Journal of neuroimaging : official journal of the American Society of Neuroimaging
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Comparative Study
Hippocampal surface deformation accuracy in T1-weighted volumetric MRI sequences in subjects with epilepsy.
To demonstrate the accuracy across different acquisition and analysis methods, we evaluated the variability in hippocampal volumetric and surface displacement measurements resulting from two different MRI (magnetic resonance imaging) acquisition protocols. ⋯ Statistical comparison of hippocampal volumes and statistically thresholded HDM-LD surfaces in TLE patients showed no differences between the segmentations obtained in the two MRI acquisition sequences. This validates the robustness across MRI sequences of the HDM-LD technique for estimating volume and surface changes in subjects with epilepsy.
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Case Reports Comparative Study
7T MRI-Histologic Correlation Study of Low Specific Absorption Rate T2-Weighted GRASE Sequences in the Detection of White Matter Involvement in Multiple Sclerosis.
The high value of the specific absorption rate (SAR) of radio-frequency (RF) energy arising from the series of RF refocusing pulses in T2-weighted (T2-w) turbo spin echo (TSE) MRI hampers its clinical application at 7.0 Tesla (7T). T2-w gradient and spin echo (GRASE) uses the speed from gradient refocusing in combination with the chemical-shift/static magnetic field (B0) inhomogeneity insensitivity from spin-echo refocusing to acquire T2-w images with a limited number of refocusing RF pulses, thus reducing SAR. ⋯ T2-w GRASE images may replace T2-w TSE for clinical use. However, even at 7T, both sequences fail in detecting and characterizing MS disease beyond visible WM-Ls.
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Pediatric spinal trauma is unique. The developing pediatric spinal column and spinal cord deal with direct impact and indirect acceleration/deceleration or shear forces very different compared to adult patients. In addition children are exposed to different kind of traumas. ⋯ Magnetic resonance imaging is more sensitive for disco-ligamentous and spinal cord injuries. Depending on the clinical presentation and timing of trauma the various imaging modalities will be employed. In the current review article, a summary of the epidemiology and distribution of posttraumatic lesions is discussed in the context of the normal anatomical variations due to progressing development of the child.
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We investigated the relationship between transcranial Doppler (TCD) pulsatility index (PI) and central aortic pressure by measurement of the aortic augmentation index (AIx). ⋯ TCD PI was significantly related with central aortic pressure, especially PP. The PI in the MCA and BA is closely associated with the pulsatile component of BP in the systemic circulation.
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Comparative Study
Wall shear stress in major cerebral arteries as a function of age and gender--a study of 301 healthy volunteers.
The hemodynamic force of wall shear stress (WSS) has demonstrated a critical role in atherogenesis. ⋯ The overall decline in MWSS observed with age may be due to a decrease in flow. However, the marked drop in MWSS between the 48-57 and 58-67 age groups corresponded with an increase in diameter and systolic blood pressure rather than a significant drop in flow.