K-space trajectory mapping and its application for ultrashort Echo time imaging

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F68081731%3A_____%2F17%3A00470615" target="_blank" >RIV/68081731:_____/17:00470615 - isvavai.cz</a>

Nalezeny alternativní kódy

RIV/00216224:14740/17:00094674

Výsledek na webu

<a href="http://dx.doi.org/10.1016/j.mri.2016.10.012" target="_blank" >http://dx.doi.org/10.1016/j.mri.2016.10.012</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1016/j.mri.2016.10.012" target="_blank" >10.1016/j.mri.2016.10.012</a>

Jazyk výsledku

angličtina

Název v původním jazyce

K-space trajectory mapping and its application for ultrashort Echo time imaging

Popis výsledku v původním jazyce

MR images are affected by system delays and gradient field imperfections which induce discrepancies between prescribed and actual k-space trajectories. This could be even more critical for non-Cartesian data acquisitions where even a small deviation from the assumed k-space trajectory results in severe image degradation and artifacts. Knowledge of the actual k-space trajectories is therefore crucial and can be incorporated in the reconstruction of high quality non-Cartesian images. A novel MR method for the calibration of actual gradient waveforms was developed using a combination of phase encoding increments and subsequent detection of the exact time point at which the corresponding trajectory is crossing the k-space origin. The measured sets of points were fitted to a parametrical model to calculate the complete actual acquisition trajectory. Measurements performed on phantoms and volunteers, positioned both in- and off-isocenter of the magnet, clearly demonstrate the improvement in reconstructed ultrashort echo time (UTE) images, when information from calibration of k-space sampling trajectories is employed in the MR image reconstruction procedure. The unique feature of the proposed method is its robustness and simple experimental setup, making it suitable for quick acquisition trajectory calibration procedures e.g. for non-Cartesian radial fast imaging.

Název v anglickém jazyce

K-space trajectory mapping and its application for ultrashort Echo time imaging

Popis výsledku anglicky

MR images are affected by system delays and gradient field imperfections which induce discrepancies between prescribed and actual k-space trajectories. This could be even more critical for non-Cartesian data acquisitions where even a small deviation from the assumed k-space trajectory results in severe image degradation and artifacts. Knowledge of the actual k-space trajectories is therefore crucial and can be incorporated in the reconstruction of high quality non-Cartesian images. A novel MR method for the calibration of actual gradient waveforms was developed using a combination of phase encoding increments and subsequent detection of the exact time point at which the corresponding trajectory is crossing the k-space origin. The measured sets of points were fitted to a parametrical model to calculate the complete actual acquisition trajectory. Measurements performed on phantoms and volunteers, positioned both in- and off-isocenter of the magnet, clearly demonstrate the improvement in reconstructed ultrashort echo time (UTE) images, when information from calibration of k-space sampling trajectories is employed in the MR image reconstruction procedure. The unique feature of the proposed method is its robustness and simple experimental setup, making it suitable for quick acquisition trajectory calibration procedures e.g. for non-Cartesian radial fast imaging.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

20601 - Medical engineering

Projekt

<a href="/cs/project/GA15-12607S" target="_blank" >GA15-12607S: Návrh a optimalizace pulzních sekvenci s ultrakrátkým echо-časem pro spolehlivou detekci obsahu myelinu v lidském mozku pomocí MR zobrazování.</a><br>

Návaznosti

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Rok uplatnění

2017

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název periodika

Magnetic Resonance Imaging

ISSN

0730-725X

e-ISSN

—

Svazek periodika

36

Číslo periodika v rámci svazku

February

Stát vydavatele periodika

US - Spojené státy americké

Počet stran výsledku

9

Strana od-do

68-76

Kód UT WoS článku

000393536100010

EID výsledku v databázi Scopus

2-s2.0-84994508591