Background:
Leptomeningeal enhancement (LME) is a key feature of Susac syndrome (SuS) but is only occasionally depicted on post-contrast T1-weighted images (T1-WI).
Objective:
As post-contrast ...fluid-attenuated inversion recovery (FLAIR) may be more sensitive, our aim was to assess LME in SuS on this sequence.
Methods:
From 2010 to 2020, 20 patients with definite SuS diagnosis were retrospectively enrolled in this multicentre study. Two radiologists independently assessed the number of LME on post-contrast FLAIR and T1-WI acquisitions performed before any treatment. A chi-square test was used to compare both sequences and the interrater agreement was calculated.
Results:
Thirty-five magnetic resonance imagings (MRIs) were performed before treatment, including 19 post-contrast FLAIR images in 17 patients and 25 post-contrast T1-WI in 19 patients. In terms of patients, LME was observed on all post-contrast FLAIR, contrary to post-contrast T1-WI (17/17 (100%) vs. 15/19 (79%), p < 0.05). In terms of sequences, LME was observed on all post-contrast FLAIR, contrary to post-contrast T1-WI (19/19 (100%) vs. 16/25 (64%), p < 0.005). LME was disseminated at both supratentorial (19/19) and infratentorial (18/19) levels on post-contrast FLAIR, contrary to post-contrast T1-WI (3/25 and 9/25, respectively). Interrater agreement was excellent for post-contrast FLAIR (κ = 0.95) but only moderate for post-contrast T1-WI (κ = 0.61).
Conclusion:
LME was always observed and easily visible on post-contrast FLAIR images prior to SuS treatment. In association with other MRI features, it is highly indicative of SuS.
Background and Purpose- Convexity subarachnoid hemorrhage (cSAH) is an increasingly recognized presentation of cerebral amyloid angiopathy (CAA), usually revealed by transient symptoms, but data on ...its outcome are limited. We compared the risk of future intracerebral hemorrhage (ICH), cSAH, and death in patients with CAA after cSAH and after lobar ICH. Methods- Consecutive patients with probable CAA, based on the Boston criteria, presenting with cSAH (CAA-cSAH) or lobar ICH (CAA-ICH) were included. We obtained baseline clinical and magnetic resonance imaging data and follow-up information. Univariable and multivariable analyses were used to compare incidence rate for symptomatic ICH, symptomatic cSAH, and late-death (beyond 30 days) between patients with CAA-cSAH and CAA-ICH. Results- Among 105 patients (mean age, 76.7±7.5 years) enrolled, 44 participants presented with CAA-cSAH and 61 with CAA-ICH. The median follow-up was 22.2 months (interquartile range, 12.6-34.4). The symptomatic ICH rate (per person-year) was 10.5% (95% CI, 5.6-19.4) in patients with CAA-cSAH compared with 8.5% (95% CI, 4.4-16.4) in those with CAA-ICH (adjusted hazard ratio, 1.05; 95% CI, 0.32-3.43). The annual incidence rates of symptomatic cSAH (9.9% versus 3.8%; adjusted hazard ratio, 1.77; 95% CI, 0.43-7.28) and death (9.5% versus 17.8%; adjusted hazard ratio, 0.56; 95% CI, 0.22-1.43) were not significantly different between patients with CAA-cSAH and those with CAA-ICH. Conclusions- Patients with CAA-related cSAH have a poor outcome, with similar high risk of future ICH and long-term mortality than CAA patients after lobar ICH. Our findings may have important prognostic implication and guide management of patients with cSAH in CAA.
Acute ischaemic stroke represents the most common cause of new sudden neurological deficit, but other diseases mimicking stroke happen in about one-third of the cases. Magnetic resonance imaging ...(MRI) is the best technique to identify those ‘stroke mimics’. In this article, we propose a diagnostic approach of those stroke mimics on MRI according to an algorithm based on diffusion-weighted imaging (DWI), which can be abnormal or normal, followed by the results of other common additional MRI sequences, such as T2 with gradient recalled echo weighted imaging (T2-GRE) and fluid-attenuated inversion recovery (FLAIR). Analysis of the signal intensity of the parenchyma, the intracranial arteries and, overall, of the veins, is crucial on T2-GRE, while anatomic distribution of the parenchymal lesions is essential on FLAIR. Among stroke mimics with abnormal DWI, T2-GRE demonstrates obvious abnormalities in case of intracerebral haemorrhage or cerebral amyloid angiopathy, but this sequence also allows to propose alternative diagnoses when DWI is negative, such as in migraine aura or headaches with associated neurological deficits and lymphocytosis (HaNDL), in which cortical venous prominence is observed at the acute phase on T2-GRE. FLAIR is also of major interest when DWI is positive by better showing evocative distribution of cerebral lesions in case of seizure (involving the hippocampus, pulvinar and cortex), hypoglycaemia (bilateral lesions in the posterior limb of the internal capsules, corona radiata, striata or splenium of the corpus callosum) or in posterior reversible encephalopathy syndrome (PRES). Other real stroke mimics such as mitochondrial myopathy, encephalopathy, lactic acidosis, stroke-like episodes (MELAS), Susac’s syndrome, brain tumour, demyelinating diseases and herpes simplex encephalitis are also included in our detailed and practical algorithm.
Key points
• About 30% of sudden neurological deficits are due to non-ischaemic causes.
• MRI is the best technique to identify stroke mimics.
• Our practical illustrated algorithm based on DWI helps to recognise stroke mimics.
Background
Multiple sclerosis (MS) patients represent a population potentially affected by the intracerebral accumulation of gadolinium-based contrast agents (GBCA) due to repeated magnetic resonance ...imaging (MRI) performed during their lifetime; however, MRI is still the best tool to monitor MS inflammatory activity.
Objective
This study aimed to evaluate the relevance of GBCA injections during the MRI follow-up of MS patients under natalizumab (Tysabri) treatment.
Methods
The MRI data results were retrospectively reviewed in a monocentric study (University Hospital of Toulouse, France) from all consecutive patients treated with natalizumab from January 2014 to January 2017. For each examination during the whole MRI follow-up, new lesions (enhancing and non-enhancing) were analyzed.
Results
A total of 129 patients were included in this study (65% female, mean age = 41 years, mean treatment duration 6.5 years, 50% positive for John Cunningham virus) and benefited from 735 MRIs with GBCA. Only 3 MRIs showed a new enhancing lesion, systematically encountered after treatment discontinuation.
Conclusion
According to this study based on the clinical and radiological practice, the systematic use of GBCA seems of limited relevance in the MRI follow-up of asymptomatic patients treated continuously with natalizumab.
The spectrum of Myelin Oligodendrocytes Glycoprotein (MOG) antibody disease constitutes a recently described challenging entity, referring to a relatively new spectrum of autoimmune disorders with ...antibodies against MOG predominantly involving the optic nerve and spinal cord. The purpose of this article is to describe MRI features of MOG-AD involvement in the optic nerves, spinal cord and the brain of adults.
Purpose
Despite a high variability, the hotspot method is widely used to calculate the cerebral blood volume (CBV) of glioblastomas on DSC-MRI. Our aim was to investigate inter- and intra-observer ...reproducibility of parameters calculated with the hotspot or a volume method and that of an original parameter assessing the fraction of pixels in the tumour volume displaying rCBV > 2: %rCBV > 2.
Methods
Twenty-seven consecutive patients with untreated glioblastoma (age: 63, women: 11) were retrospectively included. Three observers calculated the maximum tumour CBV value (rCBVmax) normalized with a reference ROI in the contralateral white matter (CBVWM) with (i) the hotspot method and (ii) with a volume method following tumour segmentation on 3D contrast–enhanced T1-WI. From this volume method, %rCBV > 2 was also assessed. After 8–12 weeks, one observer repeated all delineations. Intraclass (ICC) and Lin’s (LCC) correlation coefficients were used to determine reproducibility.
Results
Inter-observer reproducibility of rCBVmax was fair with the hotspot and good with the volume method (ICC = 0.46 vs 0.65,
p
> 0.05). For CBVWM, it was fair with the hotspot and excellent with the volume method (0.53 vs 0.84,
p
< 0.05). Reproducibility of one pairwise combination of observers was significantly better for both rCBVmax and CBVWM (LCC = 0.33 vs 0.75; 0.52 vs 0.89,
p
< 0.05). %rCBV > 2 showed excellent inter- and intra-observer reproducibility (ICC = 0.94 and 0.91).
Conclusion
Calculated in glioblastomas with a volume method, rCBVmax and CBVWM yielded good to excellent reproducibility but only fair with the hotspot method. Overall, the volume analysis offers a highly reproducible parameter, %rCBV > 2, that could be promising during the follow-up of such heterogeneous tumours.
Background and Purpose- Identifying underlying cerebral amyloid angiopathy (CAA) in patients with intracerebral hemorrhage (ICH) has important clinical implication. Convexity subarachnoid hemorrhage ...(cSAH) and subdural hemorrhage (SDH) are computed tomography features of CAA-related ICH. We explored whether cSAH and SDH could be additional magnetic resonance imaging markers of CAA in lobar ICH survivors. Methods- We analyzed data from consecutive patients with acute lobar ICH associated with CAA (CAA-ICH) or not attributed to CAA (non-CAA-ICH). Magnetic resonance imaging scans were analyzed for cSAH, SDH, and markers of small vessel disease. The associations of cSAH and SDH with the diagnosis of probable CAA based on the modified Boston criteria were explored using multivariable models. Results- We included 165 patients with acute lobar ICH (mean age 70±13 years): 72 patients with CAA-ICH and 93 with non-CAA-ICH. Patients with CAA-ICH had a higher prevalence of cSAH (73.6% versus 39.8%; P<0.001) and SDH (37.5% versus 21.5%; P=0.02) than non-CAA-ICH. In multivariate logistic regression analysis, the presence of cSAH was independently associated with CAA-ICH (odds ratio, 2.97; 95% CI, 1.26-6.99; P=0.013), whereas there was no association between SDH and CAA-ICH. Conclusions- Among survivors of acute lobar ICH, the presence of cSAH is associated with the magnetic resonance imaging-based diagnosis of CAA. Further studies should investigate whether cSAH help improve the sensitivity of magnetic resonance imaging for in vivo diagnosis of CAA.
Objective
To evaluate the efficacy of computed tomography (CT)-guided radiofrequency (RF) ablation for the treatment of osteoid osteomas in common and in technically challenging locations.
Materials ...and methods
Twenty-three patients with osteoid osteomas in common (nine cases) and technically challenging 14 cases: intra-articular (
n
= 7), spinal (
n
= 5), metaphyseal (
n
= 2) positions were treated with CT-guided RF ablation. Therapy was performed under conscious sedation with a seven-array expandable RF electrode for 8–10 min at 80–110°C and power of 90–110 W. The patients went home under instruction. A brief pain inventory (BPI) score was calculated before and after (1 day, 4 weeks, 6 months and 1 year) treatment.
Results
All procedures were technically successful. Primary clinical success was 91.3% (21 of total 23 patients), despite the lesions’ locations. BPI score was dramatically reduced after the procedure, and the decrease in BPI score was significant (
P
< 0.001, paired
t
-test;
n
− 1 = 22) for all periods during follow up. Two patients had persistent pain after 1 month and were treated successfully with a second procedure (secondary success rate 100%). No immediate or delayed complications were observed.
Conclusion
CT-guided RF ablation is safe and highly effective for treatment of osteoid osteomas, even in technically difficult positions.
Évaluer la capacité de la séquence de diffusion réalisée sur le cerveau, à détecter l’hématome de paroi des dissections carotidiennes.
Étude rétrospective d’une cohorte de 110 patients de moins de ...55 ans (40 femmes, âge moyen : 46,79 ans) admis à la phase aiguë d’un déficit neurologique, d’une céphalée ou d’une cervicalgie et ayant bénéficié au minimum d’une séquence de diffusion standard à 3 Tesla sur le cerveau. Parmi eux étaient inclus 50 patients (14 femmes, âge moyen : 46,72) ayant consécutivement eu une dissection carotidienne, dont le diagnostic avait été posé par écho-Doppler, IRM ou artériographie. Dans l’ensemble de la cohorte anonymisée, a été analysé en aveugle, séparément par un radiologue senior et un junior, uniquement sur la séquence de diffusion, la présence d’un hypersignal en croissant ou circulaire en projection des segments sous-pétreux des artères carotides internes (Fig. 1), dans l’hypothèse qu’il corresponde à un hématome de paroi d’une dissection.
Le radiologue senior retrouvait 46 hypersignaux diffusion sous-pétreux chez 43/50 patients présentant une dissection, aucun chez les patients ne présentant pas de dissection (sensibilité 86 %, spécificité 100 %). Le radiologue junior retrouvait 48 hypersignaux diffusion sous-pétreux chez 45/50 patients présentant une dissection, aucun chez les patients ne présentant pas de dissection (sensibilité 90 %, spécificité 100 %). Le kappa inter observateur, calculé à 0,99, était excellent.
Dans notre cohorte, la séquence de diffusion standard réalisée à la phase aiguë d’un AVC ou d’une suspicion clinique de dissection a détecté à elle seule près de 90 % des dissections carotidiennes.
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