Human liver CEST imaging at 7 T: Impact of B1+ shimming.
Saved in:
| Title: | Human liver CEST imaging at 7 T: Impact of B1+ shimming. |
|---|---|
| Authors: | Bulanov, Petr1,2 (AUTHOR) peter.a.bulanov@gmail.com, Menshchikov, Petr1 (AUTHOR), Grimm, Johannes A.1,2 (AUTHOR), Lutz, Max2 (AUTHOR), Orzada, Stephan1 (AUTHOR), Boyd, Philip S.1 (AUTHOR), Bachert, Peter1,2 (AUTHOR), Ladd, Mark E.1,2,3 (AUTHOR), Korzowski, Andreas1 (AUTHOR), Schmitter, Sebastian1,4,5 (AUTHOR) |
| Source: | Magnetic Resonance in Medicine. Oct2025, Vol. 94 Issue 4, p1604-1615. 12p. |
| Subjects: | Liver, Magnetic resonance imaging, Overhauser effect (Nuclear physics), Magnetization transfer |
| Abstract: | Purpose: To explore the feasibility of CEST imaging in the human liver at 7 T with B1+$$ {B}_1^{+} $$ shimming. Methods: CEST MRI was performed on a 7 T whole‐body scanner with a parallel transmission (pTx) system in five healthy volunteers. Static pTx (B1+$$ {B}_1^{+} $$ shimming) was applied to locally maximize the B1+$$ {B}_1^{+} $$ magnitude per input power within a given region of interest (ROI) of approximately 30 mm diameter (ROIshim). Relaxation‐compensated inverse magnetization transfer ratio (MTRRex) values were quantified for amide protons, guanidino protons, and relayed nuclear Overhauser effect signals based on five‐pool Lorentzian fit analysis. MTRRex values were corrected for B1 inhomogeneities using an absolute, accurate MR fingerprinting–based B1+$$ {B}_1^{+} $$ mapping technique. Results: Within the ROIshim, reliable MTRRex values could be calculated for an average of 85% of voxels. The mean MTRRex values and corresponding coefficient of variations across the group are: 0.113 ± 0.009, 8.8% for amide; 0.167 ± 0.010, 6.3% for nuclear Overhauser effect; and 0.079 ± 0.010, 12.9% for guanidino. MTRRex values exhibit low variation between subjects, as reflected by low coefficient of variations. Conclusion: In this study, we have demonstrated for the first time the feasibility of acquiring and quantifying relaxation‐compensated CEST contrasts in the human liver at ultrahigh field. The application of static pTx effectively eliminates B1+$$ {B}_1^{+} $$ dropouts and allows for accurate CEST contrast quantification within the selected ROI. In addition, the proposed B1+$$ {B}_1^{+} $$ mapping technique shows efficacy for enhanced MTRRex B1 corrections in the abdomen. [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.
Login for full access.
|
|
Be the first to leave a comment!
