Bill Johnson, Albuquerque, NM (NM = New Mexico, not North Montana) Sergio Salles-Cunha, PhD has investigated calcific vessels, but I am having difficulty finding the references. I recall a presentation he made some years ago that dealt with variability of the partially compressible vessels. Ankle pressures were not reproducible on the pre-lead pipe vessels. Will keep looking for this one, unless one of you find it first. We routinely do toe pressures on patients with histories of diabetes, at least the ones that still have toes. I can recall a couple where even the toe was incompressible, (one patient's brachials were also incompressible, not by stethoscope, but by Doppler) so worry a bit about being misled by partial compressibility, even in the toe. We do not routinely do segmental pressures at this point. We do have a TCPO2 unit, and particularly on diabetics, use it to obtain some hopefully objective information. TCPO2 has some other wrinkles, though. Ambient room temperature (even though the probe warms the sensor site), probe site selection (tissue depth) and patient anxiety level (vasoconstriction) worry me some. Also, our unit at least, is awfully time-consuming to calibrate and use.