B0 navigator enables respiratory motion navigation in radial stack‐of‐stars liver Look‐Locker T1 mapping.
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| Title: | B |
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| Authors: | Stelter, Jonathan1 (AUTHOR) jonathan.stelter@tum.de, Weiss, Kilian2 (AUTHOR), Spieker, Veronika3,4 (AUTHOR), Schnabel, Julia A.3,4,5 (AUTHOR), Braren, Rickmer F.1 (AUTHOR), Karampinos, Dimitrios C.1,6,7 (AUTHOR) |
| Source: | Magnetic Resonance in Medicine. Oct2025, Vol. 94 Issue 4, p1458-1468. 11p. |
| Subjects: | Respiratory mechanics, Motion compensation (Signal processing), Computer-assisted image analysis (Medicine), Automatic tracking, Diagnostic imaging, Magnetic resonance imaging, Image quality in imaging systems |
| Abstract: | Purpose: To develop a B0$$ {B}_0 $$ self‐navigation approach to estimate respiratory motion for motion‐corrected liver T1$$ {T}_1 $$ mapping using a Look‐Locker acquisition with radial stack‐of‐stars trajectory. Methods: The proposed method derives 1D field‐map profiles from the oversampled k‐space center to estimate a normalized breathing curve and the B0$$ {B}_0 $$ variation amplitude for each slice and coil. B0$$ {B}_0 $$ drift and contrast variations, inherent to the Look‐Locker acquisition, were modeled and corrected by fitting and demodulating drift and offset terms. The breathing curve was employed to bin data into motion states for motion‐resolved reconstruction, followed by water‐specific T1$$ {T}_1 $$ mapping. Simulations with an anatomical body model and in vivo experiments with a Look‐Locker multi‐echo gradient echo sequence were performed to validate the technique. The estimated normalized breathing curve was compared with magnitude‐ and phase‐based self‐navigation approaches using principal component analysis. Results: The proposed B0$$ {B}_0 $$ self‐navigation reliably estimated the normalized breathing curve and the B0$$ {B}_0 $$ variation amplitude in simulations and in vivo. B0$$ {B}_0 $$ variation amplitudes increased with greater tissue displacement, with median values across slices and coils ranging from 4 to 15 Hz at 3 T in volunteers. Motion‐resolved reconstruction using the estimated breathing curve reduced motion artifacts and improved image and T1$$ {T}_1 $$ mapping quality compared to motion‐averaged reconstruction. Conclusion: B0$$ {B}_0 $$ self‐navigation allows estimation of respiratory motion in acquisitions with varying contrast and quantifies the B0$$ {B}_0 $$ variation amplitude, providing a possible surrogate signal for tissue displacement and enabling self‐gated liver T1$$ {T}_1 $$ mapping using a Look‐Locker approach. [ABSTRACT FROM AUTHOR] |
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| Database: | Engineering Source |
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| Abstract: | Purpose: To develop a B0$$ {B}_0 $$ self‐navigation approach to estimate respiratory motion for motion‐corrected liver T1$$ {T}_1 $$ mapping using a Look‐Locker acquisition with radial stack‐of‐stars trajectory. Methods: The proposed method derives 1D field‐map profiles from the oversampled k‐space center to estimate a normalized breathing curve and the B0$$ {B}_0 $$ variation amplitude for each slice and coil. B0$$ {B}_0 $$ drift and contrast variations, inherent to the Look‐Locker acquisition, were modeled and corrected by fitting and demodulating drift and offset terms. The breathing curve was employed to bin data into motion states for motion‐resolved reconstruction, followed by water‐specific T1$$ {T}_1 $$ mapping. Simulations with an anatomical body model and in vivo experiments with a Look‐Locker multi‐echo gradient echo sequence were performed to validate the technique. The estimated normalized breathing curve was compared with magnitude‐ and phase‐based self‐navigation approaches using principal component analysis. Results: The proposed B0$$ {B}_0 $$ self‐navigation reliably estimated the normalized breathing curve and the B0$$ {B}_0 $$ variation amplitude in simulations and in vivo. B0$$ {B}_0 $$ variation amplitudes increased with greater tissue displacement, with median values across slices and coils ranging from 4 to 15 Hz at 3 T in volunteers. Motion‐resolved reconstruction using the estimated breathing curve reduced motion artifacts and improved image and T1$$ {T}_1 $$ mapping quality compared to motion‐averaged reconstruction. Conclusion: B0$$ {B}_0 $$ self‐navigation allows estimation of respiratory motion in acquisitions with varying contrast and quantifies the B0$$ {B}_0 $$ variation amplitude, providing a possible surrogate signal for tissue displacement and enabling self‐gated liver T1$$ {T}_1 $$ mapping using a Look‐Locker approach. [ABSTRACT FROM AUTHOR] |
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| ISSN: | 07403194 |
| DOI: | 10.1002/mrm.30567 |
