Comparison between Tc-99m N-NOET and Tl-201 in the assessment of patients with known or suspected coronary artery disease

✍ Scribed by Paramjit Jeetley; Nikant K. Sabharwal; Prem Soman; Chris Kinsey; Usha Raval; Uday Bhonsle; Avijit Lahiri

• Publisher: Springer
• Year: 2004
• Tongue: English
• Weight: 246 KB
• Volume: 11
• Category: Article
• ISSN: 1071-3581
• DOI: 10.1016/j.nuclcard.2004.05.010

✦ Synopsis

Background:

Technetium 99m n-ethoxy-n-ethyl dithiocarbamate (n-noet) is a new radionuclide tracer for cardiac single photon emission computed tomography (spect) imaging. it combines the advantageous properties of a tc-99m agent with the redistribution characteristics of thallium 201. we directly compared the two agents in patients with known or suspected coronary artery disease.

Methods and results:

Fifty patients underwent treadmill exercise tc-99m n-noet and tl-201 spect studies. images were acquired at stress, redistribution, and reinjection. segmental analysis was carried out, and direct comparisons were made with corresponding segments. a stress score index was calculated and compared with the degree of lung uptake for each patient. from the 50 patients, 2657 of 2664 exercise, redistribution, and reinjection segments (99%) were interpreted. there was excellent agreement between the two modalities (weighted kappa = 0.83). of the patients, 24 demonstrated reversible ischemia by tl-201 spect reinjection imaging, of which tc-99m n-noet stress-redistribution imaging correctly identified 14 (58%); this improved significantly to 20 patients (83%) ( p = .03) when a reinjection protocol was used. a higher stress score index was seen in those patients with significant lung uptake (lung-heart ratio > or =0.6) after tc-99m n-noet stress imaging (1.6 vs 1.3, p = .03).

Conclusion:

Spect imaging with tc-99m n-noet is comparable to tl-201 for the diagnosis of coronary artery disease. significant lung uptake with stress tc-99m n-noet may also indicate the severity of disease.