Comparison of Several Potential Myocardial Imaging Agents

摘要

Although myocardial imaging is currently dominated by Tl-201, several alternative agents with improved physiologic or radionuclidic properties have been proposed. Based on human and animal studies in the literature, the metabolism of several of these compounds was studied for the purpose of generating radiation dose estimates. Dose estimates are listed for several I-123 labeled free fatty acids, an I-123 labeled phosphonium compound, Rb-82, Cu-64, F-18 FDG (all compounds which are taken up by the normal myocardium), and for Tc-99m pyrophosphate (PYP) (which localizes in myocardial infarcts). Dose estimates could not be generated for C-11 palmitate, but this compound was included in a comparison of myocardial retention times. For the I-123 labeled compounds, I-124 was included as a contaminant in generating the dose estimates. Radiation doses were lowest for Rb-82 (gonads 0.3 to 0.5 mu Gy/MBq, heart wall 15 mu Gy/MBq). Doses for the I-123 labeled fatty acids were similar to one another, with IPPA being the lowest (gonads 20 mu Gy/MBq, heart wall 15 mu Gy/MBq). Doses for Tc-99m PYP were also low (gonads 4 to 7 mu Gy/MBq, heart wall 4 mu Gy/MBq, skeleton 15 mu Gy/MBq). The desirability of these compounds is discussed briefly, considering half life, imaging mode and energy, and dosimetry, including a comparison of the effective whole body dose equivalents. 34 refs., 11 tabs. (ERA citation 11:028515)