Brain MRI findings in neurologically symptomatic COVID-19 patients: a systematic review and meta-analysis.

BACKGROUND: Coronavirus disease 2019 (COVID-19) has been associated with nervous system involvement, with more than one-third of COVID-19 patients experiencing neurological manifestations. Utilizing a systematic review, this study aims to summarize brain MRI findings in COVID-19 patients presenting with neurological symptoms. METHODS: Systematic review was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-analysis (PRISMA) checklist. The electronic databases of PubMed/MEDLINE, Embase, Scopus, and Web of Science were systematically searched for literature addressing brain MRI findings in COVID-19 patients with neurological symptoms. RESULTS: 25 publications containing a total number of 3118 COVID-19 patients with neurological symptoms who underwent MRI were included. The most common MRI findings and the respective pooled incidences in decreasing order were acute/subacute infarct (22%), olfactory bulb abnormalities (22%), white matter abnormalities (20%), cerebral microbleeds (17%), grey matter abnormalities (12%), leptomeningeal enhancement (10%), ADEM (Acute Disseminated Encephalomyelitis) or ADEM-like lesions (10%), non-traumatic ICH (10%), cranial neuropathy (8%), cortical gray matter signal changes compatible with encephalitis (8%), basal ganglia abnormalities (5%), PRES (Posterior Reversible Encephalopathy Syndrome) (3%), hypoxic-ischemic lesions (4%), venous thrombosis (2%), and cytotoxic lesions of the corpus callosum (2%). CONCLUSION: The present study revealed that a considerable proportion of patients with COVID-19 might harbor neurological abnormalities detectable by MRI. Among various findings, the most common MRI alterations are acute/subacute infarction, olfactory bulb abnormalities, white matter abnormalities, and cerebral microbleeds.

Deep learning phase error correction for cerebrovascular 4D flow MRI.

Background phase errors in 4D Flow MRI may negatively impact blood flow quantification. In this study, we assessed their impact on cerebrovascular flow volume measurements, evaluated the benefit of manual image-based correction, and assessed the potential of a convolutional neural network (CNN), a form of deep learning, to directly infer the correction vector field. With IRB waiver of informed consent, we retrospectively identified 96 MRI exams from 48 patients who underwent cerebrovascular 4D Flow MRI from October 2015 to 2020. Flow measurements of the anterior, posterior, and venous circulation were performed to assess inflow-outflow error and the benefit of manual image-based phase error correction. A CNN was then trained to directly infer the phase-error correction field, without segmentation, from 4D Flow volumes to automate correction, reserving from 23 exams for testing. Statistical analyses included Spearman correlation, Bland-Altman, Wilcoxon-signed rank (WSR) and F-tests. Prior to correction, there was strong correlation between inflow and outflow (ρ = 0.833-0.947) measurements with the largest discrepancy in the venous circulation. Manual phase error correction improved inflow-outflow correlation (ρ = 0.945-0.981) and decreased variance (p < 0.001, F-test). Fully automated CNN correction was non-inferior to manual correction with no significant differences in correlation (ρ = 0.971 vs ρ = 0.982) or bias (p = 0.82, Wilcoxon-Signed Rank test) of inflow and outflow measurements. Residual background phase error can impair inflow-outflow consistency of cerebrovascular flow volume measurements. A CNN can be used to directly infer the phase-error vector field to fully automate phase error correction.

Balloon Gliding Technique: A novel use of balloon guiding catheters in accessing challenging circulations when treating acute ischemic stroke.

BACKGROUND: Challenging arterial anatomy delays, or prevents timely endovascular treatment (EVT) of acute ischemic stroke (AIS). We introduce a new technique called 'Balloon Gliding Technique (BGT)' to overcome difficult arterial anatomy during EVT of AIS, utilizing flow-assistance to access challenging circulations. METHODS: Retrospective review of a prospectively collected database of all patients presenting to a single institution with AIS who underwent EVT was performed from January 2021 to June 2021. Patients in whom BGT was performed were assessed. BGT consists of advancing the balloon guide catheter in the cervical carotid artery while its balloon is inflated, and therefore carried by downstream flow. RESULTS: Of 51 patients presenting with AIS secondary to large vessel occlusion during the study period, five patients underwent BGT. All five patients had anterior circulation large vessel occlusions. Mean age of the BGT patients was 92.2 years, and all patients were females. A type 3 arch was present in all patients. BGT was performed in all cases following initial failure of conventional techniques to cannulate the target circulation. BGT was successful in achieving distal cervical carotid access in 4 out of the 5 patients in whom BGT was attempted. Successful recanalization (modified treatment in cerebral ischemia 2b-3) was obtained in all cases with no complications. CONCLUSIONS: Balloon Gliding Technique (BGT) is a safe technique that can safely overcome challenging anatomy during endovascular treatment of acute ischemic stroke. Further studies can assist in demonstrating both its safety and effectiveness.

Robotics and Artificial Intelligence in Endovascular Neurosurgery.

The use of artificial intelligence (AI) and robotics in endovascular neurosurgery promises to transform neurovascular care. We present a review of the recently published neurosurgical literature on artificial intelligence and robotics in endovascular neurosurgery to provide insights into the current advances and applications of this technology. The PubMed database was searched for "neurosurgery" OR "endovascular" OR "interventional" AND "robotics" OR "artificial intelligence" between January 2016 and August 2021. A total of 1296 articles were identified, and after applying the inclusion and exclusion criteria, 38 manuscripts were selected for review and analysis. These manuscripts were divided into four categories: 1) robotics and AI for the diagnosis of cerebrovascular pathology, 2) robotics and AI for the treatment of cerebrovascular pathology, 3) robotics and AI for training in neuroendovascular procedures, and 4) robotics and AI for clinical outcome optimization. The 38 articles presented include 23 articles on AI-based diagnosis of cerebrovascular disease, 10 articles on AI-based treatment of cerebrovascular disease, two articles on AI-based training techniques for neuroendovascular procedures, and three articles reporting AI prediction models of clinical outcomes in vascular disorders of the brain. Innovation with robotics and AI focus on diagnostic efficiency, optimizing treatment and interventional procedures, improving physician procedural performance, and predicting clinical outcomes with the use of artificial intelligence and robotics. Experimental studies with robotic systems have demonstrated safety and efficacy in treating cerebrovascular disorders, and novel microcatheterization techniques may permit access to deeper brain regions. Other studies show that pre-procedural simulations increase overall physician performance. Artificial intelligence also shows superiority over existing statistical tools in predicting clinical outcomes. The recent advances and current usage of robotics and AI in the endovascular neurosurgery field suggest that the collaboration between physicians and machines has a bright future for the improvement of patient care. The aim of this work is to equip the medical readership, in particular the neurosurgical specialty, with tools to better understand and apply findings from research on artificial intelligence and robotics in endovascular neurosurgery.

Robotics for neuroendovascular intervention: Background and primer.

The simultaneous growth of robotic-assisted surgery and telemedicine in recent years has only been accelerated by the recent coronavirus disease 2019 pandemic. Robotic assistance for neurovascular intervention has garnered significant interest due to opportunities for tele-stroke models of care for remote underserved areas. Lessons learned from medical robots in interventional cardiology and neurosurgery have contributed to incremental but vital advances in medical robotics despite important limitations. In this article, we discuss robot types and their clinical justification and ethics, as well as a general overview on available robots in thoracic/abdominal surgery, neurosurgery, and cardiac electrophysiology. We conclude with current clinical research in neuroendovascular intervention and a perspective on future directions.

Soft robotic steerable microcatheter for the endovascular treatment of cerebral disorders.

Catheters used for endovascular navigation in interventional procedures lack dexterity at the distal tip. Neurointerventionists, in particular, encounter challenges in up to 25% of aneurysm cases largely due to the inability to steer and navigate the tip of the microcatheters through tortuous vasculature to access aneurysms. We overcome this problem with submillimeter diameter, hydraulically actuated hyperelastic polymer devices at the distal tip of microcatheters to enable active steerability. Controlled by hand, the devices offer complete 3D orientation of the tip. Using saline as a working fluid, we demonstrate guidewire-free navigation, access, and coil deployment in vivo, offering safety, ease of use, and design flexibility absent in other approaches to endovascular intervention. We demonstrate the ability of our device to navigate through vessels and to deliver embolization coils to the cerebral vessels in a live porcine model. This indicates the potential for microhydraulic soft robotics to solve difficult access and treatment problems in endovascular intervention.

State of the Art: Venous Causes of Pulsatile Tinnitus and Diagnostic Considerations Guiding Endovascular Therapy.

Venous variants and pathologic abnormalities are the most common causes of pulsatile tinnitus. These conditions include causes of turbulence within normally located veins and sinuses, and abnormally enlarged or abnormally located veins in close transmissive proximity to the conductive auditory pathway. Such disorders include pathologic abnormalities of the lateral sinus (transverse sinus stenosis and sigmoid sinus wall anomalies), abnormalities and variants of the emissary veins, and anomalies of the jugular bulb and jugular vein. Despite being the most common causes for pulsatile tinnitus, venous variants and pathologic abnormalities are often overlooked in the workup of pulsatile tinnitus. Such oversights can result in delayed patient care and prolonged patient discomfort. Advances in both cerebrovascular imaging and endovascular techniques allow for improved diagnostic accuracy and an increasing range of endovascular therapeutic options to address pulsatile tinnitus. This review illustrates the venous causes of pulsatile tinnitus and demonstrates the associated endovascular treatment. © RSNA, 2021.

Matching Imaging Services to Clinical Context: Why Less May Be More.

Radiologists are facing an evolving dilemma of increased imaging examination volumes while maintaining the highest levels of diagnostic quality. This scenario places radiologists at risk for error, burnout, and loss of opportunities that add value beyond imaging interpretations. We propose a new framework categorizing radiology tests based on clinical intent, level of imaging technique, and appropriate level of reporting detail.

Gender Disparity in Radiology Society Committees and Leadership in North America and Comparison With Other Continents.

PURPOSE: To evaluate gender distribution in radiology professional society leadership positions. Our study intends to assess and compare the gender distribution among leadership roles and professional society committee memberships of the radiology societies and seek an understanding of potential associations between gender, academic research metrics, institutional academic rank, and leadership roles. METHODS: We identified radiology professional society committee members to assess relative gender composition in 28 radiology societies in North America, Europe, and Australia/New Zealand. The research metrics were obtained from the SCOPUS database and demographics and institutional affiliation through institutional websites' internet searches. Gender distribution by academic ranks and other discontinuous variables were analyzed using the Chi-Square test. Wallis tests. RESULTS: Of the 3011 members of society committees, 67.9% were male, and 32.1% female. Among all the society members, the data showed that the proportion of committee members holding leadership positions was comparable between males (25.7%) and females (22.5%). However, when we did a subgroup analysis and disaggregated the data by leadership positions, we noted that among those who held the leadership positions, the proportion of males was more significant (n = 526, 70.7%) compared to females (n = 218, 29.3%). Overall, males had higher median publications, citations, H-indices, and active years of research (P< 0.0001). At all university academic ranks, men outnumbered females (P = 0.0015, Chi-square 15.38), with the most considerable disparity at the rank of professor (71.9% male, 28.1% female, P = 0.0003). CONCLUSION: There was male predominance amongst committee members in radiology societies. Our study found no significant differences between those in leadership positions, suggesting that once a member of a committee, females are equally likely as males to attain leadership positions. Analysis of committee members' academic rank and committee leaders demonstrated underrepresentation of females at higher academic ranks, and males overall had higher research metrics than females.

Impact of Coronavirus Disease 2019 (COVID-19) on the Practice of Clinical Radiology.

The speed at which coronavirus disease 2019 (COVID-19) spread quickly fractured the radiology practice model in ways that were never considered. In March 2020, most practices saw an unprecedented drop in their volume of greater than 50%. The profound changes that have interrupted the arc of the radiology narrative may substantially dictate how health care and radiology services are delivered in the future. We examine the impact of COVID-19 on the future of radiology practice across the following domains: employment, compensation, and practice structure; location and hours of work; workplace environment and safety; activities beyond the "usual scope" of radiology practice; and CME, national meetings, and professional organizations. Our purpose is to share ideas that can help inform adaptive planning.

Early-Stage Radiology Volume Effects and Considerations with the Coronavirus Disease 2019 (COVID-19) Pandemic: Adaptations, Risks, and Lessons Learned.

OBJECTIVE: The coronavirus disease 2019 (COVID-19) pandemic resulted in significant loss of radiologic volume as a result of shelter-at-home mandates and delay of non-time-sensitive imaging studies to preserve capacity for the pandemic. We analyze the volume-related impact of the COVID-19 pandemic on six academic medical systems (AMSs), three in high COVID-19 surge (high-surge) and three in low COVID-19 surge (low-surge) regions, and a large national private practice coalition. We sought to assess adaptations, risks of actions, and lessons learned. METHODS: Percent change of 2020 volume per week was compared with the corresponding 2019 volume calculated for each of the 14 imaging modalities and overall total, outpatient, emergency, and inpatient studies in high-surge AMSs and low-surge AMSs and the practice coalition. RESULTS: Steep examination volume drops occurred during week 11, with slow recovery starting week 17. The lowest total AMS volume drop was 40% compared with the same period the previous year, and the largest was 70%. The greatest decreases were seen with screening mammography and dual-energy x-ray absorptiometry scans, and the smallest decreases were seen with PET/CT, x-ray, and interventional radiology. Inpatient volume was least impacted compared with outpatient or emergency imaging. CONCLUSION: Large percentage drops in volume were seen from weeks 11 through 17, were seen with screening studies, and were larger for the high-surge AMSs than for the low-surge AMSs. The lowest drops in volume were seen with modalities in which delays in imaging had greater perceived adverse consequences.

Operational Radiology Recovery in Academic Radiology Departments After the COVID-19 Pandemic: Moving Toward Normalcy.

This article presents a current snapshot in time, describing how radiology departments around the country are planning recovery from the baseline of the coronavirus disease 2019 pandemic, with a focus on different domains of recovery such as managing appointment availability, patient safety and workflow changes, and operational data and analytics. An e-mail survey was sent through the Society of Chairs of Academic Radiology Departments list server to 114 academic radiology departments. On the basis of data reported by the 38 survey respondents, best practices and shared experience are described for three key areas: (1) planning for recovery, (2) creating a new normal, and (3) measuring and forecasting. Radiology practices should be aware of the common approaches and preparations academic radiology departments have taken to reopening imaging in the post-coronavirus disease 2019 world. This should all be done when maintaining a safe and patient-centric environment and preparing to minimize the impact of future outbreaks or pandemics.

Aspiration Thrombectomy Versus Stent Retriever Thrombectomy Alone for Acute Ischemic Stroke: A Systematic Review and Meta-Analysis.

Introduction This meta-analysis was conducted to assess the safety and efficacy of aspiration thrombectomy versus stent retriever thrombectomy for acute ischemic stroke (AIS). Methods We queried online databases for original studies comparing aspiration thrombectomy with stent retriever thrombectomy in patients with AIS. After article selection, data were extracted on multiple baseline characteristics and prespecified endpoints. Dichotomous data were presented as risk ratios (RRs) and corresponding 95% confidence intervals (CIs); continuous data as mean differences and 95% CIs. The data were pooled using a random-effects model. Subgroup analysis was conducted based on study type, site of occlusion, and age. Results We shortlisted nine relevant studies (n=1453 patients; n=690 receiving aspiration thrombectomy and n=763 receiving stent retriever thrombectomy). Meta-analysis demonstrated no significant difference between the two groups in the rates of successful recanalization (RR: 0.96 [0.87, 1.06]; p=0.42), excellent functional outcome (RR: 0.90 [0.80, 1.01]; p=0.06), or procedure time (weighted mean difference (WMD): -5.39 minutes [-11.81, 1.04]; p=0.10). However, when removing the study by Nishi et al., sensitivity analysis resulted in a significant reduction in procedure time with aspiration (WMD: -11.01 [-15.54, -6.49]; p<0.0001). No significant difference was observed in safety outcomes, including all-cause mortality (RR: 0.82 [0.57, 1.19]; p=0.30), intracranial hemorrhage (RR: 0.93 [0.55, 1.59]; p=0.80), symptomatic intracranial hemorrhage (RR: 0.72[0.42, 1.21]; p=0.57), or embolization to new territory (RR: 0.71 [0.42, 1.19]; p=0.19). Subgroup analysis revealed that aspiration thrombectomy led to significantly better outcomes in patients with a mean age ≤65 (RR: 1.15 [1.03, 1.29]; p=0.001), and stent retriever thrombectomy led to increased recanalization success in patients with a mean age >65 (RR: 0.89 [0.80, 1.00]; p=0.05). Conclusions Our updated meta-analysis reveals that both aspiration and stent retriever thrombectomy are comparably effective in the management of AIS. Shorter procedure times may potentially be attained with aspiration thrombectomy, and outcomes with each procedure may be age-dependent.

The Business Case for Diversity and Inclusion.

Although there is an increasing understanding of the importance of diversity and inclusion in all aspects of radiology training and practice, many radiology practices have yet to invest into programs that raise awareness and assure that diversity and inclusion goals are met. In many instances, leadership fails to see the value of such investments. Here, we explore what can be learned from other industries in making the business case for diversity and inclusion.

Coil migration during or after endovascular coiling of cerebral aneurysms.

BACKGROUND: Coil migration is a complication of endovascular coiling of cerebral aneurysms that has not been well studied. OBJECTIVE: To report the frequency, risk factors, management strategies, and outcomes of coil migration. METHODS: This was a retrospective analysis of the clinical and radiological data of patients who underwent cerebral aneurysm coiling complicated by coil migration at five neuroendovascular centers in the United States, Canada, and France between 2008 and 2018. RESULTS: Eighteen cases of coil migration met our study criteria with an occurrence of 0.3% (18/6071 cases) (procedural migration: 55%, delayed migration: 45%). The mean aneurysm maximal diameter, neck, and height to neck ratio in migration cases were 3.4±1.4 mm (range 2-7.6 mm), 2.4±0.9 mm (range 1.2-4.4 mm), and 1.4±0.4 (range 1-2.15), respectively. The 2 mm diameter coil was the most common (39%, range 1-2.5 mm) migrated coil. The length of the migrated coil was ≤4 cm in 95% of cases.Patients managed conservatively (5/18, 28%) did well. Thromboembolic and/or hemorrhagic complications were noted in 6/10 migration patients treated by endovascular modalities and in all migration patients who underwent surgical treatment (4/4). Three deaths occurred (3/18, 17%) related to high Hunt and Hess grade subarachnoid hemorrhage. CONCLUSION: Coil migration is an uncommon but important complication of cerebral aneurysm coiling. Small aneurysms, aspect ratio <1.6, and small coils are significant risk factors. Endovascular treatment, such as using a stent retriever, can be considered for procedural, proximal migration, and/or in cases of vessel occlusion. Delayed or distal migration should be managed conservatively.

Novel Geographic Thematic Study of the Largest Radiology Societies Globally: How Is Gender Structure Biased Within Editorial Boards?

OBJECTIVE. Radiology has traditionally been a male-dominated medical specialty, and this is also reflected in the authorship of radiology publications and the composition of radiology journal editorial boards. The purpose of this study was to quantify the extent of the gender disparities reflected within the journal editorial boards of the largest international radiologic societies. MATERIALS AND METHODS. Methods were crafted to generate a geographically based gender analysis of the editorial boards of the largest general radiologic societies globally. All editorial board members of journals that were published by societies included in the study and that had an impact factor of 1 or greater were assessed to determine the gender composition of the board and the research productivity and career advancement of its members. Analyzed metrics included gender, academic rank, departmental leadership positions, subspecialty, total number of peer-reviewed publications, total number of citations, the h-index, and total number of years of active research. RESULTS. Significant gender disparity was noted across the six journal editorial boards included. Overall, 80.87% of editorial board members were men and 19.13% were women. Men were more prevalent than women across all academic ranks. Male editorial board members had longer publishing careers (22.5 vs 18 years; p = 0.015), a higher total number of publications (110 vs 65 publications; p < 0.001), and a higher h-index (25 vs 19; p < 0.001) than their female counterparts. Female editorial board members at higher academic ranks were less represented on editorial boards and were also less likely to have formal departmental leadership titles. CONCLUSION. Editorial boards have significant gender disparities, with no specific geographic regional variation noted. Male editorial board members published more, had higher h-indexes, and held more departmental leadership positions than their female counterparts.