We present numerical simulations of blood flow through a brain vascular aneurysm with an artificial stent using Smoothed Particle Hydrodynamics (SPH). The aim of this work is to analyze how the flow into an aneurysm c...We present numerical simulations of blood flow through a brain vascular aneurysm with an artificial stent using Smoothed Particle Hydrodynamics (SPH). The aim of this work is to analyze how the flow into an aneurysm changes using different stent configurations. The initial conditions for the simulations were constructed from angiographic images of a real patient with an aneurysm. The wall shear stresses, pressure and highest velocity within the artery, and other particular quantities are calculated which are of medical specific interest. The numerical simulations of the cerebral circulation help doctors to determine if the patient’s own vascular anatomy has the conditions to allow arterial stenting by endovascular method before the surgery or even evaluate the effect of different stent structure and materials. The results show that the flow downstream the aneurysm is highly modified by the stent configuration and that the best choice for reducing the flow in the aneurysm is to use a completely extended Endeavor stent.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
Objective To explore effects of decompressive craniectomy on cerebral blood flow volume and brain metabolism in different aged patients with severe traumatic brain injury. Methods 71 cases were divided into three grou...Objective To explore effects of decompressive craniectomy on cerebral blood flow volume and brain metabolism in different aged patients with severe traumatic brain injury. Methods 71 cases were divided into three groups according age: group A( 【 30 years) ,group B ( 30 ～ 50 years) 。展开更多
DI-3n-butyiphthalide can effectively treat cerebral ischemia; however, the mechanisms underlying the effects of dl-3n-butylphthalide on microcirculation disorders following diffuse brain injury remain unclear. In this...DI-3n-butyiphthalide can effectively treat cerebral ischemia; however, the mechanisms underlying the effects of dl-3n-butylphthalide on microcirculation disorders following diffuse brain injury remain unclear. In this study, models of diffuse brain injury were established in Sprague-Dawley rats with the vertical impact method. DI-3n-butylphthalide at 80 and 160 mg/kg was given via intraperitoneal injection immediately after diffuse brain injury. Ultrastructural changes in the cerebral cortex were observed using electron microscopy. Cerebral blood flow was measured by laser Doppler flowmetry, vascular density was marked by tannic acid-ferric chloride staining, vascular permeability was es- timated by the Evans blue method, brain water content was measured using the dry-wet method, and rat behavior was measured by motor function and sensory function tests. At 6, 24, 48, and 72 hours after administration of dl-3n-butylphthalide, reduced cerebral ultrastructure damage, in- creased vascular density and cerebral blood flow, and improved motor and sensory functions were observed. Our findings demonstrate that dl-3n-butylphthalide may have protective effects against diffuse brain injury by ameliorating microcirculation disorder and reducing blood-brain barrier dam- age and cerebral edema.展开更多
Traumatic brain injury is a major cause of death and disability. This is a brief report based on a symposium presentation to the 2014 Chinese Neurotrauma Association Meeting in San Francisco, USA. It covers the work f...Traumatic brain injury is a major cause of death and disability. This is a brief report based on a symposium presentation to the 2014 Chinese Neurotrauma Association Meeting in San Francisco, USA. It covers the work from our laboratory in applying multimodal MRI to study experimental traumatic brain injury in rats with comparisons made to behavioral tests and histology. MRI protocols include structural, perfusion, manganese-enhanced, diffusion-tensor MRI, and MRI of blood-brain barrier integrity and cerebrovascular reactivity.展开更多
Restorative cell-based therapies for experimental brain injury, such as stroke and traumatic brain injury,substantially improve functional outcome. We discuss and review state of the art magnetic resonance imaging met...Restorative cell-based therapies for experimental brain injury, such as stroke and traumatic brain injury,substantially improve functional outcome. We discuss and review state of the art magnetic resonance imaging methodologies and their applications related to cell-based treatment after brain injury. We focus on the potential of magnetic resonance imaging technique and its associated challenges to obtain useful new information related to cell migration, distribution, and quantitation, as well as vascular and neuronal remodeling in response to cell-based therapy after brain injury. The noninvasive nature of imaging might more readily help with translation of cell-based therapy from the laboratory to the clinic.展开更多
<strong>Objective</strong><span style="font-family:;" "=""><span style="font-family:Verdana;"><strong>: </strong>To evaluate the clinical value of...<strong>Objective</strong><span style="font-family:;" "=""><span style="font-family:Verdana;"><strong>: </strong>To evaluate the clinical value of transcranial color Doppler ultrasound (TCCD) in assessing cerebral function after cardiopulmonary resuscitation (CPR). </span><b><span style="font-family:Verdana;">Methods</span></b><span style="font-family:Verdana;">: A prospective study was conducted in 52 patients with cardiac arrest treated by CPR from January 2018 to January 2020, and its clinical data were analyzed</span></span><span style="font-family:Verdana;">. </span><span style="font-family:;" "=""><span style="font-family:Verdana;">According to classification of cerebral performance category (CPC), 31 cases (CPC grade 1 - 2) were selected in the good prognosis group and 21 cases (CPC grade 3 - 5) in the poor prognosis group. The cerebral blood flow was measured by transcranial Doppler ultrasound (TCCD) 24 h after CPR, and the differences were compared between the two groups in stroke index, diastolic blood flow velocity (Vd), systolic peak blood flow velocity (Vs) and mean peak blood flow velocity (Vm). The ROC curve of cerebral blood flow after CPR was drawn to predict the prognosis of brain function. </span><b><span style="font-family:Verdana;">Results</span></b><span style="font-family:Verdana;">: The data showed that the pulsatility index of middle cerebral artery of the poor prognosis group decreased within 24 h</span></span><span style="font-family:Verdana;">;</span><span style="font-family:Verdana;">the difference between the two groups was statistically significant (p < 0.05);the Vd, Vs, Vm increased in the good prognosis group</span><span style="font-family:Verdana;">;</span><span style="font-family:;" "=""><span style="font-family:Verdana;">the difference between the two groups was statistically significant (p < 0.05). The ROC curve of cerebral blood flow after CPR was drawn to predict the prognosis of brain function, and the results showed that the area under the curve and the optimal critical value of cerebral blood flow were 0.731 and 5.69. The sensitivity and specificity were 67.3% and 79.1% respectively. </span><b><span style="font-family:Verdana;">Conclusion</span></b><span style="font-family:Verdana;">: The cerebral blood flow increase in the early stage of successful CPR is positively correlated with the prognosis of cerebral functional resuscitation. Monitoring intracranial blood flow after CPR by TCCD has clinical value to evaluate prognosis of brain function.</span></span>展开更多
Brain trauma (BT) is extremely common in the Western society, and has been identified as the main cause of death and disability in the under-40 age group. Many aspects of the pathophysiological mechanisms involved and...Brain trauma (BT) is extremely common in the Western society, and has been identified as the main cause of death and disability in the under-40 age group. Many aspects of the pathophysiological mechanisms involved and the effect of changes in cerebral metabolism are unclear. The aim of this study was to establish the rela- tionship between anatomical changes and deranged cerebral perfusion in patients with cerebral contusions, using Computed Tomography (CT) and Single Proton Emission Computed Tomography (SPECT). Twenty- two (22) patients who had suffered BT were recruited. All patients underwent SPECT and CT head scans on the same day. 18 were men. Patient average age was 45.6. Patients were assessed using the Glasgow scale (average 10.6). Cause of trauma included traffic accidents (9 patients) and falls (13 patients). A 4-slice spiral CT scan was performed. For each contusion, areas of bleeding, edema, and healthy perilesional tissue were distinguished. SPECT was performed with 20 mCi of 99 mTcECD using a dual-head gamma camera (128 × 128 matrix). CT scan revealed a single lesion in 12 patients, and more than one lesion in 10. The biggest le- sions found on CT were located in the frontal region in 13 patients;temporal region in 4;and parietal region in 1;four patients had poorly defined lesions. A total absence of perfusion was visible in 18 patients in the hemorrhagic area and in 14 patients in the edema, In 7 cases SPECT showed hypoperfusion that did not cor- respond to any morphological changes on the CT scan. Quantitative of fused lesions appearing on both CT scan and SPECT revealed severe perfusion defects in the hemorrhagic area (17.8%) and in the edema (29.4%). In our study, regional cerebral blood flow add relevant information on encephalic damage in pa- tients with BT.展开更多
文摘We present numerical simulations of blood flow through a brain vascular aneurysm with an artificial stent using Smoothed Particle Hydrodynamics (SPH). The aim of this work is to analyze how the flow into an aneurysm changes using different stent configurations. The initial conditions for the simulations were constructed from angiographic images of a real patient with an aneurysm. The wall shear stresses, pressure and highest velocity within the artery, and other particular quantities are calculated which are of medical specific interest. The numerical simulations of the cerebral circulation help doctors to determine if the patient’s own vascular anatomy has the conditions to allow arterial stenting by endovascular method before the surgery or even evaluate the effect of different stent structure and materials. The results show that the flow downstream the aneurysm is highly modified by the stent configuration and that the best choice for reducing the flow in the aneurysm is to use a completely extended Endeavor stent.
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Objective To explore effects of decompressive craniectomy on cerebral blood flow volume and brain metabolism in different aged patients with severe traumatic brain injury. Methods 71 cases were divided into three groups according age: group A( 【 30 years) ,group B ( 30 ～ 50 years) 。
基金supported by the grants from Hebei Province Science and Technology Ministry,No.20276102DKey Project of Hebei Province Education Ministry,No.ZD2010106
文摘DI-3n-butyiphthalide can effectively treat cerebral ischemia; however, the mechanisms underlying the effects of dl-3n-butylphthalide on microcirculation disorders following diffuse brain injury remain unclear. In this study, models of diffuse brain injury were established in Sprague-Dawley rats with the vertical impact method. DI-3n-butylphthalide at 80 and 160 mg/kg was given via intraperitoneal injection immediately after diffuse brain injury. Ultrastructural changes in the cerebral cortex were observed using electron microscopy. Cerebral blood flow was measured by laser Doppler flowmetry, vascular density was marked by tannic acid-ferric chloride staining, vascular permeability was es- timated by the Evans blue method, brain water content was measured using the dry-wet method, and rat behavior was measured by motor function and sensory function tests. At 6, 24, 48, and 72 hours after administration of dl-3n-butylphthalide, reduced cerebral ultrastructure damage, in- creased vascular density and cerebral blood flow, and improved motor and sensory functions were observed. Our findings demonstrate that dl-3n-butylphthalide may have protective effects against diffuse brain injury by ameliorating microcirculation disorder and reducing blood-brain barrier dam- age and cerebral edema.
文摘Traumatic brain injury is a major cause of death and disability. This is a brief report based on a symposium presentation to the 2014 Chinese Neurotrauma Association Meeting in San Francisco, USA. It covers the work from our laboratory in applying multimodal MRI to study experimental traumatic brain injury in rats with comparisons made to behavioral tests and histology. MRI protocols include structural, perfusion, manganese-enhanced, diffusion-tensor MRI, and MRI of blood-brain barrier integrity and cerebrovascular reactivity.
基金supported by NIH grants RO1 NS64134 and RO1 NS 48349
文摘Restorative cell-based therapies for experimental brain injury, such as stroke and traumatic brain injury,substantially improve functional outcome. We discuss and review state of the art magnetic resonance imaging methodologies and their applications related to cell-based treatment after brain injury. We focus on the potential of magnetic resonance imaging technique and its associated challenges to obtain useful new information related to cell migration, distribution, and quantitation, as well as vascular and neuronal remodeling in response to cell-based therapy after brain injury. The noninvasive nature of imaging might more readily help with translation of cell-based therapy from the laboratory to the clinic.
文摘<strong>Objective</strong><span style="font-family:;" "=""><span style="font-family:Verdana;"><strong>: </strong>To evaluate the clinical value of transcranial color Doppler ultrasound (TCCD) in assessing cerebral function after cardiopulmonary resuscitation (CPR). </span><b><span style="font-family:Verdana;">Methods</span></b><span style="font-family:Verdana;">: A prospective study was conducted in 52 patients with cardiac arrest treated by CPR from January 2018 to January 2020, and its clinical data were analyzed</span></span><span style="font-family:Verdana;">. </span><span style="font-family:;" "=""><span style="font-family:Verdana;">According to classification of cerebral performance category (CPC), 31 cases (CPC grade 1 - 2) were selected in the good prognosis group and 21 cases (CPC grade 3 - 5) in the poor prognosis group. The cerebral blood flow was measured by transcranial Doppler ultrasound (TCCD) 24 h after CPR, and the differences were compared between the two groups in stroke index, diastolic blood flow velocity (Vd), systolic peak blood flow velocity (Vs) and mean peak blood flow velocity (Vm). The ROC curve of cerebral blood flow after CPR was drawn to predict the prognosis of brain function. </span><b><span style="font-family:Verdana;">Results</span></b><span style="font-family:Verdana;">: The data showed that the pulsatility index of middle cerebral artery of the poor prognosis group decreased within 24 h</span></span><span style="font-family:Verdana;">;</span><span style="font-family:Verdana;">the difference between the two groups was statistically significant (p < 0.05);the Vd, Vs, Vm increased in the good prognosis group</span><span style="font-family:Verdana;">;</span><span style="font-family:;" "=""><span style="font-family:Verdana;">the difference between the two groups was statistically significant (p < 0.05). The ROC curve of cerebral blood flow after CPR was drawn to predict the prognosis of brain function, and the results showed that the area under the curve and the optimal critical value of cerebral blood flow were 0.731 and 5.69. The sensitivity and specificity were 67.3% and 79.1% respectively. </span><b><span style="font-family:Verdana;">Conclusion</span></b><span style="font-family:Verdana;">: The cerebral blood flow increase in the early stage of successful CPR is positively correlated with the prognosis of cerebral functional resuscitation. Monitoring intracranial blood flow after CPR by TCCD has clinical value to evaluate prognosis of brain function.</span></span>
文摘Brain trauma (BT) is extremely common in the Western society, and has been identified as the main cause of death and disability in the under-40 age group. Many aspects of the pathophysiological mechanisms involved and the effect of changes in cerebral metabolism are unclear. The aim of this study was to establish the rela- tionship between anatomical changes and deranged cerebral perfusion in patients with cerebral contusions, using Computed Tomography (CT) and Single Proton Emission Computed Tomography (SPECT). Twenty- two (22) patients who had suffered BT were recruited. All patients underwent SPECT and CT head scans on the same day. 18 were men. Patient average age was 45.6. Patients were assessed using the Glasgow scale (average 10.6). Cause of trauma included traffic accidents (9 patients) and falls (13 patients). A 4-slice spiral CT scan was performed. For each contusion, areas of bleeding, edema, and healthy perilesional tissue were distinguished. SPECT was performed with 20 mCi of 99 mTcECD using a dual-head gamma camera (128 × 128 matrix). CT scan revealed a single lesion in 12 patients, and more than one lesion in 10. The biggest le- sions found on CT were located in the frontal region in 13 patients;temporal region in 4;and parietal region in 1;four patients had poorly defined lesions. A total absence of perfusion was visible in 18 patients in the hemorrhagic area and in 14 patients in the edema, In 7 cases SPECT showed hypoperfusion that did not cor- respond to any morphological changes on the CT scan. Quantitative of fused lesions appearing on both CT scan and SPECT revealed severe perfusion defects in the hemorrhagic area (17.8%) and in the edema (29.4%). In our study, regional cerebral blood flow add relevant information on encephalic damage in pa- tients with BT.
