Early diagnosis of acute ischemic stroke and observation of thrombolytic therapy by 7.0T magnetic resonance

Abstract

Objective To investigate the early diagnosis of acute ischemic stroke, and to evaluate the effect of early thrombolytic therapy. Methods 70 male C57BL/6J mice were stratified in group , sham group (n=6), non-thrombolytic therapy group (n=15), thrombolytic therapy group (n=49). The models of focal cerebral ischemia was induced via photothrombosis, the Magnetic resonance angiography (MRA) and apparent diffusion coefficient (ADC) of the magnetic resonance were used as criteria for successful modeling. The mice were treated with urokinase as a thrombolytic drug, then behavioral scores were observed. Acquisition of Diffusion-weighted imaging (DWI), ADC, Three-dimensional fast low angle shot (3D-Flash) and T2 signal by Magnetic resonance (MRI). Results In the fast-moving test of the balance beam, the speed of sham mice (30.97±7.32)×0.01 m/s was significantly faster than that of thrombolytic mice (15.39±8.82)×0.01 m/s and mice without thrombolytic therapy (2.56±2.80)×0.01 m/s. The modified neurological deficits scores (mNSS) of sham group (0.50±0.54) was significantly lower than that of thrombolytic mice (4.87±2.34) and non-thrombolytic mice (9.83±1.59). The ADC score of ipsilateral cerebrum (0.62±0.13)×0.001 mm2/sec of the model mice was lower than that of the contralateral ADC (0.43±0.07)×0.001 mm2/sec. After the completion of the model, the contralateral middle cerebral artery was still smooth and the ipsilateral middle cerebral artery occlusion. According to different treatment, a part of the ipsilateral middle cerebral artery were opened, the rate of the middle cerebral artery occlusion were opened is about 61.2%, non-thrombotic mice obstruction of the middle cerebral artery opening rate is about 6.67%. The infarct size (10.52±4.41) mm2 in the thrombolytic therapy group was significantly smaller than that in the untreated mice (23.38±1.66) mm2. Conclusion 7.0T MRI can be used as a criteria for the early diagnosis of acute ischemic stroke, to evaluate the effect of middle cerebral artery occlusion and recanalization. Key words: Ischemic stroke; Urokinase; Behavioral analysis; Magnetic resonance imaging