Free-breathing variable flip angle balanced SSFP cardiac cine imaging with reduced SAR at 3T.
To develop a free-breathing variable flip angle (VFA) balanced steady-state free precession (bSSFP) cardiac cine imaging technique with reduced specific absorption rate (SAR) at 3 Tesla.



Free-breathing VFA (FB-VFA) images in the short-axis and four-chamber views were acquired using an optimal VFA scheme, then compared with conventional breath-hold constant flip angle (BH-CFA) acquisitions. Two cardiac MRI experts used a 5-point scale to score images from healthy subjects (N = 10). The left ventricular ejection fraction, end diastolic volume (LVEDV), end systolic volume, stroke volume (LVSV), and end diastolic myocardial mass (LVEDM) were determined by manual contour analysis for BH-CFA and FB-VFA. A pilot evaluation of FB-VFA was performed in one patient with Duchenne muscular dystrophy.



FB-VFA SAR was 25% lower than BH-CFA with similar blood-myocardium contrast. The qualitative FB-VFA score was lower than the BH-CFA for the short-axis (3.1 ± 0.5 versus 4.3 ± 0.8; P < 0.05) and the four-chamber view (3.4 ± 0.4 versus 4.6 ± 0.6; P < 0.05). The LVEDV and the LVSV were 5% and 12% larger (P < 0.05) for FB-VFA compared with BH-CFA. There was no difference in LVEDM.



FB-VFA bSSFP cardiac cine imaging decreased the SAR at 3T with image quality sufficient to perform cardiac functional analysis. Magn Reson Med 76:1210-1216, 2016. © 2015 Wiley Periodicals, Inc.
Department of Radiological Sciences, University of California, Los Angeles, California, USA.|Department of Bioengineering, University of California, Los Angeles, California, USA.
Subashini
S
Srinivasan
Siemens Canada Limited, Winnipeg, Manitoba, Canada.
Randall M
RM
Kroeker
Department of Radiological Sciences, University of California, Los Angeles, California, USA.
Simon
S
Gabriel
Department of Radiological Sciences, University of California, Los Angeles, California, USA.
Adam
A
Plotnik
Department of Radiological Sciences, University of California, Los Angeles, California, USA.
Sergio R
SR
Godinez
Department of Radiological Sciences, University of California, Los Angeles, California, USA.|Biomedical Physics Interdepartmental Program, University of California, Los Angeles, California, USA.
Peng
P
Hu
Department of Pediatrics, University of California, Los Angeles, California, USA.
Nancy
N
Halnon
Department of Radiological Sciences, University of California, Los Angeles, California, USA.|Biomedical Physics Interdepartmental Program, University of California, Los Angeles, California, USA.
J Paul
JP
Finn
Department of Radiological Sciences, University of California, Los Angeles, California, USA. daniel.ennis@ucla.edu.|Department of Bioengineering, University of California, Los Angeles, California, USA. daniel.ennis@ucla.edu.|Biomedical Physics Interdepartmental Program, University of California, Los Angeles, California, USA. daniel.ennis@ucla.edu.
Daniel B
DB
Ennis
D065638:Absorption, Radiation; D000328:Adult; D000465:Algorithms; D005260:Female; D006334:Heart Function Tests / Q000379:methods; D006352:Heart Ventricles / Q000000981:diagnostic imaging*; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D019028:Magnetic Resonance Imaging, Cine / Q000379:methods*; D008297:Male; D000069079:Radiation Exposure / Q000032:analysis*; D015203:Reproducibility of Results; D015656:Respiratory Mechanics; D055425:Respiratory-Gated Imaging Techniques / Q000379:methods*; D012680:Sensitivity and Specificity; D012815:Signal Processing, Computer-Assisted
bSSFP; free-breathing cardiac cine imaging; variable flip angle