Multimodal magnetic resonance imaging for assessing lacunar infarction after proximal middle cerebral artery occlusion in a canine model

作者：Lu Shan shan; Liu Sheng; Zu Qing quan; Xu Xiao quan; Wang Jian wei; Yu Jing; Sun Lei; Shi Hai bin^*

来源：Chinese Medical Journal, 2013, 126(2): 311-317.

DOI：10.3760/cma.j.issn.0366-6999.20121983

• animal model
• middle cerebral occlusion
• lacunar infarction
• magnetic resonance imaging

Background A new lacunar infarction model was recently established in beagle dogs through proximal middle cerebral artery (MCA) occlusion by thrombus. This study aimed to characterize the model by nnultimodal magnetic resonance imaging (MRI) and to investigate its potential role for the future stroke research.
Methods The left proximal MCA was embolized with an autologous thrombus in six beagles. Diffusion-weighted imaging (DWI) and T2-weighted imaging (T2WI) were performed every half hour during the first six hours after occlusion, followed by three time points at 12 hours, 24 hours, and one week. Perfusion-weighted imaging (PWI) and magnetic resonance angiography (MRA) were carried out at six hours, 24 hours and one week. The PWI-DWI mismatch ratio was defined as (PWI-DWI)/DWI ischemic volume.
Results Lacunar infarcts induced by MCA occlusion were located in the left caudate nucleus and internal capsule. All the lesions could be detected within two hours by DWI. Lesion volume on DWI increased in a time dependent manner, from (87.19 +/- 67.16) mm(3) at one hour up to (368.98 +/- 217.05) mm(3) at 24 hours (P=0.009), while that on PWI gradually decreased from (7315.00 +/- 2054.38) mm(3) at six hours to (4900.33 +/- 1319.71) mm(3) at 24 hours and (3334.33 +/- 1195.11) mm(3) at one week (P=0.002). The mismatch ratio was 41.93 +/- 22.75 at six hours after ischemia, showing "extensive mismatch", and decreased to 18.10 +/- 13.74 at 24 hours (P=0.002). No MCA recanalization was observed within 24 hours after MCA occlusion.
Conclusions Lacunar infarction induced by proximal MCA occlusion could be detected early by DWI and was characterized by extensive PWI-DWI mismatch. Multimodal MRI is useful to demonstrate the natural evolution of PWI-DWI mismatch. This ischemic model could be further used for investigating early thrombolysis in lacunar stroke showing extensive mismatch.

• 出版日期2013-1-20
• 单位南京医科大学