High Resolution 3D Magnetic Resonance Fingerprinting with Hybrid Radial-Interleaved EPI Acquisition for Knee Cartilage T1 , T2 Mapping
10.13104/imri.2021.25.3.141
- Author:
Dongyeob HAN
1
;
Taehwa HONG
;
Yonghan LEE
;
Dong-Hyun KIM
Author Information
1. School of Electrical and Electronic Engineering, Yonsei University, Seoul, Korea
- Publication Type:Original Article
- From:Investigative Magnetic Resonance Imaging
2021;25(3):141-155
- CountryRepublic of Korea
- Language:English
-
Abstract:
Purpose:To develop a 3D magnetic resonance fingerprinting (MRF) method for application in high resolution knee cartilage PD, T1 , T2 mapping.
Materials and Methods:A novel 3D acquisition trajectory with golden-angle rotating radial in kxy direction and interleaved echo planar imaging (EPI) acquisition in the kz direction was implemented in the MRF framework. A centric order was applied to the interleaved EPI acquisition to reduce Nyquist ghosting artifact due to field inhomogeneity. For the reconstruction, singular value decomposition (SVD) compression method was used to accelerate reconstruction time and conjugate gradient sensitivity-encoding (CG-SENSE) was performed to overcome low SNR of the high resolution data. Phantom experiments were performed to verify the proposed method. In vivo experiments were performed on 6 healthy volunteers and 2 early osteoarthritis (OA) patients.
Results:In the phantom experiments, the T1 and T2 values of the proposed method were in good agreement with the spin-echo references. The results from the in vivo scans showed high quality proton density (PD), T1 , T2 map with EPI echo train length (NETL = 4), acceleration factor in through plane (Rz = 5), and number of radial spokes (Nspk = 4). In patients, high T2 values (50-60 ms) were seen in all transverse, sagittal, and coronal views and the damaged cartilage regions were in agreement with the hyper-intensity regions shown on conventional turbo spin-echo (TSE) images.
Conclusion:The proposed 3D MRF method can acquire high resolution (0.5 mm3 ) quantitative maps in practical scan time (~ 7 min and 10 sec) with full coverage of the knee (FOV: 160 × 160 × 120 mm3 ).
