Searching for prognostic variables for secondary worsening after ischaemic stroke.

Secondary worsening of stroke symptoms is described in 13-37% of stroke patients, but the exact mechanism of this phenomenon remains unclear. The aim of this study is to find prognostic variables in correlation to secondary worsening of stroke symptoms in patients with lacunar or cortical strokes. In this prospective observational study we included all patients with ischaemic stroke; patients with transient ischaemic attack were excluded. Patients undergoing thrombolysis and becoming symptom-free after 24 h were still included in our analyses. Secondary worsening of stroke symptoms was defined as an increase of two or more points on the NIH Stroke Scale (NIHSS). The NIHSS score was assessed on admission, at discharge, and when patients had symptoms that indicated worsening of stroke. Applying univariate and multivariable analysis, we studied the relation between symptoms indicating secondary worsening of stroke and prognostic variables such as extreme nocturnal blood pressure falls (>20% of the average blood pressure), infection, diabetes mellitus, hypertension, smoking, dyslipidaemia, a history of cardiovascular or cerebrovascular disease and thrombolysis. This study included 202 patients with a mean age of 72 years, 48.8% were men and 43% had a lacunar stroke. Secondary worsening of stroke symptoms occurred in 13.5% of all patients, more often but not significantly (NS) after lacunar than cortical strokes (16.8 and 11.4%, respectively), and in patients with extreme nocturnal blood pressure falls versus without (15.6 and 11.8%, respectively (NS)). There was no significant relation between the analysed prognostic variables and secondary worsening of stroke symptoms. This study did not show significant correlation between several variables and secondary worsening of stroke symptoms in patients with recent ischaemic stroke.

Multimodality imaging of carotid artery plaques: 18F-fluoro-2-deoxyglucose positron emission tomography, computed tomography, and magnetic resonance imaging.

BACKGROUND AND PURPOSE: This study's objective was to compare (18)F-fluoro-2-deoxyglucose positron emission tomography ((18)F-FDG PET), CT, and MRI of carotid plaque assessment. MATERIALS AND METHODS: Fifty patients with symptomatic carotid atherosclerosis underwent (18)F-FDG PET/CT and MRI. Correlations and agreement between imaging findings were assessed by Spearman and Pearson rank correlation tests, t tests, and Bland-Altman plots. RESULTS: Spearman rho between plaque (18)F-FDG standard uptake values and CT/MRI findings varied from -0.088 to 0.385. Maximum standard uptake value was significantly larger in plaques with intraplaque hemorrhage (1.56 vs 1.47; P=0.032). Standard uptake values did not significantly differ between plaques with an intact and thick fibrous cap and plaques with a thin or ruptured fibrous cap on MRI. (1.21 vs 1.23; P=0.323; and 1.45 vs 1.54; P=0.727). Pearson rho between CT and MRI measurements varied from 0.554 to 0.794 (P<0.001). For lipid-rich necrotic core volume, the CT-MRI correlation was stronger in mildly (10%) calcified plaques (Pearson rho 0.730 vs 0.475). Mean difference in measurement +/-95% limits of agreement between CT and MRI for minimum lumen area, volumes of vessel wall, lipid-rich necrotic core, calcifications, and fibrous tissue were 0.4+/-18.1 mm(2) (P=0.744), -41.9 +/-761.7 mm(3) (P=0.450), 78.4+/-305.0 mm(3) (P<0.001), 180.5+/-625.7 mm(3) (P=0.001), and -296.0+/-415.8 mm(3) (P<0.001), respectively. CONCLUSIONS: Overall, correlations between (18)F-FDG PET and CT/MRI findings are weak. Correlations between CT and MRI measurements are moderate to strong, but there is considerable variation in absolute differences.

Reproducibility of fibrous cap status assessment of carotid artery plaques by contrast-enhanced MRI.

BACKGROUND AND PURPOSE: Reproducibility in identifying the fibrous cap (FC) of carotid artery plaques by noncontrast-enhanced MRI has been shown to be poor. The objective of this study was to assess the reproducibility of multisequence MRI, including contrast-enhanced images, in assessing FC status. METHODS: Forty-five symptomatic patients with 30% to 69% carotid artery stenosis underwent a multisequence MRI protocol, which included contrast-enhanced images. FC status (ie, discrimination between fibrotic and/or calcified plaques, plaques with a lipid-rich necrotic core and an intact and thick FC, and plaques with a lipid-rich necrotic core and a thin and/or ruptured FC) was independently assessed by 3 observers of which one also scored all images on a different occasion. Linear weighted kappa coefficients (kappa) were calculated as indicators of inter- and intraobserver agreement. RESULTS: On a per-slice basis, interobserver agreement was good (kappa=0.60, 0.64, and 0.71), whereas intraobserver agreement was very good (kappa=0.86). On a per-plaque basis, interobserver agreement was good (kappa=0.64, 0.69, and 0.78), whereas intraobserver agreement was very good (kappa=0.96). CONCLUSIONS: This study found good interobserver and very good intraobserver agreement in assessing FC status of carotid artery plaques. Future studies are warranted to determine the predictive value of FC status assessment by multisequence MRI, including contrast-enhanced images, on the occurrence of (recurrent) cerebral ischemic events.