Hampus Olsson1, Mads Andersen2, Mustafa Kadhim1, and Gunther Helms1
1Department of Medical Radiation Physics, Clinical Sciences Lund, Lund University, Lund, Sweden, 2Philips Healthcare, Copenhagen, Denmark
1Department of Medical Radiation Physics, Clinical Sciences Lund, Lund University, Lund, Sweden, 2Philips Healthcare, Copenhagen, Denmark
High-resolution maps of both B1+
and T1 can be obtained by an MPRAGE sequence with at least 3 volumes
when also producing a PD-weighted and T1-weighted driven equilibrium.
Calculations do not require a lookup table.
Figure 1. Schematic of the DE-MPRAGE approach
showing the progression of Mz (solid blue line) during a cycle of TC=8004
ms. The first half of TC is readout with αPD (gray area) and the second half is
readout with αT1 (white area). Vertical black lines denote center of k-space
using linear k-space ordering. Dashed blue lines show the PD-weighted and T1-weighted
DEs. Dotted blue lines show from which volumes/maps each map is obtained.
Figure 2. Maps of T1 and B1+
derived through either a LUT-based approach (A), without an independent reference for the PD-w DE, SPD, (B) and with an independent reference
(C). Compared to C, the T1 maps in A and B are overestimated while
the B1+ maps are underestimated.
