Sex discrepancies in the population incidence of stroke and hemorrhage related to atrial fibrillation or flutter.

INTRODUCTION: Atrial fibrillation or flutter (AF) is a well-known risk factor for ischemic stroke. While female sex has been associated with higher stroke risk among AF patients, overall sex-specific real-world burdens of AF-related strokes and hemorrhages are unknown. METHODS: The 2016-2020 National Inpatient Sample was queried for hospitalizations, morbidity, and mortality due to AF-related ischemic strokes and bleeds. Patient demographic information, vascular risk factors, comorbidities, and stroke characteristics were extracted using ICD-10 codes. Overall incidences were calculated using total population estimates provided by the United States Census Bureau, and relative risk was calculated by comparing annual incidences between men and women. RESULTS: 2,420,870 ischemic stroke hospitalizations were identified; 542,635 (22.4%) were associated with AF. Overall, women had similar risk of hospitalization due to AF-related ischemic strokes compared to men; however, women had a higher risk of morbidity and mortality (RR 1.13 and 1.17, respectively; both p<0.001). In contrast, women had lower incidences of hospitalization, morbidity, and mortality due to AF-related bleeds (RR 0.82, 0.94, and 0.74, respectively; all p<0.001). Among patients with AF-related ischemic strokes, women had lower rates of anticoagulation use, higher rates of large vessel occlusion, and higher stroke severity (all p<0.001). These trends persisted among patients 80 years or older (all p<0.001). CONCLUSION: Women in the United States have higher incidences of morbidity and mortality from AF-related ischemic strokes than men. Future studies should investigate strategies to reduce morbidity and mortality due to AF-related strokes in women.

Time-driven activity-based costing (TDABC) of direct-to-angiography pathway for acute ischemic stroke patients with suspected large vessel occlusion.

INTRODUCTION: Direct-to-angiography (DTA) is a novel care pathway for endovascular treatment (EVT) of acute ischemic stroke (AIS) that has been shown to reduce time-to-treatment and improve clinical outcomes for EVT-eligible patients. The institutional costs of adopting the DTA pathway and the many factors affecting costs have not been studied. In this study, we assess the costs and main cost drivers associated with the DTA pathway compared to the conventional CT pathway for patients presenting with AIS and suspected LVO in the anterior circulation. METHODS: Time driven activity based costing (TDABC) model was used to compare costs of DTA and conventional pathways from the healthcare institution perspective. Process mapping was used to outline all activities and resources (personnel, equipment, materials) needed for each step in both pathways. The cost model was developed using our institutional patient database and average New York state wages for personnel costs. Total, incremental and proportional costs were calculated based on institutional and patient factors affecting the pathways. RESULTS: DTA pathway accrued additional $82,583.61 (9%) in total costs compared to the conventional approach for all AIS patients. For EVT-ineligible patients, the DTA pathway incurred additional $82,964.37 (76%) in total costs compared to the CT pathway. For EVT eligible patients, the total and per-patient costs were greater in the CT pathway by $380.76 (0.04%) and $5.60 (0.04%) respectively. CONCLUSION: As the DTA pathway incurred additional $82,964.37 for EVT-ineligible patients, appropriate patient selection criteria are needed to avoid transferring EVT-ineligible patients to the angiography suite.

Associations of Osteoarthritis With Thrombectomy Utilization and Outcomes for Large Vessel Acute Ischemic Stroke.

BACKGROUND: Osteoarthritis and other musculoskeletal disorders are the leading causes of disability in the United States. While osteoarthritis is not a direct risk factor for stroke, osteoarthritis may impact patient selection for endovascular thrombectomy (EVT) due to prestroke disability. This study investigates associations of osteoarthritis with EVT utilization and outcomes. METHODS: This was a large-scale cross-sectional study of the 2016 to 2019 National Inpatient Sample database. Adult patients with anterior large vessel ischemic strokes were identified. Patient demographics, stroke risk factors, stroke etiology, presence of osteoarthritis, medical comorbidities, EVT, intravenous thrombolysis treatments, and discharge destinations were recorded. Primary outcome was the rate of EVT treatment. Secondary outcomes include rates of discharge to home and in-hospital mortality. Propensity score matching and multivariable logistic regression models were used to account for possible confounders. RESULTS: Two hundred fifty-two thousand five hundred five patients were identified, of whom 8.5% (21 500 patients) had osteoarthritis. After propensity score matching for 32 clinical variables, osteoarthritis patients were found to be 17.3% less likely to receive EVT than non-osteoarthritis patients (14.4% versus 17.3%, respectively; P<0.001). In multivariable logistic regression analysis, osteoarthritis was associated with 22.6% lower odds of receiving EVT (OR, 0.77 [95% CI, 0.70-0.86]; P<0.001), an effect size larger than any medical comorbidity captured in this study other than dementia and nonstroke neurological disease. Among those treated with EVT, multivariable logistic regression models showed that osteoarthritis was not associated with different odds of being discharged home (OR, 0.99 [95% CI, 0.81-1.21]; P=0.93); however, osteoarthritis was marginally associated with lower odds of in-hospital mortality (OR, 0.74 [95% CI, 0.54-1.01]; P=0.054). CONCLUSIONS: Large vessel ischemic stroke patients with osteoarthritis were significantly less likely to receive EVT therapy despite similar post-EVT outcomes. These results warrant further investigation and prompt a critical review of current patient selection practices for stroke EVT therapy, specifically for patients with baseline disability due to musculoskeletal conditions such as osteoarthritis.

Contrast Agent Administration as a Source of Liability: A Legal Database Analysis.

Background Radiology ranks high in terms of specialties implicated in medical malpractice claims. While most radiologists understand the risks of liability for missed findings or lapses of communication, liability for the use of contrast agents in imaging procedures may be underappreciated. Purpose To review the clinical context and outcomes of lawsuits alleging medical malpractice for contrast-related imaging procedures. Materials and Methods Two large U.S. legal databases were queried using the terms "Contrast" and "Radiology OR Radiologist" from database inception to October 31, 2022, to identify cases with published decisions or settlements related to medical malpractice in patients who underwent contrast-related imaging procedures. The search results were screened to include only those cases involving the practice area of health care law where there was at least one claim of medical negligence against a health care institution or provider. Data on the medical complications alleged by patients after contrast agent administration and on the trial were extracted and reported using descriptive statistics. Results A total of 151 published case summaries were included in the analysis. Anaphylactic reaction following contrast agent administration was the most common medical complication observed (30% [45 of 151 cases]), of which failure to diagnose developing anaphylaxis or failure to treat the anaphylactic reaction made up the majority of allegations (93% [42 of 45]). Inappropriate management of contrast media extravasation (27% [41 of 151]) and alleged contrast agent-induced acute kidney injury (13% [19 of 151]) were the next most frequent causes of lawsuits. Of the 11 cases of alleged kidney injury that went to trial, all resulted in a judgment in favor of the defense. Conclusion This study highlights the key reasons for medical malpractice lawsuits associated with use of contrast media and outcomes from these lawsuits. © RSNA, 2023 Supplemental material is available for this article. See also the editorial by Trop in this issue.

Dual-energy CT imaging of chronic subdural hematoma membranes: technical note.

This technical note describes a novel dual-energy CT (DECT) protocol with iodine map reconstruction that will enable visualization of chronic subdural hematoma (CSDH) membranes. We describe the technique and discuss the potential implications for surgical management. The cohort included 36 patients with 50 hematomas. Enhancing external membrane was demonstrated in all the 50 hematomas, incomplete internal membrane in 13, and complete internal membrane in 23 hematomas. A spandrel sign at the transition zone that indicates partial or complete formation of internal membrane was demonstrated in 36 hematomas. KEY POINTS: • Iodine maps from 5-min delayed post-contrast DECT provide spectral contrast difference and facilitate segregation of chronic subdural hematoma membranes. • The ability to image the membranes helps in assessing the degree of organization of the hematoma by providing the information about the membrane thickness, volume, complexity of the membranes, and the proportion of the liquefied component within the hematoma before surgical procedures are undertaken. • Membrane visualization helps in the localization of the transition zone and extension of the membranes over the cerebral lobes helping in the determination of craniotomy location and size, during membranectomy.

Radiographic signs of advanced cerebral venous thrombosis negatively modulate the effectiveness of endovascular treatments.

INTRODUCTION: Endovascular treatment (EVT) is a therapeutic option for cerebral venous thrombosis (CVT); however, its benefit over conservative medical management has not been proven. Whether current patient selection practices are appropriate for EVT is unclear. METHODS: This was a nationwide study of the 2016-2020 National Inpatient Sample database. Adult CVT patients and EVT treatments were identified. Patient demographics, medical comorbidities, CVT risk factors, and CVT manifestations were identified. Presence of radiographic signs of advanced and severe CVT (venous infarction, cerebral edema, and intracranial hemorrhage) were recorded. Primary and secondary outcomes were good discharge outcomes and in-hospital mortality, respectively. RESULTS: 17,130 CVT patients were identified, and 56.7% had good discharge outcomes while 4.6% died during hospitalization. 945 (5.5%) received EVT, and EVT patients were more likely to have cerebral infarction (35.4% vs. 21.8%, p<0.001), edema (35.4% vs. 20.1%, p<0.001), and hemorrhage (37.6% vs. 19.7%, p<0.001). After multivariable adjustments, EVT for patients without infarction, edema, or hemorrhage was moderately associated with higher odds of good outcomes (OR 1.86 [95%CI 0.98 - 3.53], p=0.059) and resulted in zero deaths. However, with increasing burden of radiographic signs of advanced CVT measured by the cumulative presence of infraction, edema, and hemorrhage, EVT was associated with decreasing odds of good outcomes and increasing odds of in-hospital mortality compared to medical management (interaction p=0.046 and 0.029, respectively). CONCLUSIONS: EVT may lead to higher rates of favorable hospitalization outcomes in patients who have not yet developed overt parenchymal manifestations of backpressure changes; presence of infarction, edema, and hemorrhage may diminish the short-term effectiveness of EVT.

Traumatic Cervical Cerebrovascular Injury and the Role of CTA: AJR Expert Panel Narrative Review.

Traumatic cerebrovascular injury (CVI) involving the cervical carotid and vertebral arteries is rare but can lead to stroke, hemodynamic compromise, and mortality in the absence of early diagnosis and treatment. The diagnosis of both blunt CVI (BCVI) and penetrating CVI is based on cerebrovascular imaging. The most commonly used screening criteria for BCVI include the expanded Denver criteria and the Memphis criteria, each providing varying thresholds for subsequent imaging. Neck CTA has supplanted catheter-based digital subtraction angiography as the preferred screening modality for CVI in patients with trauma. This AJR Expert Panel Narrative Review describes the current state of CTA-based cervical imaging in trauma. We review the most common screening criteria for BCVI, discuss BCVI grading scales that are based on neck CTA, describe the diagnostic performance of CTA in the context of other imaging modalities and evolving treatment strategies, and provide a practical guide for neck CTA implementation.

CT With CTA Versus MRI in Patients Presenting to the Emergency Department With Dizziness: Analysis Using Propensity Score Matching.

BACKGROUND. CT with CTA is widely used to exclude stroke in patients with dizziness, although MRI has higher sensitivity. OBJECTIVE. The purpose of this article was to compare patients presenting to the emergency department (ED) with dizziness who undergo CT with CTA alone versus those who undergo MRI in terms of stroke-related management and outcomes. METHODS. This retrospective study included 1917 patients (mean age, 59.5 years; 776 men, 1141 women) presenting to the ED with dizziness from January 1, 2018, to December 31, 2021. A first propensity score matching analysis incorporated demographic characteristics, medical history, findings from the review of systems, physical examination findings, and symptoms to construct matched groups of patients discharged from the ED after undergoing head CT with head and neck CTA alone and patients who underwent brain MRI (with or without CT and CTA). Outcomes were compared. A second analysis compared matched patients discharged after CT with CTA alone and patients who underwent specialized abbreviated MRI using multiplanar high-resolution DWI for increased sensitivity for posterior circulation stroke. Sensitivity analyses were performed involving MRI examinations performed as the first or only neuroimaging examination and involving alternative matching and imputation techniques. RESULTS. In the first analysis (406 patients per group), patients who underwent MRI, compared with patients who underwent CT with CTA alone, showed greater frequency of critical neuroimaging results (10.1% vs 4.7%, p = .005), change in secondary stroke prevention medication (9.6% vs 3.2%, p = .001), and subsequent echocardiography evaluation (6.4% vs 1.0%, p < .001). In the second analysis (100 patients per group), patients who underwent specialized abbreviated MRI, compared with patients who underwent CT with CTA alone, showed greater frequency of critical neuroimaging results (10.0% vs 2.0%, p = .04), change in secondary stroke prevention medication (14.0% vs 1.0%, p = .001), and subsequent echocardiography evaluation (12.0% vs 2.0%, p = .01) and lower frequency of 90-day ED readmissions (12.0% vs 28.0%, p = .008). Sensitivity analyses showed qualitatively similar findings. CONCLUSION. A proportion of patients discharged after CT with CTA alone may have benefitted from alternative or additional evaluation by MRI (including MRI using a specialized abbreviated protocol). CLINICAL IMPACT. Use of MRI may motivate clinically impactful management changes in patients presenting with dizziness.

Clinical implications of Peri-hematomal edema microperfusion fraction in intracerebral hemorrhage intravoxel incoherent motion imaging - A pilot study.

BACKGROUND AND PURPOSE: Perihematomal edema (PHE) represents the secondary brain injury after intracerebral hemorrhage (ICH). However, neurobiological characteristics of post-ICH parenchymal injury other than PHE volume have not been fully characterized. Using intravoxel incoherent motion imaging (IVIM), we explored the clinical correlates of PHE diffusion and (micro)perfusion metrics in subacute ICH. MATERIALS AND METHODS: In 41 consecutive patients scanned 1-to-7 days after supratentorial ICH, we determined the mean diffusion (D), pseudo-diffusion (D*), and perfusion fraction (F) within manually segmented PHE. Using univariable and multivariable statistics, we evaluated the relationship of these IVIM metrics with 3-month outcome based on the modified Rankin Scale (mRS). RESULTS: In our cohort, the average (± standard deviation) age of patients was 68.6±15.6 years, median (interquartile) baseline National Institute of Health Stroke Scale (NIHSS) was 7 (3-13), 11 (27 %) patients had poor outcomes (mRS>3), and 4 (10 %) deceased during the follow-up period. In univariable analyses, admission NIHSS (p < 0.001), ICH volume (p = 0.019), ICH+PHE volume (p = 0.016), and average F of the PHE (p = 0.005) had significant correlation with 3-month mRS. In multivariable model, the admission NIHSS (p = 0.006) and average F perfusion fraction of the PHE (p = 0.003) were predictors of 3-month mRS. CONCLUSION: The IVIM perfusion fraction (F) maps represent the blood flow within microvasculature. Our pilot study shows that higher PHE microperfusion in subacute ICH is associated with worse outcomes. Once validated in larger cohorts, IVIM metrics may provide insight into neurobiology of post-ICH secondary brain injury and identify at-risk patients who may benefit from neuroprotective therapy.

Age-related topographic map of magnetic resonance diffusion metrics in neonatal brains.

Accelerated maturation of brain parenchyma close to term-equivalent age leads to rapid changes in diffusion-weighted imaging (DWI) and diffusion tensor imaging (DTI) metrics of neonatal brains, which can complicate the evaluation and interpretation of these scans. In this study, we characterized the topography of age-related evolution of diffusion metrics in neonatal brains. We included 565 neonates who had MRI between 0 and 3 months of age, with no structural or signal abnormality-including 162 who had DTI scans. We analyzed the age-related changes of apparent diffusion coefficient (ADC) values throughout brain and DTI metrics (fractional anisotropy [FA] and mean diffusivity [MD]) along white matter (WM) tracts. Rate of change in ADC, FA, and MD values across 5 mm cubic voxels was calculated. There was significant reduction of ADC and MD values and increase of FA with increasing gestational age (GA) throughout neonates' brain, with the highest temporal rates in subcortical WM, corticospinal tract, cerebellar WM, and vermis. GA at birth had significant effect on ADC values in convexity cortex and corpus callosum as well as FA/MD values in corpus callosum, after correcting for GA at scan. We developed online interactive atlases depicting age-specific normative values of ADC (ages 34-46 weeks), and FA/MD (35-41 weeks). Our results show a rapid decrease in diffusivity metrics of cerebral/cerebellar WM and vermis in the first few weeks of neonatal age, likely attributable to myelination. In addition, prematurity and low GA at birth may result in lasting delay in corpus callosum myelination and cerebral cortex cellularity.

Diversity in Radiology: Current Status and Trends Over the Past Decade.

Background There have been growing efforts nationally and institutionally toward diversity in radiology. Purpose To analyze sex and racial and ethnic diversity over time (2010-2019) for the various levels of the U.S. academic radiology physician workforce in context of the available pipeline of medical students and trainees. Materials and Methods Data on sex and race and ethnicity were collected among medical school applicants, graduates, radiology residency applicants, residents, and different levels of academic radiology faculty. All trainee data were obtained from two time points, 2010-2011 and 2019-2020. Radiology faculty data were collected from 2010 to 2019. The sex and racial and ethnic composition at each academic level was compared between 2010 and 2019 using the χ2 test and a significance level of P < .05. Results In 2019, the percentage of female faculty among radiology instructors was 38% (251 of 655); assistant professors, 31% (1503 of 4801); associate professors, 28% (600 of 2161); professors, 22% (424 of 1901); and department chairs, 17% (37 of 220). The proportion of female faculty increased from 2010 to 2019, with the greatest relative increase in percentages among the more senior faculty positions. However, the proportion of female department chairs has only increased from 13% (27 of 203) in 2010 to 17% (37 of 220) in 2019. Across training levels, the most abrupt change in composition of female trainees occurred from medical school matriculates (52%, 11 160 of 21 614) to radiology residency applicants (29%, 656 of 2274), which largely stayed unchanged from 2010 to 2019. The proportion of Black or African American department chairs was 5% (10 of 220) in 2019, which was higher compared with that of assistant professor, associate professor, and professor levels for Black or African American faculty (3% [130 of 4949], 2% [41 of 2208], and 2% [35 of 1924], respectively), with proportions of Hispanic faculty at 5% (240 of 4949), 4% (96 of 2208), and 3% (60 of 1924), respectively. These proportions have not changed since 2010. Conclusion Identifying and addressing reasons for the low proportion of female radiology residency applicants despite a highly diverse pool of medical students would be key to increasing female representation in the field. The low representation of African American and Hispanic individuals in academic radiology is seen at all levels and has not changed much over time. Efforts to increase diversity may need to be focused toward the medical school and residency application levels. © RSNA, 2022 Online supplemental material is available for this article. See also the editorial by Pandharipande and Shah in this issue.

A systematic review of cost-effectiveness analyses on endovascular thrombectomy in ischemic stroke patients.

OBJECTIVE: The objective of this study was to examine the published cost-effectiveness analyses (CEAs) on endovascular thrombectomy (EVT) in acute stroke patients, with a particular focus on the practice of accounting for costs and utilities. METHODS: We conducted a systematic review of published CEAs on EVT in acute stroke patients from 1/1/2009 to 10/1/2019. Published CEAs were searched in Ovid Embase, Ovid MEDLINE, and Web of Science. Cost or comparative effectiveness analyses were excluded. Risk of bias and quality assessment was based on the Consolidated Health Economic Evaluation Reporting Standard checklist. RESULTS: Twenty-one studies were included in the final analysis, from the USA, Canada, Europe, Asia, and Australia. They all concluded EVT to be cost-effective, but with significant variations in methodology. Fifteen studies employed a long-term horizon (> 20 years), while only 11 incorporated risk of recurrent strokes. The willingness-to-pay (WTP) threshold varied from $10,000/quality-adjusted life year (QALY) to $120,000/QALY, with $50,000/QALY and $100,000/QALY being the most commonly used. Five studies undertook a societal perspective, but only one accounted for indirect costs. Seventeen studies based outcomes on 90-day modified Rankin Scale (mRS) scores, and 9 of these 17 studies grouped outcomes by mRS 0-2 and 3-5. Among these 9 studies, the range of QALY score reported for mRS 0-2 was 0.71-0.85 QALY, and that of mRS 3-5 was 0.21-0.40. CONCLUSIONS: Our study reveals significant heterogeneity in previously published thrombectomy CEAs, highlighting need for better standardization in future CEAs. KEY POINTS: • All included studies concluded thrombectomy to be cost-effective, from both long- and short-term perspectives. • Only 5 out of 22 studies undertook a societal perspective, and only 1 accounted for indirect costs. • The range of value for mRS 0-2 was 0.71-0.85 quality-adjusted life year (QALY) and 0.21-0.40 QALY for mRS 3-5.

Head and Neck CTA Utilization: Analysis of Ordering Frequency and Nonroutine Results Communication, With Focus on the 50 Most Common Emergency Department Clinical Presentations.

BACKGROUND. Utilization of head and neck CTA in the emergency department (ED) has grown disproportionately to other neuroimaging examinations. OBJECTIVE. The purpose of this article was to characterize utilization of head and neck CTA in the ED, comparing utilization and frequency of nonroutine results communication among patients' chief concerns. METHODS. All adult ED visits for a single health care system from January 2014 to December 2017 were retrospectively reviewed. Variables recorded included chief concerns, whether head and neck CTA was performed, and, if so, whether the report documented nonroutine results communication. The 50 chief concerns resulting in the highest number of head and neck CTA examinations were identified. Frequencies of head and neck CTA ordering and of nonroutine results communication were calculated. A subset of reports documenting nonroutine communication were manually reviewed. RESULTS. Head and neck CTA was ordered in 2.5% (17,903) of 708,145 ED visits in 236,476 patients (mean age, 49.8 ± 20.5 [SD] years; 110,952 men, 125,521 women, 3 unknown sex). Head and neck CTA was ordered for 833 distinct chief concerns. Nonroutine results communication was documented for 17.6% (3155/17,903) of examinations. Among the 50 chief concerns associated with the highest number of examinations, frequency of ordering head and neck CTA ranged from less than 0.5% (five concerns) to 55.2% (stroke code), and frequency of nonroutine communication ranged from 5.6% (transient ischemic attack) to 67.5% (unresponsive). Chief concerns not among the 50 most common accounted for 50.0% (8956/17,903) of examinations; these exhibited a collective frequency of nonroutine communication of 4.8% (429/8956). Manual review of 11.1% (350/3155) of reports with a nonroutine communication indicated an acute finding related to the indication in 51.1%, nonemergent but potentially explanatory finding in 14.0%, incidental finding in 28.0%, and communication of negative results in 6.9%. CONCLUSION. Head and neck CTA is ordered in 2.5% of ED visits for a wide range of chief concerns. Frequencies of ordering and of nonroutine results communication are highly variable among chief concerns. Acute indication-related findings account for half of nonroutine radiologist communications. CLINICAL IMPACT. Insight into patterns regarding head and neck CTA ordering and nonroutine results may help optimize patient selection and radiologist communications in the ED setting.

Scenarios to improve CT head utilization in the emergency department delineated by critical results reporting.

PURPOSE: Increasing use of advanced imaging in the emergency department (ED) has resulted in higher cost without better outcomes. Our goal was to evaluate the yield of CT head exams by scenario to guide efforts at improving patient selection. METHODS: We performed a retrospective study at an academic medical center over 4 years (1/1/2014-12/31/2017). The chief complaint, imaging order, and exam result text were obtained for all adult ED encounters. For the 50 most common chief complaints leading to CT head exams, the ratio of exams to total encounters and ratio of critical results to imaging studies were calculated. Significant difference in "yield" was assessed via binomial test. RESULTS: Over 708,145 adult ED encounters, 58,783 CT head exams were ordered, with an overall critical result yield of 8.0%. The three most common chief complaints had higher yield (p < 0.05): altered mental status (9.8%), fall (9.7%), and new headache (10.1%). Lower yield (p < 0.05) was found for 19 chief complaints: dizziness (6.2%), falls in patients > 65 years old (7.1%), syncope (5.3%), seizure with known epilepsy (4.8%), chest pain (3.7%), head injury (4.9%), headache re-evaluation (7.0%), alcohol intoxication (2.5%), fatigue (6.5%), headache-recurrent or in the setting of known migraines (5.2%), hypertension (4.4%), lethargy (5.8%), loss of consciousness (5.3%), migraine (3.2%), psychiatric evaluation (2.9%), near syncope (4.6%), drug problem (3.1%), symptomatically decreased blood sugar (3.2%), and suicidal (1.7%). CONCLUSION: Our study provides a priority list of low yield scenarios of CT head use for improvement of patient selection.

Clinical Outcomes and Costs of Recurrent Ischemic Stroke: A Systematic Review.

OBJECTIVE: Recurrent stroke patients suffer significant morbidity and mortality, representing almost 30% of the stroke population. Our objective was to determine the clinical outcomes and costs of recurrent ischemic stroke (recurrent-IS). METHODS: Our study protocol was registered with the International Prospective Register of Systematic Reviews (CRD42020192709). Following PRISMA guidelines, our medical librarian conducted a search in EMBASE, PubMed, Web-of-Science, Scopus, and CINAHL (last performed on August 25, 2020). INCLUSION CRITERIA: (1) Studies reporting clinical outcomes and/or costs of recurrent-IS; (2) Original research published in English in year 2010 or later; (3) Study participants aged ≥18 years. EXCLUSION CRITERIA: (1) Case reports/studies, abstracts/posters, Editorial letters/reviews; (2) Studies analyzing interventions other than intravenous thrombolysis and thrombectomy. Four independent reviewers selected studies with review of titles/abstracts and full-text, and performed data extraction. Discrepancies were resolved by a senior independent arbitrator. Risk-of-bias was assessed using the Mixed Methods Appraisal Tool. RESULTS: Initial search yielded 20,428 studies. Based on inclusion/exclusion criteria, 9 studies were selected, consisting of 24,499 recurrent-IS patients. In 5 studies, recurrent-IS ranged from 4.4-56.8% of the ischemic stroke cohorts at 3 or 12 months, or undefined follow-up. Mean age was 60-80 years and female proportions were 38.5-61.1%. Clinical outcomes included mortality 11.6-25.9% for in-hospital, 30-days, or 4-years (3 studies). In one study from the U.S., mean in-hospital costs were $17,121(SD-$53,693) and 1-year disability costs were $34,639(SD-$76,586) per patient. CONCLUSIONS: Our study highlights the paucity of data on clinical outcomes and costs of recurrent-IS and identifies gaps in existing literature to direct future research.

Bridging Thrombolysis Achieved Better Outcomes Than Direct Thrombectomy After Large Vessel Occlusion: An Updated Meta-Analysis.

The utility and necessity of pretreatment with intravenous thrombolysis (IVT) before mechanical thrombectomy (MT) remains an issue of strong debate. This study aims to compare the outcomes of bridging thrombolysis (BT, IVT+MT) with direct MT (d-MT) after large vessel ischemic stroke based on the most up-to-date evidence. MEDLINE, EMBASE, Scopus, and the Cochrane Library from January 2017 to June 2020 were searched for studies that directly compared the outcomes of the 2 strategies. Methodological quality was assessed using the Quality in Prognostic Studies tool. Combined estimates of odds ratios (ORs) of BT versus d-MT were derived. Multiple subgroup analyses were performed, especially for IVT-eligible patients. Thirty studies involving 7191 patients in the BT group and 4891 patients in the d-MT group were included. Methodological quality was generally high. Compared with patients in the d-MT group, patients in the BT group showed significantly better functional independence (modified Rankin Scale score 0-2) at 90 days (OR=1.43 [95% CI, 1.28-1.61]), had lower mortality at 90 days (OR=0.67 [95% CI, 0.60-0.75]), and achieved higher successful recanalization (modified Thrombolysis in Cerebral Ischemia score 2b-3) rate (OR=1.23 [95% CI, 1.07-1.42]). No significant difference was detected in the occurrence of symptomatic intracranial hemorrhage between 2 groups (OR=1.01 [95% CI, 0.86-1.19]). Subgroup analysis showed that functional independence frequency remained significantly higher in BT group regardless of IVT eligibility or study design. Compared with d-MT, bridging with IVT led to better clinical outcomes, lower mortality at 90 days, and higher successful recanalization rates, without increasing the risk of near-term hemorrhagic complications. The benefits of BT based on this most recent literature evidence support the current guidelines of using BT.

Assessment of Intracranial Atherosclerotic Plaques Using 3D Black-Blood MRI: Comparison With 3D Time-of-Flight MRA and DSA.

BACKGROUND: Noninvasive assessment of intracranial stenosis is important to manage ischemic stroke patients. However, few previous studies have compared 3D black-blood MRI with 3D time-of-flight (TOF), magnetic resonance angiography (MRA), and digital subtraction angiography (DSA) for intracranial artery plaque assessment. PURPOSE: To compare 3D black-blood MRI and 3D TOF-MRA, using DSA as the reference standard for intracranial stenosis and atherosclerotic plaque assessment in patients with posterior circulation stroke or transient ischemic attacks (TIAs). STUDY TYPE: Prospective, cohort study. POPULATION: One hundred and one patients with posterior circulation stroke and/or TIA (age 63 ± 10 years, 84 male) who underwent DSA and MRI within 4 weeks of each other. FIELD STRENGTH/SEQUENCE: 3D fast-spin-echo MRI for intracranial vessel wall imaging (IVWI) and 3D TOF at 3T. ASSESSMENT: Two radiologists independently measured the degree of stenosis on 3D IVWI and TOF, using DSA as a reference. Plaque enhancement was recorded when the plaque was stenosis-free on DSA. STATISTICAL TESTS: Shapiro-Wilk's test, Student's t-test, Mann-Whitney U-test, Spearman correlation, Bland-Altman analysis, and interclass correlation coefficient (ICC). RESULTS: A total of 238 intracranial plaques (203 posterior, 35 anterior) were included. 3D IVWI showed better agreement with DSA in measuring stenosis than TOF (ICC = 0.89 vs. 0.64). 3D IVWI had higher sensitivity and specificity for detecting stenosis >50% and stenosis >75% than TOF, using DSA as the standard. TOF significantly overestimated the degree of stenosis compared to DSA (65 ± 19% vs. 51 ± 15%, P < 0.001). DSA did not observe 62 nonstenotic plaques (26.1%) that were shown only on 3D IVWI, in which 36 plaques (58.1%) showed contrast enhancement. The interreader agreement for measuring stenosis were excellent, with ICCs >0.90 for all three modalities. DATA CONCLUSION: 3D black-blood MRI is accurate and reproducible for quantifying intracranial artery stenosis compared with DSA, and performs better than 3D TOF. As compared to DSA, it detects more nonstenotic plaques. Level of Evidence 1 Technical Efficacy Stage 2 J. MAGN. RESON. IMAGING 2021;53:469-478.

Admission computed tomography radiomic signatures outperform hematoma volume in predicting baseline clinical severity and functional outcome in the ATACH-2 trial intracerebral hemorrhage population.

BACKGROUND AND PURPOSE: Radiomics provides a framework for automated extraction of high-dimensional feature sets from medical images. We aimed to determine radiomics signature correlates of admission clinical severity and medium-term outcome from intracerebral hemorrhage (ICH) lesions on baseline head computed tomography (CT). METHODS: We used the ATACH-2 (Antihypertensive Treatment of Acute Cerebral Hemorrhage II) trial dataset. Patients included in this analysis (n = 895) were randomly allocated to discovery (n = 448) and independent validation (n = 447) cohorts. We extracted 1130 radiomics features from hematoma lesions on baseline noncontrast head CT scans and generated radiomics signatures associated with admission Glasgow Coma Scale (GCS), admission National Institutes of Health Stroke Scale (NIHSS), and 3-month modified Rankin Scale (mRS) scores. Spearman's correlation between radiomics signatures and corresponding target variables was compared with hematoma volume. RESULTS: In the discovery cohort, radiomics signatures, compared to ICH volume, had a significantly stronger association with admission GCS (0.47 vs. 0.44, p = 0.008), admission NIHSS (0.69 vs. 0.57, p < 0.001), and 3-month mRS scores (0.44 vs. 0.32, p < 0.001). Similarly, in independent validation, radiomics signatures, compared to ICH volume, had a significantly stronger association with admission GCS (0.43 vs. 0.41, p = 0.02), NIHSS (0.64 vs. 0.56, p < 0.001), and 3-month mRS scores (0.43 vs. 0.33, p < 0.001). In multiple regression analysis adjusted for known predictors of ICH outcome, the radiomics signature was an independent predictor of 3-month mRS in both cohorts. CONCLUSIONS: Limited by the enrollment criteria of the ATACH-2 trial, we showed that radiomics features quantifying hematoma texture, density, and shape on baseline CT can provide imaging correlates for clinical presentation and 3-month outcome. These findings couldtrigger a paradigm shift where imaging biomarkers may improve current modelsfor prognostication, risk-stratification, and treatment triage of ICH patients.

Comparison of Drug-Eluting Embolics versus Conventional Transarterial Chemoembolization for the Treatment of Patients with Unresectable Hepatocellular Carcinoma: A Cost-Effectiveness Analysis.

PURPOSE: To compare the cost-effectiveness of using doxorubicin-loaded drug-eluting embolic (DEE) transarterial chemoembolization versus that of using conventional transarterial chemoembolization for patients with unresectable hepatocellular carcinoma (HCC). MATERIALS AND METHODS: A decision-analysis model was constructed over the lifespan of a payer's perspective. The model simulated the clinical course, including periprocedural complications, additional transarterial chemoembolization or other treatments (ablation, radioembolization, or systemic treatment), palliative care, and death, of patients with unresectable HCC. All clinical parameters were derived from the literature. Base case calculations, probabilistic sensitivity analyses, and multiple two-way sensitivity analyses were performed. RESULTS: In the base case calculations for patients with a median age of 67 years (range for conventional transarterial chemoembolization: 28-88 years, range for DEE-transarterial chemoembolization: 16-93 years), conventional transarterial chemoembolization yielded a health benefit of 2.11 quality-adjusted life years (QALY) at a cost of $125,324, whereas DEE-transarterial chemoembolization yielded 1.71 QALY for $144,816. In 10,000 Monte Carlo simulations, conventional transarterial chemoembolization continued to be a more cost-effective strategy. conventional transarterial chemoembolization was cost-effective when the complication risks for both the procedures were simultaneously varied from 0% to 30%. DEE-transarterial chemoembolization became cost-effective if the conventional transarterial chemoembolization mortality exceeded that of DEE-transarterial chemoembolization by 17% in absolute values. The two-way sensitivity analyses demonstrated that conventional transarterial chemoembolization was cost-effective until the risk of disease progression was >0.4% of that for DEE-transarterial chemoembolization in absolute values. Our analysis showed that DEE-transarterial chemoembolization would be more cost-effective if it offered >2.5% higher overall survival benefit than conventional transarterial chemoembolization in absolute values. CONCLUSIONS: Compared with DEE-transarterial chemoembolization, conventional transarterial chemoembolization yielded a higher number of QALY at a lower cost, making it the more cost-effective of the 2 modalities.

Expedited and Comprehensive Management of Low-Risk TIA Patients in the Emergency Department is Safe and Less Costly.

OBJECTIVES: Transient ischemic attack (TIA) can be a warning sign of an impending stroke. The objective of our study is to assess the feasibility, safety, and cost savings of a comprehensive TIA protocol in the emergency room for low-risk TIA patients. MATERIALS AND METHODS: This is a retrospective, single-center cohort study performed at an academic comprehensive stroke center. We implemented an emergency department-based TIA protocol pathway for low-risk TIA patients (defined as ABCD2 score < 4 and without significant vessel stenosis) who were able to undergo vascular imaging and a brain MRI in the emergency room. Patients were set up with rapid outpatient follow-up in our stroke clinic and scheduled for an outpatient echocardiogram, if indicated. We compared this cohort to TIA patients admitted prior to the implementation of the TIA protocol who would have qualified. Outcomes of interest included length of stay, hospital cost, radiographic and echocardiogram findings, recurrent neurovascular events within 30 days, and final diagnosis. RESULTS: A total of 138 patients were assessed (65 patients in the pre-pathway cohort, 73 in the expedited, post-TIA pathway implementation cohort). Average time from MRI order to MRI end was 6.4 h compared to 2.3 h in the pre- and post-pathway cohorts, respectively (p < 0.0001). The average length of stay for the pre-pathway group was 28.8 h in the pre-pathway cohort compared to 7.7 h in the post-pathway cohort (p < 0.0001). There were no differences in neuroimaging or echocardiographic findings. There were no differences in the 30 days re-presentation for stroke or TIA or mortality between the two groups. The direct cost per TIA admission was $2,944.50 compared to $1,610.50 for TIA patients triaged through the pathway at our institution. CONCLUSIONS: This study demonstrates the feasibility, safety, and cost-savings of a comprehensive, emergency department-based TIA protocol. Further study is needed to confirm overall benefit of an expedited approach to TIA patient management and guide clinical practice recommendations.