Analysis of intracranial atherosclerotic plaque enhancement using high-resolution MR imaging in patients with ischemic stroke / 中华放射学杂志

ABSTRACT

Objective To assess the enhancement feature of intracranial atherosclerotic plaque in the vessel supplying the territory of infarction by using high-resolution MR imaging.To analyze the correlation between the degree of plaque enhancement , time elapsed and the concentration of hypersensitive C-reactive protein ( hs-CRP ).Methods The characteristics of vessel walls and intracranial vascular stenoses were retrospectively analyzed in 81 patients with ischemic strokes.All subjects were imaged with a traditional stroke MR protocol and HR-MRI scanning for plaque on a 3.0 T MRI scanner.According to the elapsed time between infarct and MR examination , all cases were classified into early stage (12 weeks, n=10).The characteristics of vessel walls and degrees of enhancement of atherosclerotic plaques were assessed and the concentrations of hs-CRP in all patients were determined.The Kruskal-Wallis H test was used to compare the degree of enhancement and hs-CRP concentration among the early , middle and late stage.The concentration of hs-CRP was presented as median ( interquartile range ).The Spearman correlation was used to analyze the correlation between elapsed time , hs-CRP concentration and degree of enhancement.Results Fifty-five (55/81) plaques were located at the M1 segments, and the other 26 (26/81) plaques were at the basilar artery.The degree and presence of enhancement from strong to none were 29, 25 and 4 in the early stage;4, 6 and 3 in the middle stage and 0, 4, 6 in the late stage, respectively.The degree and presence of enhancement were significantly different among them (H=16.934,P<0.01).There was a remarkable trend of decreasing degree and presence of enhancement of the atherosclerotic plaque relative to increasing time after the ischemic event(r=-0.792,P<0.01).The serum hs-CRP concentration for early, middle and late stage were 7.0(3.0, 13.0), 2.27(1.0, 3.03) and 1.88(0.50, 4.0)mg/L (H=14.345,P<0.01) , respectively.There was a trend of decreasing hs-CRP concentration relative to the time elapsed ( r =-0.357,P<0.01).The degrees of enhancement of the plaques were parallel to the levels of hs -CRP( r=0.526,P<0.01).Conclusions Enhanced HR-MRI scanning may clearly demonstrate the enhancement characteristics of intracranial atherosclerotic plaques as an indicator of inflammation.It might play an important role to detect risk factors for intracranial plaque rupture and subsequent acute ischemic stroke .