To evaluate the reliability of three dimensional spiral fast spin echo pseudo-continuous arterial spin labeling(3D pc-ASL)in measuring cerebral blood flow(CBF)with different post-labeling delay time(PLD)in the resting...To evaluate the reliability of three dimensional spiral fast spin echo pseudo-continuous arterial spin labeling(3D pc-ASL)in measuring cerebral blood flow(CBF)with different post-labeling delay time(PLD)in the resting state and the right finger taping state.Methods 3D pc-ASL and three dimensional T1-weighted fast spoiled gradient recalled echo(3D T1-FSPGR)sequence were applied to eight healthy subjects twice at the same time each day for one week interval.ASL data acquisition was performed with post-labeling delay time(PLD)1.5 seconds and 2.0 seconds in the resting state and the right finger taping state respectively.CBF mapping was calculated and CBF value of both the gray matter(GM)and white matter(WM)was automatically extracted.The reliability was evaluated using the intraclass correlation coefficient(ICC)and Bland and Altman plot.Results ICC of the GM(0.84)and WM(0.92)was lower at PLD 1.5 seconds than that(GM,0.88;WM,0.94)at PLD 2.0 seconds in the resting state,and ICC of GM(0.88)was higher in the right finger taping state than that in the resting state at PLD 1.5 seconds.ICC of the GM and WM was 0.71 and 0.78 for PLD 1.5 seconds and PLD 2.0 seconds in the resting state at the first scan,and ICC of the GM and WM was 0.83 and 0.79 at the second scan,respectively.Conclusion This work demonstrated that 3D pc-ASL might be a reliable imaging technique to measure CBF over the whole brain at different PLD in the resting state or controlled state.展开更多
Conventional neuroimaging techniques cannot truly reflect the change of regional cerebral blood flow in patients with carpal tunnel syndrome.Pseudo-continuous arterial spinning labeling(pCASL)as an efficient non-invas...Conventional neuroimaging techniques cannot truly reflect the change of regional cerebral blood flow in patients with carpal tunnel syndrome.Pseudo-continuous arterial spinning labeling(pCASL)as an efficient non-invasive neuroimaging technique can be applied to directly quantify the neuronal activities of individual brain regions that show the persistent symptoms owing to its better spatial resolution and increased signal-to-noise ratio.Therefore,this prospective observational study was conducted in 27 eligible female carpal tunnel syndrome,aged 57.7±6.51 years.Psychometric tests,nerve conduction studies and pCASL neuroimaging assessment were performed.The results showed that the relevant activated brain regions in the cortical,subcrotical,and cerebral regions were correlated with numbness,pain,functionality,median nerve status and motor amplitude of median nerve(K=21–2849,r=–0.77–0.76,P<0.05).There was a tendency of pain processing which shifted from the nociceptive circuitry to the emotional and cognitive one during the process of chronic pain caused by carpal tunnel syndrome.It suggests the necessity of addressing the ignored cognitive or emotional state when managing patients with carpal tunnel syndrome.Approval for this study was obtained from the Institutional Review Board of The University of Hong Kong/Hospital Authority Hong Kong West,China(HKU/HA HKW IRB,approval No.UW17-129)on April 11,2017.This study was registered in Clinical Trial Registry of The University of Hong Kong,China(registration number:HKUCTR-2220)on April 24,2017.展开更多
BACKGROUND Type 2 diabetes mellitus(T2DM) has been strongly associated with an increased risk of developing cognitive dysfunction and dementia.The mechanisms of diabetes-associated cognitive dysfunction(DACD) have not...BACKGROUND Type 2 diabetes mellitus(T2DM) has been strongly associated with an increased risk of developing cognitive dysfunction and dementia.The mechanisms of diabetes-associated cognitive dysfunction(DACD) have not been fully elucidated to date.Some studies proved lower cerebral blood flow(CBF) in the hippocampus was associated with poor executive function and memory in T2DM.Increasing evidence showed that diabetes leads to abnormal vascular endothelial growth factor(VEGF) expression and CBF changes in humans and animal models.In this study,we hypothesized that DACD was correlated with CBF alteration as measured by three-dimensional(3D) arterial spin labeling(3D-ASL) and VEGF expression in the hippocampus.AIM To assess the correlation between CBF(measured by 3D-ASL and VEGF expression) and DACD in a rat model of T2DM.METHODS Forty Sprague-Dawley male rats were divided into control and T2DM groups.The T2DM group was established by feeding rats a high-fat diet and glucose to induce impaired glucose tolerance and then injecting them with streptozotocin to induce T2DM.Cognitive function was assessed using the Morris water maze experiment.The CBF changes were measured by 3D-ASL magnetic resonance imaging.VEGF expression was determined using immunofluorescence.RESULTS The escape latency time significantly reduced 15 wk after streptozotocin injection in the T2DM group.The total distance traveled was longer in the T2DM group;also,the platform was crossed fewer times.The percentage of distance in the target zone significantly decreased.CBF decreased in the bilateral hippocampus in the T2DM group.No difference was found between the right CBF value and the left CBF value in the T2DM group.The VEGF expression level in the hippocampus was lower in the T2DM group and correlated with the CBF value.The escape latency negatively correlated with the CBF value.The number of rats crossing the platform positively correlated with the CBF value.CONCLUSION Low CBF in the hippocampus and decreased VEGF expression might be crucial in DACD.CBF measured by 3D-ASL might serve as a noninvasive imaging biomarker for cognitive impairment associated with T2DM.展开更多
Arterial spin labeling(ASL) is a magnetic resonance imaging technique for measuring tissue perfusion using a freely diffusible intrinsic tracer.As compared with other perfusion techniques,ASL offers several advantages...Arterial spin labeling(ASL) is a magnetic resonance imaging technique for measuring tissue perfusion using a freely diffusible intrinsic tracer.As compared with other perfusion techniques,ASL offers several advantages and is now available for routine clinical practice in many institutions.Its noninvasive nature and ability to quantitatively measure tissue perfusion make ASL ideal for research and clinical studies.Recent technical advances have increased its sensitivity and also extended its potential applications.This review focuses on some basic knowledge of ASL perfusion,emerging techniques and clinical applications in neuroimaging.展开更多
Cerebral blood flow is strongly associated with brain function, and is the main symptom and diagnostic basis for a variety of encephalopathies. However, changes in cerebral blood flow after mild traumatic brain injury...Cerebral blood flow is strongly associated with brain function, and is the main symptom and diagnostic basis for a variety of encephalopathies. However, changes in cerebral blood flow after mild traumatic brain injury remain poorly understood. This study sought to observe changes in cerebral blood flow in different regions after mild traumatic brain injury using pulsed arterial spin labeling. Our results demonstrate maximal cerebral blood flow in gray matter and minimal in the white matter of patients with mild traumatic brain injury. At the acute and subacute stages, cerebral blood flow was reduced in the occipital lobe, parietal lobe, central region, subcutaneous region, and frontal lobe. Cerebral blood flow was restored at the chronic stage. At the acute, subacute, and chronic stages, changes in cerebral blood flow were not apparent in the insula. Cerebral blood flow in the temporal lobe and limbic lobe diminished at the acute and subacute stages, but was restored at the chronic stage. These findings suggest that pulsed arterial spin labeling can precisely measure cerebral blood flow in various brain regions, and may play a reference role in evaluating a patient＇s condition and judging prognosis after traumatic brain injury.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
Purpose: We report the results of applying arterial spin labeling (ASL) to intracranial dural arteriovenous fistula (DAVF). Methods: Sixteen patients with angiographically confirmed DAVF underwent ASL on a clinical 1....Purpose: We report the results of applying arterial spin labeling (ASL) to intracranial dural arteriovenous fistula (DAVF). Methods: Sixteen patients with angiographically confirmed DAVF underwent ASL on a clinical 1.5 T or 3 T MR system. ASL was performed by Q2TIPS (second version of quantitative imaging of perfusion by using a single subtraction MRI pulse sequence with thin-slice TI1 periodic saturation) with echo-planar imaging. Draining veins such as dural venous sinus and cortical veins were evaluated on ASL. Results: ASL clearly depicted draining dural venous sinus in all patients with DAVF Borden type I (6/6, 100%) and type II (4/4, 100%). ASL depicted cortical venous reflux in only one patient with DAVF Borden type II (1/4, 25%). ASL depicted drainage directly into cortical veins in all patients with Borden type III (6/6, 100%). Conclusion: Our preliminary study suggests that ASL can depict draining veins in patients with DAVF.展开更多
MULTIPLE sclerosis(MS)is a common inflammatory demyelinating disorder of central nervous system,and the disease burder could be well evaluated by conventional magnetic resonance imaging(MRI),1 including T2-weighted,fl...MULTIPLE sclerosis(MS)is a common inflammatory demyelinating disorder of central nervous system,and the disease burder could be well evaluated by conventional magnetic resonance imaging(MRI),1 including T2-weighted,fluid-attenuatd inversion recovery,and postcontrast T1-weighted sequences.2 We展开更多
Cerebrovascular disease is a disease with high morbidity,disability and mortality rates,which seri-ously affects the daily life of patients and is a heavy burden on families and society.Arterial spin labeling(ASL)is a...Cerebrovascular disease is a disease with high morbidity,disability and mortality rates,which seri-ously affects the daily life of patients and is a heavy burden on families and society.Arterial spin labeling(ASL)is a magnetic resonance imaging(MRI)technology that uses the magnetic labeling of hydrogen atoms in arterial blood as tracers to noninvasively evaluate brain blood flow.ASL does not require injection of an exogenous contrast agent,and has the advantages of no radiation,simplicity and low cost.In cerebrovascular diseases,ASL can evaluate the collateral cerebrovascular circulation and abnormal perfusion of brain tissue,which can provide a reliable basis for early diagnosis and clinical decision-making.This study reviewed ASL and its application in the diagnosis,treatment and prognosis of cerebrovascular diseases.展开更多
Epilepsy affects all age groups and is one of the most common and disabling neurological disorders worldwide.Drug-resistant epilepsy(DRE),status epilepticus(SE),and sudden unexpected death in epilepsy(SUDEP),which are...Epilepsy affects all age groups and is one of the most common and disabling neurological disorders worldwide.Drug-resistant epilepsy(DRE),status epilepticus(SE),and sudden unexpected death in epilepsy(SUDEP),which are associated with considerable healthcare costs and mortality,have always been difficult to address and become the focus of clinical research.The rapid identification of seizure onset and accurate localization of epileptic foci are crucial for the treatment and prognosis of people with DRE,SE,or near-SUDEP.However,most of the conventional neuroimaging techniques for assessing cerebral blood flow of people with epilepsy are restricted by time consumption,limited resolution,and ionizing radiation.Arterial spin labeling(ASL)is a newly powerful non-contrast magnetic resonance imaging technique that enables the quantitative evaluation of brain perfusion,characterized by its unique advantages of reproducibility and easy accessibility.Recent studies have demonstrated the potential advantages of ASL for the diagnosis and evaluation of epilepsy.Therefore,in this review,we discussed the complementary value of ASL in evaluating and characterizing the basic substrates underlying refractory epilepsy and epileptic emergencies.展开更多
The kidneys are essential for maintaining homeostasis,are responsible for the reabsorption of water,glucose and amino acids,and filter the blood by removing waste.Acute kidney injury(AKI) is a syndrome characterized b...The kidneys are essential for maintaining homeostasis,are responsible for the reabsorption of water,glucose and amino acids,and filter the blood by removing waste.Acute kidney injury(AKI) is a syndrome characterized by the rapid loss of renal excretory function and the accumulation of end metabolic products of urea and creatinine.AKI is associated with the later development of chronic kidney disease and end-stage kidney disease,and may eventually be fatal.Early diagnosis of AKI and assessments of the effects of treatment,however,are challenging.The pathophysiological mechanism of AKI is thought to be the imbalance between oxygen supply and demand in the kidneys.We have assessed the ability of arterial spin labeling(ASL) perfusion magnetic resonance imaging(MRI),without the administration of contrast media,to quantify renal blood flow(RBF) non-invasively.We found that RBF was significantly lower in AKI patients than in healthy volunteers.These results suggest that ASL perfusion MRI,a noninvasive measurement of RBF,may be useful in the early diagnosis of AKI.展开更多
基金Supported by the Foundation for Medical and Health Sci&Tech Innovation Project of Sanya(2016YW37)the Special Financial Grant from China Postdoctoral Science Foundation(2014T70960)
文摘To evaluate the reliability of three dimensional spiral fast spin echo pseudo-continuous arterial spin labeling(3D pc-ASL)in measuring cerebral blood flow(CBF)with different post-labeling delay time(PLD)in the resting state and the right finger taping state.Methods 3D pc-ASL and three dimensional T1-weighted fast spoiled gradient recalled echo(3D T1-FSPGR)sequence were applied to eight healthy subjects twice at the same time each day for one week interval.ASL data acquisition was performed with post-labeling delay time(PLD)1.5 seconds and 2.0 seconds in the resting state and the right finger taping state respectively.CBF mapping was calculated and CBF value of both the gray matter(GM)and white matter(WM)was automatically extracted.The reliability was evaluated using the intraclass correlation coefficient(ICC)and Bland and Altman plot.Results ICC of the GM(0.84)and WM(0.92)was lower at PLD 1.5 seconds than that(GM,0.88;WM,0.94)at PLD 2.0 seconds in the resting state,and ICC of GM(0.88)was higher in the right finger taping state than that in the resting state at PLD 1.5 seconds.ICC of the GM and WM was 0.71 and 0.78 for PLD 1.5 seconds and PLD 2.0 seconds in the resting state at the first scan,and ICC of the GM and WM was 0.83 and 0.79 at the second scan,respectively.Conclusion This work demonstrated that 3D pc-ASL might be a reliable imaging technique to measure CBF over the whole brain at different PLD in the resting state or controlled state.
文摘Conventional neuroimaging techniques cannot truly reflect the change of regional cerebral blood flow in patients with carpal tunnel syndrome.Pseudo-continuous arterial spinning labeling(pCASL)as an efficient non-invasive neuroimaging technique can be applied to directly quantify the neuronal activities of individual brain regions that show the persistent symptoms owing to its better spatial resolution and increased signal-to-noise ratio.Therefore,this prospective observational study was conducted in 27 eligible female carpal tunnel syndrome,aged 57.7±6.51 years.Psychometric tests,nerve conduction studies and pCASL neuroimaging assessment were performed.The results showed that the relevant activated brain regions in the cortical,subcrotical,and cerebral regions were correlated with numbness,pain,functionality,median nerve status and motor amplitude of median nerve(K=21–2849,r=–0.77–0.76,P<0.05).There was a tendency of pain processing which shifted from the nociceptive circuitry to the emotional and cognitive one during the process of chronic pain caused by carpal tunnel syndrome.It suggests the necessity of addressing the ignored cognitive or emotional state when managing patients with carpal tunnel syndrome.Approval for this study was obtained from the Institutional Review Board of The University of Hong Kong/Hospital Authority Hong Kong West,China(HKU/HA HKW IRB,approval No.UW17-129)on April 11,2017.This study was registered in Clinical Trial Registry of The University of Hong Kong,China(registration number:HKUCTR-2220)on April 24,2017.
基金Supported by The Endocrine Clinical Medical Center of Yunnan ProvinceNo.ZX20190202+2 种基金the Fund of the Diabetic Innovation Team in Yunnan Province,No.2019HC002the Special Joint Fund from Yunnan Provincial Department of Science and Technology and Kunming Medical University,Kunming,Yunnan,China,No.2018FE001(-267)the SKY Image Research Fund,China,No. Z-2014-07-2003-12。
文摘BACKGROUND Type 2 diabetes mellitus(T2DM) has been strongly associated with an increased risk of developing cognitive dysfunction and dementia.The mechanisms of diabetes-associated cognitive dysfunction(DACD) have not been fully elucidated to date.Some studies proved lower cerebral blood flow(CBF) in the hippocampus was associated with poor executive function and memory in T2DM.Increasing evidence showed that diabetes leads to abnormal vascular endothelial growth factor(VEGF) expression and CBF changes in humans and animal models.In this study,we hypothesized that DACD was correlated with CBF alteration as measured by three-dimensional(3D) arterial spin labeling(3D-ASL) and VEGF expression in the hippocampus.AIM To assess the correlation between CBF(measured by 3D-ASL and VEGF expression) and DACD in a rat model of T2DM.METHODS Forty Sprague-Dawley male rats were divided into control and T2DM groups.The T2DM group was established by feeding rats a high-fat diet and glucose to induce impaired glucose tolerance and then injecting them with streptozotocin to induce T2DM.Cognitive function was assessed using the Morris water maze experiment.The CBF changes were measured by 3D-ASL magnetic resonance imaging.VEGF expression was determined using immunofluorescence.RESULTS The escape latency time significantly reduced 15 wk after streptozotocin injection in the T2DM group.The total distance traveled was longer in the T2DM group;also,the platform was crossed fewer times.The percentage of distance in the target zone significantly decreased.CBF decreased in the bilateral hippocampus in the T2DM group.No difference was found between the right CBF value and the left CBF value in the T2DM group.The VEGF expression level in the hippocampus was lower in the T2DM group and correlated with the CBF value.The escape latency negatively correlated with the CBF value.The number of rats crossing the platform positively correlated with the CBF value.CONCLUSION Low CBF in the hippocampus and decreased VEGF expression might be crucial in DACD.CBF measured by 3D-ASL might serve as a noninvasive imaging biomarker for cognitive impairment associated with T2DM.
文摘Arterial spin labeling(ASL) is a magnetic resonance imaging technique for measuring tissue perfusion using a freely diffusible intrinsic tracer.As compared with other perfusion techniques,ASL offers several advantages and is now available for routine clinical practice in many institutions.Its noninvasive nature and ability to quantitatively measure tissue perfusion make ASL ideal for research and clinical studies.Recent technical advances have increased its sensitivity and also extended its potential applications.This review focuses on some basic knowledge of ASL perfusion,emerging techniques and clinical applications in neuroimaging.
文摘Cerebral blood flow is strongly associated with brain function, and is the main symptom and diagnostic basis for a variety of encephalopathies. However, changes in cerebral blood flow after mild traumatic brain injury remain poorly understood. This study sought to observe changes in cerebral blood flow in different regions after mild traumatic brain injury using pulsed arterial spin labeling. Our results demonstrate maximal cerebral blood flow in gray matter and minimal in the white matter of patients with mild traumatic brain injury. At the acute and subacute stages, cerebral blood flow was reduced in the occipital lobe, parietal lobe, central region, subcutaneous region, and frontal lobe. Cerebral blood flow was restored at the chronic stage. At the acute, subacute, and chronic stages, changes in cerebral blood flow were not apparent in the insula. Cerebral blood flow in the temporal lobe and limbic lobe diminished at the acute and subacute stages, but was restored at the chronic stage. These findings suggest that pulsed arterial spin labeling can precisely measure cerebral blood flow in various brain regions, and may play a reference role in evaluating a patient＇s condition and judging prognosis after traumatic brain injury.
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.
文摘Purpose: We report the results of applying arterial spin labeling (ASL) to intracranial dural arteriovenous fistula (DAVF). Methods: Sixteen patients with angiographically confirmed DAVF underwent ASL on a clinical 1.5 T or 3 T MR system. ASL was performed by Q2TIPS (second version of quantitative imaging of perfusion by using a single subtraction MRI pulse sequence with thin-slice TI1 periodic saturation) with echo-planar imaging. Draining veins such as dural venous sinus and cortical veins were evaluated on ASL. Results: ASL clearly depicted draining dural venous sinus in all patients with DAVF Borden type I (6/6, 100%) and type II (4/4, 100%). ASL depicted cortical venous reflux in only one patient with DAVF Borden type II (1/4, 25%). ASL depicted drainage directly into cortical veins in all patients with Borden type III (6/6, 100%). Conclusion: Our preliminary study suggests that ASL can depict draining veins in patients with DAVF.
文摘MULTIPLE sclerosis(MS)is a common inflammatory demyelinating disorder of central nervous system,and the disease burder could be well evaluated by conventional magnetic resonance imaging(MRI),1 including T2-weighted,fluid-attenuatd inversion recovery,and postcontrast T1-weighted sequences.2 We
文摘Cerebrovascular disease is a disease with high morbidity,disability and mortality rates,which seri-ously affects the daily life of patients and is a heavy burden on families and society.Arterial spin labeling(ASL)is a magnetic resonance imaging(MRI)technology that uses the magnetic labeling of hydrogen atoms in arterial blood as tracers to noninvasively evaluate brain blood flow.ASL does not require injection of an exogenous contrast agent,and has the advantages of no radiation,simplicity and low cost.In cerebrovascular diseases,ASL can evaluate the collateral cerebrovascular circulation and abnormal perfusion of brain tissue,which can provide a reliable basis for early diagnosis and clinical decision-making.This study reviewed ASL and its application in the diagnosis,treatment and prognosis of cerebrovascular diseases.
文摘Epilepsy affects all age groups and is one of the most common and disabling neurological disorders worldwide.Drug-resistant epilepsy(DRE),status epilepticus(SE),and sudden unexpected death in epilepsy(SUDEP),which are associated with considerable healthcare costs and mortality,have always been difficult to address and become the focus of clinical research.The rapid identification of seizure onset and accurate localization of epileptic foci are crucial for the treatment and prognosis of people with DRE,SE,or near-SUDEP.However,most of the conventional neuroimaging techniques for assessing cerebral blood flow of people with epilepsy are restricted by time consumption,limited resolution,and ionizing radiation.Arterial spin labeling(ASL)is a newly powerful non-contrast magnetic resonance imaging technique that enables the quantitative evaluation of brain perfusion,characterized by its unique advantages of reproducibility and easy accessibility.Recent studies have demonstrated the potential advantages of ASL for the diagnosis and evaluation of epilepsy.Therefore,in this review,we discussed the complementary value of ASL in evaluating and characterizing the basic substrates underlying refractory epilepsy and epileptic emergencies.
基金supported by the Capital Health Research and Development Projects of Beijing (2011-4021-02)
文摘The kidneys are essential for maintaining homeostasis,are responsible for the reabsorption of water,glucose and amino acids,and filter the blood by removing waste.Acute kidney injury(AKI) is a syndrome characterized by the rapid loss of renal excretory function and the accumulation of end metabolic products of urea and creatinine.AKI is associated with the later development of chronic kidney disease and end-stage kidney disease,and may eventually be fatal.Early diagnosis of AKI and assessments of the effects of treatment,however,are challenging.The pathophysiological mechanism of AKI is thought to be the imbalance between oxygen supply and demand in the kidneys.We have assessed the ability of arterial spin labeling(ASL) perfusion magnetic resonance imaging(MRI),without the administration of contrast media,to quantify renal blood flow(RBF) non-invasively.We found that RBF was significantly lower in AKI patients than in healthy volunteers.These results suggest that ASL perfusion MRI,a noninvasive measurement of RBF,may be useful in the early diagnosis of AKI.
