Department of Physics, University of Ottawa-Carleton University Institute of Physics, Ottawa, ON, Canada.
J Nucl Cardiol. 2013 Aug;20(4):578-91. doi: 10.1007/s12350-013-9721-3. Epub 2013 May 9.
Diagnosis of coronary disease and microvascular dysfunction may be improved by comparing myocardial perfusion scans with a database defining the lower limit of normal myocardial blood flow and flow reserve (MFR). To maximize disease detection sensitivity, a small normal range is desirable. Both (13)N-ammonia and (82)Rb tracers are used to quantify blood flow and MFR using positron emission tomography (PET). The goal of this study was to investigate the trade-off between noise and accuracy in both (82)Rb and (13)N-ammonia normal databases formed using a net retention model.
Fourteen subjects with <5% risk of CAD underwent rest and stress (82)Rb and (13)N-ammonia dynamic PET imaging in a randomized order within 2 weeks. Myocardial blood flow was quantified using a one-compartment model for (82)Rb, and a two-compartment model for (13)N-ammonia. A simplified model was used to estimate tracer retention, with tracer-specific net extraction functions derived to obtain flow estimates.
Normal variability of retention reserve was equivalent for both tracers (±15% globally, ±16% regionally) and was lower in comparison to compartment model results (P < .05). The two-compartment model for (13)N-ammonia had the smallest normal range of global blood flow resulting in a lower limit of normal MFR = 2.2 (mean - 2 SD).
These results suggest that the retention model may have higher sensitivity for detection and localization of abnormal flow and MFR using (82)Rb and (13)N-ammonia, whereas the (13)N-ammonia two-compartment model has higher precision for absolute flow quantification.
通过将心肌灌注扫描与定义正常心肌血流和血流储备下限的数据库进行比较，可以改善对冠心病和微血管功能障碍的诊断。为了最大限度地提高疾病检测灵敏度，希望正常范围较小。正电子发射断层扫描（PET）使用（13）N-氨和（82）Rb 示踪剂来量化血流和血流储备比（MFR）。本研究的目的是研究使用净保留模型形成的（82）Rb 和（13）N-氨正常数据库中噪声与准确性之间的权衡。
14 名 CAD 风险<5%的患者在 2 周内以随机顺序进行静息和应激（82）Rb 和（13）N-氨动态 PET 成像。使用单室模型量化（82）Rb 的心肌血流，使用双室模型量化（13）N-氨。使用简化模型估计示踪剂保留，使用示踪剂特异性净提取函数获得流量估计值。
两种示踪剂的保留储备正常变异性相当（全球范围内为±15%，局部范围内为±16%），与房室模型结果相比，保留储备正常变异性较低（P<0.05）。（13）N-氨的双室模型导致全球血流的正常范围最小，从而导致正常 MFR=2.2（平均值-2 个标准差）。
这些结果表明，保留模型可能对使用（82）Rb 和（13）N-氨检测和定位异常血流和 MFR 具有更高的敏感性，而（13）N-氨双室模型对绝对血流定量具有更高的精度。
