Technetium-99m sestamibi myocardial imaging: Same-day rest-stress studies and dipyridamole

• Published in: The American journal of cardiology Vol. 66; no. 13; pp. E80 - E84
• Main Author: Taillefer, Raymond
• Format: Journal Article Conference Proceeding
• Language: English
• Published: New York, NY Elsevier Inc 16.10.1990; Elsevier
• Subjects: 550601 - Medicine- Unsealed Radionuclides in Diagnostics; BETA DECAY RADIOISOTOPES; BETA-MINUS DECAY RADIOISOTOPES; Biological and medical sciences; BODY; CARDIOVASCULAR AGENTS; CARDIOVASCULAR DISEASES; CARDIOVASCULAR SYSTEM; Coronary Disease - diagnostic imaging; DAYS LIVING RADIOISOTOPES; DIAGNOSIS; Dipyridamole; DISEASES; DRUGS; ELECTRON CAPTURE RADIOISOTOPES; EVALUATION; EXERCISE; Exercise Test; HEART; Heart - diagnostic imaging; HEAVY NUCLEI; HOURS LIVING RADIOISOTOPES; Humans; IMAGE PROCESSING; INTERMEDIATE MASS NUCLEI; Investigative techniques, diagnostic techniques (general aspects); ISOMERIC NUCLEI; ISOMERIC TRANSITION ISOTOPES; ISOTOPES; LABELLED COMPOUNDS; Medical sciences; MUSCLES; MYOCARDIUM; Nitriles; NUCLEI; ODD-EVEN NUCLEI; Organotechnetium Compounds; ORGANS; PATIENTS; PROCESSING; Prospective Studies; RADIOISOTOPES; RADIOLOGY AND NUCLEAR MEDICINE; Radionuclide investigations; RADIOPHARMACEUTICALS; Rest; SECONDS LIVING RADIOISOTOPES; TECHNETIUM 99; TECHNETIUM ISOTOPES; Technetium Tc 99m Sestamibi; THALLIUM 201; THALLIUM ISOTOPES; Thallium Radioisotopes; Time Factors; Tomography, Emission-Computed, Single-Photon; VASODILATORS; YEARS LIVING RADIOISOTOPES
• ISSN: 0002-9149; 1879-1913
• DOI: 10.1016/0002-9149(90)90617-A

Unlike thallium-201, technetium-99m (Tc-99m) sestamibi does not redistribute in the myocardium after injection. Thus, 2 separate injections, 1 at rest and the other at stress (or after dipyridamole), are required to differentiate ischemia from scar. From a physical viewpoint, a 24-hour interval between the 2 injections is preferable for detection of coronary artery disease (CAD) with Tc-99m sestamibi imaging. However, same-day studies are more convenient in clinical practice. Results of studies using different Tc-99m sestamibi injection protocols are presented with emphasis on the advantages of a rest-stress injection sequence with a low dose at rest (7 mCi) followed 2 hours later by a higher dose at stress (25 mCi). A prospective study was conducted in a patient population with proven CAD using same-day studies to compare a rest-stress (7 and 25 mCi, respectively) to a stress-rest (7 and 25 mCi) Tc-99m sestamibi injection sequence. There was an agreement in 87.3% of the analyzed segments between the 2 protocols. However, the largest discordance for type of defect applied to 7.4% of the segments judged ischemic in the rest-stress protocol, which were called scars on stress-rest. This study showed that a rest-stress sequence is preferable when using a same-day protocol with a short time interval (<2 hours) between the 2 Tc-99m sestamibi injections because the rest image performed initially represents a “true” rest study, which is not necessarily the case with the stress-rest sequence. Preliminary studies were performed to evaluate dipyridamole with Tc-99m sestamibi imaging in normal subjects and in patients with CAD. These studies showed that treadmill and dipyridamole Tc-99m sestamibi imaging are comparable and the results are similar to those obtained with thallium-201.