Angiography: Radiation Exposure and Standard Projections

Abstract

Invasive cardiology is responsible for the greatest ionizing dose in congenital heart disease. Staff and patients are exposed to deterministic risks, mainly skin erythema and cataracts at current doses, and stochastic risks in the form of tumors and fatal and nonfatal cancer. For any given dose, children, and specially infants, are three to six times more sensitive to cancer development than adults. Standard measurement for angiography is the dose area product, Gray square centimeter, and for computed tomography the dose length product, mGy centimeter, and they are not comparable. Effective dose measured in Sieverts allows cross-modality comparisons and characterizes stochastic cancer risk. Conventional angiography displays only a two-dimensional projection of complex three-dimensional structures so many acquisitions (simultaneously or sequentially) are needed for a correct interpretation. Computed tomography and/or magnetic resonance shows splendid but manipulated three dimensions of the heart and vessels, not in real time, although some improvements have been done aimed to use them as a sort of road mapping. Angiographic computed tomography has been recently added to current angiographic sets with some apparent advantages, but with no concludent results yet, as to choose the best angulation with no overlapping or foreshortened profile for a particular disease. Some recommendations for angulations are also suggested.