Ten-year trends, disparities, and clinical impact of stroke thrombectomy and thrombolysis: A single center experience 2012-2021.

OBJECTIVES: As indications for acute ischemic stroke treatment expand, it is unclear whether disparities in treatment utilization and outcome still exist. The main objective of this study was to investigate disparities in acute ischemic stroke treatment and determine impact on outcome. MATERIALS AND METHODS: Retrospective observational cohort study of consecutive ischemic stroke admissions to a comprehensive stroke center from 2012-2021 was performed. Primary exposure was intravenous thrombolysis and/or endovascular thrombectomy. Primary end points were discharge modified Rankin Scale, home disposition, and expired/hospice. Multivariable logistic regression analyses were conducted to elucidate disparities in treatment utilization and determine impact on outcome. RESULTS: Of 517,615 inpatient visits, there were 7,540 (1.46 %) ischemic stroke admissions, increasing from 1.14 % to 1.79 % from 2012-2021. Intravenous thrombolysis significantly decreased from 14.4 % to 9.8 % while endovascular thrombectomy significantly increased from 0.8 % to 10.5 %. Both intravenous thrombolysis and endovascular thrombectomy increased odds of discharge home and modified Rankin Scale 0-2, and thrombectomy decreased odds of expired/hospice. After adjusting for covariates, decreased odds of thrombectomy was associated with Medicaid insurance (Odds Ratio [95 % Confidence Interval] 0.55 [0.32-0.93]), age 80+ (0.49 [0.35-0.69]), prior stroke (0.49 [0.31-0.77]), and diabetes mellitus (0.55 [0.39-0.79]), while low median household income (<$80,000/year) increased odds of no acute treatment (1.34 [1.16-1.56]). No sex or racial disparities were observed. Medicaid and low-income were not associated with worse clinical outcomes. CONCLUSIONS: Less endovascular thrombectomy occurred in Medicaid, older, prior stroke, and diabetic patients, while low-income was associated with no treatment. The observed socioeconomic disparities did not impact discharge outcome.

Diagnostic Accuracy of Cone-Beam CT for Acute Intracranial Hemorrhage: A Systematic Review and Meta-analysis.

OBJECTIVE: Our purpose was to synthesize evidence in the literature to determine the diagnostic accuracy of Cone-Beam CT (CBCT) for detection of intracranial hemorrhage (ICH) and hemorrhage types, including intraparenchymal (IPH), subarachnoid (SAH), and intraventricular (IVH). METHODS: We performed a meta-analysis following the Preferred Reporting Items for Systematic Review and Meta-Analyses (PRISMA) guidelines. Our protocol was registered with International Prospective Register of Systematic Reviews (PROSPERO-CRD42021261915). Systematic searches were last performed on April 30, 2024 in EMBASE, PubMed, Web-of-Science, Scopus, and CINAHL databases. Inclusion criteria were: (1) Studies reporting diagnostic metrics of CBCT for ICH; (2) Studies using a reference standard to determine ICH. Exclusion criteria were: (1) Case reports, abstracts, reviews; (2) Studies without patient-level data. Pooled-estimates and 95% confidence intervals (CI) were calculated for diagnostic Odds ratio (DOR), sensitivity, and specificity using random-effects and common-effects models. Mixed Methods Appraisal Tool was used to evaluate risk-of-bias. RESULTS: Seven studies were included in the meta-analysis yielding 466 patients. Mean/median age ranged from 54-75 years. Females represented 51.4% (222/432) in reported studies. Multidetector-CT was the reference standard in all studies. DOR, pooled-sensitivity, and pooled-specificity for ICH were 5.28 (95%CI:4.11-6.46), 0.88 (95%CI:0.79-0.97), and 0.99 (95%CI:0.98-1.0). Pooled-sensitivity for IPH, SAH, and IVH were 0.98 (95%CI:0.95-1.0), 0.82 (95%CI:0.57-1.0), and 0.78 (95%CI:0.55-1.0). Pooled-specificity for IPH, SAH, and IVH were 0.99 (95%CI:0.98-1.0), 0.99 (95%CI:0.97-1.0), and 1.0 (95%CI:0.98-1.0). DISCUSSION: CBCT had moderate DOR and high pooled-specificity for ICH and hemorrhage types. However, pooled-sensitivity varied by hemorrhage type, with the highest sensitivity for IPH, followed by SAH and IVH.

Global Health Initiatives: International Physician-to-Physician Consultation Programs.

PURPOSE: The goal of this article is to provide technical and operational blueprints for two successful global telehealth programs. METHODS: The authors designed a physician-to-physician consultation program to provide subspecialty expertise to physicians in war-torn Ukraine. Leveraging secure web applications, telehealth platforms, and image-sharing platforms, the authors repeatedly iterated upon infrastructure and workflows, which in turn facilitated the development of a parallel international program for US Department of State (DOS) employees and families. The authors provide descriptive statistics and metrics of both programs' successes and failures and detail iterative improvements with workflow visuals. To measure the added value of subspecialty imaging consultation, two radiologists performed a retrospective comparative review of the DOS program imaging reports, comparing the initial report to the consult report in consensus, measuring diagnostic report agreement, and rating the clinical impact of identified discrepancies on a three-point scale (mild, moderate, or major). Bivariate analyses using χ2 tests were conducted to assess associations between diagnostic discrepancies and patient or imaging factors. P values <.05 were considered to indicate statistical significance. RESULTS: The Ukraine program (May 2022 to August 2023) provided 114 patient consultations with 77 subspecialty radiology consults, >50 WhatsApp chats, and >1,000 messages exchanged, with a 92% overall consult request response rate. The DOS program (November 2022 to July 2023) provided 275 consultations with 70 subspecialty radiology consults and a 36% to 38% rate of alternative diagnoses, with 20% rated as incurring moderate or major clinical impact. Bivariate analyses demonstrated no significant patient or imaging association with diagnostic disagreements (P > .05 for all). CONCLUSIONS: Global telehealth infrastructure and multiple applications and platforms can be optimized in a workflow to provide efficient, high-level clinical and imaging consultation services across the globe.

Maternal and Fetal Radiation-Induced Cancer Risk From Computed Tomography Pulmonary Angiography During Pregnancy: A Retrospective Cohort Study Across a Multihospital Integrated Health Care Network.

OBJECTIVE: Computed tomography pulmonary angiogram (CTPA) is important to evaluate suspected pulmonary embolism in pregnancy but has maternal/fetal radiation risks. The objective of this study was to estimate maternal and fetal radiation-induced cancer risk from CTPA during pregnancy. METHODS: Simulation modeling via the National Cancer Institute's Radiation Risk Assessment Tool was used to estimate excess cancer risks from 17 organ doses from CTPA during pregnancy, with doses determined by a radiation dose indexing monitoring system. Organ doses were obtained from a radiation dose indexing monitoring system. Maternal and fetal cancer risks per 100,000 were calculated for male and female fetuses and several maternal ages. RESULTS: The 534 CTPA examinations had top 3 maternal organ doses to the breast, lung, and stomach of 17.34, 15.53, and 9.43 mSv, respectively, with a mean uterine dose of 0.21 mSv. The total maternal excess risks of developing cancer per 100,000 were 181, 151, 121, 107, 94.5, 84, and 74.4, respectively, for a 20-, 25-, 30-, 35-, 40-, 45-, and 50-year-old woman undergoing CTPA, compared with baseline cancer risks of 41,408 for 20-year-old patients. The total fetal excess risks of developing cancer per 100,000 were 12.3 and 7.3 for female and male fetuses, respectively, when compared with baseline cancer risks of 41,227 and 48,291. DISCUSSION: Excess risk of developing cancer from CTPA was small relative to baseline cancer risk for pregnant patients and fetuses, decreased for pregnant patients with increasing maternal age, and was greater for female fetuses than male fetuses.

Acute ischemic stroke outcomes in patients with COVID-19: a systematic review and meta-analysis.

BACKGROUND: Although patients with COVID-19 have a higher risk of acute ischemic stroke (AIS), the impact on stroke outcomes remains uncertain. AIMS: To determine the clinical outcomes of patients with AIS and COVID-19 (AIS-COVID+). METHODS: We performed a systematic review and meta-analysis following the Preferred Reporting Items for Systematic Review and Meta-Analyses (PRISMA) guidelines. Our protocol was registered with the International Prospective Register of Systematic Reviews (CRD42020211977). Systematic searches were last performed on June 3, 2021 in EMBASE, PubMed, Web-of-Science, Scopus, and CINAHL Databases. INCLUSION CRITERIA: (1) studies reporting outcomes on AIS-COVID+; (2) original articles published in 2020 or later; (3) study participants aged ≥18 years. EXCLUSION CRITERIA: (1) case reports with <5 patients, abstracts, review articles; (2) studies analyzing novel interventions. Risk of bias was assessed using the Mixed Methods Appraisal Tool. Random-effects models estimated the pooled OR and 95% confidence intervals (95% CI) for mortality, modified Rankin Scale (mRS) score, length of stay (LOS), and discharge disposition. RESULTS: Of the 43 selected studies, 46.5% (20/43) reported patients with AIS without COVID-19 (AIS-COVID-) for comparison. Random-effects model included 7294 AIS-COVID+ and 158 401 AIS-COVID-. Compared with AIS-COVID-, AIS-COVID+ patients had higher in-hospital mortality (OR=3.87 (95% CI 2.75 to 5.45), P<0.001), less mRS scores 0-2 (OR=0.53 (95% CI 0.46 to 0.62), P<0.001), longer LOS (mean difference=4.21 days (95% CI 1.96 to 6.47), P<0.001), and less home discharge (OR=0.31 (95% CI 0.21 to 0.47), P<0.001). CONCLUSIONS: Patients with AIS-COVID had worse outcomes, with almost fourfold increased mortality, half the odds of mRS scores 0-2, and one-third the odds of home discharge. These findings confirm the significant impact of COVID-19 on early stroke outcomes.

Ten-Year Trend in Advanced Imaging Utilization for Suspected Pulmonary Embolism in Pregnancy.

PURPOSE: Advanced imaging is essential to diagnose pulmonary embolism (PE) in pregnancy, but there are associated maternal and fetal radiation risks. The purpose of this study was to evaluate the 10-year trend in advanced imaging utilization for the evaluation of suspected PE in pregnancy. METHODS: The authors evaluated pregnant women with advanced imaging using CT pulmonary angiography (CTPA) or lung scintigraphy (LS) for evaluation of suspected PE presenting to two tertiary hospitals from 2007 to 2016. The rate of imaging was evaluated relative to positive PE rate and local pregnancy rate. positive PE was defined as a new acute PE finding on any advanced imaging within 3 days of first advanced imaging test. Local pregnancy rates were defined per 1,000 pregnancies in the county serviced by both hospitals. Chi-square testing was used to evaluate statistical significance (P < .05) in the utilization trend of advanced imaging and relative to local pregnancy rates and evaluations positive for PE. RESULTS: A total of 707 pregnant patients were identified, of whom 92.5% (n = 654) underwent CTPA and 7.5% (n = 53) underwent LS. Regression analysis showed an average increase of 5.2 advanced imaging studies per year (P < .001), with 61 and 105 studies performed in 2007 and 2016, respectively. Additionally, there was an average increase of 0.08 (P < .001) advanced imaging studies per 1,000 local pregnancies per year, doubling from 0.7 in 2007 to 1.4 in 2016 (P < .001). Finally, there was a decrease of 0.004 (P = .009) in advanced imaging positive for PE, from 3% (2 of 61) in 2007 to 0% (0 of 100) in 2016. CONCLUSIONS: Advanced imaging utilization increased by 72% over the 10-year window, driven by higher use of CTPA. Although the detection rate of PE on advanced imaging has decreased, the utilization rate among pregnant patients doubled during this period. These results highlight the need to consider the radiation risks and costs of advanced imaging in specific patient populations.

Gender-Based Disparity in Acute Stroke Imaging Utilization and the Impact on Treatment and Outcomes: 2012 to 2021.

INTRODUCTION: Prior studies have revealed significant socio-economic disparities in neuro-imaging and treatment utilization for patients with acute ischemic stroke (AIS). In this study, we sought to evaluate whether a sex-based disparity exists in neuro-imaging and to determine its etiology and association with acute treatment and outcomes. MATERIALS AND METHODS: This was a retrospective study of consecutive patients with AIS admitted to a comprehensive stroke center between 2012 and 2021. Patient demographic and clinical characteristics, neuro-imaging, acute treatment, and early clinical outcomes were extracted from the electronic medical records. Trend analysis, bivariate analysis of patient characteristics by sex, and multivariable logistic regression analyses were conducted. RESULTS: Of the 7,540 AIS episodes registered from 2012 to 2021, 47.9% were female patients. After adjusting for demographic, clinical, and temporal factors, significantly higher utilization of CTA was found for male patients (odds ratio = 1.20 [95% confidence interval 1.07-1.34]), particularly from socio-economically advantaged groups, and in years 2015 and 2019, representing the years endovascular thrombectomy recommendations changed. Despite this, male patients had significantly lower intravenous thrombolysis utilization (odds ratio = 0.83 [95% confidence interval 0.71-0.96]) and similar endovascular thrombectomy rates as female patients. There were no significant sex differences in early clinical outcomes, and no relevant clinical or demographic factors explained the CT angiography utilization disparity. CONCLUSION: Despite higher CT angiography utilization in socio-economically advantaged male patients with AIS, likely overutilization due to implicit biases following guideline updates, the rates of acute treatment, and early clinical outcomes were unaffected.

Implementation of the Management of Anticoagulation in the Periprocedural Period App into an Electronic Health Record: A Cost-Effectiveness Analysis.

The Management of Anticoagulation in the Periprocedural Period (MAPPP) app is a free tool providing up-to-date guidelines on the periprocedural management of patients on long-term anticoagulants. After validating its effectiveness in the post-procedural period, we aimed to study its overall cost-effectiveness. SF-12 surveys were sent to eligible patients, converted into SF-6D forms, and subsequently into quality-adjusted life years (QALYs) to calculate the incremental cost-effectiveness ratio (ICER). The number of 30-day readmissions was used to calculate hospitalization costs, utilizing publicly available data. From 1/1/2018 to 1/31/2019, 642 patients were screened for enrollment, with an overall response rate of 94% (164/175) among the consented and 49% (164/336) among all eligible patients. The average QALY score was 0.7134 (95% CI [0.6836, 0.7431]) for the patients whose treatment plan followed the MAPPP app recommendations (acceptance group) and 0.7104 (95% CI [0.6760, 0.7448]) for those who did not (rejection group), without statistically significant differences. The difference in ICER scores was -$429 866.67, with the negative sign demonstrating that acceptance was the dominant strategy. By utilizing QALYs and ICER scores we have shown that the acceptance of MAPPP app recommendations is the dominant strategy for the periprocedural management of patients on long-term anticoagulation.

Drivers of Ischemic Stroke Hospital Cost Trends Among Older Adults in the United States.

PURPOSE: The increased use of neuroimaging and innovations in ischemic stroke (IS) treatment have improved outcomes, but the impact on median hospital costs is not well understood. METHODS: A retrospective study was conducted using Medicare 5% claims data for 75,525 consecutive index IS hospitalizations for patients aged ≥65 years from 2012 to 2019 (values in 2019 dollars). IS episode cost was calculated in each year for trend analysis and stratified by cost components, including neuroimaging (CT angiography [CTA], CT perfusion [CTP], MRI, and MR angiography [MRA]), treatment (endovascular thrombectomy [EVT] and/or intravenous thrombolysis), and patient sociodemographic factors. Logistic regression was performed to analyze the drivers of high-cost episodes and median regression to assess drivers of median costs. RESULTS: The median IS episode cost increased by 4.9% from $9,509 in 2012 to $9,973 in 2019 (P = .0021). Treatment with EVT resulted in the greatest odds of having a high-cost (>$20,000) hospitalization (odds ratio [OR], 71.86; 95% confidence interval [CI], 54.62-94.55), as did intravenous thrombolysis treatment (OR, 3.19; 95% CI, 2.90-3.52). Controlling for other factors, neuroimaging with CTA (OR, 1.72; 95% CI, 1.58-1.87), CTP (OR, 1.32; 95% CI, 1.14-1.52), and/or MRA (OR, 1.26; 95% CI, 1.15-1.38) had greater odds of having high-cost episodes than those without CTA, CTP, and MRA. Length of stay > 4 days (OR, 4.34; 95% CI, 3.99-4.72) and in-hospital mortality (OR, 1.85; 95% CI, 1.63-2.10) were also associated with high-cost episodes. CONCLUSIONS: From 2012 to 2019, the median IS episode cost increased by 4.9%, with EVT as the main cost driver. However, the increasing treatment cost trends have been partially offset by decreases in median length of stay and in-hospital mortality.

Contrast-associated acute kidney injury in acute ischemic stroke patients following multi-dose iodinated contrast.

BACKGROUND AND OBJECTIVE: lthough intravenous contrast in neuroimaging has become increasingly important in selecting patients for stroke treatment, clinical concerns remain regarding contrast-associated acute kidney injury (CA-AKI). Given the increasing utilization of CT angiography and/or perfusion coupled with cerebral angiography, the purpose of this study was to assess the association of CA-AKI and multi-dose iodinated contrast in acute ischemic stroke (AIS) patients. MATERIALS AND METHODS: etrospective review of AIS patients at a comprehensive stroke center was performed from January 2018 to December 2019. Data collection included patient demographics, stroke risk factors, stroke severity, discharge disposition, modified Rankin Scale, contrast type/volume, and creatinine levels (baseline, 48-72 h). CA-AKI was defined as creatinine increase ≥ 25 % from baseline. Bivariate analyses and multivariable logistic regression models were implemented to compare AIS patients with multi-dose and single-dose contrast. RESULTS: Of 440 AIS patients, 215 (48.9 %) were exposed to a single-dose contrast, and 225 (51.1 %) received multi-dose. In single-dose patients, CA-AKI at 48/72 h was 9.7 %/10.2 % compared to 8.0 %/8.9 % in multi-dose patients. Multi-dose patients were significantly more likely to receive a higher volume of contrast (mean 142.1 mL versus 80.8 mL; p < 0.001), but there was no significant difference in their creatinine levels or CA-AKI. NIHSS score (OR=1.08, 95 % CI=[1.04,1.13]), and patient transfer from another hospital (OR=3.84, 95 % CI=[1.94,7.62]) were significantly associated with multi-dose contrast. CONCLUSIONS: No significant association between multi-dose iodinated contrast and CA-AKI was seen in AIS patients. Concerns of CA-AKI should not deter physicians from pursuing timely and appropriate contrast-enhanced neuroimaging that may optimize treatment outcomes in AIS patients.

Neuroimaging in acute ischemic stroke: Trends, disparities, and clinical impact.

INTRODUCTION: Clinical studies over the past decade expanded the eligibility criteria for endovascular therapy, with advanced imaging selection and new devices leading to higher rates of good outcomes. Herein, we explore the current trends in neuroimaging, associated factors, and impact on treatment and clinical outcomes. MATERIALS AND METHODS: This is a retrospective study of consecutive acute ischemic stroke patients, admitted to a comprehensive stroke center from 2016 to 2020. Patient characteristics, including age, sex, race, arrival method, admission National Institutes of Health Stroke Scale score and last known well to arrival time; imaging and treatment utilization; and discharge outcome by modified Rankin Scale and disposition were extracted from medical records. Trend and multivariable logistic regression analyses were performed, and trends were stratified by patient characteristics. RESULTS: Of 4,125 acute ischemic stroke episodes, 15.1% received intravenous thrombolysis only, and 7.5% received endovascular thrombectomy from 2016 to 2020. Neuroimaging utilization trends significantly increased for computed tomography angiography (CTA) (48.7% to 75.2%, p < 0.001) and computed tomography perfusion (CTP) (0.26% to 32.9%, p < 0.001), and decreased for magnetic resonance angiography (MRA) (43.2% to 24.7%, p < 0.001). These trends held after adjusting for patient characteristics. Endovascular thrombectomy and intravenous thrombolysis were significantly more common in patients with CTA and CTP (p < 0.0001), and these treatments were associated with good clinical outcomes after controlling for patient characteristics. CONCLUSION: We found significantly increased trends in CTA and CTP imaging, which were associated with endovascular thrombectomy and intravenous thrombolysis utilization, in acute ischemic stroke patients from 2016 to 2020.

Hypoperfusion Intensity Ratio is Associated with Stroke Mechanism in Patients Undergoing Mechanical Thrombectomy.

BACKGROUND: Hypoperfusion Intensity Ratio (HIR), defined as Tmax >10s/Tmax >6s on computed tomography perfusion (CTP), and stroke mechanisms have been independently correlated with angiographic collaterals and patient outcomes. Slowly developing atherosclerotic stenosis may foster collateral development, whereas cardioembolic occlusion may occur before collaterals mature. We hypothesized that favorable HIR is associated with large artery atherosclerosis (LAA) stroke mechanism and good clinical outcome. METHODS: Retrospective study of consecutive endovascularly-treated stroke patients with intracranial ICA or MCA M1/M2 occlusions, who underwent CTP before intervention, between January 2018 and August 2021. Patients were dichotomized into LAA+ or LAA- based on presence of LAA on angiography. HIR was dichotomized into favorable (HIR+) or unfavorable (HIR-) groups based on published thresholds. Good early outcome was defined as discharge mRS of 0-2. Bivariate and multivariable logistic regression were performed. RESULTS: 143 patients met inclusion. 21/143 were LAA+ (15%) and 65/143 (45%) were HIR+. HIR+ was significantly more frequent in LAA+ patients (67% vs. 42%, p= 0.035). Controlling for demographics, stroke severity, imaging findings, and medical comorbidities, LAA+ remained independently associated with HIR+ (OR 5.37 [95% CI 1.43 - 20.14]; p=0.013) as did smaller infarction core volume (<30 mL of CBF <30%: OR 7.92 [95% CI 2.27 - 27.64]; p = 0.001). HIR+ was not associated with good clinical outcome. CONCLUSIONS: Large artery atherosclerosis was independently associated with favorable HIR in patients undergoing mechanical thrombectomy. While favorable HIR was associated with smaller pre-treatment core infarcts, reflecting more robust collaterals, it was not associated with good clinical outcome.

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.

Updated Trends, Disparities, and Clinical Impact of Neuroimaging Utilization in Ischemic Stroke in the Medicare Population: 2012 to 2019.

OBJECTIVE: The purpose of this study was to update trends, investigate sociodemographic disparities, and evaluate the impact on mortality of stroke neuroimaging across the United States from 2012 to 2019. METHODS: Retrospective cohort study using CMS Medicare 5% Research Identifiable Files, representing consecutive ischemic stroke emergency department or hospitalized patients aged ≥65 years. A total of 85,547 stroke episodes with demographic and clinical information were analyzed using Cochran-Mantel-Haenszel tests and logistic regression. Outcome measures were neuroimaging (CT angiography [CTA], CT perfusion [CTP], MRI, MR angiography [MRA]) utilization, acute treatment (endovascular thrombectomy [EVT] and intravenous thrombolysis [IVT]), and mortality while in the hospital and at 30 days and 1 year post discharge. RESULTS: Significantly increasing utilization trends for CTA (250%), CTP (428%) and MRI (18%), and a decreasing trend for MRA (-33%) were observed from 2012 to 2019 (P < .0001). Controlling for covariates in the logistic regression models, CTA and CTP were significantly associated with higher EVT and IVT utilization. Although CTA, MRI, and MRA were associated with lower mortality, CTP was associated with higher mortality post discharge. Less neuroimaging was performed in rural patients; older patients (≥80 years) had lower utilization of CTA, MRI, and MRA; female patients had lower rates of CTA; and Black patients had lower utilization of CTA and CTP. CONCLUSIONS: CTA and CTP utilization increased in the Medicare ischemic stroke population from 2012 to 2019 and both were associated with greater EVT and IVT use. However, disparities exist in neuroimaging utilization across all demographic groups, and further understanding of the root causes of these disparities will be crucial to achieving equity in stroke care.

Vertebrobasilar Stroke: Association Between Infarction Patterns and Quantitative Magnetic Resonance Angiography Flow State.

Background Treatment and prognosis of vertebrobasilar atherosclerotic disease differs depending on stroke mechanism, such as artery-to-artery embolism, branch atheromatous disease, and hemodynamic ischemia. Our aim was to investigate the relationship between infarction pattern and flow status using quantitative magnetic resonance angiography (QMRA), to determine the validity of using infarction patterns to infer stroke mechanism. Methods and Results This is a retrospective study of patients with ischemic stroke with intra- or extracranial vertebrobasilar atherosclerotic stenosis, who underwent magnetic resonance imaging of the brain, neurovascular imaging, and QMRA, between 2009 and 2021. Patients with cerebral infarction predating or following QMRA by ≥1 year, or QMRA studies performed for basilar thrombosis, vertebral dissection, or only postangioplasty/stenting, were excluded. Poststenotic flow (basilar and posterior cerebral arteries) was dichotomized as low-flow or normal-flow based on published criteria. Of 1211 consecutive patients who underwent QMRA noninvasive optimal analysis, 69 met inclusion. Mixed patterns were most common (46.4%), followed by perforator (23.2%), borderzone (14.5%), and territorial (15.9%). Patients with low-flow had a significantly higher rate of borderzone+ patterns (borderzone alone or in mixed pattern) compared with patients with normal-flow (77.4% low-flow versus 39.5% normal-flow, P=0.002). Borderzone+ patterns were associated with 61.5% probability of low-flow state, while no borderzone (perforator/territorial) patterns were associated with 76.7% probability of normal-flow state. Conclusions Borderzone infarction pattern (alone or mixed) was associated with low poststenotic posterior circulation flow by QMRA. However, borderzone pattern only moderately predicted low-flow state, and may be an unreliable flow marker. Therefore, infarct topography may complement, but should not replace hemodynamic studies to establish flow status.

Striving for Socioeconomic Equity in Ischemic Stroke Care: Imaging and Acute Treatment Utilization From a Comprehensive Stroke Center.

PURPOSE: Prior studies have shown socioeconomic disparities in advanced neuroimaging and acute treatment utilization in patients with ischemic stroke. The authors analyzed whether socioeconomic factors were associated with stroke neuroimaging and acute treatment utilization at a comprehensive stroke center. METHODS: A retrospective study of consecutive acute ischemic stroke discharges from 2012 to 2020 at a comprehensive stroke center was performed. Differences in neuroimaging (CT angiography [CTA], CT perfusion, MRI, and MR angiography [MRA]) and acute treatment (intravenous thrombolysis [IVT] and endovascular thrombectomy [EVT]) utilization were evaluated on the basis of socioeconomic factors of age, sex, race, insurance type, and neighborhood-level median household income. Chi-square tests were used for bivariate analyses. Multivariable logistic regression analyses were performed to determine associations between socioeconomic factors and neuroimaging or treatment utilization while controlling for stroke-specific factors and comorbidities. RESULTS: Among 6,140 ischemic stroke discharges, race and insurance type were not significantly associated with lower utilization of neuroimaging (CTA, CT perfusion, MRI, and MRA) or acute stroke treatment (IVT and EVT) after controlling for stroke-specific factors and comorbidities. However, median household income < $80,000/year was associated with lower IVT use (odds ratio [OR], 0.74; 95% confidence interval [CI], 0.63-0.87). In addition, age ≥ 80 years had lower CTA (OR, 0.62; 95% CI, 0.51-0.75) and EVT (OR, 0.53; 95% CI, 0.39-0.73) utilization, and female sex had lower CTA (OR, 0.78; 95% CI, 0.65-0.93) utilization. Significantly higher utilization was observed for MRI in Asian (OR, 1.33; 95% CI, 1.04-1.69) and uninsured (OR, 1.64; 95% CI, 1.07-2.50) patients and for MRA (OR, 1.24; 95% CI, 1.04-1.49) and EVT (OR, 1.62; 95% CI, 1.20-2.20) in privately insured patients. CONCLUSIONS: Once access to a comprehensive stroke center is achieved, socioeconomic disparities in the utilization of health care resources, particularly advanced neuroimaging and acute treatment, may be improved in patients with ischemic stroke.

Cost-Consequence Analysis of Advanced Imaging in Acute Ischemic Stroke Care.

Introduction: The purpose of this study was to illustrate the potential costs and health consequences of implementing advanced CT angiography and perfusion (CTAP) as the initial imaging in patients presenting with acute ischemic stroke (AIS) symptoms at a comprehensive stroke center (CSC). Methods: A decision-simulation model based on the American Heart Association's recommendations for AIS care pathways was developed to assess imaging strategies for a 5-year period from the institutional perspective. The following strategies were compared: (1) advanced CTAP imaging: NCCT + CTA + CT perfusion at the time of presentation; (2) standard-of-care: non-contrast CT (NCCT) at the time of presentation, with CT angiography (CTA) ± CT perfusion only in select patients (initial imaging to exclude hemorrhage and extensive ischemia) for mechanical thrombectomy (MT) evaluation. Model parameters were defined with evidence-based data. Cost-consequence and sensitivity analyses were performed. The modified Rankin Scale (mRS) at 90 days was used as the outcome measure. Results: The decision-simulation modeling revealed that adoption of the advanced CTAP imaging increased per-patient imaging costs by 1.19% ($9.28/$779.72), increased per-patient treatment costs by 33.25% ($729.96/$2,195.24), and decreased other per-patient acute care costs by 0.7% (-$114.12/$16,285.85). The large increase in treatment costs was caused by higher proportion of patients being treated. However, improved outcomes lowered the other per-patient acute care costs. Over the five-year period, advanced CTAP imaging led to 1.63% (66/4,040) more patients with good outcomes (90-day mRS 0-2), 2.23% (66/2,960) fewer patients with poor outcomes (90-day mRS 3-5), and no change in mortality (90-day mRS 6). Our CT equipment utilization analysis showed that the demand for CT equipment in terms of scanner time (minutes) was 24% lower in the advanced CTAP imaging strategy compared to the standard-of-care strategy. The number of EVT procedures performed at the CSC may increase by 50%. Conclusions: Our study reveals that adoption of advanced CTAP imaging at presentation increases the demand for treatment of acute ischemic stroke patients as more patients are diagnosed within the treatment time window compared to standard-of-care imaging. Advanced imaging also leads to more patients with good functional outcomes and fewer patients with dependent functional status.

CT pulmonary angiography in pregnancy: Specific conversion factors to estimate effective radiation dose from dose length product: A retrospective cross-sectional study across a multi-hospital integrated healthcare network.

PURPOSE: Effective dose describes radiation-related cancer risk from CT scans and is estimated using a readily available conversion factor (k-factor), which varies by body part and study type. To purpose of this study is to determine the specific k-factor for CTPA in pregnant patients and its predictive factors. METHODS: This retrospective cross-sectional study evaluates CTPA in pregnancy across a multihospital integrated healthcare network from January 2012 to April 2017. Patient and CTPA-related data were obtained from the electronic health record and a radiation dose index monitoring system. Each patient's effective dose was determined by patient-specific Monte-Carlo simulation with Cristy phantoms and divided by patient dose-length-product to determine the k-factor. K-factor for pregnant patients was compared to the k-factor for adults of standard physique with a one-sample t-test. Bivariate and multivariable analyses were performed for patient and CT predictors of k-factor. RESULTS: A total of 534 patients were included. The mean k-factor for all patients was 0.0249 (mSv·mGy-1·cm-1), 78% greater than k-factor of 0.014 (p < 0.001) suggested for the general adult population. Multivariable analysis demonstrated lower k-factors with increasing pitch (p = 0.0002), patient size (p < 0.001), and scan length (p < 0.0001). The 120 kVp (p < 0.001) and 140 kVp (p = 0.0028) analyses showed a larger k-factor than 80 and 100 kVp studies combined. CONCLUSIONS: Specific k-factor for CTPA in pregnant patients is greater than the previously used generic chest CT k-factor and should be used to estimate the effective dose for CTPA exams in pregnancy.

Recovery of outpatient imaging utilization during the first wave of the COVID-19 pandemic.

OBJECTIVE: During the COVID-19 pandemic, Radiology practices experienced marked reductions in outpatient imaging volumes. Our purpose was to evaluate the timing, rate, and degree of recovery of outpatient imaging during the first wave of the pandemic. We also sought to ascertain the relationship of outpatient imaging recovery to the incidence of COVID-19 cases. METHODS: Retrospective study of outpatient imaging volumes in a large healthcare system was performed from January 1, 2019-August 25, 2020. Dataset was split to compare Pre-COVID (weeks 1-9), Peak-COVID (weeks 10-15) and Recovery-COVID (weeks 16-34) periods. Chi-square and Independent-samples t-tests compared weekly outpatient imaging volumes in 2020 and 2019. Regression analyses assessed the rate of decline and recovery in Peak-COVID and Recovery-COVID periods, respectively. RESULTS: Total outpatient imaging volume in 2020 (weeks 1-34) was 327,738 exams, compared to 440,314 in 2019. The 2020 mean weekly imaging volumes were significantly decreased in Peak-COVID (p = 0.0148) and Recovery-COVID (p = 0.0003) periods. Mean weekly decline rate was -2580 exams/week and recovery rate was +617 exams/week. The 2020 Post-COVID (weeks 10-34) period had an average decrease of 36.5% (4813.4/13,178.6) imaging exams/week and total estimated decrease of 120,335 exams. Significant inverse correlation (-0.8338, p < 0.0001) was seen between positive-tested COVID-19 cases and imaging utilization with 1-week lag during Post-COVID (weeks 10-34) period. CONCLUSION: Recovery of outpatient imaging volume during the first wave of COVID-19 pandemic showed a gradual return to pre-pandemic levels over the course of 3-4 months. The rate of imaging utilization was inversely associated with new positive-tested COVID-19 cases with a 1-week lag.