Influence of k-space trajectory corrections on proton density mapping with ultrashort echo time imaging: Application for imaging of short T2 components in white matter

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216224%3A14740%2F18%3A00101216" target="_blank" >RIV/00216224:14740/18:00101216 - isvavai.cz</a>

Nalezeny alternativní kódy

RIV/68081731:_____/18:00491279 RIV/65269705:_____/18:00069532

Výsledek na webu

<a href="http://dx.doi.org/10.1016/j.mri.2018.04.020" target="_blank" >http://dx.doi.org/10.1016/j.mri.2018.04.020</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1016/j.mri.2018.04.020" target="_blank" >10.1016/j.mri.2018.04.020</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Influence of k-space trajectory corrections on proton density mapping with ultrashort echo time imaging: Application for imaging of short T2 components in white matter

Popis výsledku v původním jazyce

Purpose: To evaluate the impact of MR gradient system imperfections and limitations for the quantitative mapping of short T2* signals performed by ultrashort echo time (UTE) acquisition approach. Materials and methods: The measurement of short T2* signals from a phantom and a healthy volunteer study (8 subjects of average age 28 4 years) were performed on a 3T scanner. The characteristics of the gradient system were obtained using calibration method performed directly on the measured subject or phantom. This information was used to calculate the actual sampling trajectory with the help of a parametric eddy current model. The actual sample positions were used to reconstruct corrected images and compared with uncorrected data. Results: Comparison of both approaches, i.e., without and with correction of k-space sampling trajectories revealed substantial improvement when correction was applied. The phantom experiments demonstrate substantial in-plane signal intensity variations for uncorrected sampling trajectories. In the case of the volunteer study, this led to significant differences in relative proton density (RPD) estimation between the uncorrected and corrected data (P = 0.0117 by Wilcoxon matched-pairs test) and provides for about 15% higher values for short T2* components of white matter (WM) in the case of uncorrected images. Conclusion: The imperfection of the applied gradients could induce errors in k-space data sampling which further propagates into the fidelity of the UTE images and jeopardizes precision of quantification. However, the study proved that measurement of gradient errors together with correction of sample positions can contribute to increased accuracy and unbiased characterization of short T2* signals.

Název v anglickém jazyce

Influence of k-space trajectory corrections on proton density mapping with ultrashort echo time imaging: Application for imaging of short T2 components in white matter

Popis výsledku anglicky

Purpose: To evaluate the impact of MR gradient system imperfections and limitations for the quantitative mapping of short T2* signals performed by ultrashort echo time (UTE) acquisition approach. Materials and methods: The measurement of short T2* signals from a phantom and a healthy volunteer study (8 subjects of average age 28 4 years) were performed on a 3T scanner. The characteristics of the gradient system were obtained using calibration method performed directly on the measured subject or phantom. This information was used to calculate the actual sampling trajectory with the help of a parametric eddy current model. The actual sample positions were used to reconstruct corrected images and compared with uncorrected data. Results: Comparison of both approaches, i.e., without and with correction of k-space sampling trajectories revealed substantial improvement when correction was applied. The phantom experiments demonstrate substantial in-plane signal intensity variations for uncorrected sampling trajectories. In the case of the volunteer study, this led to significant differences in relative proton density (RPD) estimation between the uncorrected and corrected data (P = 0.0117 by Wilcoxon matched-pairs test) and provides for about 15% higher values for short T2* components of white matter (WM) in the case of uncorrected images. Conclusion: The imperfection of the applied gradients could induce errors in k-space data sampling which further propagates into the fidelity of the UTE images and jeopardizes precision of quantification. However, the study proved that measurement of gradient errors together with correction of sample positions can contribute to increased accuracy and unbiased characterization of short T2* signals.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

30224 - Radiology, nuclear medicine and medical imaging

Projekt

Výsledek vznikl pri realizaci vícero projektů. Více informací v záložce Projekty.

Návaznosti

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)

Rok uplatnění

2018

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

51

Číslo periodika v rámci svazku

SEP

Stát vydavatele periodika

US - Spojené státy americké

Počet stran výsledku

9

Strana od-do

87-95

Kód UT WoS článku

000437819200012

EID výsledku v databázi Scopus

2-s2.0-85046688616