- 作者：Bernard Songy ; David Lussato ; Mohamed Guernou ; Mathieu Queneau
- 刊名：Archives of Cardiovascular Diseases Supplements
- 出版年：2011
- 出版时间：January 2011
- 年：2011
- 卷：3
- 期：1
- 页码：8
- 全文大小：65 K
Background
Thallium 201 is the most efficient radiotracer for myocardial perfusion imaging but leads to relative high radiation exposure for patients.Objectives
We used a new cardiac CZT camera to decrease the effective dose with thallium-201 in myocardial perfusion imaging.
Methods
We prospectively studied 137 consecutive patients referred for stress myocardial perfusion imaging and who previously had in the last 5 years a myocardial SPECT with thallium-201. We injected at stress a low dose of thallium 201 (1 to 1.2 MBq/kg, i.e. 74 MBq for 70 kgs), performed stress myocardial imaging in 5 to 7 mn with a CZT camera GE Discovery NM 530c and redistribution imaging when initial images were abnormal, with reinjection (37 MBq) when previous myocardial infarction or severe defect or without reinjection in other cases. We compared the CZT scan with the scan previously performed in the last 5 years with conventional dual head tomographic Anger camera (CC) with a regular dose of thallium-201.
Results
Patients had known coronary artery diseases in 85 % of cases, myocardial scar in 38 % and ischemia in 20 % .
The average stress dose was 88 MBq versus 125 MBq previously (?0 % )
The average time for camera acquisition was 6 mn versus 13 mn (?4 % )
The cardiac counts statistic was higher with CZT (>1 Mcts)
By comparison with CC, the quality of CZT images was better (better delineation of left ventricular cavity, visualization of papillary muscles, easier thickening analysis) in 70 % of cases, equal in 24 % and worse in 6 % (6 artefacts, 2 digestive contaminations)
Comparison of artefacts showed 30 unmodified, 29 less and 6 additionnal artefacts.
By comparison with the previous SPECT, we missed no pathological image; furthermore, we detected 5 true pathological images which were missed with the CC.
Calculated effective dose was less than 12 mSv when no reinjection and less than 18 mSv when reinjection.
Conclusions
With reduced activities of thallium 201 (?0 % ) and effective doses between 12 and 18 mSv, CZT camera gives reliable high quality imaging