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Objectives: To determine whether fast scanned MRI using a 1.5-T scanner is a reliable method for the detection and characterization of acute ischemic stroke in comparison with conventional MRI., Methods: From May 2015 to June 2016, 862 patients (FLAIR, n = 482; GRE, n = 380; MRA, n = 190) were prospectively enrolled in the study, with informed consent and under institutional review board approval. The patients underwent both fast (EPI-FLAIR, ETL-FLAIR, TR-FLAIR, EPI-GRE, parallel-GRE, fast CE-MRA) and conventional MRI (FLAIR, GRE, time-of-flight MRA, fast CE-MRA). Two neuroradiologists independently assessed agreements in acute and chronic ischemic hyperintensity, hyperintense vessels (FLAIR), microbleeds, susceptibility vessel signs, hemorrhagic transformation (GRE), stenosis (MRA), and image quality (all MRI), between fast and conventional MRI. Agreements between fast and conventional MRI were evaluated by generalized estimating equations. Z-scores were used for comparisons of the percentage agreement among fast FLAIR sequences and fast GRE sequences and between conventional and fast MRA., Results: Agreements of more than 80% were achieved between fast and conventional MRI (ETL-FLAIR, 96%; TR-FLAIR, 97%; EPI-GRE, 96%; parallel-GRE, 98%; fast CE-MRA, 86%). ETL- and TR-FLAIR were significantly superior to EPI-FLAIR in the detection of acute ischemic hyperintensity and hyperintense vessels, while parallel-GRE was significantly superior to EPI-GRE in the detection of susceptibility vessel sign (p value < 0.05 for all). There were no significant differences in the other scores and image qualities (p value > 0.05)., Conclusions: Fast MRI at 1.5 T is a reliable method for the detection and characterization of acute ischemic stroke in comparison with conventional MRI., Key Points: • Fast MRI at 1.5 T may achieve a high intermethod reliability in the detection and characterization of acute ischemic stroke with a reduction in scan time in comparison with conventional MRI.

Background: Intracerebral microbleeds (MBs) are frequently observed in intracerebral hemorrhage (ICH) patients. Although MBs have been shown to be pathogenetically related with ICH, it is not known whether MBs are predictors of recurrent ICHs., Methods: Among 220 acute symptomatic primary ICH patients, 112 patients who underwent gradient-echo T2*-weighted MR imaging (GRE) within 10 days after symptom onset were considered for this study. Among them, the final 63 patients who consented to follow-up clinical, laboratory and GRE studies were included. The presence and number of ICHs (mean diameter >5 mm) and MBs on baseline and follow-up GRE were evaluated. The relationship of recurrent ICHs with initial and follow-up clinical and laboratory data as well as the MBs was assessed., Results: Among 63 patients, 43 (68.3%) had MBs (median, 2; range, 1 to 17) on baseline GRE. Seven (11.1%) patients (6 with initial MBs; 1 without initial MBs) developed recurrent ICHs, and 19 (30.2%) had new MBs during a median 23.3 months (range, 8.3 to 33.0) of follow-up. The number of initial MBs on baseline GRE was significantly (p < 0.0001) associated with development of recurrent ICHs whereas other clinical and laboratory data were not., Conclusions: Recurrent ICHs and MBs are common after long-term follow-up of primary ICH. The number of MBs on baseline GRE may predict the recurrence of the ICH.

Objective: To identify the timelines of magnetic resonance imaging (MRI) abnormalities and their relationships with the clinical outcomes of patients with new‐onset refractory status epilepticus (NORSE). Methods: This retrospective observational study enrolled patients with NORSE who were admitted from March 2008 to July 2018. MRI abnormalities were analyzed visually with the readers blinded to the clinical characteristics of the patients. Poor functional outcome was defined as a Glasgow Outcome Scale score ≤ 3 at discharge. Subsequent pharmacoresistant epilepsy was defined as seizures not controlled by two or more anti‐seizure medications 6 months after discharge. Results: Among 39 patients with NORSE, 32 (82.1%) exhibited an MRI abnormality. The most common abnormalities were persisting mesial temporal lobe signal abnormality (51.3%); initial diffuse leptomeningeal enhancement within 16 days from seizure onset (15/35, 42.9%); and hippocampal atrophy, which started to appear 26 days after seizure onset (15/26, 57.7%). Only three patients had claustrum abnormalities. Patients with insular involvement had longer treatment delay than those without (24.0 vs 5.5 hours, respectively, P =.02). Duration of status epilepticus (SE) tended to have a linear association with hippocampal atrophy (P =.055). Patients with diffuse leptomeningeal enhancement were more likely to have a poor functional outcome and to develop subsequent pharmacoresistant epilepsy than those without this finding (93.3% vs 15.0%, P <.001; 75.0% vs 22.2%, P =.004, respectively); the results were significant even after adjusting for age, sex, and duration of SE. Hippocampal atrophy and diffuse cortical atrophy were also significantly associated with poor functional outcomes (P =.001 and P =.002, respectively), and patients with these conditions were more likely to develop subsequent pharmacoresistant epilepsy than those without these conditions, after adjusting for age and sex (P =.035 and P =.048, respectively), but not after adjusting for duration of SE. Significance: Initial diffuse leptomeningeal enhancement and later hippocampal atrophy were associated with a poor functional outcome and subsequent pharmacoresistant epilepsy. [ABSTRACT FROM AUTHOR]

Objectives: The use of dexmedetomidine and ketamine (DEX–KET) combination for magnetic resonance imaging (MRI) sedation has not been evaluated. We investigated the efficacy and safety of DEX–KET for sedation of patients undergoing MRI of the brain. Methods: This quasi-experimental study was conducted to compare the DEX–KET combination and midazolam for MRI sedation. We included 72 patients undergoing brain MRI following bolus injection of midazolam or DEX–KET. In August 1, 2016 a new MRI sedation protocol was implemented. After protocol implementation, bolus doses of DEX–KET were administered (DEX–KET group). Thirty-six patients from the MIDA group and 36 patients from the DEX–KET group underwent MRI sequences and were compared regarding the MRI scan time and sedation-related complications (desaturation, hypotension, cardiorespiratory arrest, and aspiration pneumonia). Results: All MRI sequences were completed for 30 patients (83.3%) from the MIDA group and for 33 patients (91.7%) from the DEX–KET group (P = 0.476). The median MRI scan time was 100.0 min (interquartile range, 87.0–111.5 min) in the MIDA group and 53.5 min (interquartile range, 45.0–60.5 min) in the DEX–KET group (P < 0.001). Complications occurred in 24 (66.7%) and 8 (22.2%) patients of the MIDA and DEX–KET group, respectively (P < 0.001). Conclusions: The efficacy of DEX–KET sedation was comparable to that of midazolam for MRI examination. DEX–KET was related to shorter scan time and lower occurrence of complications compared to midazolam. [ABSTRACT FROM AUTHOR]

Emerging evidence has suggested that hydrogen sulfide (H2S) may alleviate the cellular damage associated with cerebral ischemia/reperfusion (I/R) injury. In this study, we assessed using 1H-magnetic resonance imaging/magnetic resonance spectroscopy (1H-MRI/MRS) and histologic analysis whether H2S administration prior to reperfusion has neuroprotective effects. We also evaluated for differences in the effects of H2S treatment at 2 time points. 1H-MRI/MRS data were obtained at baseline, and at 3, 9, and 24 h after ischemia from 4 groups: sham, control (I/R injury), sodium hydrosulfide (NaHS)-30 and NaHS-1 (NaHS delivery at 30 and 1 min before reperfusion, respectively). The total infarct volume and the midline shift at 24 h post-ischemia were lowest in the NaHS-1, followed by the NaHS-30 and control groups. Peri-infarct volume was significantly lower in the NaHS-1 compared to NaHS-30 and control animals. The relative apparent diffusion coefficient (ADC) in the peri-infarct region showed that the NaHS-1 group had significantly lower values compared to the NaHS-30 and control animals and that NaHS-1 rats showed significantly higher relative T2 values in the peri-infarct region compared to the controls. The relative ADC value, relative T2 value, levels of N-acetyl-L-aspartate (NAA), and the NAA, glutamate, and taurine combination score (NGT) in the ischemic core region at 24 h post-ischemia did not differ significantly between the 2 NaHS groups and the control except that the NAA and NGT values were higher in the peri-infarct region of the NaHS-1 animals at 9 h post-ischemia. In the ischemic core and peri-infarct regions, the apoptosis rate was lowest in the NaHS-1 group, followed by the NaHS-30 and control groups. Our results suggest that H2S treatment has neuroprotective effects on the peri-infarct region during the evolution of I/R injury. Furthermore, our findings indicate that the administration of H2S immediately prior to reperfusion produces the highest neuroprotective effects. [ABSTRACT FROM AUTHOR]

Objectives: To investigate the prevalence of cerebrovascular stenosis and white matter lesions on preoperative magnetic resonance angiography (MRA) and magnetic resonance imaging (MRI) in liver transplantation candidates.Methods: This retrospective study included 1,460 consecutive patients with liver cirrhosis (LC) who underwent MRA with/without brain MRI for pretransplantation evaluation. These patients were matched with 5,331 controls using propensity scores, and the prevalences of significant cerebrovascular stenosis and white matter lesions were compared.Results: A matched analysis of 1,264 pairs demonstrated that the prevalence of significant stenosis was comparable between LC patients and controls (2.2% vs. 1.4%, P = 0.143). LC and most of LC-related parameters were not associated with stenosis. Significant white matter lesions were more common in LC patients (2.8% vs. 1.3%, P = 0.036). A high Model for End-Stage Liver Disease (MELD) score (OR 1.11, CI 1.03-1.20, P = 0.008, for infarction; OR 1.1, CI 1.04-1.16, P = 0.001, for haemorrhage) and stroke history (OR 179.06, CI 45.19-709.45, P < 0.001) were predictors of perioperative stroke.Conclusions: LC patients and control subjects demonstrated similar cerebrovascular stenosis prevalences, whereas white matter lesions were more common in LC patients. A high MELD score and stroke history contribute as predictors of perioperative stroke.Key Points: • Routine preoperative MR imaging in liver transplantation candidates may not be necessary. • Liver cirrhosis patients and control subjects had similar prevalences of significant cerebrovascular stenosis. • Liver cirrhosis and cirrhosis-related parameters were not correlated with significant cerebrovascular stenosis. • Significant white matter lesions were more frequent in liver cirrhosis patients. [ABSTRACT FROM AUTHOR]

Background: The effect of biochemical aspirin resistance (BAR) on ischemic stroke has not been well established. Early recurrent ischemic lesions (ERILs) on diffusion-weighted imaging (DWI) are proposed as potential surrogate markers of clinically recurrent stroke. Methods: We included 117 consecutive patients who (1) were admitted within 24 h of symptom onset; (2) had an ischemic stroke confirmed by DWI; (3) underwent follow-up DWI within seven days after onset, and (4) received aspirin treatment. BAR was measured using the VerifyNow® Aspirin Assay. We analyzed the associations between BAR and any ERILs (overall ERILs), and between BAR and ERILs occurring outside the vascular territories of index stroke (distant ERILs). Results: BAR was observed in 16 (13.7%) patients. Overall ERILs were detected in 34 (29.1%), and distant ERILs in 10 (8.5%) patients. Patients with BAR were more likely to develop ERILs, but the association was not significant (OR 2.13; 95% CI 0.72–6.29; p = 0.234). However, BAR was independently related to distant ERILs by logistic regression analysis (OR 6.01; 95% CI 1.29–28.09; p = 0.023). Conclusions: BAR was associated with distant ERILs but not with overall ERILs during the first week after ischemic stroke. Copyright © 2010 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

Objectives: Many comatose patients following cardiac arrest have ischemic brain injury. Diffusion-weighted imaging is a sensitive tool to identify hypoxic-ischemic brain injury. The accurate prediction of the prognosis for comatose cardiac arrest survivors has been challenging, and thus, a multimodal approach, combining diffusion-weighted image findings, could be feasible. The aim of this study was to assess regional brain injury on diffusion-weighted imaging and to test the potential association with its neurologic outcome in patients treated with target temperature management after out-of-hospital cardiac arrest.Design and Setting: A multicenter, registry-based, retrospective cohort study was conducted using cases from 24 hospitals across South Korea. Of the 930 adult (≥18 yr) nontraumatic out-of-hospital cardiac arrest patients treated with target temperature management between January 2007 and December 2012 at these hospitals, we included the patients who underwent brain diffusion-weighted imaging in the first week after cardiac arrest. The brain regions examined included the four cerebral lobes, basal ganglia-thalamus, brain stem, and cerebellum. Imaging results were compared between a good neurologic outcome, defined as a cerebral performance category score of 1 or 2, and a poor neurologic outcome (cerebral performance category score≥3).Measurement and Main Results: Poor neurologic outcome occurred in 118 of the 172 patients analyzed (68.6%). Positive diffusion-weighted image findings, defined as any regional brain injury lesion in diffusion-weighted imaging, were present in 106 patients. Positive diffusion-weighted image findings had 93% sensitivity, 86% specificity, 76% positive predictive value, and 96% negative predictive value for a poor neurologic outcome. The poor outcome group had higher numbers of affected brain lesions than the good outcome group (3.8±1.9 vs 0.1±0.6; p<0.01). By multivariate analysis, positive diffusion-weighted image findings (odds ratio, 58.2; 95% CI, 13.29-254.91) and lack of a shockable rhythm (odds ratio, 0.13; 95% CI, 0.03-0.57) were associated with a poor neurologic outcome.Conclusions: Diffusion-weighted imaging allows reliable prediction of poor neurologic outcome in comatose patients treated with target temperature management after out-of-hospital cardiac arrest. Further prospective validation study will be required to generalize this result. [ABSTRACT FROM AUTHOR]