In vivo tracing of superparamagnetic iron oxide-labeled bone marrow mesenchymal stem cells transplanted for traumatic brain injury by susceptibility weighted imaging in a rat model / 中华创伤杂志(英文版)

<p><b>OBJECTIVE</b>To label rat bone marrow mesenchymal stem cells (BMSCs) with superparamagnetic iron oxide (SPIO) in vitro, and to monitor the survival and location of these labeled BMSCs in a rat model of traumatic brain injury (TBI) by susceptibility weighted imaging (SWI) sequence.</p><p><b>METHODS</b>BMSCs were cultured in vitro and then labeled with SPIO. Totally 24 male Sprague Dawley (SD) rats weighing 200-250 g were randomly divided into 4 groups: Groups A-D (n equal to 6 for each group). Moderate TBI models of all the rats were developed in the left hemisphere following Feeney's method. Group A was the experimental group and stereotaxic transplantation of BMSCs labeled with SPIO into the region nearby the contusion was conducted in this group 24 hours after TBI modeling. The other three groups were control groups with transplantation of SPIO, unlabeled BMSCs and injection of nutrient solution respectively conducted in Groups B, C and D at the same time. Monitoring of these SPIO-labeled BMSCs by SWI was performed one day, one week and three weeks after implantation.</p><p><b>RESULTS</b>Numerous BMSCs were successfully labeled with SPIO. They were positive for Prussian blue staining and intracytoplasm positive blue stained particles were found under a microscope (200). Scattered little iron particles were observed in the vesicles by electron microscopy (5000). MRI of the transplantation sites of the left hemisphere demonstrated a low signal intensity on magnitude images, phase images and SWI images for all the test rats in Group A, and the lesion in the left parietal cortex demonstrated a semicircular low intensity on SWI images, which clearly showed the distribution and migration of BMSCs in the first and third weeks. For Group B, a low signal intensity by MRI was only observed on the first day but undetected during the following examination. No signals were observed in Groups C and D at any time points.</p><p><b>CONCLUSION</b>SWI sequence in vivo can consecutively and noninvasively trace and demonstrate the status and distribution of BMSCs labeled with SPIO in the brain of TBI model rats.</p>

Application of MRI in indirect temporomandibular joint injury without condylar fracture / 中华创伤杂志(英文版)

<p><b>OBJECTIVE</b>To discuss the application of MRI in indirect temporomandibular joint injury without condylar fracture.</p><p><b>METHODS</b>MRI examination on temporomandibular joint was conducted in 28 patients with indirect injury to temporomandibular joint without condylar fracture. The scanning sequence included T(1)WI, PDWI on oblique sagittal section at both open and closed mouth positions, and T(1)WI, T(2)WI on oblique coronal section. The MRI appearance was analyzed by 2 senior radiologists.</p><p><b>RESULTS</b>Among the 56 temporomandibular joints of 28 patients, 35 joints exhibited pathological changes on MRI, in which there were 9 bone injuries, 21 articular disc dislocation, 24 intracapsular hematocele and hydrops.</p><p><b>CONCLUSIONS</b>MRI can clearly reveal bone injury, articular disc dislocation as well as articular capsule abnormality in the indirect injury of temporomandibular joint without condylar fracture. It is highly advocated in clinical use.</p>

Study of paroxysmal kinesigenic dyskinesia with fMRI / 浙江大学学报·医学版

<p><b>OBJECTIVE</b>To detect the differences in subcortical structures between patients with paroxysmal kinesigenic dyskinesia (PKD) and normal subjects during movement preparation and execution.</p><p><b>METHODS</b>The PKD patients performed a movement task, in which a CUE signal (preparation) indicated the movement sequence prior to the appearance of an imperative GO signal (execution). Event-related functional magnetic resonance imaging (fMRI) and 3dDeconvolve program of AFNI were used to estimate the hemodynamic response function and to generate activation maps.</p><p><b>RESULT</b>During movement preparation, the activated brain areas in PKD patients were less than those of normal subject, and there was no activation in basal ganglia in PKD patients. During execution, the activation was also less in PKD patients except in bilateral M1.</p><p><b>CONCLUSION</b>During intermission, abnormalities of the brain still exist in PKD patients when during preparing or performing movement. The movement circuit in the brain displays an unusual state. The attack may be caused by reducing of inhibition in brain areas.</p>

Lateralized distribution of motor areas involved in voluntary movement / 浙江大学学报·医学版

<p><b>OBJECTIVE</b>To investigate the brain functional laterality in motor areas during motor execution systematically.</p><p><b>METHODS</b>Functional magnetic resonance imaging (fMRI) was employed combined with right hand sequential finger movement task to investigate brain activation pattern and laterality in 8 right-handed subjects. 3dDeconvolve program of AFNI was used to estimate the hemodynamic response function and to generate activation maps. Then the laterality index (LI) was calculated and tested statistically.</p><p><b>RESULT</b>All motor areas including the areas which were previously considered to be engage in movement preparation only were activated in movement execution. In the activation map, it appeared left lateralization in cerebra and right lateralization in cerebella. After further statistical test, it was found that in primary motor area (M1), supplementary motor area (SMA) and posterior parietal cortex (PPC), there were left lateralization. While in premotor cortex (PMC), cingulate gyrus and basal ganglia (BG), the lateralization tendency was not obvious. The activation in cerebella is characterized with right lateralization.</p><p><b>CONCLUSION</b>Though there are tiny differences among subjects, most of the motor areas appear lateralized activation. Past studies only observed laterality in several motor areas. It may be due to the difficulty of the task or the experimental design.</p>