Simon Reichert1, Dennis Kleimaier1, and Lothar Schad1
1Computer Assisted Clinical Medicine, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
1Computer Assisted Clinical Medicine, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
Low rank reconstruction and a fit of the undersampled
data (NUSF) were implemented and quantitatively compared for simulated and
measured 23Na TQTPPI data. In both cases, the measurement time can
be reduced by a factor of 5 without significantly decreasing the accuracy.
a) The TQTPPI pulse sequence consisted of three 90° pulses and an
additional 180° refocusing pulse. In
every phase step both the evolution time and a phase are incremented. b) A
fully sampled TQTPPI FID and the corresponding NUS TQTPPI FID are shown. The
undersampling pattern was sinusoidal Poisson gap sampling c) A Fourier
transformation leads to a sparse spectrum consisting of SQ and TQ signals. The
Fourier transform of the NUS FID shows an increased noise level and reduced SQ
and TQ signals. The spectrum and FID can be recovered using CS.
Variation of undersampling factor in the range of 2 to
16 using simulated data. The parameters were: ATQ/ASQ=10%,
SNR=70, T2S=39ms and T2F=10ms. a), b) and c) show ATQ/ASQ,
T2S and T2F, respectively. The deviation to ground
truth was less than 5% for undersampling factors up to 5. For T2S there
is a small offset for NUSF.