In:
Magnetic Resonance in Medicine, Wiley, Vol. 81, No. 2 ( 2019-02), p. 839-851
Abstract:
Acquisition timing and B 1 calibration are two key factors that affect the quality and accuracy of hyperpolarized 13 C MRI. The goal of this project was to develop a new approach using regional bolus tracking to trigger Bloch‐Siegert B 1 mapping and real‐time B 1 calibration based on regional B 1 measurements, followed by dynamic imaging of hyperpolarized 13 C metabolites in vivo. Methods The proposed approach was implemented on a system which allows real‐time data processing and real‐time control on the sequence. Real‐time center frequency calibration upon the bolus arrival was also added. The feasibility of applying the proposed framework for in vivo hyperpolarized 13 C imaging was tested on healthy rats, tumor‐bearing mice and a healthy volunteer on a clinical 3T scanner following hyperpolarized [1‐ 13 C]pyruvate injection. Multichannel receive coils were used in the human study. Results Automatic acquisition timing based on either regional bolus peak or bolus arrival was achieved with the proposed framework. Reduced blurring artifacts in real‐time reconstructed images were observed with real‐time center frequency calibration. Real‐time computed B 1 scaling factors agreed with real‐time acquired B 1 maps. Flip angle correction using B 1 maps results in a more consistent quantification of metabolic activity (i.e, pyruvate‐to‐lactate conversion, k PL ). Experiment recordings are provided to demonstrate the real‐time actions during the experiment. Conclusions The proposed method was successfully demonstrated on animals and a human volunteer, and is anticipated to improve the efficient use of the hyperpolarized signal as well as the accuracy and robustness of hyperpolarized 13 C imaging.
Type of Medium:
Online Resource
ISSN:
0740-3194
,
1522-2594
Language:
English
Publisher:
Wiley
Publication Date:
2019
detail.hit.zdb_id:
605774-3
detail.hit.zdb_id:
1493786-4
