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 multimodal magneti...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 multimodal 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 （T2Wl） 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-DWl）/DWl 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 DWl increased in a time dependent manner, from （87.19±67.16） mm3 at one hour up to （368.98±217.05） mm3 at 24 hours （P=0.009）, while that on PWl gradually decreased from （7315.00±2054.38） mm3at six hours to （4900.33±1319.71） mm3 at 24 hours and （3334.33±1195.11） mm3 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 DWl and was characterized by extensive PWI-DWl mismatch. Multimodal MRI is useful to demonstrate the natural evolution of PWI-DWl mismatch. This ischemic model could be further used for investigating early thrombolysis in lacunar stroke showing extensive mismatch.展开更多
BACKGROUND Early thrombolytic therapy is crucial to treat acute cerebral infarction,especially since the onset of thrombolytic therapy takes 1-6 h.Therefore,early diagnosis and evaluation of cerebral infarction is imp...BACKGROUND Early thrombolytic therapy is crucial to treat acute cerebral infarction,especially since the onset of thrombolytic therapy takes 1-6 h.Therefore,early diagnosis and evaluation of cerebral infarction is important.AIM To investigate the diagnostic value of magnetic resonance multi-delay threedimensional arterial spin labeling(3DASL)and diffusion kurtosis imaging(DKI)in evaluating the perfusion and infarct area size in patients with acute cerebral ischemia.METHODS Eighty-four patients who experienced acute cerebral ischemia from March 2019 to February 2021 were included.All patients in the acute stage underwent magnetic resonance-based examination,and the data were processed by the system’s own software.The apparent diffusion coefficient(ADC),average diffusion coefficient(MD),axial diffusion(AD),radial diffusion(RD),average kurtosis(MK),radial kurtosis(fairly RK),axial kurtosis(AK),and perfusion parameters post-labeling delays(PLD)in the focal area and its corresponding area were compared.The correlation between the lesion area of cerebral infarction under MK and MD and T2-weighted imaging(T2WI)was analyzed.RESULTS The DKI parameters of focal and control areas in the study subjects were compared.The ADC,MD,AD,and RD values in the lesion area were significantly lower than those in the control area.The MK,RK,and AK values in the lesion area were significantly higher than those in the control area.The MK/MD value in the infarct lesions was used to determine the matching situation.MK/MD<5 mm was considered matching and MK/MD≥5 mm was considered mismatching.PLD1.5s and PLD2.5s perfusion parameters in the central,peripheral,and control areas of the infarct lesions in MK/MD-matched and-unmatched patients were not significantly different.PLD1.5s and PLD2.5s perfusion parameter values in the central area of the infarct lesions in MK/MD-matched and-unmatched patients were significantly lower than those in peripheral and control areas.The MK and MD maps showed a lesion area of 20.08±5.74 cm^(2) and 22.09±5.58 cm^(2),respectively.T2WI showed a lesion area of 19.76±5.02 cm^(2).There were no significant differences in the cerebral infarction lesion areas measured using the three methods.MK,MD,and T2WI showed a good correlation.CONCLUSION DKI parameters showed significant difference between the focal and control areas in patients with acute ischemic cerebral infarction.3DASL can effectively determine the changes in perfusion levels in the lesion area.There was a high correlation between the area of the infarct lesions diagnosed by DKI and T2WI.展开更多
Background： There are few studies for evaluating plaque characteristics of nonstenotic basilar arteries （BA）. Our aim was to determine entire BA plaques with a three-dimensional volumetric isotropic turbo spin-echo...Background： There are few studies for evaluating plaque characteristics of nonstenotic basilar arteries （BA）. Our aim was to determine entire BA plaques with a three-dimensional volumetric isotropic turbo spin-echo acquisition （VISTA） and investigate the differences between the patients with and without isolated pontine infarction （IPI）. Methods： Twenty-four consecutive symptomatic patients with nonstenotic BA on time of flight magnetic resonance angiography （TOF MRA） were enrolled from China-Japan Friendship Hospital between January 2014 and December 2014. BA was classified as ＂normal＂ or ＂irregular＂ based on TOF MRA, and ＂normal wall＂, ＂slight wall-thickening＂, and ＂plaque＂ based on three-dimensional VISTA images. Outcomes from MRA and VISTA were compared. Patients were categorized as IPI and non-lPl groups based on the diffusion-weighted imaging. Clinical and plaque characteristics were compared between the two groups. Results： A total of 1024 image slices including 311 （30.37%） plaque slices, 427 （41.70%） slight wall-thickening slices, and 286 （27.93%） normal wall slices for the entire BA from 23 patients were finally included for analysis. VISTA images detected plaques in all the 9 （100%） irregular MRA patients and 7 of 14 （50%） normal MRA patients. IPl was found in 11 （47.83%） patients. Compared to non-IPI group, the IPI group had a higher percentage of plaque slices （P = 0.001 ） and lower percentage of normal wall slices （P = 0.014） than non-IPl group. Conclusions： Three-dimensional V1STA images enable detection of BA plaques not visualized by MRA. BA plaques could be found in both the IPl and non-IPl group. However, IPI group showed plaques more extensively in BA than the non-IPI group.展开更多
基金This study was supported by the National Natural Science Foundation of China （No. 30870710, No. 81000653） and the Foundation of Research and Innovation Program for Postgraduates in Jiangsu Province （No. CXZZll.0718）.
文摘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 multimodal 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 （T2Wl） 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-DWl）/DWl 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 DWl increased in a time dependent manner, from （87.19±67.16） mm3 at one hour up to （368.98±217.05） mm3 at 24 hours （P=0.009）, while that on PWl gradually decreased from （7315.00±2054.38） mm3at six hours to （4900.33±1319.71） mm3 at 24 hours and （3334.33±1195.11） mm3 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 DWl and was characterized by extensive PWI-DWl mismatch. Multimodal MRI is useful to demonstrate the natural evolution of PWI-DWl mismatch. This ischemic model could be further used for investigating early thrombolysis in lacunar stroke showing extensive mismatch.
文摘BACKGROUND Early thrombolytic therapy is crucial to treat acute cerebral infarction,especially since the onset of thrombolytic therapy takes 1-6 h.Therefore,early diagnosis and evaluation of cerebral infarction is important.AIM To investigate the diagnostic value of magnetic resonance multi-delay threedimensional arterial spin labeling(3DASL)and diffusion kurtosis imaging(DKI)in evaluating the perfusion and infarct area size in patients with acute cerebral ischemia.METHODS Eighty-four patients who experienced acute cerebral ischemia from March 2019 to February 2021 were included.All patients in the acute stage underwent magnetic resonance-based examination,and the data were processed by the system’s own software.The apparent diffusion coefficient(ADC),average diffusion coefficient(MD),axial diffusion(AD),radial diffusion(RD),average kurtosis(MK),radial kurtosis(fairly RK),axial kurtosis(AK),and perfusion parameters post-labeling delays(PLD)in the focal area and its corresponding area were compared.The correlation between the lesion area of cerebral infarction under MK and MD and T2-weighted imaging(T2WI)was analyzed.RESULTS The DKI parameters of focal and control areas in the study subjects were compared.The ADC,MD,AD,and RD values in the lesion area were significantly lower than those in the control area.The MK,RK,and AK values in the lesion area were significantly higher than those in the control area.The MK/MD value in the infarct lesions was used to determine the matching situation.MK/MD<5 mm was considered matching and MK/MD≥5 mm was considered mismatching.PLD1.5s and PLD2.5s perfusion parameters in the central,peripheral,and control areas of the infarct lesions in MK/MD-matched and-unmatched patients were not significantly different.PLD1.5s and PLD2.5s perfusion parameter values in the central area of the infarct lesions in MK/MD-matched and-unmatched patients were significantly lower than those in peripheral and control areas.The MK and MD maps showed a lesion area of 20.08±5.74 cm^(2) and 22.09±5.58 cm^(2),respectively.T2WI showed a lesion area of 19.76±5.02 cm^(2).There were no significant differences in the cerebral infarction lesion areas measured using the three methods.MK,MD,and T2WI showed a good correlation.CONCLUSION DKI parameters showed significant difference between the focal and control areas in patients with acute ischemic cerebral infarction.3DASL can effectively determine the changes in perfusion levels in the lesion area.There was a high correlation between the area of the infarct lesions diagnosed by DKI and T2WI.
基金This study was supported by grants from China- Japan Friendship Hospital Youth Science and Technology Excellence Project （No. 2014-QNYC-A-04）, National Natural Science Foundation of China （No. 81173595, No. 30670731, No. 81070925 and No. 81471767）, and National Basic Research Program （973 Program） of China （No. 2013CB733805）.
文摘Background： There are few studies for evaluating plaque characteristics of nonstenotic basilar arteries （BA）. Our aim was to determine entire BA plaques with a three-dimensional volumetric isotropic turbo spin-echo acquisition （VISTA） and investigate the differences between the patients with and without isolated pontine infarction （IPI）. Methods： Twenty-four consecutive symptomatic patients with nonstenotic BA on time of flight magnetic resonance angiography （TOF MRA） were enrolled from China-Japan Friendship Hospital between January 2014 and December 2014. BA was classified as ＂normal＂ or ＂irregular＂ based on TOF MRA, and ＂normal wall＂, ＂slight wall-thickening＂, and ＂plaque＂ based on three-dimensional VISTA images. Outcomes from MRA and VISTA were compared. Patients were categorized as IPI and non-lPl groups based on the diffusion-weighted imaging. Clinical and plaque characteristics were compared between the two groups. Results： A total of 1024 image slices including 311 （30.37%） plaque slices, 427 （41.70%） slight wall-thickening slices, and 286 （27.93%） normal wall slices for the entire BA from 23 patients were finally included for analysis. VISTA images detected plaques in all the 9 （100%） irregular MRA patients and 7 of 14 （50%） normal MRA patients. IPl was found in 11 （47.83%） patients. Compared to non-IPI group, the IPI group had a higher percentage of plaque slices （P = 0.001 ） and lower percentage of normal wall slices （P = 0.014） than non-IPl group. Conclusions： Three-dimensional V1STA images enable detection of BA plaques not visualized by MRA. BA plaques could be found in both the IPl and non-IPl group. However, IPI group showed plaques more extensively in BA than the non-IPI group.
