Microwave signal transmission: shortest path or shortest time?

[fparveen]

Hello,

I have an antenna emitting microwave radiation and a multi-layered brain model in front of it having a tumor. For calculating round trip travel time of the microwave signal to-and-from the antenna and the tumor, will I have to consider the shortest path or the shortest time?

Thanks in advance.

 

[BradtheRad]

It seems more likely that brain tissue absorbs microwaves rather than reflect them back toward the source.
However perhaps bone tissue might reflect them.

Ultrasound reflects from internal tissue. It's a common medical procedure. Dolphins are able to emit ultrasound and detect the echo from another animal, thereby visualizing its internal organs, sick or injured condition, etc.

There is magnetic resonance imaging (MRI).

There is CAT scan although the description doesn't mention microwaves.