Detection of Microhemorrhage in Posterior Reversible Encephalopathy Syndrome Using Susceptibility-Weighted Imaging

Hemorrhage in posterior reversible encephalopathy syndrome occurs in 15-17% of patients but can be underestimated by using conventional MRI. Thus, these authors used SWI to study 31 patients with PRES and found that microbleeds were present in nearly 65% and subarachnoid hemorrhage in 10%. In some patients, microhemorrhages persisted after PRES resolved and in others these developed after its onset. Although the clinical significance of these small bleeds is not known, they could be caused by endothelial cell damage

Comparison of Spin-Echo T1- and T2-Weighted and Gradient-Echo T1-Weighted Images at 3T in Evaluating Very Preterm Neonates at Term-Equivalent Age

Term-equivalent imaging can assess myelination status in very preterm infants (<30 weeks' gestational age at birth). However, myelination assessment has yet to be compared among GRE-T1WI, SE-T1WI, and SE-T2WI at 3T. We aimed to compare the rates of myelination among those 3 sequences in 11 very preterm neonates who underwent 3T MR imaging at term-equivalent age and subsequently had normal neurologic development. On each sequence, 2 neuroradiologists individually assessed 22 structures. SE-T2WI depicted a higher myelination rate (present in 58.2%–66.4% of all structures) than either GRE-T1WI (51.6%–63.9%) or SE-T1WI (20.5%–38.5%), while GRE-T1WI had the highest interobserver agreement (κ, 0.56; P < .0001). Myelination was present in 90%–100% of patients within the corpus callosum splenium, DSCP, ICP, lateral lemniscus, and spinal tract/nucleus of cranial nerve V on SE-T2WI, and in the DSCP, ICP, lateral lemniscus, medial lemniscus, pyramidal decussation, PLIC, and superior cerebellar peduncle on GRE-T1WI, occurring in similar structures as previously shown at 1.5T and 1T. However, it is not clear whether these findings represent true myelination versus precursors to myelination

Measurement and Analysis of Brain Deformation during Neurosurgery

Recent studies have shown that the surface of the brain is deformed by up to 20mm after the skull is opened during neurosurgery, which could lead to substantial error in commercial image guided surgery systems. We quantitatively analyse the intraoperative brain deformation of 24 subjects to investigate whether simple rules can describe or predict the deformation. Interventional MR images acquired at the start and end of the procedure are registered non-rigidly to obtain deformation values throughout the brain. Deformation patterns are investigated quantitatively with respect to the location and magnitude of deformation, and to the distribution and principal direction of the displacements. We also measure the volume change of the lateral ventricles by manual segmentation. Our study indicates that brain..

Distinguishing 3 classes of corpus callosal abnormalities in consanguineous families

Objective: We sought to create a classification system for pediatric corpus callosal abnormalities (CCA) based upon midline sagittal brain MRI. We used the term CCA for patients with structural variants of the corpus callosum, excluding patients with interhemispheric cyst variant or pure dysplasia without hypoplasia. Currently, no system exists for nonsyndromic forms of CCA, and attempts to create such a system have been hampered by highly variable morphology in patients with sporadic CCA. We reasoned that any useful strategy should classify affected family members within the same type, and that phenotypic variability should be minimized in patients with recessive disease