More articles from Adult Brain
- Electrophysiologic Validation of Diffusion Tensor Imaging Tractography during Deep Brain Stimulation Surgery
Eleven patients underwent subthalamic nucleus deep brain stimulation. DTI and high-resolution T1- and T2-weighted MRI were performed at 3T. The electrode positions and current amplitudes that elicited corticospinal tract effects during the operation were studied to determine relative corticospinal tract distance. The mean intraoperative electrophysiologic corticospinal tract distance was 3.0 mm +/- 0.6 mm; the mean image-derived corticospinal tract distance (DTI fiber tractography) was 3.0 mm +/- 1.3 mm. DTI fiber tractography depicted the medial corticospinal border in concordance with electrophysiology under 2 different conditions and modeling approaches. Under both conditions, the electrophysiologic measurements were clearly related to the DTI fiber tractography.
- Improved Leakage Correction for Single-Echo Dynamic Susceptibility Contrast Perfusion MRI Estimates of Relative Cerebral Blood Volume in High-Grade Gliomas by Accounting for Bidirectional Contrast Agent Exchange
The authors' hypothesis is that incorporating bidirectional contrast agent transport into the DSC MR imaging signal model will improve rCBV estimates in brain tumors. A unidirectional contrast agent extravasation model (Boxerman-Weisskoff) was compared with a bidirectional contrast agent exchange model. For both models, they compared the goodness of fit with the parent leakage-contaminated relaxation rate curves and the difference between modeled interstitial relaxation rate curves and dynamic contrast-enhanced MR imaging in 21 patients with glioblastoma. The authors conclude that the bidirectional model more accurately corrects for the T1 or T2* enhancement arising from contrast agent extravasation due to blood-brain barrier disruption in high-grade gliomas by incorporating interstitial washout rates into the DSC MR imaging relaxation rate model.