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Application of center-out k-space trajectories to three-dimensional imaging of structure and blood transport in the human brain

A novel non-invasive imaging method of unique k-space trajectory named “3D center-out EPI with cylindrical encoding” was developed and implemented for fast imaging of the human brain. The method based on a variant of 3D hybrid EPI combines advantages of the Cartesian and the radial encoding to achieve ultra-short echo time independent of spatial
resolution and reasonably short echo train length yielding a quality image of high signal-to-noise ratio. Unlike rectilinear sampling, the method offers not only less motion and flow artifacts but enables also the undersampling capability. As a result, the method improves temporal resolution by shortening the measurement time. Nonetheless, artifacts induced from
long-term drifts of the magnetic field as well as geometrical distortions caused by B0 inhomogeneity were removed with the average phase of the k-space center lines and an additional field map scan. Compared to other cylindrical k-space trajectories based on echo-planar imaging, which lead to progressively increasing echo time upon increasing the spatial resolution, the proposed method offers more benefits. As a significant application, imaging readout of the novel technique was applied to true 3D cine imaging which was later used in the combination of pseudo-continuous arterial spin labeling module in order to track a short arterial spin labeling (ASL) bolus of well-defined length along the fast passage through the large vessel compartment of the brain. Parametric maps of ASL signal change, estimated time-to-peak and ASL bolus width were extracted in order to characterize the macrovascular compartments of the brain-feeding arteries. Consequently, bolus dispersion within a single arterial branch was also assessed.

Identiferoai:union.ndltd.org:DRESDEN/oai:qucosa.de:bsz:15-qucosa-211022
Date26 September 2016
CreatorsShrestha, Manoj
ContributorsUniversität Leipzig,, Prof. Dr. rer. nat. Daniel Huster, Prof. Dr. rer. nat. Harald E. Möller, Prof. Dr. rer. nat. Jürgen Haase, Dr. rer. nat. habil. André Pampel
PublisherUniversitätsbibliothek Leipzig
Source SetsHochschulschriftenserver (HSSS) der SLUB Dresden
LanguageEnglish
Detected LanguageEnglish
Typedoc-type:doctoralThesis
Formatapplication/pdf

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