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Background and Purpose: Recent clinical trials demonstrated the benefit of thrombectomy beyond 6h based on the automated measurement of infarct volume exclusively with the RAPID software. We aimed to compare eight tools commonly used for the measurement of infarct volume and see whether they would lead to similar thrombectomy decisions based on the Diffusion-weighted-imaging or computerized-tomography-perfusion Assessment with clinical mismatch in the triage of Wake-up and late-presenting strokes undergoing Neurointervention with Trevo (DAWN) trial imaging inclusion criteria., Materials and Methods: The diffusion-weighted-imaging (DWI) infarct volume of 36 patients was measured with 3 automated tools (including RAPID) and 5 non-automated tools. The agreement for the measurements of DWI infarct volume and the resulting thrombectomy decisions were assessed with intraclass correlation coefficient (ICC) and Fleiss' Kappa (K) statistics., Results: The correlation for the measurement of DWI infarct volume between all 9 tools was excellent (ICC>0.8). After dichotomization, agreement was substantial for any of the cut-points used in DAWN trial. Discrepancies involving at least one of the tools for thrombectomy decisions based on DAWN criteria occurred in one third of cases. Compared with RAPID, the use of any other tool for treatment decision based on DAWN criteria would have led to contradictory decisions in 6% to 19% of cases., Conclusion: There are several currently available tools for the measurement of DWI infarct volume with excellent correlation. Despite the high agreement demonstrated in our study, frequent discrepancies between measurements in some dichotomized configurations led to frequent diverging thrombectomy decisions when applying DAWN criteria., (Copyright © 2020 Elsevier Masson SAS. All rights reserved.)

Background and Purpose: Mechanical thrombectomy (MT) has dramatically changed the landscape of stroke care as well as stroke care organization. Public health institutions are faced with the challenge of swiftly providing equal access to this high technical level procedure with rapidly broadening indications, and constantly developing techniques. The aim of this study was to present a current nationwide overview of technical MT practices in France as well as local organizations., Materials and Methods: Thrombectomy capable French stroke centers, and physicians performing MT were invited to participate to a nationwide survey, disseminated through an existing trainee-led research network (the JENI-RC) under the aegis of the French Society of Neuroradiology. The survey was composed of 64 questions to collect both individual practices and general center-based information., Results: All French centers (100%) answered the survey, and 74% (110/148) of active interventional neuroradiologists (INR) performing MT completed individual questionnaires. The mean number of INR per center performing MT was 3.7±1.85, and 85% of the centers were organized for 24/7 continuity of care. MRI was the most commonly used imaging modality for stroke diagnosis and patients' selection, and perfusion imaging was routinely available in 85% of the centers. Half of centers performed yearly between 100 and 200 MT. Anesthesiologic, and technical considerations are also developed in the manuscript., Conclusions: This nationwide survey highlights the impressive response to the challenge of reorganization of stroke care with regards to mechanical thrombectomy in France. Technical and management disparities remain. Most centers remain understaffed to properly function in the long term, but the inflow of INT trainees is substantial., (Copyright © 2020 Elsevier Masson SAS. All rights reserved.)

Cerebral amyloid angiopathy (CAA) is a frequent age-related small vessel disease (SVD) with cardinal magnetic resonance imaging (MRI) signatures that are hemorrhagic in nature, and include the presence of strictly lobar (superficial) cerebral microbleeds and intracerebral hemorrhages as well as cortical superficial siderosis. When investigating a patient with suspected CAA in the context of intracranial hemorrhage (parenchymal or subarachnoid) or cognitive dysfunction, various MRI parameters influence the optimal detection and characterization (and prognostication) of this frequent SVD. The present report describes the influence of imaging techniques on the detection of the key hemorrhagic CAA imaging signatures in clinical practice, in research studies, and the imaging parameters that must be understood when encountering a CAA patient, as well as reviewing CAA literature., (Copyright © 2017 Elsevier Masson SAS. All rights reserved.)

The management of patients with unruptured intracranial aneurysms (UIAs) is a complex clinical challenge and constitutes an immense field of research. While a preponderant proportion of these aneurysms never rupture, the consequences of such an event are severe and represent an important healthcare problem. To date, however, the natural history of UIAs is not completely understood and there is no accurate means to discriminate the UIAs that will rupture from those that will not. Yet, a good understanding of the recent evidence and future perspectives is needed when advising a patient with IA to tailor any information to the given patient's level of risk and psychoaffective status. Thus, this review addresses the current concepts of epidemiology, risk factors, detection and management of UIAs., (Copyright © 2017 Elsevier Masson SAS. All rights reserved.)

Background and Purpose: Triage imaging facilitates the timely recognition of acute stroke with prognostic implications. Improvement in MR acquisition speed is needed given the extreme time constraints before treatment. We compared an ultrafast Echo-Planar FLAIR sequence (EPI-FLAIR) and a conventional FLAIR sequence (cFLAIR) for their diagnostic performances and ability to estimate the age of infarction., Material and Methods: Between June and August 2014, 125 consecutive patients (age 69±18 years, 48% men) admitted for a suspicion of acute (≤48-hrs) stroke were explored by both FLAIR sequences at 1.5-Tesla. EPI-FLAIR (15-sec) and cFLAIR (2-min and 15-sec) were compared by two readers, blinded to clinical data., Results: EPI-FLAIR was less prone to kinetic artefacts than cFLAIR (2-3% vs. 23-49% depending on the reader, P<0.001). Diagnostic concordance was excellent for both readers (к>0.9). Amongst 8 hemorrhages, one subarachnoid hemorrhage presenting as a sudden deficit was missed on EPI-FLAIR sequence. Amongst 60 infarctions, cFLAIR and EPI-FLAIR were concordant in 50 (83%), while signal changes were visible on cFLAIR only in the remaining 10 (17%) cases. Amongst the 43 patients with known onset time (n=17 within 4.5hrs), FLAIR-DWI mismatch identified<4.5-hrs infarction with the same sensitivity (65%) using cFLAIR and EPI-FLAIR, but the positive predictive value (PPV) was higher for cFLAIR than for EPI-FLAIR (73% vs. 50%, P=0.008)., Conclusion: EPI-FLAIR allows a drastic reduction of acquisition time devoted to FLAIR sequence and minimizes motion artifacts. Compared with cFLAIR, it is however associated with increased risk of undiagnosed stroke mimics and lower PPV for identifying<4.5-hrs infarctions., (Copyright © 2017 Elsevier Masson SAS. All rights reserved.)

Stroke mimics account for up to a third of suspected strokes. The main causes are epileptic deficit, migraine aura, hypoglycemia, and functional disorders. Accurate recognition of stroke mimics is important for adequate identification of candidates for thrombolysis. This decreases the number of unnecessary treatments and invasive vascular investigations. Correctly identifying the cause of symptoms also avoids delaying proper care. Therefore, this pictorial review focuses on what the radiologist should know about the most common MRI patterns of stroke mimics in the first hours after onset of symptoms. The issues linked to the accurate diagnosis of stroke mimics in the management of candidates for thrombolysis will be discussed., (Copyright © 2014 Elsevier Masson SAS. All rights reserved.)