Baseline MRI determines the risk for converting to clinically definite multiple sclerosis and correlates with disability at 5 years. The proportion of patients developing disability is low during the first 5 years but rapidly increases shortly after.

We observed a high prevalence of OB in CIS. OB and MR imaging (Paty's and Fazekas' criteria) have high sensitivity. Barkhof's criteria have a higher specificity. Both OB and MR imaging criteria have a high negative predictive value.

One year after symptom onset, more than three times as many patients with CIS were diagnosed with MS using new diagnostic criteria incorporating MRI results compared to older criteria. However, the proposed MRI criteria require further prospective studies to optimize sensitivity and specificity.

Presence of the susceptibility sign proximal to MCA bifurcation provides fast and accurate detection of acute proximal MCA or ICA thrombotic occlusion.

Background and Purpose-Early neurological deterioration (END) occurs in approximately one third of all ischemic stroke patients and is associated with a poor outcome. Our study sought to assess the value of ultra-early MRI in the prediction of END in stroke patients. Methods-Between August 1999 and November 2001, 38 stroke patients with a proven middle cerebral artery (MCA) or intracranial internal carotid artery (ICA) occlusion on MR angiography underwent perfusion-weighted imaging (PWI) and diffusion-weighted imaging (DWI) within 6 hours after onset, and 30 fulfilled all inclusion criteria. Control DWI and MR angiography were performed between days 3 and 5. Cranial CT was performed to rule out hemorrhagic transformation. Vascular risk factors, temperature, blood pressure, glycemia, and blood count were assessed on admission. National Institutes of Health Stroke Scale (NIHSS) scores were obtained at baseline and at 6, 12, 24, and 48 hours. At the same time points, transcranial Doppler (TCD) examinations were conducted to assess arterial recanalization. END was defined as an increase in the NIHSS score Ͼ4. A logistic regression model was applied to detect independent predictors of END. The Kruskal-Wallis test was used to evaluate the relationship between infarct growth and duration of vessel occlusion. Results-Initial MR angiography showed an occlusion of intracranial ICA in 7 patients (23.3%), of proximal MCA in 14 (46.6%), and of distal MCA in the remaining 9 (30%). A PWI-DWI mismatch Ͼ20% was observed in 28 patients (93.3%). END occurred in 7 patients (23.3%). Baseline NIHSS score (Pϭ0.05), proximal site of occlusion (Pϭ0.002), initial DWI (Pϭ0.002) and PWI (Pϭ0.003) volumes, and reduced PWI-DWI mismatch (Pϭ0.038) were associated with END in the univariate analysis. Only hyperacute DWI volume remained as a predictor of END when a logistic regression model was applied (odds ratio, 11.5; 95% CI, 2.31 to 57.10; Pϭ0.0028). A receiver operator characteristic curve identified a cutoff point of DWI Ͼ89 cm 3 (sensitivity, 85.7%; specificity, 95.7%) to predict END. A graded response was seen in DWI lesion expansion in relation to duration of arterial occlusion (Pϭ0.017). Conclusions-Ultra-early