Ultrafast and robust T2 mapping using optimized single‐shot multi‐echo planar imaging with alternating blips.

Saved in:
Bibliographic Details
Title: Ultrafast and robust T2 mapping using optimized single‐shot multi‐echo planar imaging with alternating blips.
Authors: Utkur, Mustafa1 (AUTHOR) mustafa.utkur@childrens.harvard.edu, Timms, Liam1 (AUTHOR) liam.timms@childrens.harvard.edu, Kurugol, Sila1 (AUTHOR), Afacan, Onur1 (AUTHOR)
Source: Magnetic Resonance in Medicine. Aug2025, Vol. 94 Issue 2, p530-540. 11p.
Subjects: Magnetic resonance imaging, Magnetic flux density, Diffusion magnetic resonance imaging, Phase coding, Fetal brain
Abstract: Purpose: To develop a rapid, motion‐robust T2$$ {\mathrm{T}}_2 $$ mapping technique suitable for clinical use across the body, including traditionally challenging, motion‐prone patient populations or body parts. Methods: A novel single‐shot multi‐echo spin‐echo EPI sequence with alternating phase encoding direction on each echo was implemented. This sequence acquires multiple echoes to measure T2$$ {\mathrm{T}}_2 $$ from a single RF excitation. The alternating phase encoding gradient polarity enables the correction of geometric distortions in EPI using post‐processing software. Stimulated echoes were removed by optimizing spoiler gradients. Diffusion MRI can also be achieved by incorporating diffusion‐encoding gradients. Results: Phantom experiments showed no significant difference between measured and reference T2$$ {\mathrm{T}}_2 $$ values, indicating high precision and repeatability. In vivo, brain T2$$ {\mathrm{T}}_2 $$ maps exhibited similar anatomical detail and tissue contrast as a reference sequence, with T2$$ {\mathrm{T}}_2 $$ values of 70.0 ±$$ \kern0.5em \pm \kern0.5em $$ 4.0 ms for gray matter, 56.8 ±$$ \kern0.5em \pm \kern0.5em $$ 3.4 ms for the white matter at a magnetic field strength of 3 Tesla. High‐quality diffusion‐weighted images with minimal distortion were generated, even at high b‐values. T2$$ {\mathrm{T}}_2 $$ mapping results from the kidney and fetal brain showcased the method's applicability across different anatomical regions and patient populations. Conclusion: The single‐shot multi‐echo EPI sequence provided a basis for rapid, accurate T2$$ {\mathrm{T}}_2 $$ relaxation mapping by correcting distortion and mitigating motion artifacts. This sequence enhances the clinical feasibility of quantitative T2$$ {\mathrm{T}}_2 $$ mapping across diverse patient populations and body areas. [ABSTRACT FROM AUTHOR]
Copyright of Magnetic Resonance in Medicine is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites without the copyright holder's express written permission. Additionally, content may not be used with any artificial intelligence tools or machine learning technologies. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
Database: Engineering Source
Full text is not displayed to guests.
Description
Abstract:Purpose: To develop a rapid, motion‐robust T2$$ {\mathrm{T}}_2 $$ mapping technique suitable for clinical use across the body, including traditionally challenging, motion‐prone patient populations or body parts. Methods: A novel single‐shot multi‐echo spin‐echo EPI sequence with alternating phase encoding direction on each echo was implemented. This sequence acquires multiple echoes to measure T2$$ {\mathrm{T}}_2 $$ from a single RF excitation. The alternating phase encoding gradient polarity enables the correction of geometric distortions in EPI using post‐processing software. Stimulated echoes were removed by optimizing spoiler gradients. Diffusion MRI can also be achieved by incorporating diffusion‐encoding gradients. Results: Phantom experiments showed no significant difference between measured and reference T2$$ {\mathrm{T}}_2 $$ values, indicating high precision and repeatability. In vivo, brain T2$$ {\mathrm{T}}_2 $$ maps exhibited similar anatomical detail and tissue contrast as a reference sequence, with T2$$ {\mathrm{T}}_2 $$ values of 70.0 ±$$ \kern0.5em \pm \kern0.5em $$ 4.0 ms for gray matter, 56.8 ±$$ \kern0.5em \pm \kern0.5em $$ 3.4 ms for the white matter at a magnetic field strength of 3 Tesla. High‐quality diffusion‐weighted images with minimal distortion were generated, even at high b‐values. T2$$ {\mathrm{T}}_2 $$ mapping results from the kidney and fetal brain showcased the method's applicability across different anatomical regions and patient populations. Conclusion: The single‐shot multi‐echo EPI sequence provided a basis for rapid, accurate T2$$ {\mathrm{T}}_2 $$ relaxation mapping by correcting distortion and mitigating motion artifacts. This sequence enhances the clinical feasibility of quantitative T2$$ {\mathrm{T}}_2 $$ mapping across diverse patient populations and body areas. [ABSTRACT FROM AUTHOR]
ISSN:07403194
DOI:10.1002/mrm.30516