Basics of computed tomography angiography of the lower extremity vessels

Complete noninvasive, angiographic evaluation of the abdominal aorta and lower extremity vessels using the latest generation of multidetector row computed tomography (CT) scanners can now be accomplished in a single scan lasting less than a minute. The high spatial resolution of these new scanners and their more efficient use of contrast permit accurate depiction of disease in the smaller tibial and pedal vessels, as well as the larger diameter iliac and femoral arteries; nevertheless, many challenges and obstacles remain to its more widespread acceptance. Foremost among these, is the difficulty in accurately reconstructing the smaller leg and pedal vessels from individual CT slices, a process that must to a very great extent be done manually, and the potential nephrotoxicity of iodinated contrast material. Future advances in imaging software that could more fully automate accurate three-dimensional reconstructions of the lower extremity vasculature, and detector technology to allow for even finer resolution of the vasculature will further enhance an already powerful and clinically useful tool.