Three-dimensional T(1), T(2) and proton density mapping with inversion recovery balanced SSFP.
By combining a balanced steady-state free precession (bSSFP) readout with an initial inversion pulse, all three contrast parameters, T(1), T(2) and proton density (M(0)), may be rapidly calculated from the signal progression in time. However, here it is shown that this technique is quite sensitive to variation in the applied transmit RF (B(1)) field, leading to pronounced errors in calculated values. Two-dimensional (2D) acquisitions are taxed to accurately quantify the relaxation, as the short RF pulses required by SSFP's rapid TR contain a broad spectrum of excitation angles. A 3D excitation using a large diameter excitation coil was able to correctly quantify the parameters. While the extreme B(1) sensitivity was previously problematic and has precluded use of IR-bSSFP for relaxometry, in this work these obstacles were significantly reduced, allowing the rapid quantification of T(1), T(2) and M(0). The results may further be used to simulate image contrast from common sequences, such as a T(1)-weighted or fluid-attenuated inversion recovery (FLAIR) examination.
Newbould
Rexford D
RD
GSK Clinical Imaging Centre, Hammersmith Hospital, W12 0NN London, UK.
Skare
Stefan T
ST
Alley
Marcus T
MT
Gold
Garry E
GE
Bammer
Roland
R
D016477:Artifacts; D001931:Brain Mapping / Q000379:methods; D003198:Computer Simulation; D003287:Contrast Media / Q000494:pharmacology; D003952:Diagnostic Imaging / Q000379:methods*; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods; D021621:Imaging, Three-Dimensional; D008279:Magnetic Resonance Imaging / Q000379:methods; D015233:Models, Statistical; D011522:Protons
D003287:Contrast Media; D011522:Protons