Magnetic resonance susceptibility weighted imaging in detecting intracranial calcification and hemorrhage / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Computed tomography (CT) is better than routine magnetic resonance imaging (MRI) in detecting intracranial calcification. This study aimed to assess the value of MR susceptibility weighted imaging (SWI) in the detection and differentiation of intracranial calcification and hemorrhage.</p><p><b>METHODS</b>Enrolled in this study were 35 patients including 13 cases of calcification demonstrated by CT and 22 cases of intracerebral hemorrhage. MR sequences used in all the subjects included axial T1WI, T2WI and SWI. The phase shift (PS) of calcification and hemorrhage on SWI was calculated and their signal features on corrected phase images were compared. The sensitivity of T1WI, T2WI and SWI in detecting intracranial calcification and hemorrhage was analyzed statistically.</p><p><b>RESULTS</b>The detection rate of SWI for cranial calcification was 98.2%, significantly higher than that of T1WI and T2WI. It was not significantly different from that of CT (P > 0.05). There were 49 hemorrhagic lesions at different stages detected on SWI, 30 on T2WI and 18 on T1WI. The average PS of calcification and hemorrhage was +0.734 +/- 0.073 and -0.112 +/- 0.032 respectively (P < 0.05). The PS of calcification was positive and presented as a high signal or the mixed signal dominated by a high signal on the corrected phase images, whereas the PS of hemorrhage was negative and presented as a low signal or the mixed signal dominated by a low signal.</p><p><b>CONCLUSIONS</b>SWI can accurately demonstrate intracranial calcification, not dependant on CT. Being more sensitive than routine MRI in detecting micro-hemorrhage, SWI may play an important role in differentiating cerebral diseases associated with calcification or hemorrhage.</p>

The application of proton magnetic resonance spectroscopy and computerized tomography in evaluating nonalcoholic fatty liver disease / 中华肝脏病杂志

<p><b>OBJECTIVE</b>To investigate the application of proton magnetic resonance spectroscopy (1HMRS) and computerized tomography (CT) in evaluating nonalcoholic fatty liver disease (NAFLD).</p><p><b>METHODS</b>Twenty-two NAFLD patients were selected, according to the Chinese Medical Association standard, and compared with 20 healthy persons (as the control group). Their body mass index (BMI), waist to hip ratio (WHR), and blood pressure (BP) were examined. The serum ALT, the concentration of fasting blood glucose (FBG), total cholesterol (TC), triglyceride (TG), and uric acid (UA) were tested simultaneously. The severity of hepatosteatosis was evaluated by 1HMRS and CT scans of their livers. The intrahepatic content of lipid (IHCL) and CT liver and spleen ratios were measured.</p><p><b>RESULTS</b>The BMI, WHR, serum ALT, FBG, TG, and UA were all elevated significantly in the NAFLD group and were (28.4+/-2.4) kg/m2, 0.91+/-0.04, (71.5+/-24.8) U/L, (5.67+/-0.61) mmol/L, (2.48+/-1.46) mmol/L, (420.7+/-57.5)micromol/L, respectively, P less than 0.01 or 0.05. Meanwhile, in the NAFLD group, the IHCL calculated by 1HMRS were increased and CT value ratios were decreased significantly compared with those of the control group (27.49%+/-12.27% vs 1.34%+/-0.79%, P less than 0.01). However, there was no correlation between the clinical features and the IHCL and between the clinical features and CT value ratios, but a negative correlation existed in the CT value ratio and IHCL.</p><p><b>CONCLUSIONS</b>The intrahepatic content of lipids can be measured precisely by 1HMRS, and 1HMRS is better than CT in quantitative evaluations of NAFLD.</p>

Experimental study of cell migration and functional differentiation of transplanted neural stem cells co-labeled with superparamagnetic iron oxide and BrdU in an ischemic rat model / 生物医学与环境科学（英文）

<p><b>OBJECTIVE</b>To explore the migration of transplanted neural stem cells co-labeled with superparamagnetic iron oxide (SPIO) and bromodeoxyuridine (Brdu) using the 4.7T MR system and to study the cell differentiation with immuno-histochemical method in ischemic rats.</p><p><b>METHODS</b>Rat neural stem cells (NSCs) co-labelled with SPIO mediated by poly-L-lysine and bromodeoxyuridine (BrdU) were transplanted into the unaffected side of rat brain with middle cerebral artery occlusion (MCAO). At weeks 1, 2, 3, 4, 5, and 6 after MCAO, migration of the labelled cells was monitored by MRI. At week 6, the rats were killed and their brain tissue was cut according to the migration site of transplanted cells indicated by MRI and subjected to Prussian blue staining and immunohistochemical staining to observe the migration and differentiation of the transplanted NSCs.</p><p><b>RESULTS</b>Three weeks after transplantation, the linear hypointensity area derived from the migration of labelled NSCs was observed by MRI in the corpus callosum adjacent to the injection site. Six weeks after the transplantation, the linear hypointensity area was moved toward the midline along the corpus callosum. MRI findings were confirmed by Prussian blue staining and immunohistochemical staining of the specimen at week 6 after the transplantation. Flourescence co-labelled immunohistochemical methods demonstrated that the transplanted NSCs could differentiate into astrocytes and neurons.</p><p><b>CONCLUSION</b>MRI can monitor the migration of SPIO-labelled NSCs after transplantation in a dynamical and non-invasive manner. NSCs transplanted into ischemic rats can differentiate into astrocytes and neurons during the process of migration.</p>

MRI tracking of transplanted neural stem cells labeled with superparamagnetic iron oxide in ischemic model / 中华器官移植杂志

Objective To explore the migration of transplanted neural stem cells labeled with SPIO with 4.7T MR system and study cell differentiation by immunohistochemistry in ischemic rats. Methods Rat neural stem cells(NSCs)co-labeled with SPIO mediated by poly-L-lysine and bromode- oxyuridine(BrdU)were transplanted into the middle cerebral artery occlusion(MCAO)rats after 14 days when MCAO model was made successfully.4.7T MR scanner was used to monitor the migration of transplanted cells after 1.2,3,4,5 and 6 weeks post-transplantation.After MRI examination at 6th week,the rats were killed and Prussian blue staining and immunohistochemistric staining were per- formed to study migration and functional differentiation of NSCs.Results Three weeks after trans- plantation,linear hypointensity area derived from migration of labeled NSCs was observed in the corpus callosum adjacent to the injection site.Six weeks after transplantation,linear hypointensity area was moved toward the midline along the corpus callosurn.MRI findings were confirmed by Prussian blue staining and immunohistochemical straining.Co-labeled immunohistochemical methods demonstrated transplanted NSCs could differentiated into astrocytes and neurons.Conclusion MRI is very useful in demonstrating the migration path of labeled NSCs.Transplanted NSCs into ischemic rats can differen- tiated into astrocytes and neurons during the process of migration.

Study of multi-slice helical CT perfusion imaging in cerebral neoplasms / 中华放射学杂志

Objective To study the potential of multi-slice spiral CT perfusion imaging in the assessment of cerebral neoplasms.Methods Multi-slice helical CT perfusion imaging was performed in 38 patients with cerebral tumors.The perfusion imaging of the tumor was carried out by cine scan technique (ls/1 rotation) with slice thickness 5 mm/4i,reconstructed slice thickness 10 mm/2i.Contrast injection was done by using 50 ml nonionic contrast agent(300 mg I/ml),at a flow rate of 3.5 ml/s with a power injector,and 5 seconds delay,and data acquisition lasted for 45 seconds.The scanning images were processed in ADW 4.0 workstation.BF、BV、PS values of tumors were calculated and statistically analysed. Results 38 patients with cerebral neoplasms included 9 cases of gradeⅠ—Ⅱgliomas(group 1),10 cases of gradeⅢ—Ⅳgliomas (group 2),9 eases of metastases (group 3)and 10 cases of meningiomas (group 4).All raw data was transformed to square root so as to be consistent with normal distribution.BF~(1/2) values for groupl to group 4 were (5.99?1.03)、(7.55?1.57)、(7.72?2.02 )、(11.40?2.13)ml?rain~(-1)?kg~(-1).The differences in BF~(1/2) were statistically significant between group 1 and group 2,between group 1 and group 3,between group 1 and group 4,between group 2 and group 4,between group 3 and group 4(t_(1,2)=6.89,t_(1,3)=4.59,t_(1,4)=11.03,t_(2.4)=10.58,t_(3,4)=7.65,P＜0.05),and there was no statistically significant difference between group 2 and group 3(t_(2.3)=1.17,P＞0.05);BF~(1/2) values for groupl to group 4 were (1.01?0.19)、(1.42?0.38)、(1.25?0.33)、(1.60?0.24)ml?kg~(-1).The differences in BF~(1/2) were statistically significant between every two groups (t_(1,2)=7.15,t_(1.3)=3.71, t_(1.4)=5.93,t_(2.3)=2.94,t_(2,4)=2.72,t_(3.4)=4.46,P＜0.05 );PS~(1/2) values for groupl to group 4 were (1.70?0.37)、(3.63?0.95)、(4.29?1.30)、(5.69?1.03)ml?min~(-1)?kg~(-2).The differences in PS~(1/2) were statistically significant between every two groups(t_(1.2)=11.53,t_(1.3)=10.61,t_(1.4)=16.77,t_(2.3)=3.69, t_(2,4)=9.94,t_(3,4)=5.52,P＜0.05).Conclusion Multi-slice helical CT perfusion imaging is very useful to evaluate tumor vessels of cerebral neoplasmas and it can provide information of incremental benefit in diagnosis,in staging of tumor grade,in the distinction of benign from maglignant cerebral neoplasmas and in differentiating intracerebral neoplasmas from extracerebral neoplasmas.

Proton MR spectroscopy study in neonates with hypoxic ischemic encephalopathy / 中华放射学杂志

Objective To investigate the metabolic alterations in the brain of neonates with HIE and correlate those alterations with clinical grading and prognosis of HIE.Methods Fourty-six eases of full-term neonates diagnosed as HIE clinically were performed MRI and 1~H-MRS,9 healthy neonates without the evidence of asphyxia were studied as controls,1~H-MRS techniques included single voxel proton MRS and two dimensional muhi-voxel chemical shift spectroscopy imaging,point resolved spectroscopy sequence was used for 1~H-MRS.Metabolic changes in the spectroscopy were analyzed in neonates with HIE,and study the relationgship between MRS findings and prognosis.Results(1)The typical 1~H-MRS manifestations of full- term neonates suffering from HIE were as follows:the peaks of Lac were elevated,GLx-? were elevated and NAA were decreased.(2)GLx-?/Cr ratio in control,mild,moderate and severe HIE group was 0.16, 0.21,0.64,and 1.31,respectively.Lac/Cr ratio in control,mild,moderate and severe HIE group was 0.12,0.14,0.19,and 0.26,respectively.There was a significant difference in the ratio of GLx-? and Lac/Cr between HIE group and control group(t=5.01,P