1. Planning, which among other things, requires accu-
rate identi?cation of the location and spatial extent of
the pathology to be treated,

2. guidance, which in addition to 1., requires accurate
prediction of the location and spatial extent of the
thermal lesion before its formation,

3. treatment monitoring, which requires the ability to
image with high contrast the location and extent of
regions of ablated tissue,

4. monitoring of response, which among other things,
requires the ability to observe changes in tissue ar-
chitecture and blood ?ow due to tissue healing.