Sayre George A, Bacharach Stephen L, Dae Michael W, Seo Youngho
Department of Radiology and Biomedical Imaging, University of California, San Francisco, California 94107, USA.
Nucl Med Commun. 2012 Jan;33(1):4-13. doi: 10.1097/MNM.0b013e32834c13b5.
For many cardiac clinics, list-mode PET is impractical. Therefore, separate dynamic and ECG-gated acquisitions are needed to detect harmful stenoses, indicate affected coronary arteries, and estimate stenosis severity. However, physicians usually order gated studies only because of dose, time, and cost limitations. These gated studies are limited to detection. In an effort to remove these limitations, we developed a novel curve-fitting algorithm [incomplete data (ICD)] to accurately calculate coronary flow reserve (CFR) from a combined dynamic-ECG protocol of a length equal to a typical gated scan.
We selected several retrospective dynamic studies to simulate shortened dynamic acquisitions of the combined protocol and compared (a) the accuracy of ICD and a nominal method in extrapolating the complete functional form of arterial input functions (AIFs); and (b) the accuracy of ICD and ICD-AP (ICD with a-posteriori knowledge of complete-data AIFs) in predicting CFRs.
According to the Akaike information criterion, AIFs predicted by ICD were more accurate than those predicted by the nominal method in 11 out of 12 studies. CFRs predicted by ICD and ICD-AP were similar to complete-data predictions (PICD=0.94 and PICD-AP=0.91) and had similar average errors (eICD=2.82% and eICD-AP=2.79%).
According to a nuclear cardiologist and an expert analyst of PET data, both ICD and ICD-AP predicted CFR values with sufficient accuracy for the clinic. Therefore, by using our method, physicians in cardiac clinics would have access to the necessary amount of information to differentiate between single-vessel and triple-vessel disease for treatment decision making.
对于许多心脏科诊所而言，列表模式正电子发射断层扫描（PET）并不实用。因此，需要分别进行动态采集和心电图门控采集，以检测有害狭窄、指示受影响的冠状动脉并评估狭窄程度。然而，由于剂量、时间和成本限制，医生通常仅安排门控研究。这些门控研究仅限于检测。为了消除这些限制，我们开发了一种新颖的曲线拟合算法[不完全数据（ICD）]，以从长度等于典型门控扫描的动态 - 心电图联合协议中准确计算冠状动脉血流储备（CFR）。
我们选择了几项回顾性动态研究，以模拟联合协议缩短的动态采集，并比较了（a）ICD和一种标称方法在外推动脉输入函数（AIF）完整功能形式方面的准确性；以及（b）ICD和ICD - AP（具有完整数据AIF后验知识的ICD）在预测CFR方面的准确性。
根据赤池信息准则，在12项研究中的11项中，ICD预测的AIF比标称方法预测的更准确。ICD和ICD - AP预测的CFR与完整数据预测相似（PICD = 0.94和PICD - AP = 0.91），并且平均误差相似（eICD = 2.82％和eICD - AP = 2.79％）。
根据一位核心脏病专家和一位PET数据专家分析师的意见，ICD和ICD - AP预测的CFR值对于临床而言准确性足够。因此，通过使用我们的方法，心脏科诊所的医生将能够获得必要的信息量，以便在单支血管疾病和三支血管疾病之间进行区分，从而做出治疗决策。
