Perihematomal perfusion typing and spot sign of acute intracerebral hemorrhage with multimode computed tomography: a preliminary study / 中国医学科学杂志(英文版)

<p><b>UNLABELLED</b>OBJECTIVE To explore the perihematomal perfusion typing and spot sign on computed tomography angiography (CTA) source images in order to assist in individualizing therapeutic decisions for patients with intracerebral hemorrhage by possibly forecasting perihematomal ischemia and hematoma enlargement. METHODS We examined 58 patients with spontaneous intracerebral hemorrhage by computed tomography perfusion and CTA within 6 hours after symptom onset. Hematoma volumes were determined from non-contrast CT images and compared between first and second CT images. The perfusion of hematoma region and perihematoma region was evaluated for presence or absence of the perihematomal penumbra. Three kinds of perihematoma perfusion typing were defined according to the perfusion of hematoma region and perihematoma region. CTA source images was reviewed to make sure presence or absence of the spot sign. RESULTS Finally, 53 patients (34 males, 19 females) were enrolled in our study according to exclusion criteria. Finally, 21 patients were classified into the normal group, 23 patients were classified into the mild group, and 9 patients were classified into the severe group. There were significant differences in hematoma size between the presence and absence of the perihematomal penumbra group (P<0.05). Thirteen (24.5%) patients presented with spot sign. Hematoma expansion occurred in 15 (28.3%) patients on follow-up. In which 12 patients were with spot sign. Sensitivity, specificity, positive predictive value, and negative predictive value for expansion were 80.0%, 97.4%, 92.3%, and 92.5%, respectively.</p><p><b>CONCLUSION</b>In acute intracerebral hemorrhage patients, the perihematoma perfusion typing and CTA spot sign provide more radiological information that might assist in individualizing therapeutic decisions for patients by possibly forecasting perihematomal ischemia and hematoma enlargement.</p>

Distribution of wall shear stress in carotid plaques using magnetic resonance imaging and computational fluid dynamics analysis: a preliminary study / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Wall shear stress is an important factor in the destabilization of atherosclerotic plaques. The purpose of this study was to assess the distribution of wall shear stress in advanced carotid plaques using high resolution magnetic resonance imaging and computational fluid dynamics.</p><p><b>METHODS</b>Eight diseased internal carotid arteries in seven patients were evaluated. High resolution magnetic resonance imaging was used to visualize the plaque structures, and the mechanic stress in the plaque was obtained by combining vascular imaging post-processing with computational fluid dynamics.</p><p><b>RESULTS</b>Wall shear stresses in the plaques in all cases were higher than those in control group. Maximal shear stresses in the plaques were observed at the top of plaque hills, as well as the shoulders of the plaques. Among them, the maximal shear stress in the ruptured plaque was observed in the rupture location in three cases and at the shoulder of fibrous cap in two cases. The maximal shear stress was also seen at the region of calcification, in thrombus region and in the thickest region of plaque in the other three cases, respectively.</p><p><b>CONCLUSION</b>Determination of maximal shear stress at the plaque may be useful for predicting the rupture location of the plaque and may play an important role in assessing plaque vulnerability.</p>

Cerebral microbleeds - prevalence, distribution and risk factors in northeast population without preceding large-area stroke / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Cerebral microbleeds (CMBs) occur frequently in patients suspected of cerebrovascular disease and they are the principle radiographic findings in patients with sub-clinical neurological impairment. The objective of this study was to assess the prevalence, distribution, severity and associated clinical features of CMBs in a prospective hospital patient based cohort undergoing brain MRI for suspected cerebrovascular disease, excluding cases with known intracranial hemorrhage or prior large-area stroke.</p><p><b>METHODS</b>The study population consisted of 447 patients who were evaluated with T2*-gradient echo sequences to detect the CMBs lesion number, location, and their association with white matter hyperintensities and clinical parameters, including blood pressure.</p><p><b>RESULTS</b>CMB lesions were presented in 95 of the 447 patients (21.3%). The distribution of CMBs was 43.95% cortical, 19.77% thalamic, 14.41% in the brainstem, 11.58% cerebellar, 6.21% periventricular white matter, 5.64% involving the basal ganglia regions, and 0.28% involving the hippocampus. There was a statistically significant association between the presence of CMBs and advancing age (adjusted OR 2.082, P < 0.01), the severity of hypertension (adjusted OR 2.208, P < 0.01). Also there was a statistically significant (P < 0.01) correlation between the presence of CMBs and the severity of hypertension and white matter lesions.</p><p><b>CONCLUSIONS</b>CMBs occur frequently in patients with no prior large-area stroke who were referred for brain MRI for suspected cerebrovascular disease. The severity of CMBs correlates with the severity of hypertension and the presence of cerebral white matter changes detected by MRI.</p>

Clinical and imaging features of hypothalamic hamartoma in children / 中国当代儿科杂志

<p><b>OBJECTIVE</b>To study clinical and imaging features of hypothalamic hamartoma in children.</p><p><b>METHODS</b>Imaging findings and clinical manifestations of 38 children with hypothalamic hamartomas were retrospectively reviewed. The patients included 25 boys and 13 girls, ranging in age of onset from 1 month to 15 years. All the 38 patients were examined with pre-contrast and post-contrast T1 weighted MR imaging and with non-contrast T2 weighted MR imaging. Meanwhile, 10 patients received CT scan. Hypothalamic hamartomas were confimed by pathologic examinations in the 38 patients.</p><p><b>RESULTS</b>Gelastic epilepsy, precocious puberty, other types of epilepsy and disturbance of intelligence were main manifestations in the 38 patients. Gelastic epilepsy was found as an initial clinical symptom in 17 cases, precocious puberty in 13 cases and other types of epilepsy in 8 cases. All masses were located in the suprasellar and interpeduncular cistern. They showed iso-density on CT scan, and homogeneous signal iso-intense to gray matter on T1 and T2 weighted MR images. With contrast MR images, there was no enhancement in the mass. The size or pedunculation of the mass was not correlated with clinical features.</p><p><b>CONCLUSIONS</b>Hypothalamic hamartoma may be characterized by precocious puberty and/or gelastic epilepsy and specific imaging findings mentioned above.</p>

Application of 1H-magnetic resonance spectroscopy in differential diagnosis of brain low-grade gliomas and demyelinating diseases / 中国医学科学院学报

<p><b>OBJECTIVE</b>To study the clinical value of 1H-magnetic resonance spectroscopy (1H-MRS) in differential diagnosis of brain low-grade gliomas and demyelinating diseases.</p><p><b>METHODS</b>1H-MRS was performed in 24 patients with low-grade gliomas and 22 patients with demyelinating diseases and the results were retrospectively reviewed. The metabolites including N-acetyl aspartate (NAA), choline (Cho), and creatine (Cr) were detected in different areas including lesions and the normal brain. The ratios of NAA/Cr, NAA/Cho, and Cho/Cr were also computed.</p><p><b>RESULTS</b>Compared with the normal brain tissue, low-grade gliomas and demyelinating diseases had significantly different ratios of NAA/Cr, NAA/Cho, and Cho/Cr (P < 0.05). The ratios of NAA/Cho and Cho/Cr were significantly different between low-grade gliomas and demyelinating diseases (P < 0.05), while the ratio of NAA/Cr was not significantly different (P > 0.05).</p><p><b>CONCLUSIONS</b>The ratio of NAA/Cho and Cho/Cr is remarkably different between low-grade gliomas and demyelinating diseases. It can a useful indicator for differential diagnosis of these two diseases by 1H-MRS.</p>

"Palpation by imaging": magnetic resonance elastography / 中国医学科学杂志(英文版)

Elasticity is an important physical property of human tissues. There is a tremendous difference in elasticity between normal and pathological tissues. Noninvasive evaluation of the elasticity of human tissues would be valuable for clinical practice. Magnetic resonance elastography (MRE) is a recently developed noninvasive imaging technique that can directly visualize and quantitatively measure tissue elasticity. This article reviewed the MRE technique and its current status.

Function magnetic resonance imaging and diffusion tensor tractography in patients with brain gliomas involving motor areas: clinical application and outcome / 中华外科杂志

<p><b>OBJECTIVE</b>To explore the role of preoperative blood oxygen level dependent (BOLD) functional magnetic resonance imaging (fMRI) and diffusion tensor tractography (DTT) to identify the relationship between motor cortical area, pyramidal tracts with brain gliomas in neurosurgical treatment of intraoperative electrical stimulation for gliomas involving motor areas at 3T.</p><p><b>METHODS</b>Twenty-eight patients with brain gliomas involving motor areas were included. They underwent MRI examination, which included conventional T1WI, T2WI, BOLD-fMRI of bilateral hands movement paradigm and diffusion tensor imaging (DTI). The data of BOLD-fMRI and DTI were transferred to the workstation (Leonardo syngo 2003A, Siemens) and analyzed. Activation mapping of hands movement, fractional Anisotropy (FA) Color and three dimensional pyramidal tracts were produced. The relationship between motor cortical area, pyramidal tracts and brain gliomas was demonstrated, which was used to optimize the pre-surgical planning. With guidance of the result of BOLD-fMRI and DTT, all patients received microsurgery under anaesthesia retaining consciousness using intraoperative motor functional brain mapping with the method of direct electrical stimulations. The brain lesions were removed as far as possible in the case of eloquent areas and sub-cortical important white matters preservation. The preoperative and postoperative KPS of all patients were operated to evaluate the state of patients.</p><p><b>RESULTS</b>BOLD-fMRI, DTI were performed successfully in 28 patients. The relationship between the primary motor cortex, premotor area, supplementary motor area, pyramidal tracts and brain gliomas localized by preoperative fMRI and DTI. Under anaesthesia retaining consciousness, the primary motor area was monitored by the method of direct electrical stimulations with the guidance of preoperative BOLD-fMRI. There was good correlation between preoperative fMRI and intraoperative cortical stimulation. Furthermore, the preoperative mappings and DTT could make up for the un-monitored motor areas and pyramidal tracts during operative cortical stimulation. Comparing the preoperative KPS, the postoperative KPS was advanced.</p><p><b>CONCLUSIONS</b>BOLD-fMRI and DTT could non-invasively localize the relationship between brain motor cortex, pyramidal tracts and brain gliomas in vivo to optimize the surgical planning, guide the microsurgery under anaesthesia retaining consciousness using intraoperative motor functional brain mapping with the method of direct electrical stimulations and remove brain tumors as far as possible in the case of eloquent areas and sub-cortical important white matters preservation.</p>

A Model of Focal Cortical Infarctionin Rat:Mini mally Invasive Craniotomy / 中国康复理论与实践

@#ObjectiveTo develop a stable model of focal cerebral infarction in rat to study the curative effect of neural stem cells transplantation.MethodsThirty-seven rats were selected which were divided into two groups in random, experimental group and control group. The focal infarction model was developed by the ligation of the left middle cerebral artery followed by the ligation of the ipsilateral common carotid artery and the temporary clip occlusion of the contralateral common carotid artery for 1.5 h. The operation adopted minimally invasive craniotomy though temporal bone. The model was evaluated by examining the neurologic deficits, ink perfusion, TTC staining and Magnetic Resonance imaging.ResultsAll the rats were in good condition after the operation, the mortality rate was 6.25% after 4 weeks. Ink perfusion and TTC staining confirmed that the ischemia was confined to the cortex. The areas of infarction measured 83.52 mm3 by Magnetic Resonance imaging after 4 weeks.ConclusionA stable focal cerebral infarction model can be achieved by minimally invasive craniotomy. It is superior for its homogeneity of infarction volume and site, and its low mortality. It can be used for the study of transplantation of neural stem cells.

CT perfusion imaging study of perihematomal cerebral blood flow in experimental intracerebral hemorrhage / 中国康复理论与实践

@#ObjectiveTo study the mechanism of hemodynamic alternation surrounding the hematoma in the acute stage of intracerebral hemorrhage (ICH) in rats.MethodsSeventy male Sprague Dawley rats were randomly divided into ICH group and sham operated group, which were microinjected with 40 μl fresh autologous blood or saline into the right caudatum respectively. The each group was divided into 7 subgroups at 1h,3h,6h,12h,24h,48h and 72h after the ICH. CT perfusion imaging in measurements of regional cerebral blood flow adjacent to hematomas was performed. The ratios of side to side were measured at the regions around the hematomas by personal computer aided mapping. So the parameters of regional cerebral blood flow(rCBF), regional cerebral blood volume(rCBV) and mean transit time(MTT) were calculated respectively.ResultsThe rCBF and rCBV adjacent to the hematomas were lower than those of the outer region pronouncedly. The alternation of rCBF around the hematoma were fluctuated, which reduced to the valley at 1h after ICH, and then gradually returned to the peaks at 6h and 24h after ICH. In the meantime, the rCBV around the hematoma reduced to the valley at 1h after ICH, and then gradually increased to the peak at 24h after ICH.ConclusionThe abnormal hemodynamic changes can be found in the perihematomal region after ICH. The alternation of rCBF around the hematomas are fluctuated, but the changes of rCBV remain continuous increase. The mass effect of hematoma, intracranial hypertension caused by the mass effect of hematoma, and the autoregulation of cerebral blood flow motivated by the initial depression of cerebral blood flow play a very important role in the changes of cerebral blood flow.

Visualization and analysis of flow patterns of human carotid bifurcation by computational fluid dynamics / 中华放射学杂志

Objective To investigate flow patterns at carotid bifurcation in vivo by combining computational fluid dynamics(CFD)and MR angiography imaging.Methods Seven subjects underwent contrast-enhanced MR angiography of carotid artery in Siemens 3.0 T MR.Flow patterns of the carotid artery bifurcation were calculated and visualized by combining MR vascular imaging post-processing and CFD. Results The flow patterns of the carotid bifurcations in 7 subjects were varied with different phases of a cardiac cycle.The turbulent flow and back flow occurred at bifurcation and proximal of internal carotid artery (ICA)and external carotid artery(ECA),their occurrence and conformation were varied with different phase of a cardiac cycle.The turbulent flow and back flow faded out quickly when the blood flow to the distal of ICA and ECA.Conclusion CFD combined with MR angiography can be utilized to visualize the cyclical change of flow patterns of carotid bifurcation with different phases of a cardiac cycle.

Diffusion tensor tractography of language functional areas and fiber pathways in normal human brain / 中华放射学杂志

0.05),the mean FA on the left was higher than the right(t=1.912,P