Prognostic significance of MRI contrast enhancement in newly diagnosed glioblastoma, IDH-wildtype according to WHO 2021 classification.

BACKGROUND AND OBJECTIVES: Contrast enhancement in glioblastoma, IDH-wildtype is common but not systematic. In the era of the WHO 2021 Classification of CNS Tumors, the prognostic impact of a contrast enhancement and the pattern of contrast enhancement is not clearly elucidated. METHODS: We performed an observational, retrospective, single-centre cohort study at a tertiary neurosurgical oncology centre (January 2006 - December 2022). We screened adult patients with a newly-diagnosed glioblastoma, IDH-wildtype in order to assess the prognosis role of the contrast enhancement and the pattern of contrast enhancement. RESULTS: We included 1149 glioblastomas, IDH-wildtype: 26 (2.3%) had a no contrast enhancement, 45 (4.0%) had a faint and patchy contrast enhancement, 118 (10.5%) had a nodular contrast enhancement, and 960 (85.5%) had a ring-like contrast enhancement. Overall survival was longer in non-contrast enhanced glioblastomas (26.7 months) than in contrast enhanced glioblastomas (10.9 months) (p < 0.001). In contrast enhanced glioblastomas, a ring-like pattern was associated with shorter overall survival than in faint and patchy and nodular patterns (10.0 months versus 13.0 months, respectively) (p = 0.033). Whatever the presence of a contrast enhancement and the pattern of contrast enhancement, surgical resection was an independent predictor of longer overall survival, while age ≥ 70 years, preoperative KPS score < 70, tumour volume ≥ 30cm3, and postoperative residual contrast enhancement were independent predictors of shorter overall survival. CONCLUSION: A contrast enhancement is present in the majority (97.7%) of glioblastomas, IDH-wildtype and, regardless of the pattern, is associated with a shorter overall survival. The ring-like pattern of contrast enhancement is typical in glioblastomas, IDH-wildtype (85.5%) and remains an independent predictor of shorter overall survival compared to other patterns (faint and patchy and nodular).

Impact of frailty on survival glioblastoma, IDH-wildtype patients.

PURPOSE: Frailty increases the risk of mortality among patients. We studied the prognostic significance of frailty using the modified 5-item frailty index (5-mFI) in patients harboring a newly diagnosed supratentorial glioblastoma, IDH-wildtype. METHODS: We retrospectively reviewed records of patients surgical treated at a single neurosurgical institution at the standard radiochemotherapy era (January 2006 - December 2021). Inclusion criteria were: age ≥ 18, newly diagnosed glioblastoma, IDH-wildtype, supratentorial location, available data to assess the 5-mFI index. RESULTS: A total of 694 adult patients were included. The median overall survival was longer in the non-frail subgroup (5-mFI < 2, n = 538 patients; 14.3 months, 95%CI 12.5-16.0) than in the frail subgroup (5-mFI ≥ 2, n = 156 patients; 4.7 months, 95%CI 4.0-6.5 months; p < 0.001). 5-mFI ≥ 2 (adjusted Hazard Ratio (aHR) 1.31; 95%CI 1.07-1.61; p = 0.009) was an independent predictor of a shorter overall survival while age ≤ 60 years (aHR 0.78; 95%CI 0.66-0.93; p = 0.007), KPS score ≥ 70 (aHR 0.71; 95%CI 0.58-0.87; p = 0.001), unilateral location (aHR 0.67; 95%CI 0.52-0.87; p = 0.002), total removal (aHR 0.54; 95%CI 0.44-0.64; p < 0.0001), and standard radiochemotherapy protocol (aHR 0.32; 95%CI 0.26-0.38; p < 0.0001) were independent predictors of a longer overall survival. Frailty remained an independent predictor of overall survival within the subgroup of patients undergoing a first-line oncological treatment after surgery (n = 549) and within the subgroup of patients who benefited from a total removal plus adjuvant standard radiochemotherapy (n = 209). CONCLUSION: In newly diagnosed supratentorial glioblastoma, IDH-wildtype patients treated at the standard combined radiochemotherapy era, frailty, defined using a 5-mFI score ≥ 2 was an independent predictor of overall survival.

Radiographic growth rate as a predictor of aggressiveness of diffuse gliomas without 1p19q codeletion.

OBJECTIVE: The 2021 WHO classification of CNS tumors has refined the definition of adult-type diffuse gliomas without 1p19q codeletion. Nevertheless, the aggressiveness of gliomas is based exclusively on histomolecular criteria performed on a limited sample of the tumor. The authors aimed to assess whether the spontaneous radiographic tumor growth rate is associated with tumor aggressiveness and allows preoperative identification of malignancy grade of adult-type diffuse gliomas without 1p19q codeletion. METHODS: The authors retrospectively reviewed the records of adult patients harboring a newly diagnosed supratentorial diffuse glioma without 1p19q codeletion, with available preoperative MRI follow-up between January 2008 and April 2022. The spontaneous radiographic tumor growth rate was quantified by tumor volume segmentation and regression of the evolution of the mean tumor diameter over time and was compared with clinical, imaging, histomolecular, and survival data. RESULTS: Ninety-six patients were included. The spontaneous radiographic tumor growth rates (mean 17.8 ± 38.8 mm/year, range 0-243.5 mm/year) significantly varied according to IDH1/2 mutation (p < 0.001), grade of malignancy (p < 0.001), and presence of microvascular proliferation (p < 0.001). The spontaneous radiographic tumor growth rate allowed preoperative identification of high-grade cases: 100% of grade 3 and 4 IDH-mutant diffuse astrocytomas had a spontaneous radiographic tumor growth rate ≥ 8.0 mm/year, and 100% of IDH-wild-type glioblastomas had a spontaneous radiographic tumor growth rate ≥ 42.0 mm/year. A spontaneous radiographic growth rate ≥ 8.0 mm/year was an independent predictor of shorter progression-free (p = 0.014) and overall (p = 0.007) survival. A mitotic count threshold ≥ 4 mitoses was the optimal threshold for identifying aggressive IDH-mutant astrocytomas based on spontaneous radiographic tumor growth. CONCLUSIONS: The spontaneous radiographic tumor growth rates could be used as an additional tool to preoperatively screen tumor aggressiveness of adult-type diffuse gliomas without 1p19q codeletion.

Remote Diffusion-Weighted Imaging Lesions and Intracerebral Hemorrhage: A Systematic Review and Meta-Analysis.

BACKGROUND: Remote diffusion-weighted imaging lesions (RDWILs) in the context of spontaneous intracerebral hemorrhage (ICH) are associated with an increased risk of recurrent stroke, worse functional outcome, and death. To update current knowledge on RDWILs, we conducted a systematic review and meta-analysis of the prevalence, associated factors and presumed causes of RDWILs. METHODS: We searched Pubmed, Embase, and Cochrane up to June 2022 for studies reporting RDWILs in adults with symptomatic ICH of no-identified-cause, assessed by magnetic resonance imaging, and analyzed associations between baseline variables and RDWILs in random-effects meta-analyses. RESULTS: Eighteen observational studies (7 prospective), reporting 5211 patients were included, of whom 1386 had ≥1 RDWIL (pooled prevalence: 23.5% [19.0-28.6]). RDWIL presence was associated with neuroimaging features of microangiopathy, atrial fibrillation (odds ratio, 3.67 [1.80-7.49]), clinical severity (mean difference in National Institutes of Health Stroke Scale score, 1.58 points [0.50-2.66]), elevated blood pressure (mean difference, 14.02 mmHg [9.44-18.60]), ICH volume (mean difference, 2.78 mL [0.97-4.60]), and subarachnoid (odds ratio, 1.80 [1.00-3.24]) or intraventricular (odds ratio, 1.53 [1.28-1.83]) hemorrhage. RDWIL presence was associated with poor 3-month functional outcome (odds ratio, 1.95 [1.48-2.57]). CONCLUSIONS: RDWILs are detected in approximately 1-in-4 patients with acute ICH. Our results suggest that most RDWILs result from disruption of cerebral small vessel disease by ICH-related precipitating factors such as elevated intracranial pressure and cerebral autoregulation impairment. Their presence is associated with worse initial presentation and outcome. However, given the mostly cross-sectional designs and heterogeneity in study quality, further studies are needed to investigate whether specific ICH treatment strategies may reduce the incidence of RDWILs and in turn improve outcome and reduce stroke recurrence.

Diffusion-Weighted Imaging Lesion Reversal in Older Patients With Stroke Treated With Mechanical Thrombectomy.

BACKGROUND: Diffusion-weighted imaging lesion reversal (DWIR) is frequently observed after mechanical thrombectomy for acute ischemic stroke, but little is known about age-related differences and impact on outcome. We aimed to compare, in patients <80 versus ≥80 years old, (1) the effect of successful recanalization on DWIR and (2) the impact of DWIR on functional outcome. METHODS: We retrospectively analyzed data of patients treated for an anterior circulation acute ischemic stroke with large vessel occlusion in 2 French hospitals, who underwent baseline and 24-hour follow-up magnetic resonance imaging, with baseline DWI lesion volume ≥10 cc. The percentage of DWIR (DWIR%), was calculated as follows: DWIR%=(DWIR volume/baseline DWI volume)×100. Data on demographics, medical history, and baseline clinical and radiological characteristics were collected. RESULTS: Among 433 included patients (median age, 68 years), median DWIR% after mechanical thrombectomy was 22% (6-35) in patients ≥80, and 19% (interquartile range, 10-34) in patients <80 (P=0.948). In multivariable analyses, successful recanalization after mechanical thrombectomy was associated with higher median DWIR% in both ≥80 (P=0.004) and <80 (P=0.002) patients. In subgroup analyses performed on a minority of subjects, collateral vessels status score (n=87) and white matter hyperintensity volume (n=131) were not associated with DWIR% (P>0.2). In multivariable analyses, DWIR% was associated with increased rates of favorable 3-month outcomes in both ≥80 (P=0.003) and <80 (P=0.013) patients; the effect of DWIR% on outcome was not influenced by the age group (P interaction=0.185) Conclusions: DWIR might be an important and nonage-dependent effect of arterial recanalization, as it seems to beneficially impact 3-month outcomes of both younger and older subjects treated with mechanical thrombectomy for acute ischemic stroke and large vessel occlusion.

[Contributions and limitations of FISH analysis for the diagnosis of central nervous system tumors according to the 2021 WHO classification: Feedback from Sainte-Anne Hospital's Department of Neuropathology]. / Apports et limites de la FISH dans le diagnostic des tumeurs du système nerveux central selon la classification de l'OMS de 2021 : retour d'expérience du service de neuropathologie de l'hôpital Sainte-Anne.

The fifth edition of the World Health Organization (WHO) Classification of Tumors of the Central Nervous System has identified many new tumor types and has established, for the first time, essential and desirable diagnostic criteria for each of them. Among these, genetic alterations play an important role associated with morphology. For the first time, epigenetic data can also constitute essential and/or desirable criteria. These genetic abnormalities can be fusions, deletions or gains/amplifications and can thus be detected by fluorescence in situ hybridization techniques. The purpose of this article is to present the advantages and limitations of this technique in reference to its specific use within neuro-oncopathology in light of the 2021 WHO classification.

TAGE Score for Symptomatic Intracranial Hemorrhage Prediction After Successful Endovascular Treatment in Acute Ischemic Stroke.

BACKGROUND: Determine if early venous filling (EVF) after complete successful recanalization with mechanical thrombectomy in acute ischemic stroke is an independent predictor of symptomatic intracranial hemorrhage (sICH) and integrate EVF into a risk score for sICH prediction. METHODS: Consecutive patients with anterior acute ischemic stroke treated by mechanical thrombectomy issued from patients enrolled in the THRACE trial (Thrombectomie des Artères Cérébrales) and from 2 prospective registries were included and divided into a derivation (Center I; n=402) and validation cohorts (THRACE and center 2; n=507). EVF was evaluated by 2 blinded readers. sICH was defined according to the modified European cooperative acute stroke study II. Clinical and radiological data were analyzed in the derivation cohort (C1) to identify independent predictors of sICH and construct a predictive score test on the validation cohort (THRACE + C2). RESULTS: Symptomatic ICH rate was similar between the two cohorts (9.9% and 8.9% respectively, P=0.9). Time from onset-to-successful recanalization >270 minutes (odds ratio [OR], 7.8 [95% CI, 2.5-24]), Alberta Stroke Program Early CT Score (≤5 [OR, 2.49 (95% CI, 1.8-8.1) or 6-7 [OR, 1.15 (95% CI, 1.03-4.46)]), glucose blood level >7 mmol/L (OR, 2.92 [95% CI, 1.26-6.7]), and EVF presence (OR, 11.9 [95% CI, 3.8-37.5]) were independent predictors of sICH and constituted the Time-Alberta Stroke Program Early CT-Glycemia-EVF score. Time-Alberta Stroke Program Early CT-Glycemia-EVF score was associated with an increased risk of sICH in the derivation cohort (OR increase per unit, 1.99 [95% CI, 1.53-2.59]; P<0.001) with area under the curve, 0.832 [95% CI, 0.767-0.898]. The score had good performance in the validation cohort (area under the curve, 0.801 [95% CI, 0.69-0.91]). CONCLUSIONS: Time-Alberta Stroke Program Early CT-Glycemia-EVF score is a simple tool with readily available clinical variables with good performances for sICH prediction after mechanical thrombectomy. REGISTRATION: URL: https://www. CLINICALTRIALS: gov; Unique identifier: NCT01062698.

Synthetic FLAIR as a Substitute for FLAIR Sequence in Acute Ischemic Stroke.

Background In acute ischemic stroke (AIS), fluid-attenuated inversion recovery (FLAIR) is used for treatment decisions when onset time is unknown. Synthetic FLAIR could be generated with deep learning from information embedded in diffusion-weighted imaging (DWI) and could replace acquired FLAIR sequence (real FLAIR) and shorten MRI duration. Purpose To compare performance of synthetic and real FLAIR for DWI-FLAIR mismatch estimation and identification of patients presenting within 4.5 hours from symptom onset. Materials and Methods In this retrospective study, all pretreatment and early follow-up (<48 hours after symptom onset) MRI data sets including DWI (b = 0-1000 sec/mm2) and FLAIR sequences obtained in consecutive patients with AIS referred for reperfusion therapies between January 2002 and May 2019 were included. On the training set (80%), a generative adversarial network was trained to produce synthetic FLAIR with DWI as input. On the test set (20%), synthetic FLAIR was computed without real FLAIR knowledge. The DWI-FLAIR mismatch was evaluated on both FLAIR data sets by four independent readers. Interobserver reproducibility and DWI-FLAIR mismatch concordance between synthetic and real FLAIR were evaluated with κ statistics. Sensitivity and specificity for identification of AIS within 4.5 hours were compared in patients with known onset time by using McNemar test. Results The study included 1416 MRI scans (861 patients; median age, 71 years [interquartile range, 57-81 years]; 375 men), yielding 1134 and 282 scans for training and test sets, respectively. Regarding DWI-FLAIR mismatch, interobserver reproducibility was substantial for real and synthetic FLAIR (κ = 0.80 [95% CI: 0.74, 0.87] and 0.80 [95% CI: 0.74, 0.87], respectively). After consensus, concordance between real and synthetic FLAIR was almost perfect (κ = 0.88; 95% CI: 0.82, 0.93). Diagnostic value for identifying AIS within 4.5 hours did not differ between real and synthetic FLAIR (sensitivity: 107 of 131 [82%] vs 111 of 131 [85%], P = .2; specificity: 96 of 104 [92%] vs 96 of 104 [92%], respectively, P > .99). Conclusion Synthetic fluid-attenuated inversion recovery (FLAIR) had diagnostic performances similar to real FLAIR in depicting diffusion-weighted imaging-FLAIR mismatch and in helping to identify early acute ischemic stroke, and it may accelerate MRI protocols. © RSNA, 2022 Online supplemental material is available for this article. See also the editorial by Carroll and Hurley in this issue.

Meningioma in patients exposed to progestin drugs: results from a real-life screening program.

PURPOSE: To report the results of systematic meningioma screening program implemented by French authorities in patients exposed to progestin therapies (cyproterone (CPA), nomegestrol (NA), and chlormadinone (CMA) acetate). METHODS: We conducted a prospective monocentric study on patients who, between September 2018 and April 2021, underwent standardized MRI (injection of gadolinium, then a T2 axial FLAIR and a 3D-T1 gradient-echo sequence) for meningioma screening. RESULTS: Of the 210 included patients, 15 (7.1%) had at least one meningioma; seven (7/15, 47%) had multiple meningiomas. Meningiomas were more frequent in older patients and after exposure to CPA (13/103, 13%) compared to NA (1/22, 4%) or CMA (1/85, 1%; P = 0.005). After CPA exposure, meningiomas were associated with longer treatment duration (median = 20 vs 7 years, P = 0.001) and higher cumulative dose (median = 91 g vs. 62 g, P = 0.014). Similarly, their multiplicity was associated with higher dose of CPA (median = 244 g vs 61 g, P = 0.027). Most meningiomas were ≤ 1 cm3 (44/58, 76%) and were convexity meningiomas (36/58, 62%). At diagnosis, patients were non-symptomatic, and all were managed conservatively. Among 14 patients with meningioma who stopped progestin exposure, meningioma burden decreased in 11 (79%) cases with no case of progression during MR follow-up. CONCLUSION: Systematic MR screening in progestin-exposed patients uncovers small and multiple meningiomas, which can be managed conservatively, decreasing in size after progestin discontinuation. The high rate of meningiomas after CPA exposure reinforces the need for systematic screening. For NA and CMA, further studies are needed to identify patients most likely to benefit from screening.

Validation of a post-mortem computed tomography method for age estimation based on the 4th rib in a French population.

Age estimation is a key factor for identification procedure in forensic context. Based on anthropological findings, degenerative changes of the sternal extremity of the 4th rib are currently used for age estimation. These have been adapted to post-mortem computed tomography (PMCT). The aim of this study was to validate a post-mortem computed tomography method based on a revision of the Iscan's method on a French sample. A total of 250 PMCT (aged from 18-98 years (IQR 36-68 years, median 51 years); 68 (27%) females) from the Medicolegal Institute of Paris (MLIP) were analyzed by two radiologists. The sternal extremity of 4th right rib was scored using method adapted from Iscan et al. Weighted κ was used to evaluate intra- and inter-observer reliability and Spearman correlation was performed to evaluate relationship between age and score. Confidence intervals for individual prediction of age based on 4th rib score and sex were computed with bootstrapping. The intra-observer reliability and inter-observer reliability were almost perfect (weighted κ = 0.85 [95%CI: 0.78-0.93] and 0.82 [95%CI 0.70-0.96] respectively). We confirmed a high correlation between the 4th rib score and subject age (rho = 0.72, p < 0.001), although the confidence intervals for individual age prediction were large, spanning over several decades. This study confirms the high reliability of Iscan method applied to PMCT for age estimation, although future multimodal age prediction techniques may help reducing the span of confidence intervals for individual age estimation.Trial registration: INDS 0,509,211,020, October 2020, retrospectively registered.

Discriminating surgical bed cysts from bacterial brain abscesses after Carmustine wafer implantation in newly diagnosed IDH-wildtype glioblastomas.

Carmustine wafers can be implanted in the surgical bed of high-grade gliomas, which can induce surgical bed cyst formation, leading to clinically relevant mass effect. An observational retrospective monocentric study was conducted including 122 consecutive adult patients with a newly diagnosed supratentorial glioblastoma who underwent a surgical resection with Carmustine wafer implantation as first line treatment (2005-2018). Twenty-two patients (18.0%) developed a postoperative contrast-enhancing cyst within the surgical bed: 16 surgical bed cysts and six bacterial abscesses. All patients with a surgical bed cyst were managed conservatively, all resolved on imaging follow-up, and no patient stopped the radiochemotherapy. Independent risk factors of formation of a postoperative surgical bed cyst were age ≥ 60 years (p = 0.019), number of Carmustine wafers implanted ≥ 8 (p = 0.040), and partial resection (p = 0.025). Compared to surgical bed cysts, the occurrence of a postoperative bacterial abscess requiring surgical management was associated more frequently with a shorter time to diagnosis from surgery (p = 0.009), new neurological deficit (p < 0.001), fever (p < 0.001), residual air in the cyst (p = 0.018), a cyst diameter greater than that of the initial tumor (p = 0.027), and increased mass effect and brain edema compared to early postoperative MRI (p = 0.024). Contrast enhancement (p = 0.473) and diffusion signal abnormalities (p = 0.471) did not differ between postoperative bacterial abscesses and surgical bed cysts. Clinical and imaging findings help discriminate between surgical bed cysts and bacterial abscesses following Carmustine wafer implantation. Surgical bed cysts can be managed conservatively. Individual risk factors will help tailor their steroid therapy and imaging follow-up.

Cathodal Transcranial Direct Current Stimulation in Acute Ischemic Stroke: Pilot Randomized Controlled Trial.

Background and Purpose: In acute stroke, preventing infarct growth until complete recanalization occurs is a promising approach as an adjunct to reperfusion therapies to reduce infarct size and improve outcome. In rodent models, cathodal transcranial direct current stimulation (C-tDCS) decreases peri-infarct depolarizations and reduces infarct volume. We hypothesized that C-tDCS would nonpharmacologically reduce infarct growth in hyperacute middle cerebral artery territory stroke patients receiving reperfusion therapy. Methods: STICA (Cathodal Transcranial Direct Stimulation in Acute Middle Cerebral Artery Stroke) was a pilot single-center, double-blind, 2-arms 1:1 randomized trial evaluating the safety, feasibility, and efficacy of C-tDCS versus sham stimulation in patients eligible for recanalization therapies. Magnetic resonance imaging was obtained both on admission and 24 hours later. The primary end point was 24-hour infarct growth. Secondary outcomes were (1) National Institutes of Health Stroke Scale score difference between day 7 and admission and (2) 3-month modified Rankin Scale score. Results: Forty-five patients were randomized. Median magnetic resonance imaging-to-C-tDCS start time was 45 minutes; C-tDCS was started before completion of recanalization procedure in all patients. The intervention proved feasible in all patients. No major adverse effects occurred in either group. There was no significant difference between active and sham groups for any end point. However, an apparent trend towards smaller infarct growth in the C-tDCS arm was observed in the whole group (unadjusted median difference [IC95%]: −2.2 mL [−12.2 to 1.5]) and in the prespecified subsamples with moderate-to-severe stroke and large vessel occlusion (−5.7 mL [−21.6 to 2.6] and −7.7 mL [−24.2 to 2.6], respectively). Conclusions: C-tDCS was feasible and well tolerated. No significant difference was found between the active and sham groups. However, the data suggest potential benefits of C-tDCS in patients with National Institutes of Health Stroke Scale score of >10 or large vessel occlusion. Using the observed effect size and standard α=5% and ß=20%, samples of 102 and 86, respectively, can be estimated for future trials in patients with these characteristics. Randomized trials particularly targeting these populations may be warranted.

Evolution of the neurosurgical management of progestin-associated meningiomas: a 23-year single-center experience.

PURPOSE: The improving knowledge of interactions between meningiomas and progestin refines the management of this specific condition. We assessed the changes over time of the management of progestin-associated meningiomas. METHODS: We retrospectively studied consecutive adult patients who had at least one meningioma in the context of progestin intake (October 1995-October 2018) in a tertiary adult Neurosurgical Center. RESULTS: 71 adult women with 125 progestin-associated meningiomas were included. The number of progestin-associated meningioma patients increased over time (0.5/year before 2008, 22.0/year after 2017). Progestin treatment was an approved indication in 27.0%. A mean of 1.7 ± 1.2 meningiomas were discovered per patient (median 1, range 1-6). Surgery was performed on 36 (28.8%) meningiomas and the histopathologic grading was WHO grade 1 in 61.1% and grade 2 in 38.9%. The conservative management of meningiomas increased over time (33.3% before 2008, 64.3% after 2017) and progestin treatment withdrawal increased over time (16.7% before 2008, 95.2% after 2017). Treatment withdrawal varied depending on the progestin derivative used (88.9% with cyproterone acetate, 84.6% with chlormadinone acetate, 28.6% with nomegestrol acetate, 66.7% with progestin derivative combination). The main reason for therapeutic management of meningiomas was the presence of clinical signs. Among the 54 meningiomas managed conservatively for which the progestin had been discontinued, MRI follow-up demonstrated a regression in 29.6%, a stability in 68.5%, and an ongoing growth in 1.9% of cases. CONCLUSIONS: Conservative management, including progestin treatment discontinuation, has grown over time with promising results in terms of efficacy and safety.

Brain MRI Findings in Severe COVID-19: A Retrospective Observational Study.

Background Brain MRI parenchymal signal abnormalities have been associated with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Purpose To describe the neuroimaging findings (excluding ischemic infarcts) in patients with severe coronavirus disease 2019 (COVID-19) infection. Materials and Methods This was a retrospective study of patients evaluated from March 23, 2020, to April 27, 2020, at 16 hospitals. Inclusion criteria were (a) positive nasopharyngeal or lower respiratory tract reverse transcriptase polymerase chain reaction assays, (b) severe COVID-19 infection defined as a requirement for hospitalization and oxygen therapy, (c) neurologic manifestations, and (d) abnormal brain MRI findings. Exclusion criteria were patients with missing or noncontributory data regarding brain MRI or brain MRI showing ischemic infarcts, cerebral venous thrombosis, or chronic lesions unrelated to the current event. Categorical data were compared using the Fisher exact test. Quantitative data were compared using the Student t test or Wilcoxon test. P < .05 represented a significant difference. Results Thirty men (81%) and seven women (19%) met the inclusion criteria, with a mean age of 61 years ± 12 (standard deviation) (age range, 8-78 years). The most common neurologic manifestations were alteration of consciousness (27 of 37, 73%), abnormal wakefulness when sedation was stopped (15 of 37, 41%), confusion (12 of 37, 32%), and agitation (seven of 37, 19%). The most frequent MRI findings were signal abnormalities located in the medial temporal lobe in 16 of 37 patients (43%; 95% confidence interval [CI]: 27%, 59%), nonconfluent multifocal white matter hyperintense lesions seen with fluid-attenuated inversion recovery and diffusion-weighted sequences with variable enhancement, with associated hemorrhagic lesions in 11 of 37 patients (30%; 95% CI: 15%, 45%), and extensive and isolated white matter microhemorrhages in nine of 37 patients (24%; 95% CI: 10%, 38%). A majority of patients (20 of 37, 54%) had intracerebral hemorrhagic lesions with a more severe clinical presentation and a higher admission rate in intensive care units (20 of 20 patients [100%] vs 12 of 17 patients without hemorrhage [71%], P = .01) and development of the acute respiratory distress syndrome (20 of 20 patients [100%] vs 11 of 17 patients [65%], P = .005). Only one patient had SARS-CoV-2 RNA in the cerebrospinal fluid. Conclusion Patients with severe coronavirus disease 2019 and without ischemic infarcts had a wide range of neurologic manifestations that were associated with abnormal brain MRI scans. Eight distinctive neuroradiologic patterns were described. © RSNA, 2020.

Specificities of arterial spin labeling (ASL) abnormalities in acute seizure.

PURPOSE: Arterial spin labeling (ASL) is a non-invasive tool measuring cerebral blood flow (CBF) and is useful to assess acute neurological deficit. While acute stroke presents as hypoperfused vascular territory, epileptic activity causes cortical hyperperfusion. Other neurological conditions exhibit hyperperfusion, like migraine or secondary "luxury perfusion" in strokes. Our objectives were to evaluate the usefulness and potential specificities of ASL in acute seizure and correlate it with electroencephalogram. MATERIALS AND METHODS: Amongst a cohort of patients with neurological deficit, addressed for suspicion of stroke, we retrospectively reviewed 25 consecutive patients with seizures who underwent magnetic resonance imaging (MRI) with ASL and electroencephalography (EEG). We compared them with a control group of patients with migraine and stroke secondary re-perfusion, exhibiting ASL hyperperfusion. RESULTS: Lateralized cortical hyperperfusion (high relative CBF) was observed in all patients. Good topographic correlation with EEG was found in 18 patients (72%). Eight (32%) had hyperperfusion of ipsilateral pulvinar, 5 (20%) had hyperperfused contralateral cerebellar hemisphere, 16 (64%) presented diffusion abnormalities and 20 (80%) had underlying epileptogenic lesions. Pulvinar hyperperfusion was not observed in the control group, nor were diffusion abnormalities in migrainous patients. Contralateral cerebellar hyperperfusion was observed in two migrainous patient, without associated pulvinar activation, whereas all patients with cerebellar hyperperfusion in the study group had associated pulvinar activation. CONCLUSIONS: Elevated CBF can be observed in the epileptogenic zone, ipsilateral pulvinar and contralateral cerebellum (diaschisis) in seizure. These abnormalities seem specific when compared with other causes of hyperperfusion. Arterial spin labeling can be highly effective in the differential diagnosis of strokes.

Magnetic Resonance Imaging or Computed Tomography Before Treatment in Acute Ischemic Stroke.

Background and Purpose- The acute management of stroke patients requires a fast and efficient screening imaging modality. We compared workflow and functional outcome in acute ischemic stroke patients screened by magnetic resonance imaging (MRI) or computed tomography (CT) before treatment in the THRACE trial (Thrombectomie des Artères Cérébrales), with the emphasis on the duration of the imaging step. Methods- The THRACE randomized trial (June 2010 to February 2015) evaluated the efficacy of mechanical thrombectomy after intravenous tPA (tissue-type plasminogen activator) in ischemic stroke patients with proximal occlusion. The choice of screening imaging modality was left to each enrolling center. Differences between MRI and CT groups were assessed using univariable analysis and the impact of imaging modality on favorable 3-month functional outcome (modified Rankin Scale score of ≤2) was tested using multivariable logistic regression. Results- Four hundred one patients were included (25 centers), comprising 299 MRI-selected and 102 CT-selected patients. Median baseline National Institutes of Health Stroke Scale score was 18 in both groups. MRI scan duration (median [interquartile range]) was longer than CT (MRI: 13 minutes [10-16]; CT: 9 minutes [7-12]; P<0.001). Stroke-onset-to-imaging time (MRI: median 114 minutes [interquartile range, 89-138]; CT: 107 minutes [88-139]; P=0.19), onset-to-intravenous tPA time (MRI: 150 minutes [124-179]; CT: 150 minutes [123-180]; P=0.38) and onset-to-angiography-suite time (MRI: 200 minutes [170-250]; CT: 213 minutes [180-246]; P=0.57) did not differ between groups. Imaging modality was not significantly associated with functional outcome in the multivariable analysis. Conclusions- Although MRI scan duration is slightly longer than CT, MRI-based selection for acute ischemic stroke patients is accomplished within a timeframe similar to CT-based selection, without delaying treatment or impacting functional outcome. This should help to promote wider use of MRI, which has inherent imaging advantages over CT. Clinical Trial Registration- URL: https://www.clinicaltrials.gov . Unique identifier: NCT01062698.

Benefit from revascularization after thrombectomy according to FLAIR vascular hyperintensities-DWI mismatch.

OBJECTIVES: We tested whether FLAIR vascular hyperintensities (FVH)-DWI mismatch could identify candidates for thrombectomy most likely to benefit from revascularization. METHODS: We retrospectively reviewed 100 patients with proximal MCA occlusion from 18 stroke centers randomized in the IV-thrombolysis plus mechanical thrombectomy arm of the THRACE trial (2010-2015). We tested the associations between successful revascularization on digital subtraction angiography (modified Thrombolysis in Cerebral Infarction 2b/3) and 3-month favorable outcome (modified Rankin Scale score ≤ 2), stratified on FVH-DWI mismatch status, with secondary analyses adjusted on National Institutes of Health Stroke Scale (NIHSS) and DWI lesion volume. RESULTS: FVH-DWI mismatch was present in 79% of patients, with a similar prevalence at 1.5 T (80%) and 3 T (78%). Successful revascularization (74%) was more frequent in patients with FVH-DWI mismatch (63/79, 80%) than in patients without (11/21, 52%), p = 0.01. The OR of favorable outcome for revascularization were 15.05 (95% CI 3.12-72.61, p < 0.001) in patients with FVH-DWI mismatch and 0.83 (95% CI 0.15-4.64, p = 0.84) in patients without FVH-DWI mismatch (p = 0.011 for interaction). Similar results were observed after adjustment for NIHSS (OR = 12.73 [95% CI 2.69-60.41, p = 0.001] and 0.96 [95% CI 0.15-6.30, p = 0.96]) or for DWI volume (OR = 12.37 [95% CI 2.76-55.44, p = 0.001] and 0.91 [95% CI 0.16-5.33, p = 0.92]) in patients with and without FVH-DWI mismatch, respectively. CONCLUSIONS: The FVH-DWI mismatch identifies patients likeliest to benefit from revascularization, irrespective of initial DWI lesion volume and clinical stroke severity, and could serve as a useful surrogate marker for penumbral evaluation. KEY POINTS: • The FVH-DWI mismatch, defined by FLAIR vascular hyperintensities (FVH) located beyond the boundaries of the DWI lesion, is associated with large penumbra. • Among stroke patients with proximal middle cerebral artery occlusion referred for thrombectomy, those with FVH-DWI mismatch are most likely to benefit from revascularization. • FVH-DWI mismatch provides an alternative to PWI-DWI mismatch in order to select patients who are candidates for thrombectomy.

Optimal 4DFlow MR sequence parameters for the assessment of internal carotid artery stenosis: a simulation study.

PURPOSE: In patients with ICA stenosis, increased peak systolic velocity is a marker of stenosis at risk of ischemic stroke. 4DFlow MRI is a reproducible technique to evaluate velocities in ICA stenosis, although it seems to underestimate velocities as compared with Doppler ultrasonography. The purpose of our study was to confirm that velocities were underestimated on a new set of data acquired with a clinical 4DFlow sequence, and to devise optimal acquisition parameters for ICA stenosis exploration based on a numerical simulation. METHODS: After review board approval, 15 healthy controls and 12 patients presenting ICA stenosis were explored with Doppler ultrasonography and 4DFlow MRI. We created a 2-dimensional simulation of ICA stenosis and its corresponding 4DFlow acquisition, and compared its mean peak systolic velocity underestimation to real MRI and Doppler. We then simulated the acquisition for voxel size ranging from 0.5 to 1.25 mm and number of phases per cardiac cycle ranging from 10 to 25. RESULTS: On acquired data, 4DFlow MR underestimated peak systolic velocities (mean difference between Doppler and 4DFlow: - 35 cm/s), especially high velocities. With spatial and temporal resolutions equivalent to MR acquisition, our simulation yielded similar underestimation (mean difference: - 31 cm/s, P = 0.30). Simulations showed that 0.7-mm resolution and 20 phases per cardiac cycle would be necessary to record peak systolic velocities up to 250 cm/s. CONCLUSION: Higher spatial resolution can provide accurate peak systolic velocities measurement with 4DFlow MRI, thus allowing better ICA stenosis assessment. Further studies are needed to validate the proposed parameters.

Subsolid Lung Nodule Classification: A CT Criterion for Improving Interobserver Agreement.

Purpose To evaluate an objective computed tomographic (CT) criterion for distinguishing between part-solid (PS) and nonsolid (NS) lung nodules. Materials and Methods This study received institutional review board approval, and patients gave informed consent. Preoperative CT studies in all patients who underwent surgery for subsolid nodules between 2008 and 2015 were first reviewed by two senior radiologists, who subjectively classified the nodules as PS or NS. A second reading performed 1 month later used predefined classification criteria and involved a third senior radiologist as well as three junior radiologists. Subsolid nodules were classified as PS if a solid portion was detectable in the mediastinal window setting (nonmeasurable, < 50%, or > 50% of the entire nodule) and were otherwise classified as NS (subclassified as pure or heterogeneous). Interreader agreement was assessed with κ statistics and the intraclass correlation coefficient (ICC). Results A total of 99 nodules measuring a median of 20 mm (range, 5-47 mm) in lung window CT images were analyzed. Senior radiologist agreement on the PS/NS distinction increased from moderate (κ = 0.54; 95% confidence interval [CI]: 0.37, 0.71) to excellent (κ = 0.89; 95% CI: 0.80, 0.98) between the first and second readings. At the second readings, agreement among senior and junior radiologists was excellent for PS/NS distinction (ICC = 0.87; 95% CI: 0.83, 0.90) and for subcategorization (ICC = 0.82; 95% CI: 0.77, 0.87). When a solid portion was measurable in the mediastinal window, the specificity for adenocarcinoma invasiveness ranged from 86% to 96%. Conclusion Detection of a solid portion in the mediastinal window setting allows subsolid nodules to be classified as PS with excellent interreader agreement. If the solid portion is measurable, the specificity for adenocarcinoma invasiveness is high. © RSNA, 2017 Online supplemental material is available for this article.

Circumferential Thick Enhancement at Vessel Wall MRI Has High Specificity for Intracranial Aneurysm Instability.

Purpose To identify wall enhancement patterns on vessel wall MRI that discriminate between stable and unstable unruptured intracranial aneurysm (UIA). Materials and Methods Patients were included from November 2012 through January 2016. Vessel wall MR images were acquired at 3 T in patients with stable (incidental and nonchanging over 6 months) or unstable (symptomatic or changing over 6 months) UIA. Each aneurysm was evaluated by using a four-grade classification of enhancement: 0, none; 1, focal; 2, thin circumferential; and 3, thick (>1 mm) circumferential. Inter- and intrareader agreement for the presence and the grade of enhancement were assessed by using κ statistics and 95% confidence interval (CI). The sensitivity, specificity, and negative and positive predictive values of each enhancement grade for differentiating stable from unstable aneurysms was compared. Results The study included 263 patients with 333 aneurysms. Inter- and intrareader agreement was excellent for both the presence of enhancement (κ values, 0.82 [95% CI: 0.67, 0.99] and 0.87 [95% CI: 0.7, 1.0], respectively) and enhancement grade (κ = 0.92 [95% CI: 0.87, 0.95]). In unruptured aneurysms (n = 307), grade 3 enhancement exhibited the highest specificity (84.4%; 233 of 276; 95% CI: 80.1%, 88.7%; P = .02) and negative predictive value (94.3%; 233 of 247) for differentiating between stable and unstable lesions. There was a significant association between grade 3 enhancement and aneurysm instability (P < .0001). Conclusion In patients with intracranial aneurysm, a thick (>1 mm) circumferential pattern of wall enhancement demonstrated the highest specificity for differentiating between stable and unstable aneurysms. © RSNA, 2018.