Explaining the race paradox of coronary calcium prevalence and survival.

stress to K1 at rest. Finally, the first-pass studies used by Jerosch-Herold’s team have yielded impressive results when compared with coronary flow reserve measurements using Doppler wires (2). In truth, the best comparison would be to compare the nutritive perfusion measurements obtained with positron emission tomography (PET), because coronary flow reserve and regional nutritive perfusion can differ. Nevertheless, although technically demanding, their firstpass technique looks promising, particularly if the imaging artefact problems are overcome and validation against PET can be achieved. The Kety model approach needs further research, but it may prove to have some advantages for the reasons already outlined.