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ISMRM 2012 Prelim. Abstracts Oct 17, 2011 – Jason Su

ISMRM 2012 Prelim. Abstracts Oct 17, 2011 – Jason Su. kT points with DESPOT1 mapping @ 7T Observed modest improvements in B1 homogeneity with 1ch kT pts. Data problems: only collected 4 angles in vivo, barely gets over Ernst angle even with 2x overflipping according to AFI

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ISMRM 2012 Prelim. Abstracts Oct 17, 2011 – Jason Su

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  1. ISMRM 2012 Prelim. AbstractsOct 17, 2011 – Jason Su • kT points with DESPOT1 mapping @ 7T • Observed modest improvements in B1 homogeneity with 1ch kT pts. • Data problems: only collected 4 angles in vivo, barely gets over Ernst angle even with 2x overflipping according to AFI • Correction with a B1 map is better than kT points alone • Need get back and quantify improvement • Try to apply kT+B1 correction with our AFI data (meeting with Ives about this today) • 3T experiments? May not have enough B1 inhomogeneity to show improvement with kT+B1 correction over just B1 correction • Accelerated DESPOT1 Mapping with View Sharing • View sharing with proper scaling accelerates collection of SPGR DESPOT angles • LCAMP may go even faster but still some work to be done • MSmcDESPOT – baseline and 1yr MS study • Not much new since last time even with full 1yr set for normals • Progressive patients have greater increase in DV than CIS or RR • TBSS? • DEV/CISmcDESPOT – longitudinal MS studies with 1-3 month sampling interval • Christine and Nora are now editing lesion segmentation • Potential questions: • How does MWF/DV in a lesion change over time? • Greater shifts in EDSS than MSmcDESPOT, potential for more interesting longitudinal correlations

  2. Accelerated DESPOT1 Mapping with View Sharing • Introduction: DESPOT1 allows fast whole brain mapping of T1 with a collection of SPGR angles; typically only ~4 angles are needed, collected many more because aiming for mcDESPOT (how to spin this?); energy scaled view sharing provides a way to accelerate dynamic time series data -> consider the flip angle dimension as such • Methods: 3T, phantom and in vivo, 110x110x40 (2x2x4mm), SPGR angles, 1:1:13, manipulated fully sampled raw data to simulate undersampling patterns • Results • Conclusion: View sharing reconstructs the SPGR images with good accuracy (1%); T1 maps have systematic errors in CSF regions (need to quantify this); hope benefits follows through in mcDESPOT collection • Need to redo subtraction images w.r.t. to offline.recon, need to do histograms in parenchyma only. Should I discuss flip angle dependence of errors? Need to compare against other CS related developments in this area?

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