The suitability of gamma camera coincidence systems for nitrogen 13-labeled ammonia myocardial perfusion imaging: A quantitative comparison with full-ring PET
✍ Scribed by Fergus I McKiddie; Howard G Gemmell; E.Joyce Davidson; Andrew Welch; Mohaned Egred
- Publisher
- Springer
- Year
- 2003
- Tongue
- English
- Weight
- 214 KB
- Volume
- 10
- Category
- Article
- ISSN
- 1071-3581
No coin nor oath required. For personal study only.
✦ Synopsis
Background. The aim of this study was to examine the quality of nitrogen 13-labeled ammonia (NH 3 ) perfusion data from coincidence-capable gamma camera positron emission tomography (GC-PET) systems compared with that from full-ring positron emission tomography (FR-PET).
Methods and Results. The performance parameters of the GC-PET system were examined and found adequate for imaging at the activity levels used clinically. We studied 15 patients who underwent stress and rest N-13-labeled NH 3 perfusion imaging on FR-PET and GC-PET systems. Quantitative analysis of perfusion values showed that GC-PET uptake was significantly lower than FR-PET uptake in 67.6% of segments. Bland-Altman analysis showed that the mean difference between FR-PET and GC-PET values was from 5.3% to 5.9%. Stress FR-PET identified 49 segments as having impaired perfusion, 46 (93.9%) of which were also identified by GC-PET. Fifty-six additional segments were identified as abnormal by GC-PET. These findings indicated a general overestimation of defect size on GC-PET. Analysis of the degree of perfusion reduction also found that GC-PET tended to overestimate defect contrast. These findings are similar to those previously found by workers examining fluorine 18 -fluorodeoxyglucose uptake by both techniques.
Conclusions. Good concordance was shown between GC-PET and FR-PET systems for N-13-labeled NH 3 perfusion imaging, although further work is required to optimize the technique. (J Nucl Cardiol 2003;10:633-43.) Key Words: Gamma camera coincidence imaging • positron emission tomography • nitrogen 13-labeled ammonia • myocardial perfusion • myocardial viability
The recent development of gamma camera systems capable of coincidence detection (gamma camera positron emission tomography [GC-PET]) offers a less expensive and more widely available alternative to conventional full-ring positron emission tomography (FR-PET). 1 The performance of these systems is inferior to FR-PET especially in terms of system sensitivity 2,3 ; but the significance of this in terms of diagnostic accuracy has not been established.
Many FR-PET systems operate under considerable time pressures because of the demand for imaging of oncology patients. 4 Previous work has shown that GC-PET systems are of limited utility in the diagnosis and monitoring of treatment in oncology patients 5 because of the systems' inferior performance. However, cardiac imaging, which produces lower-resolution images, would be less affected by such a reduction in technical performance. 6 The most common cardiac application of FR-PET is the metabolism/perfusion mismatch scan for detection of myocardial viability. 7,8 This is of prime importance in the selection of patients for revascularization. 9,10 Therefore, if it can be shown that it is possible to carry out this examination adequately on GC-PET systems, access to positron emission tomography (PET) may be increased for cardiologists.