Faculty Bibliography

Background Identification of large vessel occlusion (LVO) is critical to the management of acute ischemic stroke and prerequisite to endovascular therapy in recent trials. Increasing volumes and data complexity compel the development of fast, reliable, and automated tools for LVO detection to facilitate acute imaging triage. Purpose To investigate the performance of an anterior circulation LVO detection platform in a large mixed sample of individuals with and without LVO at cerebrovascular CT angiography (CTA). Materials and Methods In this retrospective analysis, CTA data from recent cerebrovascular trials (CRISP [ClinicalTrials.gov NCT01622517] and DASH) were enriched with local repositories from 11 worldwide sites to balance demographic and technical variables in LVO-positive and LVO-negative examinations. CTA findings were reviewed independently by two neuroradiologists from different institutions for intracranial internal carotid artery (ICA) or middle cerebral artery (MCA) M1 LVO; these observers were blinded to all clinical variables and outcomes. An automated analysis platform was developed and tested for prediction of LVO presence and location relative to reader consensus. Discordance between readers with respect to LVO presence or location was adjudicated by a blinded tertiary reader at a third institution. Sensitivity, specificity, and receiver operating characteristics were assessed by an independent statistician, and subgroup analyses were conducted. Prespecified performance thresholds were set at a lower bound of the 95% CI of sensitivity and specificity of 0.8 or greater at mean times to notification of less than 3.5 minutes. Results A total of 217 study participants (mean age, 64 years ± 16 [standard deviation]; 116 men; 109 with positive findings of LVO) were evaluated. Prespecified performance thresholds were exceeded (sensitivity, 105 of 109 [96%; 95% CI: 91, 99]; specificity, 106 of 108 [98%; 95% CI: 94, 100]). Sensitivity and specificity estimates across age, sex, location, and vendor subgroups exceeded 90%. The area under the receiver operating characteristic curve was 99% (95% CI: 97, 100). Mean processing and notification time was 3 minutes 18 seconds. Conclusion The results confirm the feasibility of fast automated high-performance detection of intracranial internal carotid artery and middle cerebral artery M1 occlusions. © RSNA, 2021 See also the editorial by Kloska in this issue.

BACKGROUND AND PURPOSE/OBJECTIVE:Intracranial hemorrhage (ICH) is an important event that is diagnosed on head NCCT. Increased NCCT utilization in busy hospitals may limit timely identification of ICH. RAPID ICH is an automated hybrid 2D-3D convolutional neural network application designed to detect ICH that may allow for expedited ICH diagnosis. We determined the accuracy of RAPID ICH for ICH detection and ICH volumetric quantification on NCCT. MATERIALS AND METHODS/METHODS:NCCT scans were evaluated for ICH by RAPID ICH. Consensus detection of ICH by 3 neuroradiology experts was used as the criterion standard for RAPID ICH comparison. ICH volume was also automatically determined by RAPID ICH in patients with intraparenchymal or intraventricular hemorrhage and compared with manually segmented ICH volumes by a single neuroradiology expert. ICH detection accuracy, sensitivity, specificity, positive predictive value, negative predictive value, and positive and negative likelihood ratios by RAPID ICH were determined. RESULTS: = 0.983); the median absolute error was 3 mL. CONCLUSIONS:RAPID ICH is highly accurate in the detection of ICH and in the volumetric quantification of intraparenchymal and intraventricular hemorrhages.

The pathological cascade of tissue damage in mild traumatic brain injury is set forth by a perturbation in ionic homeostasis. However, whether this class of injury can be detected in vivo and serve as a surrogate marker of clinical outcome is unknown. We employ sodium MRI to test the hypotheses that regional and global total sodium concentrations: (i) are higher in patients than in controls and (ii) correlate with clinical presentation and neuropsychological function. Given the novelty of sodium imaging in traumatic brain injury, effect sizes from (i), and correlation types and strength from (ii), were compared to those obtained using standard diffusion imaging metrics. Twenty-seven patients (20 female, age 35.9 ± 12.2 years) within 2 months after injury and 19 controls were scanned with proton and sodium MRI at 3 Tesla. Total sodium concentration, fractional anisotropy and apparent diffusion coefficient were obtained with voxel averaging across 12 grey and white matter regions. Linear regression was used to obtain global grey and white matter total sodium concentrations. Patient outcome was assessed with global functioning, symptom profiles and neuropsychological function assessments. In the regional analysis, there were no statistically significant differences between patients and controls in apparent diffusion coefficient, while differences in sodium concentration and fractional anisotropy were found only in single regions. However, for each of the 12 regions, sodium concentration effect sizes were uni-directional, due to lower mean sodium concentration in patients compared to controls. Consequently, linear regression analysis found statistically significant lower global grey and white matter sodium concentrations in patients compared to controls. The strongest correlation with outcome was between global grey matter sodium concentration and the composite z-score from the neuropsychological testing. In conclusion, both sodium concentration and diffusion showed poor utility in differentiating patients from controls, and weak correlations with clinical presentation, when using a region-based approach. In contrast, sodium linear regression, capitalizing on partial volume correction and high sensitivity to global changes, revealed high effect sizes and associations with patient outcome. This suggests that well-recognized sodium imbalances in traumatic brain injury are (i) detectable non-invasively; (ii) non-focal; (iii) occur even when the antecedent injury is clinically mild. Finally, in contrast to our principle hypothesis, patients' sodium concentrations were lower than controls, indicating that the biological effect of traumatic brain injury on the sodium homeostasis may differ from that in other neurological disorders. Note: This figure has been annotated.

BACKGROUND AND PURPOSE/OBJECTIVE:Brain infarct growth, despite successful reperfusion, decreases the likelihood of good functional outcome after ischemic stroke. In patients undergoing reperfusion, admission glucose is associated with poor outcome but the effect of glucose level on infarct growth is not well studied. MATERIALS AND METHODS/METHODS:This is a secondary analysis of the DEFUSE 3 trial. The primary predictor was baseline glucose level and the primary outcome is the change of the ischemic core volume from the baseline to 24-hour follow-up imaging (∆core), transformed as a cube root to reduce right skew. We included DEFUSE 3 patients who were randomized to endovascular therapy, had perfusion imaging data at baseline, an MRI at 24 hours, and who achieved TICI 2b or 3. Linear regression models, both unadjusted and adjusted, were fit to the primary outcome and all models included the baseline core volume as a covariate to normalize ∆core. RESULTS:We identified 62 patients who met our inclusion criteria. The mean age was 68.1±13.1 (years), 48.4% (30/62) were men, and the median (IQR) cube root of ∆core was 2.8 (2.0-3.8) mL. There was an association between baseline glucose level and normalized ∆core in unadjusted analysis (beta coefficient 0.010, p = 0.01) and after adjusting for potential confounders (beta coefficient 0.008, p = 0.03). CONCLUSION/CONCLUSIONS:In acute ischemic stroke patients with large vessel occlusion undergoing successful endovascular reperfusion, baseline hyperglycemia is associated with infarction growth. Further study is needed to establish potential neuroprotective benefits of aggressive glycemic control prior to and after reperfusion.

BACKGROUND AND PURPOSE/OBJECTIVE:Mechanical thrombectomy (MT) has helped many patients achieve functional independence. The effect of time-to-treatment based in specific epochs and as related to Alberta Stroke Program Early CT Score (ASPECTS) has not been established. The goal of the study was to evaluate the association between last known normal (LKN)-to-puncture time and good functional outcome. METHODS:We conducted a retrospective cohort study of prospectively collected acute ischemic stroke patients undergoing MT for large vessel occlusion. We used binary logistic regression models adjusted for age, Modified Treatment in Cerebral Ischemia score, initial National Institutes of Health Stroke Scale, and noncontrast CT ASPECTS to assess the association between LKN-to-puncture time and favorable outcome defined as Modified Rankin Score 0-2 on discharge. RESULTS:Among 421 patients, 328 were included in analysis. Increased LKN-to-puncture time was associated with decreased probability of good functional outcome (adjusted odds ratio [aOR] ratio per 15-minute delay = .98; 95% confidence interval [CI], .97-.99; P = .001). This was especially true when LKN-puncture time was 0-6 hours (aOR per 15-minute delay = .94; 95% CI, .89-.99; P = .05) or ASPECTS 8-10 (aOR = .98; 95% CI, .97-.99; P = .002) as opposed to when LKN-puncture time was 6-24 hours (aOR per 15-minute delay = .99; 95% CI, .97-1.00; P = .16) and ASPECTS <8 (aOR = .98; 95% CI, .93-1.03; P = .37). CONCLUSION/CONCLUSIONS:Decreased LKN-groin puncture time improves outcome particularly in those with good ASPECTS presenting within 6 hours. Strategies to decrease reperfusion times should be investigated, particularly in those in the early time window and with good ASPECTS.

Despite the severity of coronavirus disease 2019 (COVID-19) being more frequently related to acute respiratory distress syndrome and acute cardiac and renal injuries, thromboembolic events have been increasingly reported. We report a unique series of young patients with COVID-19 presenting with cerebral venous system thrombosis. Three patients younger than 41 years of age with confirmed Severe Acute Respiratory Syndrome coronavirus 2 (SARS-Cov-2) infection had neurologic findings related to cerebral venous thrombosis. They were admitted during the short period of 10 days between March and April 2020 and were managed in an academic institution in a large city. One patient had thrombosis in both the superficial and deep systems; another had involvement of the straight sinus, vein of Galen, and internal cerebral veins; and a third patient had thrombosis of the deep medullary veins. Two patients presented with hemorrhagic venous infarcts. The median time from COVID-19 symptoms to a thrombotic event was 7 days (range, 2-7 days). One patient was diagnosed with new-onset diabetic ketoacidosis, and another one used oral contraceptive pills. Two patients were managed with both hydroxychloroquine and azithromycin; one was treated with lopinavir-ritonavir. All patients had a fatal outcome. Severe and potentially fatal deep cerebral thrombosis may complicate the initial clinical presentation of COVID-19. We urge awareness of this atypical manifestation.

BACKGROUND:Ecchordosis physaliphora (EP) is a congenital, uniformly asymptomatic, hamartomatous lesion of the primitive notochord. Herein we report, to our knowledge, the first credible case report of unprovoked intra-sphenoidal rupture resulting in recurrent pneumocephalus and cerebrospinal fluid (CSF) leak, definitively captured over serial imaging during clinical and radiologic surveillance. CASE DESCRIPTION/METHODS:A 68-year old woman with Marfan syndrome presented to the Emergency Department with the worst headache of life. Imaging demonstrated extensive pneumocephalus and revealed a small, dorsal midline clival lesion consistent with EP and a trans-sphenoidal defect. Remote imaging encounters confirmed typical EP without pneumocephalus or cortical defect, and an uneventful clinical course years preceding presentation. Over the ensuing months during neurosurgical follow-up, the patient reported recurrent headaches, imbalance, and unprovoked clear rhinorrhea. Further imaging demonstrates an apparently enlarging trans-sphenoidal defect which was managed by endoscopic trans-nasal resection and nasoseptal flap. Pathologic evaluation confirmed the diagnosis of EP and chronic dural defect. CONCLUSIONS:This represents, to our knowledge, the first unambiguous example of spontaneous EP rupture and recurrent pneumocephalus captured over serial imaging. The case further underscores rare, but potentially significant complications of EP and highlights management options. BACKGROUND:. Herein we report, to our knowledge, the first documented spontaneous rupture of EP resulting in recurrent pneumocephalus, credibly captured over serial radiologic surveillance. CLINICAL PRESENTATION/METHODS:A 68 year-old woman with history of hypertension, hyperlipidemia, and Marfan syndrome presented to the Emergency Department reporting the "worst headache of her life" after engaging in an interpersonal dispute the evening preceding presentation.

BACKGROUND AND PURPOSE/OBJECTIVE:With the spread of coronavirus disease 2019 (COVID-19) during the current worldwide pandemic, there is mounting evidence that patients affected by the illness may develop clinically significant coagulopathy with thromboembolic complications including ischemic stroke. However, there is limited data on the clinical characteristics, stroke mechanism, and outcomes of patients who have a stroke and COVID-19. METHODS:We conducted a retrospective cohort study of consecutive patients with ischemic stroke who were hospitalized between March 15, 2020, and April 19, 2020, within a major health system in New York, the current global epicenter of the pandemic. We compared the clinical characteristics of stroke patients with a concurrent diagnosis of COVID-19 to stroke patients without COVID-19 (contemporary controls). In addition, we compared patients to a historical cohort of patients with ischemic stroke discharged from our hospital system between March 15, 2019, and April 15, 2019 (historical controls). RESULTS:<0.001). When compared with contemporary controls, COVID-19 positive patients had higher admission National Institutes of Health Stroke Scale score and higher peak D-dimer levels. When compared with historical controls, COVID-19 positive patients were more likely to be younger men with elevated troponin, higher admission National Institutes of Health Stroke Scale score, and higher erythrocyte sedimentation rate. Patients with COVID-19 and stroke had significantly higher mortality than historical and contemporary controls. CONCLUSIONS:We observed a low rate of imaging-confirmed ischemic stroke in hospitalized patients with COVID-19. Most strokes were cryptogenic, possibly related to an acquired hypercoagulability, and mortality was increased. Studies are needed to determine the utility of therapeutic anticoagulation for stroke and other thrombotic event prevention in patients with COVID-19.

BACKGROUND:Little data exists on outcomes of mechanical thrombectomy (MT) in nonagenarians. We aimed to compare the procedural and discharge outcomes of MT for acute ischemic stroke (AIS) in nonagenarians versus younger patients. METHODS:Procedural outcomes and discharge disposition were compared in propensity score-matched groups of nonagenarians versus patients aged≤69 with AIS who underwent MT. Patients aged 70-89 were excluded in order to compare nonagenarians to a younger cohort that most closely approximates the age of patients in the seminal MT trials. Good discharge disposition was defined as a discharge to home or acute rehabilitation. RESULTS:Of 3010 AIS patients, 46/297(16%) nonagenarians underwent MT compared to 159/1337(12%) aged≤69 (P = 0.091). Of 78 propensity score-matched patients (N = 39 ≥90, N = 39 ≤69), the median admission NIHSS was 22 versus 20, median ASPECTS was 9 versus 9, pre-stroke mRS<4 was 82% versus 87%, 18% versus 8% received IV tPA, and mTICI≥2b was 90% versus 90%, respectively (all P>0.05). Revascularization time (569 versus 372 min), door to groin puncture time (82 versus 71 min) and groin puncture to revascularization times (39 versus 24 min) were similar in between nonagenarians and ≤69, respectively (both P>0.05). Symptomatic ICH (2.6% versus 10.3%; p = 0.165) and in-hospital death rates (10% vs 26%; p = 0.077) trended lower among nonagenarians versus aged≤69. Good discharge disposition occurred in 44% of nonagenarians versus 51% aged≤69 years (p = 0.496). CONCLUSIONS:In propensity score analysis, 90% of nonagenarians achieved successful recanalization and almost half (44%) were discharged to home/acute rehabilitation, which was similar to a younger (aged≤69 years) cohort.