Impairment of gas exchange in liver cirrhosis.

The authors used albumin aggregates whose diameters were stated to range from 15 μm to 50 μm. Assuming radioactivity relates to particle mass, not diameter, 50 μm particles would be 37 times hotter than 15 μm particles ((50/15) = 37). If the abnormal vascular channels at their narrowest exceeded 50 μm diameter, this inhomogeneity of size may have posed no problem. If any were less than 50 μm but greater than 15 μm, the hottest particles would have been preferentially caught in the lungs. Thus, without knowing the anatomy of the abnormal vessels or the distribution of particle sizes between 15 and 50 μm, there is a potential interpretative limitation on using the radioactive particle data to quantitatively assess the vascular shunts. Of interest, this would if anything underestimate the shunt, already computed to be about 40%.