Journal of neuroimaging : official journal of the American Society of Neuroimaging
-
Comparative Study
Computed tomography and transcranial Doppler findings in acute and subacute phases of intracerebral hemorrhagic stroke.
The hematoma volume is an important determinant of outcome and a predictor of clinical deterioration in patients with intracerebral hemorrhage (ICH). Our goal was to evaluate alterations in the cerebral circulation, in respect to hemorrhage and edema volume changes, using transcranial Doppler (TCD). ⋯ TCD monitoring sensitively demonstrates the hemodynamic change caused by ICH but the severity of the changes does not correlate with the volume of the ICH in acute stage. The CPP, RAP, and CBFI values are more sensitive parameters than the absolute velocity values, therefore they contribute more to the understanding of hemodynamic changes developed after spontaneous ICH.
-
Comparative Study Observational Study
Effect of SOHAM meditation on human brain: a voxel-based morphometry study.
The anatomical correlates of long-term meditators involved in practice of "SOHAM" meditation have been studied using voxel-based morphometry (VBM). The VBM analysis indicates significantly higher gray matter density in brain stem, ventral pallidum, and supplementary motor area in the meditators as compared with age-matched nonmeditators. The observed changes in brain structure are compared with other forms of meditation.
-
The "ears of the lynx" sign was previously reported as a neuroimaging finding observed in patients with autosomal recessive hereditary spastic paraplegia in association with a thin corpus callosum (ARHSP-TCC). We report a patient with a chronic form of Marchiafava-Bignami disease (MBD) that presented with this imaging feature. Diffusion tensor imaging (DTI) and fiber-tracking data support that this finding is a consequence of the structural derangement, which enlarges a preexisting border zone of the bundles of fibers from the corpus callosum (CC) genu to the forceps minor and anterior corona radiata. Therefore, we assume that despite their pathological differences, damage to the anterior portion of the CC is responsible for the imaging similarities between MBD and ARHSP-TCC.
-
Although transesophageal echocardiography (TEE) is the gold standard for right to left shunt detection, we observed that transcranial Doppler (TCD) was more sensitive and sought an explanation. ⋯ TEEs and TCDs are operator dependent and thus subject to false negatives. The lower yield and interoperator variability in TEE results appear to reflect the lack of performance protocols and engender concern about false negatives in community use. Consensus performance protocols and certification criteria for both modalities should have an impact on accuracy of shunt detection.
-
Integration of functional connectivity analysis based on resting-state functional Magnetic Resonance Imaging (fMRI) and structural connectivity analysis based on Diffusion-Weighted Imaging (DWI) has shown great potential to improve understanding of the neural networks in the human brain. However, there are sensitivity and specificity-related interpretation issues that must be addressed. ⋯ This fMRI/DWI integration study suggests that functional connectivity analysis might be a more sensitive and robust approach in understanding the connectivity between cortical regions, and can be used to improve DWI-based structural connectivity analysis.