Radionuclide angiography (RNA) Gated equilibrium method (EqRNA) First-pass method (FPRNA)

Gated equilibrium method (EqRNA) Tc-99m labeled RBCs: in vivo, in vitro, and modified in vivo approach Tc-99m human serum albumin

Comparison of First-pass & Gated perfusion methods for evaluation of ventricular function Needs 99mTc based agents as compact bolus injection Needs high sensitivity detectors, programs May be performed with rest and stress LV & RV wall motion, volumes, and ejection fraction Gated May be performed with 201Tl or 99mTc based agents Uses conventional cameras Only LV wall motion, volumes, and ejection fraction Provides LV wall thickening Accuracy dependent on endothelial border definition

Dosimetry for Tc-99m Red Blood Cells Organ Tc-99m Red Blood Cells rad/mCi Blood 0.04 Liver 0.03 Spleen 0.11 Bladder Wall 0.02 Testes 0.01 Ovaries 0.02 Heaart Wall 0.10 Total Body 0.015

Drug interfering with Tc-99m RBC labeling Mechanisms Heparin Formation of labeled heparin Methyldopa, hydralazine Oxidation of stannous ion Digoxin, prazosin, propranolol unknown Iodinated contrast media Competitionn with anion transport system

First-pass method (FPRNA) Tc-99m pertechnetate Tc-99m DTPA or Tc-99m sulfur colloid Short-lived agents: Au-195m, Ir-191m, Ta-178

Infarction-avid imaging Radiopharmaceuticals: Tc-99m Pyrophosphate, 20 mCi, i.v. Time of imaging: 3-4 hours after injection