Cardiac magnetic resonance parallel imaging at 3.0 Tesla: technical feasibility and advantages.
OBJECTIVE
To quantify changes in signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR), specific absorption rate (SAR), RF power deposition, and imaging time in cardiac magnetic resonance imaging with and without the application of parallel imaging at 1.5 T and 3.0 T.


METHODS
Phantom and volunteer data were acquired at 1.5 T and 3.0 T with and without parallel imaging.


RESULTS
Doubling field strength increased phantom SNR by a factor of 1.83. In volunteer data, SNR and CNR values increased by factors of 1.86 and 1.35, respectively. Parallel imaging (reduction factor = 2) decreased phantom SNR by a factor of 1.84 and 2.07 when compared to the full acquisition at 1.5 T and 3.0 T, respectively. In volunteers, SNR and CNR decreased by factors of 2.65 and 2.05 at 1.5 T and 1.99 and 1.75 at 3.0 T, respectively. Doubling the field strength produces a nine-fold increase in SAR (0.0751 to 0.674 W/kg). Parallel imaging reduced the total RF power deposition by a factor of two at both field strengths.


CONCLUSIONS
Parallel imaging decreases total scan time at the expense of SNR and CNR. These losses are compensated at higher field strengths. Parallel imaging is effective at reducing total power deposition by reducing total scan time.
Department of Radiology, Mayo Clinic and Foundation, Rochester, Minnesota 55905, USA. mcgee.kiaran@mayo.edu
Kiaran P
KP
McGee
Josef P
JP
Debbins
Ed B
EB
Boskamp
LeRoy
L
Blawat
Lisa
L
Angelos
Kevin F
KF
King
D000328:Adult; D000704:Analysis of Variance; D016477:Artifacts; D005240:Feasibility Studies; D006321:Heart / Q000033:anatomy & histology*; D006801:Humans; D007089:Image Enhancement; D008279:Magnetic Resonance Imaging / Q000295:instrumentation / Q000379:methods* / Q000706:statistics & numerical data; D008280:Magnetics; D008297:Male; D019047:Phantoms, Imaging; D012016:Reference Values; D012680:Sensitivity and Specificity; D012815:Signal Processing, Computer-Assisted; D013997:Time Factors