Search

BACKGROUND Three-dimensional (3D) ultrasound imaging is a new technique that maximizes the information and image quality of traditional 2-dimensional (2D) B-mode scanning. The aim of this study was to evaluate the ability of the 3D ultrasound technique to characterize ulcerated atherosclerotic carotid plaque. METHODS Using conventional 2D ultrasound, we examined 284 carotid arteries from 142 consecutive patients (101 men and 41 women; average age, 64 years). Eighty-two carotid arteries were symptomatic with atherosclerotic plaque causing 50-99% stenosis. In 62 arteries, the atherosclerotic plaques were visualized completely and were further processed to construct 3D images. Two independent observers rated plaque morphology according to a standardized protocol. RESULTS The 3D ultrasound showed carotid plaque ulceration more frequently than the 2D method (16.1% and 14.5% of plaques, for observers 1 and 2, respectively, versus 6.5% and 9.7% of plaques, for observers 1 and 2, respectively, P= .125 and P= .063, for observers 1 and 2, respectively). The interobserver reproducibility was very good for both methods (κ= .973, SE = .027, P < .001 for 3D, and κ= .885, SE = .055, P < .001 for 2D), although the 3D method was slightly superior to 2D. CONCLUSIONS 3D ultrasound reliably characterized the surface morphology of atherosclerotic carotid plaques. A trend of superiority of 3D ultrasound over 2D was found in detecting ulcers of carotid artery plaque.

Summary Purpose: To identify and describe thalamic dysfunction in patients with temporal as well as extratemporal status epilepticus (SE) and to also analyze the specific clinical, radiological, and electroencephalography (EEG) characteristics of patients with acute thalamic involvement. Methods: We retrospectively identified patients who presented with clinical and electrographic evidence of partial SE and had thalamic abnormalities on diffusion-weighted imaging (DWI) within 5 days of documentation of lateralized epileptiform discharges (group 1). The spatial and temporal characteristics of the periodic lateralized epileptiform discharges (PLEDs) and the recorded electrographic seizures were analyzed and correlated with magnetic resonance imaging (MRI)-DWI hyperintense lesions. The findings of group 1 patients were compared with those of patients with partial SE without thalamic abnormalities on DWI (group 2). Results: The two groups were similar with regard to clinical presentation and morphology of epileptiform discharges. Group 1 patients had thalamic hyperintense lesions on DWI that appeared in the region of the pulvinar nucleus, ipsilateral to the epileptiform activity. Statistically significant relationship was noted between the presence of thalamic lesions and ipsilateral cortical laminar involvement (p = 0.039) as well as seizure origin in the posterior quadrants (p = 0.038). A trend towards PLEDs originating in the posterior quadrants was also noted (p = 0.077). Discussion: Thalamic DWI hyperintense lesions may be observed after prolonged partial SE and are likely the result of excessive activity in thalamic nuclei having reciprocal connections with the involved cortex. The thalamus likely participates in the evolution and propagation of partial seizures in SE.

To identify early MRI characteristics of ischemic stroke that predict final infarct size three months poststroke.Multiparametric MRI (multispin echo T2-weighted [T2W] imaging, T1-weighted [T1W] imaging, and diffusion-weighted imaging [DWI]) was performed acutely (24 hours), subacutely (three to five days), and at three months. MRI was processed using maps of apparent diffusion coefficient (ADC), T2, and a self-organizing data analysis (ISODATA) technique. Analyses began with testing for individual MRI parameter effects, followed by multivariable modeling with assessment of predictive ability (R(2)) on final infarct size.A total of 45 patients were studied, 15 of whom were treated with tissue plasminogen activator (tPA) before acute MRI. The acute DWI and DWI-ISODATA mismatch lesion size, and the interactions of ADC, T2, and T2W imaging lesion with tPA remained in the final multivariable model (R(2) = 70%). A large acute DWI lesion or DWIISODATA lesion independently predicted increase in the final infract size, with predictive ability 68%. Predictive ability increased (R(2) = 83%) when subacute MRI parameters were included along with acute DWI, DWI-ISODATA mismatch, and acute T2W image lesion size by tPA treatment interaction. Subacute DWIacute DWI lesion size predicted an increased final infarct size (P0.01).Acute-phase DWI and DWI-ISODATA mismatch strongly predict the final infarct size. An acute-to-subacute DWI lesion size change further increases the predictive ability of the model.