Sociodemographic Factors and Screening CT Colonography Use Among Medicare Beneficiaries.

BACKGROUND. Approximately one-third of the eligible U.S. population have not undergone guideline-compliant colorectal cancer (CRC) screening. Guidelines recognize various screening strategies to increase adherence. CMS provides coverage for all recommended screening tests except CT colonography (CTC). OBJECTIVE. The purpose of this study was to compare CTC and other CRC screening tests in terms of associations of utilization with income, race and ethnicity, and urbanicity in Medicare fee-for-service beneficiaries. METHODS. This retrospective study used CMS Research Identifiable Files from January 1, 2011, through December 31, 2020. These files contain claims information for 5% of Medicare fee-for-service beneficiaries. Data were extracted for individuals 45-85 years old, and individuals with high CRC risk were excluded. Multivariable logistic regression models were constructed to determine the likelihood of undergoing CRC screening tests (as well as of undergoing diagnostic CTC, a CMS-covered test with similar physical access as screening CTC) as a function of income, race and ethnicity, and urbanicity while controlling for sex, age, Charlson comorbidity index, U.S. census region, screening year, and related conditions and procedures. RESULTS. For 12,273,363 beneficiary years (mean age, 70.5 ± 8.2 [SD] years; 2,436,849 unique beneficiaries: 6,774,837 female beneficiaries, 5,498,526 male beneficiaries), there were 785,103 CRC screenings events, including 645 for screening CTC. Compared with individuals living in communities with per capita income of less than US$25,000, individuals in communities with income of US$100,000 or more had OR for undergoing screening CTC of 5.73, optical colonoscopy (OC) of 1.36, sigmoidoscopy of 1.03, guaiac fecal occult blood test or fecal immunochemical test of 1.50, stool DNA of 1.43, and diagnostic CTC of 2.00. The OR for undergoing screening CTC was 1.00 for Hispanic individuals and 1.08 for non-Hispanic Black individuals compared with non-Hispanic White individuals. Compared with the OR for undergoing screening CTC for residents of metropolitan areas, the OR was 0.51 for residents of micropolitan areas and 0.65 for residents of small or rural areas. CONCLUSION. The association with income was substantially larger for screening CTC than for other CRC screening tests or for diagnostic CTC. CLINICAL IMPACT. Medicare's noncoverage for screening CTC may contribute to lower adherence with CRC screening guidelines for lower-income beneficiaries. Medicare coverage of CTC could reduce income-based disparities for individuals avoiding OC owing to invasiveness, need for anesthesia, or complication risk.

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.

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.

Patient and Fetal Radiation-Induced Malignancy Risk From Imaging For Evaluation of Pulmonary Embolism in Pregnancy.

BACKGROUND: Imaging for diagnosis of suspected pulmonary embolism in pregnancy presents radiation concerns for patient and fetus. OBJECTIVES: Estimate the risks of radiation-induced breast cancer and childhood leukemia from common imaging techniques for the evaluation of suspected pulmonary embolism in pregnancy. METHODS: Breast and uterine absorbed doses for various imaging techniques were input into the National Cancer Institute Radiation Risk Assessment Tool to calculate risk of breast cancer for the patient and childhood leukemia for the fetus. Absorbed doses were obtained by synthesizing data from a recent systematic review and the International Commission on Radiological Protection. Primary outcomes were the estimated excess incidences of breast cancer and childhood leukemia per 100,000 exposures. RESULTS: Baseline incidences of breast cancer for a 30-year-old woman and childhood leukemia for a male fetus were 13,341 and 939, respectively. Excess incidences of breast cancer were 0.003 and 0.275 for a single and two-view chest radiograph, respectively, 9.53 and 20.6 for low- and full-dose computed tomography pulmonary angiography (CTPA), respectively, 0.616 and 2.54 for low- and full-dose perfusion scan, respectively, and 0.732 and 2.66 for low- and full-dose ventilation perfusion scan, respectively. Excess incidences of childhood leukemia were 0.004 and 0.007 for a single and two-view chest radiograph, respectively, 0.069 and 0.490 for low- and full-dose CTPA, respectively, 0.359 and 1.47 for low- and full-dose perfusion scan, respectively, and 0.856 and 1.97 for low- and full-dose ventilation perfusion scan, respectively. CONCLUSION: Excess cancer risks for all techniques were small relative to baseline cancer risks, with CTPA techniques carrying slightly higher risk of breast cancer for the patient and ventilation perfusion techniques a higher risk of childhood leukemia.

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.

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.

Machine learning automatically detects COVID-19 using chest CTs in a large multicenter cohort.

OBJECTIVES: To investigate machine learning classifiers and interpretable models using chest CT for detection of COVID-19 and differentiation from other pneumonias, interstitial lung disease (ILD) and normal CTs. METHODS: Our retrospective multi-institutional study obtained 2446 chest CTs from 16 institutions (including 1161 COVID-19 patients). Training/validation/testing cohorts included 1011/50/100 COVID-19, 388/16/33 ILD, 189/16/33 other pneumonias, and 559/17/34 normal (no pathologies) CTs. A metric-based approach for the classification of COVID-19 used interpretable features, relying on logistic regression and random forests. A deep learning-based classifier differentiated COVID-19 via 3D features extracted directly from CT attenuation and probability distribution of airspace opacities. RESULTS: Most discriminative features of COVID-19 are the percentage of airspace opacity and peripheral and basal predominant opacities, concordant with the typical characterization of COVID-19 in the literature. Unsupervised hierarchical clustering compares feature distribution across COVID-19 and control cohorts. The metrics-based classifier achieved AUC = 0.83, sensitivity = 0.74, and specificity = 0.79 versus respectively 0.93, 0.90, and 0.83 for the DL-based classifier. Most of ambiguity comes from non-COVID-19 pneumonia with manifestations that overlap with COVID-19, as well as mild COVID-19 cases. Non-COVID-19 classification performance is 91% for ILD, 64% for other pneumonias, and 94% for no pathologies, which demonstrates the robustness of our method against different compositions of control groups. CONCLUSIONS: Our new method accurately discriminates COVID-19 from other types of pneumonia, ILD, and CTs with no pathologies, using quantitative imaging features derived from chest CT, while balancing interpretability of results and classification performance and, therefore, may be useful to facilitate diagnosis of COVID-19. KEY POINTS: • Unsupervised clustering reveals the key tomographic features including percent airspace opacity and peripheral and basal opacities most typical of COVID-19 relative to control groups. • COVID-19-positive CTs were compared with COVID-19-negative chest CTs (including a balanced distribution of non-COVID-19 pneumonia, ILD, and no pathologies). Classification accuracies for COVID-19, pneumonia, ILD, and CT scans with no pathologies are respectively 90%, 64%, 91%, and 94%. • Our deep learning (DL)-based classification method demonstrates an AUC of 0.93 (sensitivity 90%, specificity 83%). Machine learning methods applied to quantitative chest CT metrics can therefore improve diagnostic accuracy in suspected COVID-19, particularly in resource-constrained environments.

Early Thrombectomy Outcomes in Transfer Patients.

OBJECTIVE: The optimal patient transportation destination of acute ischemic stroke (AIS) patients remains uncertain. The purpose of this study was to evaluate the predictive variables that determine stroke outcomes depending on the patient transportation destination. METHODS: We performed a retrospective study using an AIS database consisting of patients who underwent thrombectomy admitted to our institution from November 1, 2011, through October 1, 2018. RESULTS: A total of 171 patients were included in the statistical analysis; 42.1% (72/171) of patients were in the mothership group (directly admitted) and 57.9% (99/171) in the drip-and-ship group (transferred). Multivariable logistic regression revealed the predictive factors for favorable outcomes were driving distance (expressed in miles) between the patient's home and a comprehensive stroke center (CSC) (odds ratio [OR] = 0.95; 95% confidence interval [CI], 0.90-0.99; P = .035), absence of diabetes mellitus (OR = 3.60; 95% CI, 1.20-10.82; P = .022), lower National Institutes of Health Stroke Scale score at admission (OR = 0.91; 95% CI, 0.85-0.97; P = .003), and shorter symptom onset to CSC arrival time (expressed in hours) (OR = 0.84; 95% CI, 0.72-0.99; P = .038). CONCLUSIONS: Our study revealed that a shorter driving distance between the patient's home and CSC, absence of diabetes, lower National Institutes of Health Stroke Scale score, and shorter onset to hospital arrival time positively impacted the outcomes of endovascularly treated AIS patients.

Cerebrovascular Complications of COVID-19.

BACKGROUND AND PURPOSE: Coronavirus disease 2019 (COVID-19) evolved quickly into a global pandemic with myriad systemic complications, including stroke. We report the largest case series to date of cerebrovascular complications of COVID-19 and compare with stroke patients without infection. METHODS: Retrospective case series of COVID-19 patients with imaging-confirmed stroke, treated at 11 hospitals in New York, between March 14 and April 26, 2020. Demographic, clinical, laboratory, imaging, and outcome data were collected, and cases were compared with date-matched controls without COVID-19 from 1 year prior. RESULTS: Eighty-six COVID-19-positive stroke cases were identified (mean age, 67.4 years; 44.2% women). Ischemic stroke (83.7%) and nonfocal neurological presentations (67.4%) predominated, commonly involving multivascular distributions (45.8%) with associated hemorrhage (20.8%). Compared with controls (n=499), COVID-19 was associated with in-hospital stroke onset (47.7% versus 5.0%; P<0.001), mortality (29.1% versus 9.0%; P<0.001), and Black/multiracial race (58.1% versus 36.9%; P=0.001). COVID-19 was the strongest independent risk factor for in-hospital stroke (odds ratio, 20.9 [95% CI, 10.4-42.2]; P<0.001), whereas COVID-19, older age, and intracranial hemorrhage independently predicted mortality. CONCLUSIONS: COVID-19 is an independent risk factor for stroke in hospitalized patients and mortality, and stroke presentations are frequently atypical.

CT Angiography for Triage of Patients with Acute Minor Stroke: A Cost-effectiveness Analysis.

Background Minor stroke is common and may represent up to two-thirds of cases of acute ischemic stroke. The cost-effectiveness of CT angiography in patients with minor stroke (National Institutes of Health Stroke Scale [NIHSS] score ≤6) is not well established. Purpose To evaluate cost-effectiveness of CT angiography in the detection of large-vessel occlusion (LVO) in patients with acute minor stroke (NIHSS score ≤6). Materials and Methods A Markov decision-analytic model with a societal perspective was constructed. Three different management strategies were evaluated: (a) no vascular imaging and best medical management, (b) CT angiography for all patients and immediate thrombectomy for LVO after intravenous thrombolysis, and (c) CT angiography for all and best medical management (including intravenous thrombolysis, with rescue thrombectomy for patients with LVO and neurologic deterioration). One-way, two-way, and probabilistic sensitivity analyses were performed. Results Base-case calculation showed that CT angiography followed by immediate thrombectomy had the lowest cost ($346 007) and highest health benefits (9.26 quality-adjusted life-years [QALYs]). CT angiography followed by best medical management with possible rescue thrombectomy for patients with LVO had a slightly higher cost ($346 500) and lower health benefits (9.09 QALYs). No vascular imaging had the highest cost and lowest health benefits. The difference in health benefits compared with the CT angiography and immediate thrombectomy strategy was 0.39 QALY, which corresponds to 142 days in perfect health per patient. The conclusion was robust in a probabilistic sensitivity analysis. CT angiography was cost-effective when the probability of LVO was greater than 0.16% in patients with acute minor stroke. The net monetary benefit of performing CT angiography was higher in younger patients ($68 950 difference between CT angiography followed by immediate thrombectomy and no vascular imaging in 55-year-old patients compared with $20 931 in 85-year-old patients). Conclusion Screening for large-vessel occlusion with CT angiography in patients with acute minor stroke is cost-effective and associated with improved health outcomes. Undetected large-vessel occlusion in the absence of vascular imaging results in worse health outcomes and higher costs. © RSNA, 2020 Online supplemental material is available for this article.

Risk of Radiation-Induced Cancer From Computed Tomography Angiography Use in Imaging Surveillance for Unruptured Cerebral Aneurysms.

Background and Purpose- Although computed tomography angiography (CTA) is an excellent, noninvasive imaging modality for surveillance of intracranial aneurysms, radiation concerns have been cited to restrict its use in surveillance imaging. The goal of this study was to estimate distributions of radiation-induced central nervous system cancer incidence from CTA surveillance for intracranial aneurysms, and the impact of frequency and duration of surveillance imaging using follow-up CTAs. Methods- Simulation-modeling approach was performed using data on CTA associated radiation risk. We used the Radiation Risk Assessment Tool, based on the data using the BEIR VII report (BEIR VII). Each CTA was assigned as a separate exposure event. Men and women, respectively, starting surveillance imaging at 30, 40, and 50 years and receiving annual CTAs were considered as separate subgroups. As a comparison, we also calculated the radiation-induced cancer risk in the same groups of patients but receiving CTAs every 2 and 5 years, respectively. Results- CTA-associated excess cancer risk per exposure increases relatively more rapidly with the first 10 exposures and plateaus after the 44th exposure. On average, per CTA incurs ≈0.0026% in excess lifetime cancer risk. Receiving CTA follow-up at a younger age, more frequent follow-up, longer surveillance period, and men are the major factors contributing to an elevated excess lifetime risk. In the highest risk group, male patient receiving annual CTA follow-ups from the age of 30 years, the excess lifetime risk is 0.115% at the age of 81 years. Conclusions- Radiation-induced brain cancer incidence associated with unruptured intracranial aneurysm surveillance strategies using CTA is low relative to the risk for aneurysmal rupture. Further cost-effectiveness/utility analyses might help assess this risk in the context of aneurysmal ruptures prevented by surveillance imaging.

Cost-Effectiveness of Computed Tomography Angiography in Management of Tiny Unruptured Intracranial Aneurysms in the United States.

Background and Purpose- Our study aims to evaluate the cost-effectiveness of computed tomography angiography (CTA) for surveillance of tiny unruptured intracranial aneurysms and the impact of CTA radiation-induced brain tumor on the overall effectiveness of CTA. Methods- A Markov decision model was constructed from a societal perspective starting with patients 30-, 40-, or 50-year-old, with incidental detection of unruptured intracranial aneurysm ≤3 mm and no prior history of subarachnoid hemorrhage. Five different management strategies were assessed (1) annual CTA surveillance, (2) biennial CTA, (3) CTA follow-up every 5 years, (4) coiling and subsequent magnetic resonance imaging follow-up, and (5) annual CTA surveillance for the first 2 years, followed by every 5-year CTA follow-up. Probabilistic, 1-way, and 2-way sensitivity analyses were performed. Results- The base case calculation shows every 5-year CTA follow-up to be the most cost-effective strategy, and the conclusion remains robust in probabilistic sensitivity analysis. It remains the dominant strategy when the annual rupture risk of nongrowing unruptured intracranial aneurysms is smaller than 2.66% or the rupture risk in growing aneurysms is <57.4%. The radiation-induced brain cancer risk is relatively low, and sensitivity analysis shows that the radiation-induced cancer risk does not influence the conclusions unless the risk exceeds 663-fold of the base case values. Conclusions- Given the current literature, every 5-year CTA imaging follow-up is the cost-effective strategy in patients with aneurysms ≤3 mm, resulting in better health outcomes and lower healthcare spending. Patients with aneurysms at high risk of rupture might need more aggressive management.

Comparative Effectiveness of Endovascular Thrombectomy in Elderly Stroke Patients.

Background and Purpose- Strokes in patients aged ≥80 years are common, and advanced age is associated with relatively poor poststroke functional outcome. The current guidelines do not recommend an upper age limit for endovascular thrombectomy (EVT). The purpose of this study is to evaluate the effectiveness of EVT in acute stroke because of large vessel occlusion for elderly patients >age 80 years. Methods- A Markov decision analytic model was constructed from a societal perspective to evaluate health outcomes in terms of quality-adjusted life years (QALYs) after EVT for acute ischemic stroke because of large vessel occlusion in patients above age 80 years. Age-specific input parameters were obtained from the most recent/comprehensive literature. Good outcome was defined as a modified Rankin Scale score ≤2. Probabilistic, 1-way, and 2-way sensitivity analyses were performed for both healthy patients and patients with disability at baseline. Results- Base case calculation showed in functionally independent patients at baseline, intravenous thrombolysis (IVT) with tPA (tissue-type plasminogen activator) only to be the better strategy with 3.76 QALYs compared to 2.93 QALYs for patients undergoing EVT. The difference in outcome is 0.83 QALY (equivalent to 303 days of life in perfect health). For patients with baseline disability, IVT only yields a utility of 1.92 QALYs and EVT yields a utility of 1.65 QALYs. The difference is 0.27 QALYs (equivalent to 99 days of life in perfect health). Multiple sensitivity analyses showed that the effectiveness of EVT is significantly determined by the morbidity and mortality after both IVT and EVT strategies, respectively. Conclusions- Our study demonstrates the impact of relevant factors on the effectiveness of EVT in patients above 80 years of age. Morbidity and mortality after both IVT and EVT strategies significantly influence the outcomes in both healthy and disabled patients at baseline. Better identification of patients not benefiting from IVT would optimize the selective use of EVT thereby improving its effectiveness.

MR Angiography Screening and Surveillance for Intracranial Aneurysms in Autosomal Dominant Polycystic Kidney Disease: A Cost-effectiveness Analysis.

Background Autosomal dominant polycystic kidney disease (ADPKD) affects one in 400 to one in 1000 individuals; 10%-11% of these individuals have intracranial aneurysms. The frequency and patterns of screening for intracranial aneurysms have not been defined. Purpose To evaluate different MR angiography screening and surveillance strategies for unruptured intracranial aneurysms in patients with ADPKD. Materials and Methods A Markov decision-analytic model was constructed accounting for both costs and outcomes from a societal perspective. Five different management strategies were evaluated: (a) no screening for intracranial aneurysm, (b) one-time screening with annual MR angiography follow-up in patients with intracranial aneurysm, (c) MR angiographic screening every 5 years with endovascular treatment in detected intracranial aneurysm, (d) MR angiography screening every 5 years with annual MR angiography follow-up in patients with intracranial aneurysm, and (e) MR angiography screening every 5 years with biennial follow-up in patients with intracranial aneurysm. One-way, two-way, and probabilistic sensitivity analyses were performed. Results Base case calculation shows that MR angiography screening of patients with ADPKD every 5 years and annual follow-up in patients with detected intracranial aneurysm is the optimal strategy (cost, $19 839; utility, 25.86 quality-adjusted life years), which becomes more favorable as the life expectancy increases beyond 6 years. The conclusion remains robust in probabilistic and one-way sensitivity analyses. When the prevalence of intracranial aneurysms is greater than 10%, annual rupture risk is 0.35%-2.5%, and the rate of de novo aneurysm detection is lower than 1.8%, MR angiography screening every 5 years with annual MR angiography follow-up is the favorable strategy. Conclusion Screening for intracranial aneurysms with MR angiography in patients with autosomal dominant polycystic kidney disease is cost-effective. Repeat screening every 5 years should be performed after a negative initial study. Annual surveillance MR angiography is optimal in patients with detected, incidental intracranial aneurysm, and treatment may be considered in patients with growing, high-risk aneurysms. © RSNA, 2019 Online supplemental material is available for this article. See also the editorial by Anzai in this issue.

Management of Unruptured Intracranial Aneurysms in Older Adults: A Cost-effectiveness Analysis.

Background Unruptured intracranial aneurysms (UIAs) are relatively common and are being increasingly diagnosed, with a significant proportion in older patients (˃ 65 years old). Serial imaging is often performed to assess change in size or morphology of UIAs since growing aneurysms are known to be at high risk for rupture. However, the frequency and duration of surveillance imaging have not been established. Purpose To evaluate the cost-effectiveness of routine treatment (aneurysm coil placement) versus four different strategies for imaging surveillance of UIAs in adults older than 65 years. Materials and Methods A Markov decision-analytic model was constructed from a societal perspective. Age-dependent input parameters were obtained from published literature. Analysis included adults older than 65 years, with incidental detection of UIA and no prior history of subarachnoid hemorrhage. Five different management strategies for UIAs in older adults were evaluated: (a) annual MR angiography, (b) biennial MR angiography, (c) MR angiography every 5 years, (d) coil placement and follow-up, and (e) limited MR angiography follow-up for the first 2 years after detection only. Outcomes were assessed in terms of quality-adjusted life-years (QALYs). Probabilistic, one-way, and two-way sensitivity analyses were performed. Results Imaging follow-up for the first 2 years after detection is the most cost-effective strategy (cost = $24 572, effectiveness = 13.73 QALYs), showing the lowest cost and highest effectiveness. The conclusion remains robust in probabilistic and one-way sensitivity analyses. Time-limited imaging follow-up remains the optimal strategy when the annual growth rate and rupture risk of growing aneurysms are varied. If annual rupture risk of nongrowing aneurysms is greater than 7.1%, coil placement should be performed directly. Conclusion Routine preventive treatment or periodic, indefinite imaging follow-up is not a cost-effective strategy in all adults older than 65 years with unruptured intracranial aneurysms. More aggressive management strategies should be reserved for patients with high risk of rupture, such as those with aneurysms larger than 7 mm and those with aneurysms in the posterior circulation. © RSNA, 2019 Online supplemental material is available for this article. See also the editorial by Cloft in this issue.

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.

Standards of Practice in Acute Ischemic Stroke Intervention International Recommendations.

After five positive randomized controlled trials showed benefit of mechanical thrombectomy in the management of acute ischemic stroke with emergent large-vessel occlusion, a multi-society meeting was organized during the 17th Congress of the World Federation of Interventional and Therapeutic Neuroradiology in October 2017 in Budapest, Hungary. This multi-society meeting was dedicated to establish standards of practice in acute ischemic stroke intervention aiming for a consensus on the minimum requirements for centers providing such treatment. In an ideal situation, all patients would be treated at a center offering a full spectrum of neuroendovascular care (a level 1 center). However, for geographical reasons, some patients are unable to reach such a center in a reasonable period of time. With this in mind, the group paid special attention to define recommendations on the prerequisites of organizing stroke centers providing medical thrombectomy for acute ischemic stroke, but not for other neurovascular diseases (level 2 centers). Finally, some centers will have a stroke unit and offer intravenous thrombolysis, but not any endovascular stroke therapy (level 3 centers). Together, these level 1, 2, and 3 centers form a complete stroke system of care. The multi-society group provides recommendations and a framework for the development of medical thrombectomy services worldwide.

Utility of MRI for cervical spine clearance in blunt trauma patients after a negative CT.

PURPOSE: To determine the utility of cervical spine MRI in blunt trauma evaluation for instability after a negative non-contrast cervical spine CT. METHODS: A review of medical records identified all adult patients with blunt trauma who underwent CT cervical spine followed by MRI within 48 h over a 33-month period. Utility of subsequent MRI was assessed in terms of findings and impact on outcome. RESULTS: A total of 1,271 patients with blunt cervical spine trauma underwent both cervical spine CT and MRI within 48 h; 1,080 patients were included in the study analysis. Sixty-six percent of patients with a CT cervical spine study had a negative study. Of these, the subsequent cervical spine MRI had positive findings in 20.9%; 92.6% had stable ligamentous or osseous injuries, 6.0% had unstable injuries and 1.3% had potentially unstable injuries. For unstable injury, the NPV for CT was 98.5%. In all 712 patients undergoing both CT and MRI, only 1.5% had unstable injuries, and only 0.42% had significant change in management. CONCLUSIONS: MRI for blunt trauma evaluation remains not infrequent at our institution. MRI may have utility only in certain patients with persistent abnormal neurological examination. KEY POINTS: • MRI has limited utility after negative cervical CT in blunt trauma. • MRI is frequently positive for non-specific soft-tissue injury. • Unstable injury missed on CT is infrequent.

Progressive T1 Shortening of the Dentate Nucleus in Patients With Multiple Sclerosis: Result of Multiple Administrations of Linear Gadolinium Contrast Agents Versus Intrinsic Disease.

OBJECTIVE: The purpose of this article is to study the effect of the administration of multiple IV doses of gadolinium-based contrast agent on the intrinsic T1 hyperintensity in the dentate nucleus and globus pallidus in patients with multiple sclerosis (MS). MATERIALS AND METHODS: A retrospective review of imaging in patients with relapsing-remitting MS was performed. Images of 20 patients who received four or more doses of gadolinium-based contrast agent were reviewed. Patients received the linear agent gadopentetate dimeglumine before 2011 and the macrocyclic agent gadobutrol from 2011 onward. Dentate nucleus-to-pons and globus pallidus-to-thalamus signal intensity (SI) ratios were evaluated. SI ratios were compared over time with multiple injections of gadolinium. Similar SI ratios were evaluated for six patients who received gadopentetate dimeglumine and then underwent multiple subsequent MRI studies without contrast agent administration. RESULTS: The increase in the dentate nucleus-to-pons SI ratio after multiple administrations of the linear agent gadopentetate dimeglumine (mean = 1.44; SD = 2.50) was significantly higher than that with the macrocyclic agent gadobutrol (mean = -0.11; SD = 2.33) (p < 0.001). The globus pallidus-to-thalamus and dentate nucleus-to-CSF ratios also increased with multiple contrast injections over time, but the changes were not found to be statistically significant. The increase in SI in the dentate nucleus was not observed in patients who stopped receiving contrast injections, after showing a previous increase over time with gadolinium. CONCLUSION: In patients with MS, SI within the dentate nucleus and globus pallidus increased on unenhanced T1-weighted images and was significantly greater with the administration of a linear agent than with a macrocyclic agent. This increase in SI over time is likely a reflection of gadolinium deposition and not due to intrinsic disease, as previously postulated.