Figure 10.

Liver thermometry. (a) Sum-of-squares image (sagittal view) of a healthy volunteer’s liver (no heating), with the target hot spot region highlighted. (b) The phase of one coil in the eight-channel cardiac array shows smooth phase within the liver, but rapidly-varying phase around the ribs (black arrows). (c) When the frame thickness is optimized (boundaries indicated by dashed black square), the masked ℓ₂ method achieves low temperature errors in the target region (inner square), and ignores phase around the ribs. (d) The reweighted ℓ₁ method also achieves low temperature errors in the target region, and ignores the phase around the ribs (black arrows). (e) The reweighted ℓ₁ method achieves a temperature error that is close to that of the masked ℓ₂ method with optimal frame thickness (black arrow), without requiring frame optimization.