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Several reports discuss the added value of postmortem computed tomography (PMCT) in the forensic analysis of mass fatality incidents (MFIs), such as the 2009 Victorian bushfires, the Grenfell tower...

Neuroimaging and especially MRI has emerged as a necessary imaging modality to detect, measure, characterize and monitor brain tumors. Advanced MRI sequences such as perfusion MRI, diffusion MRI and spectroscopy as well as new post-processing techniques such as automatic segmentation of tumors and radiomics play a crucial role in characterization and follow up of brain tumors. The purpose of this review is to provide an overview on anatomical and functional MR imaging use for brain tumors boundaries determination and tumor characterization in the specific context of radiotherapy. The usefulness of anatomical and functional MR imaging on particular challenges posed by radiotherapy such as pseudoprogression and pseudoresponse and new treatment strategies such as dose painting is also described., Les avancées en neuro-imagerie, principalement liées au développement de l’IRM, ont rendu cette modalité centrale dans la prise en charge des patients porteurs de tumeur cérébrale. L’IRM, par son approche anatomique, permet de détecter, localiser et caractériser les lésions. L’application de séquences avancées d’IRM de type imagerie de perfusion, de spectroscopie ou de diffusion, ainsi que les nouveaux post-traitements permettant une segmentation ou une caractérisation automatique des lésions, apportent de nouvelles possibilités pour affiner la caractérisation des tumeurs tant au moment du diagnostic initial que lors du traitement par radiothérapie et du suivi. Le but de cette revue de littérature est de donner un aperçu de l’utilisation des imageries IRM anatomique et fonctionnelle utilisées pour la détermination des contours des différentes tumeurs cérébrales dans le contexte particulier de la radiothérapie. L'utilité de l'IRM anatomique et fonctionnelle est également examinée, en portant une attention particulière aux défis posés par la radiothérapie, tels que la pseudoprogression et la pseudoréponse, ainsi que par de nouvelles stratégies de traitement personnalisées, comme la dose painting.

International audience; Purpose: The second edition of the artificial intelligence (AI) data challenge was organized by the French Society of Radiology with the aim to: (i), work on relevant public health issues; (ii), build large, mul-ticentre, high quality databases; and (iii), include three-dimensional (3D) information and prognostic questions. Materials and methods: Relevant clinical questions were proposed by French subspecialty colleges of radiology. Their feasibility was assessed by experts in the field of AI. A dedicated platform was set up for inclusion centers to safely upload their anonymized examinations in compliance with general data protection regulation. The quality of the database was checked by experts weekly with annotations performed by radiologists. Multidisciplinary teams competed between September 11 th and October 13 th 2019. Results: Three questions were selected using different imaging and evaluation modalities, including: pulmonary nodule detection and classification from 3D computed tomography (CT), prediction of expanded disability status scale in multiple sclerosis using 3D magnetic resonance imaging (MRI) and segmentation of muscular surface for sarcopenia estimation from two-dimensional CT. A total of 4347 examinations were gathered of which only 6% were excluded. Three independent databases from 24 individual centers were created. A total of 143 participants were split into 20 multidisciplinary teams. Conclusion: Three data challenges with over 1200 general data protection regulation compliant CT or MRI examinations each were organized. Future challenges should be made with more complex situations combining histopathological or genetic information to resemble real life situations faced by radiologists in routine practice.

The aim of this study was to evaluate the safety profile of gadoterate meglumine from clinical trials, postmarketing observational studies, and pharmacovigilance reports of adverse drug reactions (ADRs) encompassing 25 years of clinical use and over 50 million administered doses.Assessment of the safety of gadoterate meglumine through processing and review of all safety data was collected after magnetic resonance imaging procedures. All ADRs originated from 3 major sources: (1) a clinical study database including 50 phase I to IV studies involving 2822 patients, (2) a safety database including 8 postmarketing safety studies (PMSs) involving 151,050 patients, and (3) a pharmacovigilance database compiling safety experience following over 50 million doses administered between March 1989 and September 2015.Among the 2822 patients receiving gadoterate meglumine in the clinical trials, 241 (8.5%) experienced 405 postinjection adverse events (AEs), considered related to the contrast agent for 113 patients (4.0%). Serious AEs were reported for 27 patients (1.0%) and assessed as related to gadoterate meglumine for 2 patients (0.07%). None of the PMS studies showed evidence of unexpected safety issues, with a very low rate of AEs (1%). Postmarketing safety experience with over 50 million doses of gadoterate meglumine prescribed for 25 years of approved use worldwide compiled spontaneous reports for 3797 patients who experienced 8397 ADRs, yielding a very low reported incidence of ADRs of 0.007% of patients. There was no single-agent case of confirmed nephrogenic systemic fibrosis with gadoterate meglumine either from clinical development programs or from postmarketing experience.Based on clinical trials, postmarketing observational studies and pharmacovigilance data, a very low incidence of ADRs was reported with gadoterate meglumine, which has no impact on its favourable benefit-risk ratio.

Summary There is currently no evidence that treatment of unruptured aneurysms is beneficial. Confronted with the uncertainty, many clinicians are attracted by an individual calculus of risks using numbers extracted from subgroup statistics of observational studies or natural history data. The so-called natural history of unruptured aneurysms refers to a purely man-made ratio of events divided by the number of untreated patients identified by imaging, a ratio heavily influenced by referral patterns and arbitrary clinical decisions. Available studies lacked prespecified hypotheses, exposing all analyses to sampling error and bias, and sample sizes were too small to provide reliable subgroup statistics. Far from being “natural kinds” of aneurysms, subgroups were post-hoc creations. Resulting data-driven statistics can only be exploratory, the error too uncontrollable to serve for clinical decisions. A randomized trial is in order, but selection according to fixed size criteria is ill-advised, given the imprecision of imaging, the influence of other factors such as location, previous history, multiplicity of lesions, risks of treatment, age and the danger of arbitrarily excluding from a long trial a large segment of the population with aneurysms for whom the research question is most pertinent.

Preventive treatment of unruptured intracranial aneurysms is often performed but has never been proved beneficial as compared to conservative management. In a context of uncertainty, the ‘best treatment’ that can be offered to each individual is a chance to be treated and thus to be protected from rupture of the aneurysm, and an equal chance not to be treated, and hence to be exempted from possible immediate complications, using randomization. Such action is optimal unless or until an independent committee with privileged access to data judges that, given the comparative outcome of the 2 groups, preventive treatment or conservative management, is generally warranted. Potential reasons to interrupt such a study are reviewed, including insufficient recruitment, poor compliance, excessive cross-overs, unacceptable iatrogenia, and treatments being convincingly different or equivalent. We conclude that insufficient recruitment is the sole realistic event that could lead to premature interruption. This review may provide a deeper understanding of the principles justifying the necessity of the study.

Resume Les patients pris en charge a la phase aigue d’un accident vasculaire cerebral (AVC) beneficient des progres de l’imagerie. L’Imagerie par Resonance Magnetique (IRM) permet de realiser precocement, des les premieres minutes, le diagnostic de lesions ischemiques. Celles-ci sont susceptibles de regresser si un traitement adapte, visant a lever l’occlusion arterielle, est mis en route dans les premieres heures. L’IRM evalue les possibilites de mise en route de ce traitement, ecartant notamment l’eventualite d’un AVC hemorragique, determine le pronostic et, enfin, participe au diagnostic etiologique. (J Mal Vasc 2006; 31: 252-259)

Background and Purpose — Patent foramen ovale (PFO) has been identified as a potential risk factor for stroke, but the mechanisms of PFO-associated stroke remain unsettled. The aim of our study was to evaluate possible differences in stroke risk factors and stroke patterns between patients with and without PFO that may give clues to the mechanism of PFO-associated stroke. Methods — This prospective, multicentric study involved 581 young cryptogenic stroke patients. The presence of PFO and atrial septal aneurysm was assessed by transesophageal echocardiography and reviewed independently by 2 experienced sonographers. Clinical, brain, and vascular imaging findings were reviewed by 2 neurologists and 2 neuroradiologists. Results — Of the 581 stroke patients, 267 (45.9%) had PFO. Patients with PFO were younger (OR, 0.95; 95% CI, 0.93 to 0.97) and less likely to have traditional risk factors such as hypertension (OR, 0.49; 95% CI, 0.28 to 0.85), hypercholesterolemia (OR, 0.56; 95% CI, 0.34 to 0.93), or current smoking (OR, 0.67; 95% CI, 0.47 to 0.97). Features suggestive of paradoxical embolism, such as Valsalva-provoking activities or deep vein thrombosis, were not more frequent in patients with PFO. Migraine was more common in patients with PFO (27.3%) than in those without PFO (14.0%). PFO (OR, 1.75; 95% CI, 1.08 to 2.82), particularly when associated with atrial septal aneurysm (OR, 2.71; 95% CI, 1.36 to 5.41), was significantly associated with migraine after adjustment for age and sex. Conclusions — Differences in stroke risk factors and stroke patterns suggest that different stroke mechanisms occur in patients with and without PFO. PFO is significantly and independently associated with migraine, and this association is even stronger in patients with PFO and atrial septal aneurysm.

Background and Purpose— Unstable clinical course characterizes the first 24 hours after thrombolysis for anterior circulation stroke, including early neurological deterioration (END), a secondary complication consistently predictive of poor outcome. Apart from straightforward causes, such as intracerebral hemorrhage and malignant edema, the mechanism of END remains unclear in the majority of cases (END unexplained ). Based on the core/penumbra model, we tested the hypothesis that END unexplained is caused by infarct growth beyond the initial penumbra and assessed the associated vascular patterns. Methods— From our database of consecutive thrombolyzed patients (n=309), we identified 10 END unexplained cases who had undergone both admission and 24-hour MRI. Diffusion-weighted imaging lesion growth both within and beyond the acute penumbra (T max >6 seconds) was mapped voxelwise. These 10 cases were compared with 30 no-END controls extracted from the database blinded to 24-hour diffusion-weighted imaging to individually match cases (3/case) according to 4 previously identified clinical and imaging variables. Results— As predicted, lesion growth beyond initial penumbra was present in 9 of 10 END unexplained patients (substantial in 8) and its volume was significantly larger in cases than controls (2 P =0.047). All END unexplained cases had proximal arterial occlusion initially, of which only 2 had recanalized at 24 hours. Conclusions— In this exploratory study, most instances of END unexplained were related to diffusion-weighted imaging growth beyond acute penumbra. Consistent presence of proximal occlusion at admission and lack of recanalization at 24 hours in most cases suggest that hemodynamic factors played a key role, via for instance systemic instability/collateral failure or secondary thromboembolic processes. Preventing END after tissue-type plasminogen activator using, eg, early antithrombotics may therefore be feasible.

Resume Aujourd'hui, les progres technologiques de l'imagerie permettent une connaissance plus precise de l'anatomie des malformations arterioveineuses. L'imagerie par resonance magnetique apporte des informations morphologiques — dimensions, siege et rapports encephaliques de la malformation — ainsi que dynamiques, en particulier grâce aux techniques d'angiographie par resonance magnetique. L'angiographie selective des vaisseaux cerebraux et hyperselective des pedicules malformatifs, precise l'angioarchitecture de la malformation et recherche des anomalies vasculaires associees, en particulier des anevrysmes. Il semble alors possible de distinguer les malformations a haut risque hemorragique et de preciser les indications de la radiotherapie.

Resume Entre 1962 et 1986, 32 patients porteurs de meningiomes intracrâniens ont ete adresses a l'Institut Gustave-Roussy pour radiotherapie, soit apres exerese chirurgicale incomplete (huit cas), soit en raison de facteurs histologiques defavorables (cinq cas),soit apres recidives (19 cas). Dans ce dernier cas, le delai entre la chirurgie initiale et la recidive etait en moyenne de 2 ans(extremes:1 an–6 ans). L'irradiation a ete effectuee soit aux photons, soit aux electrons, soit avec une association photons-electrons.La dose totale delivree a ete en moyenne de 48 Gy (extremes: 9 Gy–65 Gy) delivree en moyenne de 35 jours et une moyenne de 19 fractions.Cette irradiation a du etre interrompue chez trois malades en raison d'une aggravation neurologique (doses: 9 Gy, 17 Gy, 20 Gy). La survie actuarielle est de 64% a 5 ans. Parmi les 32 patients, 11 sont decedes, huit de progression tumorale et trois d'autres causes (uncancer de l'ovaire et deux de cause indeterminee). Parmi les 21 malades vivants, huit ont presente une recidive; et cinq d'entre euxont pu etre reoperes dont deux avec exerese complete. Aucun des elements suivants n'a ete retrouve comme facteur susceptible d'influencer la survenue d'une recidive tumorale: l'âge, le siege, la qualite de la premiere resection chirurgicale et,dans le groupe de patients traites pour recidives, la qualite de la resection chirurgicale au moment de la recidive ainsi que le delai entre la premiere chirurgie et la recidive. Le seul facteur pronostique de la recidive retrouve de facon statistiquement significative( p = 0,003) a ete la dose totale de radiotherapie avec une survie qui atteint 74% a 10 ans lorsque la dose a ete 7 Gy contre 14% lorsque la dose a ete

The typical magnetic resonance imaging picture of arterial dissection, namely, a narrowed eccentric signal void surrounded by a semilunar signal hyper-intensity (corresponding to the mural hematoma) on T1- and T2-weighted images, has been repeatedly reported, but the sensitivity of magnetic resonance imaging for the diagnosis of cervical dissection is poorly known. Another technique, dynamic computed tomography, may provide evidence of mural hematoma, but there has been no systematic evaluation of this technique. The aims of this study were to assess both the sensitivity of routine 0.5-T magnetic resonance imaging for the detection of a typical picture of cervical artery dissection and the value of dynamic computed tomographic scans to provide evidence of dissecting hematoma. Fifteen consecutive patients with angiographically confirmed extracranial internal carotid (n = 9) or vertebral (n = 10) dissections were studied using a standardized 0.5-T spin-echo magnetic resonance imaging protocol with axial slices. Twelve of these patients had dynamic computed tomographic scans at the site of the dissection suggested by angiography. A typical magnetic resonance imaging picture of cervical artery dissection was observed in 12 of 15 (80%) patients and in 13 of 19 (68%) dissected vessels. The sensitivity of magnetic resonance imaging was higher in internal carotid (78%) than in vertebral (60%) dissections and in stenotic-type dissections (85%) than in occlusive or aneurysmal-type dissections. The dynamic computed tomographic scan showed the mural hematoma in 11 of the 12 (92%) patients and in 12 of 15 (80%) dissected vessels. Routine 0.5-T magnetic resonance imaging with axial slices is a sensitive technique for the diagnosis of dissection, but in about 20% of patients with cervical artery dissection magnetic resonance imaging will demonstrate no typical abnormality. Dynamic computed tomographic scans are a sensitive neuroimaging procedure to confirm the presence of the mural hematoma, but it needs to be directed by prior angiography.

This paper analyses the internal organisation of the primate motor thalamus. A topographic study of the three main subcortical afferent territories (the cerebellar, pallidal and nigral territories) gives a much simpler and more functionally relevant partitioning of the thalamus than consideration of conflictual cytoarchitectonic nuclei.

The purpose of this case-control study was to determine whether an asymmetry of size of the intracranial internal carotid artery (ICA) on 3D time-of-flight MR angiography (MRA) is predictive of a high-grade cervical ICA stenosis. Ninety-six stroke/TIA consecutive patients were recruited for the study, of whom 32 had unilateral high-grade ICA stenosis (>or=70% NASCET) and were included into the case group, and the remaining 64 did not have such high-grade stenosis and were included in the control group. On intracranial MRA, two observers, blinded to the characteristics of cervical ICA stenosis, independently searched for qualitative size asymmetry between ICAs and measured the cross-sectional surface of the intracranial ICAs. An intracranial size asymmetry was seen in 28 of the 32 high-grade stenoses by both readers, and in 10 (reader(1)) and 8 (reader(2)) of the 64 controls (sensitivity =88%, specificity =84-88%). In patients without agenesia of the A1 segment of the circle of Willis (n=70), sensitivity was >or=90% and specificity =96%. Surfaces ratios were significantly different (p

Background and Purpose— Hyperintense vessel sign (HVS) on fluid-attenuated inversion recovery (FLAIR) has been described in hyperacute stroke patients with arterial occlusion. We sought to determine whether HVS was more frequent in patients with intracerebral arterial stenoses than in those without stenosis regardless of the presence of a brain infarct. Methods— In this case-control study (19 symptomatic patients with multiple intracerebral arterial stenoses compared with 19 age-matched asymptomatic patients without stenosis), we looked for HVS (ie, focal or tubular hyperintensities in the subarachnoid space) on FLAIR images. We compared the proportion of HVS-positive patients in the 2 groups and evaluated the concordance between the arterial distribution of stenoses on angiogram and that of HVS on FLAIR. Results— HVS was found in 13 of 19 patients (68%) in the study group and 1 of 19 control patients (5.2%) ( P Conclusions— Although their significance remains unclear, multiple HVSs are more frequently observed in symptomatic patients with multiple intracerebral stenoses than in asymptomatic patients without stenosis.

ne evaluation nationale des internes DES, menee sous l’egide du College des enseignants de radiologie de France (CERF), a eu lieu en 2005 et a ete reconduite en 2006. Cette initiative, nee d’experiences locales, en particulier de celle de la region Nord, a ete acceptee par les representants des internes a la condition qu’il ne s’agisse pas d’un droit d’exercice. L’evaluation nationale, dont vous trouverez dans cette revue l’analyse, a ete possible grâce a la participation dans chaque region des coordonnateurs du DES et nous les en remercions vivement. Plusieurs raisons nous ont fait proposer aux internes une evaluation : 1/ elle est indissociable de tout enseignement ; 2/ il s’agit d’une demarche obligatoire pour les professionnels de sante ; 3/ nous formons aujourd’hui des specialistes europeens. Aujourd’hui, la formation des specialistes est la meme pour tous les etudiants en medecine qui, selon leur rang a l’Examen Classant National, choisissent ville de formation et specialite. Ce n’est pas le propos de cet editorial de juger du bien fonde de la reforme du troisieme cycle ; nous pensons tout de meme que ce systeme, bien qu’en coherence avec d’autres modeles europeens, est perfectible. La principale reserve que l’on peut formuler est la grande heterogeneite de l’enseignement : la formation theorique s’appuie sur des modules qui pour la plupart ne sont pas obligatoires ; dans quelques CHU seulement, les modules obligatoires sont sanctionnes par un examen ; une grande heterogeneite des stages pratiques est signalee par les internes ; ces stages necessitent un personnel forme qui n’est plus suffisamment nombreux ou qui a des charges cliniques trop lourdes pour encadrer correctement les internes. Au total, la seule validation de stages, meme si cette formation est assortie de modules d’enseignement theorique obligatoires, ne permet probablement pas de reconnaitre la competence « preprofessionnelle » des jeunes medecins.

Publisher Summary This chapter explains that the anterior part of the lateral region of the thalamus of primates is the place of discrepant interpretations. The main inconsistency concerns the distinction of a polar, most anterior subdivision. Therefore, the chapter focuses on the topography of the subcortical afferent territories—the thalamic spaces filled by sets of axonal arborizations from the same source—and addresses the question of the existence of a polar subdivision by precisely comparing the three-dimensional positions and shapes of the pallidal and nigral thalamic territories to those of the anterior part of the lateral region of the thalamus. The precise three-dimensional cartography of the pallidal and nigral territories in the anterior part of the thalamus shows that there is no thalamic subdivision in front of the two territories. There is also no polar part degenerating after hemidecortication. Thalamo-striate neurons are located in the whole extent of the pallidal and nigral territories.

Le recours de plus en plus frequent aux techniques d’imagerie vasculaire non invasives permet de repousser de plus en plus loin les indications de l’angiographie conventionnelle dont le taux de morbidite n’est pas nul. L’echographie Doppler doit etre aujourd’hui l’examen a realiser en premiere intention en raison de sa parfaite innocuite et des renseignements multiples qu’il apporte. L’ARM avec injection de gadolinium permet une etude des vaisseaux cervico-encephaliques sur une grande hauteur en un temps tres court avec une resolution spatiale satisfaisante. L’interpretation des images peut cependant etre genee par certains artefacts lies au flux. Une sequence complementaire en 3D temps de vol sans injection doit etre realisee pour une analyse precise des arteres du polygone. Les nouvelles antennes de surface permettent egalement une etude complementaire en haute resolution de la plaque d’atherome. Le scanner spirale selon la technique « multicoupes » permet une acquisition extremement rapide des images. Cette methode est peu sensible au regime d’ecoulement des flux et apporte des informations simultanees sur la lumiere et la paroi vasculaire. Le post-traitement des images est cependant assez long et necessite un operateur entraine. Les images sont par ailleurs plus fragmentaires et il s’agit d’une technique irradiante necessitant une injection d’iode. Les donnees fournies par l’association de plusieurs de ces examens et en particulier par l’echo-Doppler et l’ARM qui constituent les examens les moins invasifs, representent un nouveau « gold standard » pour l’exploration des vaisseaux cervico-encephaliques.

L’imagerie par resonance magnetique (IRM), par sa sensibilite et ses possibilites d’examen simultane du parenchyme et des vaisseaux, est devenu l’examen - cle du diagnostic des urgences neurovasculaires. Cette presentation a pour objectif : 1/ d’envisager les protocoles d’examen les plus adaptes au diagnostic en urgence des accidents vasculaires ischemiques et hemorragiques, d’origines arterielle et veineuse ; 2/ de presenter la semiologie en IRM des pathologies en cause ; 3/ de preciser la valeur pronostique de cette technique d’imagerie. Chaque type d’affections sera illustre par des exemples pratiques permettant de preciser la valeur diagnostique de l’IRM, en particulier par rapport au scanner.

The proliferation of new endovascular devices and therapeutic strategies calls for a prudent and rational evaluation of their clinical benefit. This evaluation must be done in an effective manner and in collaboration with industry. Such research initiative requires organisational and methodological support to survive and thrive in a competitive environment. We propose the formation of an international consortium, an academic alliance committed to the pursuit of effective neurovascular therapies. Such a consortium would be dedicated to the design and execution of basic science, device development and clinical trials. The Consortium is owned and operated by its members. Members are international leaders in neurointerventional research and clinical practice. The Consortium brings competency, knowledge, and expertise to industry as well as to its membership across a spectrum of research initiatives such as: expedited review of clinical trials, protocol development, surveys and systematic reviews; laboratory expertise and support for research design and grant applications to public agencies. Once objectives and protocols are approved, the Consortium provides a stable network of centers capable of timely realization of clinical trials or preclinical investigations in an optimal environment. The Consortium is a non-profit organization. The potential revenue generated from client-sponsored financial agreements will be re-directed to the academic and research objectives of the organization. The Consortium wishes to work in concert with industry, to support emerging trends in neurovascular therapeutic development. The Consortium is a realistic endeavour optimally structured to promote excellence through scientific appraisal of our treatments, and to accelerate technical progress while maximizing patients' safety and welfare.