Biomedical subjects

Alexandre A Khrapitchev

Publications and source records attributed to Alexandre A Khrapitchev.

3 recordsLinked to original sources

PubMed2006

Centric-scan SPRITE magnetic resonance imaging with prepared magnetisation.

The combination of contrast preparation with centric-scan SPRITE imaging readout is investigated. The main benefit of SPRITE, its ability to image objects with short T2, is retained. We demonstrate T1 and T2 mapping as examples of magnetisation preparation followed by magnetisation storage and spatially resolved encoding. A strategy for selection of the most advantageous imaging parameters for contrast mapping is presented.

Journal Article↗

PubMed2005

Sectoral sampling in centric-scan SPRITE magnetic resonance imaging.

A new approach to the construction of k-space trajectories for centric-scan SPRITE in both 2D and 3D is presented. All benefits of previous SPRITE methods are retained, most importantly the ability to image objects with short T*(2). This new approach gives more flexibility in the choice of number of interleaves with points more evenly distributed across k-space. All these improvements positively contribute to image quality and resolution, which can be also traded off against experimental speed. Sectoral sampling will have significant benefits for magnetisation preparation contrast imaging.

Journal Article↗

PubMedDate not supplied

Spatial dependence of dispersion.

The use of Pulsed Gradient Spin Echo (PGSE) NMR to investigate flow in porous media is well established. Using two pairs of position-encoding pulses in the PGSE experiment gives the possibility of examining velocity fluctuations, by comparing displacements, during the two encoding intervals. This method may be used to measure the asymptotic dispersion coefficient as well as the Velocity Auto-Correlation Function (VACF) in porous media flow. Some examples of two-dimensional maps of density and velocity distributions are accompanied by the first attempt to perform localized measurements of flow dispersion in porous media.

Magnetic Resonance Spectroscopy↗