With the advent of CT we entered a new area of radiological imaging.
Structures which rarely if ever were seen became apparent. In no part of
the body was the impact of CT as profound as it was in the
retroperitoneum. In the pre-CT area this region of the body could not be
directly studied and only when gross abnormalities were present could
they be appreciated. The best we could do was to try to identify a
suspected process by studying its effect on surrounding organs whose
position might have been affected by the growth. Urography, barium
studies or angiography were employed in the hope that variation in the
position of the vessels, ureter or bowel would lead us to the correct
diagnosis. With computed tomography all this changed. Modern scanners,
available to all today, permit us to appreciate details undreamed of
only few years ago. The abundance of fat in this region helps to clearly
show even the smallest of structures. We now have the ability to
recognize small vessels, lymph nodes and fascial planes. We had a tool
which permitted us to study structures which hitherto were only seen by
the anatomist or during surgical dissection.