Highly Accelerated SSFP Imaging with Controlled Aliasing in Parallel Imaging and integrated-SSFP (CAIPI-iSSFP).
10.13104/imri.2017.21.4.210
- Author:
Thomas MARTIN
1
;
Yi WANG
;
Shams RASHID
;
Xingfeng SHAO
;
Steen MOELLER
;
Peng HU
;
Kyunghyun SUNG
;
Danny JJ WANG
Author Information
1. Department of Radiological Sciences, University of California Los Angeles, California, USA.
- Publication Type:Original Article
- Keywords:
CAIPI-iSSFP;
CAIPI-bSSFP;
CAIPIRINHA;
Extended phase graphs (EPG);
Simultaneous multi-slice (SMS)
- MeSH:
Acceleration;
Artifacts;
Brain;
Liver;
White Matter
- From:Investigative Magnetic Resonance Imaging
2017;21(4):210-222
- CountryRepublic of Korea
- Language:English
-
Abstract:
PURPOSE: To develop a novel combination of controlled aliasing in parallel imaging results in higher acceleration (CAIPIRINHA) with integrated SSFP (CAIPI-iSSFP) for accelerated SSFP imaging without banding artifacts at 3T. MATERIALS AND METHODS: CAIPI-iSSFP was developed by adding a dephasing gradient to the balanced SSFP (bSSFP) pulse sequence with a gradient area that results in 2π dephasing across a single pixel. Extended phase graph (EPG) simulations were performed to show the signal behaviors of iSSFP, bSSFP, and RF-spoiled gradient echo (SPGR) sequences. In vivo experiments were performed for brain and abdominal imaging at 3T with simultaneous multi-slice (SMS) acceleration factors of 2, 3 and 4 with CAIPI-iSSFP and CAIPI-bSSFP. The image quality was evaluated by measuring the relative contrast-to-noise ratio (CNR) and by qualitatively assessing banding artifact removal in the brain. RESULTS: Banding artifacts were removed using CAIPI-iSSFP compared to CAIPI-bSSFP up to an SMS factor of 4 and 3 on brain and liver imaging, respectively. The relative CNRs between gray and white matter were on average 18% lower in CAIPI-iSSFP compared to that of CAIPI-bSSFP. CONCLUSION: This study demonstrated that CAIPI-iSSFP provides up to a factor of four acceleration, while minimizing the banding artifacts with up to a 20% decrease in the relative CNR.
