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

First-pass 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 May be performed with rest and stress 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 Cellsrad/mCi

Blood 0.04Liver 0.03Spleen 0.11Bladder Wall 0.02Testes 0.01Ovaries 0.02Heaart Wall 0.10Total Body 0.015

Drug interfering with Tc-99m RBC labeling

Drug 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