fiber layer, ganglion cell somas, and macrophage-like cells at the vitreomacular interface. Methods: We used AO-OCT imaging in a pilot study of MS participants (n = 10), including those without and with a history of optic neuritis (ON, n = 4), and healthy volunteers (HV, n = 9) to reveal pathologic changes to inner retinal cells and structures affected by MS. Results: We found that nerve fiber layer axonal bundles had 38% lower volume in MS participants (1.5 × 10-3 mm3) compared to HVs (2.4 × 10-3 mm3; P < 0.001). Retinal ganglion cell (RGC) density was 51% lower in MS participants (12.3 cells/mm2 × 1000) compared to HVs (25.0 cells/mm2 × 1000; P < 0.001). Spatial differences across the macula were observed in RGC density. RGC diameter was 15% higher in MS participants (11.7 µm) compared to HVs (10.1 µm; P < 0.001). A nonsignificant trend of higher density of macrophage-like cells in MS eyes was also observed. For all AO-OCT measures, outcomes were worse for MS participants with a history of ON compared to MS participants without a history of ON. AO-OCT measures were associated with key visual and physical disabilities in the MS cohort. Conclusions: Our findings demonstrate the utility of AO-OCT for highly sensitive and specific detection of neurodegenerative changes in MS. Moreover, the results shed light on the mechanisms that underpin specific neuronal pathology that occurs when MS attacks the retina. The new findings support the further development of AO-based biomarkers for MS.

Contrast echocardiography: a practical guideline from the British Society of Echocardiography.

Ultrasound contrast agents (UCAs) have a well-established role in clinical cardiology. Contrast echocardiography has evolved into a routine technique through the establishment of contrast protocols, an excellent safety profile, and clinical guidelines which highlight the incremental prognostic utility of contrast enhanced echocardiography. This document aims to provide practical guidance on the safe and effective use of contrast; reviews the role of individual staff groups; and training requirements to facilitate its routine use in the echocardiography laboratory.

The athlete's heart: insights from echocardiography.

The manifestations of the athlete's heart can create diagnostic challenges during an echocardiographic assessment. The classifications of the morphological and functional changes induced by sport participation are often beyond 'normal limits' making it imperative to identify any overlap between pathology and normal physiology. The phenotype of the athlete's heart is not exclusive to one chamber or function. Therefore, in this narrative review, we consider the effects of sporting discipline and training volume on the holistic athlete's heart, as well as demographic factors including ethnicity, body size, sex, and age.

British Society of Echocardiography guideline for the transthoracic echocardiographic assessment of cardiac amyloidosis.

These guidelines form an update of the BSE guideline protocol for the assessment of restrictive cardiomyopathy (Knight et al. in Echo Res Prac, 2013). Since the original recommendations were conceived in 2013, there has been an exponential rise in the diagnosis of cardiac amyloidosis fuelled by increased clinician awareness, improvements in cardiovascular imaging as well as the availability of new and effective disease modifying therapies. The initial diagnosis of cardiac amyloidosis can be challenging and is often not clear-cut on the basis of echocardiography, which for most patients presenting with heart failure symptoms remains the first-line imaging test. The role of a specialist echocardiographer will be to raise the suspicion of cardiac amyloidosis when appropriate, but the formal diagnosis of amyloid sub-type invariably requires further downstream testing. This document seeks to provide a focused review of the literature on echocardiography in cardiac amyloidosis highlighting its important role in the diagnosis, prognosis and screening of at risk individuals, before concluding with a suggested minimum data set, for use as an aide memoire when reporting.

Helicobacter pylori attachment-blocking antibodies protect against duodenal ulcer disease.

The majority of the world population carry the gastric pathogen Helicobacter pylori. Fortunately, most individuals experience only low-grade or no symptoms, but in many cases the chronic inflammatory infection develops into severe gastric disease, including duodenal ulcer disease and gastric cancer. Here we report on a protective mechanism where H. pylori attachment and accompanying chronic mucosal inflammation can be reduced by antibodies that are present in a vast majority of H. pylori carriers. These antibodies block binding of the H. pylori attachment protein BabA by mimicking BabA's binding to the ABO blood group glycans in the gastric mucosa. However, many individuals demonstrate low titers of BabA blocking antibodies, which is associated with an increased risk for duodenal ulceration, suggesting a role for these antibodies in preventing gastric disease.

Real world hospital costs following stress echocardiography in the UK: a costing study from the EVAREST/BSE-NSTEP multi-entre study.

BACKGROUND: Stress echocardiography is widely used to detect coronary artery disease, but little evidence on downstream hospital costs in real-world practice is available. We examined how stress echocardiography accuracy and downstream hospital costs vary across NHS hospitals and identified key factors that affect costs to help inform future clinical planning and guidelines. METHODS: Data on 7636 patients recruited from 31 NHS hospitals within the UK between 2014 and 2020 as part of EVAREST/BSE-NSTEP clinical study, were used. Data included all diagnostic tests, procedures, and hospital admissions for 12 months after a stress echocardiogram and were costed using the NHS national unit costs. A decision tree was built to illustrate the clinical pathway and estimate average downstream hospital costs. Multi-level regression analysis was performed to identify variation in accuracy and costs at both patient, procedural, and hospital level. Linear regression and extrapolation were used to estimate annual hospital cost-savings associated with increasing predictive accuracy at hospital and national level. RESULTS: Stress echocardiography accuracy varied with patient, hospital and operator characteristics. Hypertension, presence of wall motion abnormalities and higher number of hospital cardiology outpatient attendances annually reduced accuracy, adjusted odds ratio of 0.78 (95% CI 0.65 to 0.93), 0.27 (95% CI 0.15 to 0.48), 0.99 (95% CI 0.98 to 0.99) respectively, whereas a prior myocardial infarction, angiotensin receptor blocker medication, and greater operator experience increased accuracy, adjusted odds ratio of 1.77 (95% CI 1.34 to 2.33), 1.64 (95% CI 1.22 to 2.22), and 1.06 (95% CI 1.02 to 1.09) respectively. Average downstream costs were £646 per patient (SD 1796) with significant variation across hospitals. The average downstream costs between the 31 hospitals varied from £384-1730 per patient. False positive and false negative tests were associated with average downstream costs of £1446 (SD £601) and £4192 (SD 3332) respectively, driven by increased non-elective hospital admissions, adjusted odds ratio 2.48 (95% CI 1.08 to 5.66), 21.06 (95% CI 10.41 to 42.59) respectively. We estimated that an increase in accuracy by 1 percentage point could save the NHS in the UK £3.2 million annually. CONCLUSION: This study provides real-world evidence of downstream costs associated with stress echocardiography practice in the UK and estimates how improvements in accuracy could impact healthcare expenditure in the NHS. A real-world downstream costing approach could be adopted more widely in evaluation of imaging tests and interventions to reflect actual value for money and support realistic planning.

The Role of Experience: How Case Volume and Endourology-Fellowship Training Impact Surgical Outcomes for Ureteroscopy.

Introduction: Surgical experience is associated with superior outcomes in complex urologic cases, such as prostatectomy, nephrectomy, and cystectomy. The question remains whether experience is predictive of outcomes for less complex procedures, such as ureteroscopy (URS). Our study examined how case volume and endourology-fellowship training impacts URS outcomes. Methods: We retrospectively reviewed URS cases from 2017 to 2019 by high ureteroscopy volume urologists (HV), low ureteroscopy volume urologists (LV), endourology-fellowship trained (FT), and non-endourology FT (NFT) urologists. Surgical outcomes including stone-free rate (SFR), complication and reoperation rates, and postoperative imaging follow-up were analyzed between groups. Results: One thousand fifty-seven cases were reviewed across 23 urologists: 6 HV, 17 LV, 3 FT, and 20 NFT. Both FT and HV operated on more complex cases with lower rates of pre-stented patients. HV also operated on patients with higher rates of renal stones, lower pole involvement, and prior failed procedures. Despite this, FT and HV showed between 11.7% and 14.4% higher SFR, representing 2.7- to 3.6-fold greater odds of stone-free outcomes for primary and secondary stones. Additionally, HV and FT had a 4.9% to 7.8% lower rate of postoperative complications and a 3.3% to 4.3% lower rate of reoperations, representing 1.9- to 4.0-fold lower odds of complications. Finally, their patients had a 1.6- to 2.1-fold higher odds of postoperative imaging follow-up with a greater proportion receiving postoperative imaging within the recommended 3-month postoperative period. Conclusions: More experienced urologists, as defined by higher case volume and endourology-fellowship training, had higher SFR, lower complication and reoperation rates, and better postoperative imaging follow-up compared with less experienced urologists. Although less experienced urologists had outcomes in-line with clinical and literature standards, continued training and experience may be a predictor of better outcomes across multiple URS modalities.

[Use of isoflurane as treatment for super-refractory status epilepticus]. / Uso de isoflurano como tratamiento del estado epiléptico superrefractario.

INTRODUCTION: Super-refractory status epilepticus (SRSE) is a neurological condition with an important morbidity and mortality rate, for which few therapeutic options are available. Inhalation sedation with isoflurane is currently a compassionate-use treatment in Spanish intensive care units. Little has been written about its usefulness in the treatment of refractory and super-refractory status epilepticus, but it appears to be a useful and safe therapeutic alternative for this condition. CASE REPORTS: This article reviews three cases of SRSE treated with isoflurane. The capacity of isoflurane to control seizures was assessed by electroencephalographic monitoring. Other variables assessed were time to seizure control, survival, functional outcome and occurrence of complications secondary to isoflurane. In the three cases reviewed, isoflurane proved to be effective for seizure control in patients affected by SRSE. Seizure control was accomplished quickly and the minimum dose required to obtain a burst-suppression pattern was titrated easily and rapidly. Despite controlling epilepsy, high mortality was observed (66.66%). This is explained by both the mortality of SRSE and the underlying pathologies of the patients who died. The use of isoflurane did not give rise to any complications. CONCLUSION: With the results obtained, it is feasible to think that the use of isoflurane is not related to lesions in the central nervous system reported in other articles, and this treatment can be considered effective and safe for the control of SRSE.

TITLE: Uso de isoflurano como tratamiento del estado epiléptico superrefractario.Introducción. El estado epiléptico superrefractario (EESR) es una entidad neurológica con una importante morbimortalidad, en la que se dispone de pocas opciones terapéuticas. La sedación inhalatoria con isoflurano es un tratamiento de uso compasivo actualmente en las unidades de cuidados intensivos españolas. Existe poca documentación sobre su utilidad en el tratamiento del estado epiléptico refractario y superrefractario, pero parece ser una alternativa terapéutica útil y segura para esta patología. Casos clínicos. Este artículo es una revisión de tres casos de EESR tratados con isoflurano. Se evaluó el control de las crisis epilépticas por isoflurano mediante monitorización electroencefalográfica. Otras variables evaluadas han sido el tiempo transcurrido hasta el control de las crisis, la supervivencia, el resultado funcional y la aparición de complicaciones secundarias al isoflurano. En los tres casos revisados, el isoflurano se mostró efectivo para el control de las crisis epilépticas en pacientes afectados por EESR. El control de las crisis epilépticas se logró rápidamente, y se pudo titular fácil y rápidamente la mínima dosis que obtenía el patrón burst-suppression. A pesar del control de la epilepsia, se objetivó una elevada mortalidad (66,66%). Esto se explica tanto por la mortalidad del EESR como por las patologías subyacentes de los pacientes fallecidos. El uso de isoflurano no presentó complicaciones. Conclusión. Con los resultados obtenidos, es factible pensar que el uso de isoflurano no se relaciona con las lesiones en el sistema nervioso central descritas en otros artículos, y se puede considerar que este tratamiento es efectivo y seguro para el control del EESR.

Transthoracic Echocardiographic Assessment of the Heart in Pregnancy-a position statement on behalf of the British Society of Echocardiography and the United Kingdom Maternal Cardiology Society.

Pregnancy is a dynamic process associated with profound hormonally mediated haemodynamic changes which result in structural and functional adaptations in the cardiovascular system. An understanding of the myocardial adaptations is important for echocardiographers and clinicians undertaking or interpreting echocardiograms on pregnant and post-partum women. This guideline, on behalf of the British Society of Echocardiography and United Kingdom Maternal Cardiology Society, reviews the expected echocardiographic findings in normal pregnancy and in different cardiac disease states, as well as echocardiographic signs of decompensation. It aims to lay out a structure for echocardiographic scanning and surveillance during and after pregnancy as well as suggesting practical advice on scanning pregnant women.

Development of polarization-sensitive optical coherence tomography imaging platform and metrics to quantify electrostimulation-induced peripheral nerve injury in vivo in a small animal model.

Significance: Neuromodulation devices are rapidly evolving for the treatment of neurological diseases and conditions. Injury from implantation or long-term use without obvious functional losses is often only detectable through terminal histology. New technologies are needed that assess the peripheral nervous system (PNS) under normal and diseased or injured conditions. Aim: We aim to demonstrate an imaging and stimulation platform that can elucidate the biological mechanisms and impacts of neurostimulation in the PNS and apply it to the sciatic nerve to extract imaging metrics indicating electrical overstimulation. Approach: A sciatic nerve injury model in a 15-rat cohort was observed using a newly developed imaging and stimulation platform that can detect electrical overstimulation effects with polarization-sensitive optical coherence tomography. The sciatic nerve was electrically stimulated using a custom-developed nerve holder with embedded electrodes for 1 h, followed by a 1-h recovery period, delivered at above-threshold Shannon model k -values in experimental groups: sham control (SC, n = 5 , 0.0 mA / 0 Hz ), stimulation level 1 (SL1, n = 5 , 3.4 mA / 50 Hz , and k = 2.57 ), and stimulation level 2 (SL2, n = 5 , 6.8 mA / 100 Hz , and k = 3.17 ). Results: The stimulation and imaging system successfully captured study data across the cohort. When compared to a SC after a 1-week recovery, the fascicle closest to the stimulation lead showed an average change of + 4 % / - 309 % (SL1/SL2) in phase retardation and - 79 % / - 148 % in optical attenuation relative to SC. Analysis of immunohistochemistry (IHC) shows a + 1 % / - 36 % difference in myelin pixel counts and - 13 % / + 29 % difference in axon pixel counts, and an overall increase in cell nuclei pixel count of + 20 % / + 35 % . These metrics were consistent with IHC and hematoxylin/eosin tissue section analysis. Conclusions: The poststimulation changes observed in our study are manifestations of nerve injury and repair, specifically degeneration and angiogenesis. Optical imaging metrics quantify these processes and may help evaluate the safety and efficacy of neuromodulation devices.

Introduction to the Feature Issue on Adaptive Optics for Biomedical Applications.

The guest editors introduce a feature issue commemorating the 25th anniversary of adaptive optics in biomedical research.

Deep learning-enabled volumetric cone photoreceptor segmentation in adaptive optics optical coherence tomography images of normal and diseased eyes.

Objective quantification of photoreceptor cell morphology, such as cell diameter and outer segment length, is crucial for early, accurate, and sensitive diagnosis and prognosis of retinal neurodegenerative diseases. Adaptive optics optical coherence tomography (AO-OCT) provides three-dimensional (3-D) visualization of photoreceptor cells in the living human eye. The current gold standard for extracting cell morphology from AO-OCT images involves the tedious process of 2-D manual marking. To automate this process and extend to 3-D analysis of the volumetric data, we propose a comprehensive deep learning framework to segment individual cone cells in AO-OCT scans. Our automated method achieved human-level performance in assessing cone photoreceptors of healthy and diseased participants captured with three different AO-OCT systems representing two different types of point scanning OCT: spectral domain and swept source.