2016_Imaging for Physicists

B0 mapping

Magnitude

Difference Phase (TE1) Phase (TE2)

• Air/tissue interfaces problematic • Dynamic & HO shimming • May be measured/corrected: • Image at two different TEs • Reconstruct phase difference • Bhagwandien measured -5 to +6ppm i.e. nearly twice WFS

γΔTE Δφ

ΔB

=

0

Maximum 34 Hz (0.3 ppm)

Maximum 203 Hz (1.6 ppm @ 3T)