ABSTRACT
<p><b>OBJECTIVE</b>To study the effect of BAM bone grafting combined with inactivated autologous porous bone flap in repairing skull defect in rats.</p><p><b>METHODS</b>Seventy-two Wistar rats with skull defect were randomly divided into control group, inactivated autologous bone flap group (AB group), BAM bone-induced artificial bone material group (BAM group), and inactivated autologous bone flap with BAM bone-induced artificial bone group (BAM+AB group). The bone healing was evaluated with micro-CT and the new bone formation was assessed with histological staining at 1, 2, and 3 months after modeling.</p><p><b>RESULTS</b>Inactivated porous bone flap combined with BAM bone-induced artificial bone effectively induced vascular and fibrous tissue regeneration and osteogenesis in the cranial defects. With the inactivated porous bone flap as the scaffold, BAM bone-induced artificial bone obviously promoted the restoration of the skull appearance in the rats with cranial defects.</p><p><b>CONCLUSION</b>Inactivated autologous bone flap group and BAM bone-induced artificial bone material can promote skull healing and restoration of the original skull appearance, and can be used for reconstruction of the local anatomy of the skull surface.</p>
ABSTRACT
<p><b>OBJECTIVE</b>To assess the value of white matter fiber tractography based on magnetic resonance diffusion-tensor imaging (MR-DTI), a new noninvasive technique that helps estimate the structural connectivity of the brain, in understanding the anatomy of the white matter fiber tract.</p><p><b>METHODS</b>Six consecutive volunteers received MR-DTI examination using a GE 1.5T Sign CV/I whole-body MR system and version 2.0 Functool software for image processing. The protocol included T1WI for localization and single-shot echo-planner diffusion tensor imaging of the entire brain in axial, sagittal, and /or coronal sections.</p><p><b>RESULTS</b>White matter fiber tracts imaged by MR-DTI were consistent with known white matter fiber anatomy. The major fiber tracts were well observed in all the cases. The tracts visualized included the corpus callosum, anterior commissure, uncinate fasciculus superior and inferior longitudinal fascicules, inferior occipito-frontal fasciculus, internal capsule and corona radiate.</p><p><b>CONCLUSION</b>A set of detailed white matter fiber anatomy maps of the normal brain is obtained by means of single-shot echo-planner diffusion tensor imaging at high resolution. This technique allows rapid visualization of the white matter tracts in vivo, and provides a new reliable means for studying fiber connectivity in the brain.</p>
Subject(s)
Adult , Female , Humans , Male , Middle Aged , Young Adult , Brain , Diffusion Tensor Imaging , Methods , Image Processing, Computer-Assisted , Imaging, Three-Dimensional , MethodsABSTRACT
<p><b>OBJECTIVE</b>To evaluate the quantitative relationship between white matter tract (WMT) variation resulting from cerebral tumors and shifting of the fractional anisotropy (FA) index in magnetic resonance (MR) diffusion tensor imaging (DTI).</p><p><b>METHODS</b>Four female and 8 male patients aged from 21 to 62 years with brain malignancies (2 malignant lymphomas, 2 low-grade astrocytomas, and 8 high-grade cerebral gliomas) underwent conventional contrast-enhanced MR and DTI examinations before operation. Routine T(2)-weighted image, fractional anisotropic (FA) map, color-coded directional map, three-dimensional white matter tractography (WMT), and the FA index of bilateral internal capsule were obtained in every patient.</p><p><b>RESULTS</b>Fiber tractography derived from DTI was consistent with known white matter fiber anatomy. The DTI patterns in WMT altered by the tumor were categorized on the basis of FA1/FA2 ratio as follows: pattern 1, FA1/FA2> or =75% with normal or only slightly decreased FA; pattern 2, 50%< or =FA1/FA2<75% with WMT displacement; pattern 3, 25%< or =FA1/FA2/50% with WMT involvement; pattern 4, FA1/FA2<25% with WMT destruction.</p><p><b>CONCLUSIONS</b>DTI allows for visualization of WMT and benefits surgical planning for patients with intrinsic brain tumor. There is a positive relationship between the bilateral FA ratio (FA1/FA2) variation and WMT alterations resulting from the tumor.</p>