Water diffusion and T 2 quantification in transient-state MRI: the effect of RF pulse sequence.

Autor: Fuderer M; Radiotherapy, Imaging Division, University Medical Center Utrecht, Utrecht, The Netherlands., van der Heide O; Radiotherapy, Imaging Division, University Medical Center Utrecht, Utrecht, The Netherlands., Liu H; Radiotherapy, Imaging Division, University Medical Center Utrecht, Utrecht, The Netherlands., van den Berg CAT; Radiotherapy, Imaging Division, University Medical Center Utrecht, Utrecht, The Netherlands., Sbrizzi A; Radiotherapy, Imaging Division, University Medical Center Utrecht, Utrecht, The Netherlands.
Jazyk: angličtina
Zdroj: NMR in biomedicine [NMR Biomed] 2024 Jan; Vol. 37 (1), pp. e5044. Date of Electronic Publication: 2023 Sep 29.
DOI: 10.1002/nbm.5044
Abstrakt: In quantitative measurement of the T 2 value of tissues, the diffusion of water molecules has been recognized as a confounder. This is most notably so for transient-state quantitative mapping techniques, which allow simultaneous estimation of T 1 and T 2 . In prior work, apparently conflicting conclusions are presented on the level of diffusion-induced bias on the T 2 estimate. So far there is a lack of studies on the effect of the RF pulse angle sequence on the level of diffusion-induced bias. In this work, we show that the specific transient-state RF pulse sequence has a large effect on this level of bias. In particular, the bias level is strongly influenced by the mean value of the RF pulse angles. Also, for realistic values of the spoiling gradient area, we infer that the diffusion-induced bias is negligible for non-liquid human tissues; yet, for phantoms, the effect can be substantial (15% of the true T 2 value) for some RF pulse sequences. This should be taken into account in validation procedures.
(© 2023 The Authors. NMR in Biomedicine published by John Wiley & Sons Ltd.)
Databáze: MEDLINE
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