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Objective To study the relationship between vulnerable plaque and nonlacunar infarction, and analyze distribution regularity of carotid atherosclerotic plaque. Methods One hundred and four patients with ischemic stroke were divided into two groups: nonlacunar infarction group (64 cases) and lacunar infarction group (40 cases) based on imaging and clinical manifestation. Location, number, type,degree of carotid atherosclerotic plaque was recorded and compared between the two groups. Results Two hundred and ninety-seven plaques shown by the imaging were distributed in different areas:9 plaques located in the initial part of the carotid artery, 51 plaques located in the carotid artery, 148 plaques located in the bifurcation of the carotid artery, 27 plaques located in the internal carotid artery and 62 plaques located in the intracalvarium part of internal carotid artery. The percentage of severe or occlusion carotid artery stenosis in nonlacunar infarction group was 29.7% (19/64), which was higher than that in lacunar infarction group [10.0% (4/40)] (P = 0.019 ). The percentage of vulnerable plaque in nonlacunar infarction group was 62.5% (40/64), which was higher than that in lacunar infarction group [47.5%( 19/40)](P=0.004). Multivariate analysis showed that the degree of carotid artery stenosis(OR = 1.740,95% CI: 1.002 -3.021 ) and vulnerable plaque (OR = 2.865,95% CI: 1.047 - 7.813 ) was related with nonlacunar infarction.Conclusions The plaque is more frequently encountered at the bifurcation of the carotid artery. The degree of carotid artery stenosis and vulnerable plaque are the independent risk factors of the nonlacunar infarction.CT angiography can clearly display carotid artery stenosis, morphology and component of plaque, so it will be used as the preferred clinical examination.
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Objective To evaluate the dynamic imaging alteration of radiation-induced hepatic injuries after stereotactic radiotherapy (SRT) in hepatocellular carcinoma.Methods 18 healthy New Zealand white rabbits inoculated VX_2 carcinoma underwent 40 Gy SRT and divided into three groups randomly.The rabbits underwent identical plain and enhanced MR imaging after SRT 3 weeks,9 weeks and 20 weeks respectively. The signal-to-noise ratios of irradiation area and the surrounding normal liver on T_1WI and T_2WI imaging were calculated;The percentage enhancement of the hepatic injuried areas and the surrouding livers after Gd-DTPA enhanced was also calculated.Results After radiotherapy three weeks, the signal-to-noise ratios of irradiation areas on T_1WI and T_2WI were no difference between normal liver tissue and irradiation area; there were significant difference between normal liver tissues in radiotherapy nine weeks and twenty weeks; The difference in the signal-to-noise ratios of irradiation area were significant between after three weeks and nine weeks, twenty weeks. There were no difference in the signal-to-noise ratios of irradiation area between nine weeks and twenty weeks.The percentage enhancement of the hepatic injuries area have significant difference in arterial phase between three weeks and twenty weeks and between nine weeks and twenty weeks;The difference in portal and delay phase were significant between three weeks and nine weeks, twenty weeks, there were no difference between nine weeks and twenty weeks.Conclusion Dynamic enhanced and unenhanced MR imaging can reflect the pathological background of radiation-induced hepatic injuries in different phases.
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Objective To evluate Feridex-enhanced MRI in the diagnosis of focal hepatic lesions. Methods Conventional plain and Feridex-enhanced MR scanning was performed in 20 cases with suspected hepatic neoplasm.The number of lesions on T 2WI ,and the signal intensity of liver and lesions demonstrated on plain and enhanced scans were observed and analyzed.Results After the injection of Feridex,the signal intensity of normal liver tissue reduced significantly,while the signal intensity of lesions showed no marked changes,Feridex-enhanced MRI clearly displayed more lesions on T 2WI than plain scanning did.Conclusion Feridex-enhanced MRI is very sensitive in detecting focal hepatic lesions.