Peelukhana Srikara V, Kerr Hanan, Kolli Kranthi K, Fernandez-Ulloa Mariano, Gerson Myron, Effat Mohamed, Arif Imran, Helmy Tarek, Banerjee Rupak
Department of Mechanical and Materials Engineering, University of Cincinnati, 598 Rhodes Hall, PO Box 0072, Cincinnati, OH, 45221-0072, USA.
Ann Nucl Med. 2014 Oct;28(8):746-60. doi: 10.1007/s12149-014-0869-y. Epub 2014 Jun 21.
Cardiac positron emission tomography (PET) can lead to flow impairment quantification using PET coronary flow reserve (CFRp: ratio of stress flow to rest flow) and is superior to the current standard, single-photon emission computed tomography. In this study, our first aim was to assess the benefit of CFRp in place of invasive CFR (CFRi) by comparing the correlations of each of the indices with combined pressure and flow index CDP, and combined functional (pressure-flow) and anatomical (%area stenosis, %AS) index, LFC. The second aim was to test the correlation between CFRp and CFRi.
N-13 ammonia PET scans were performed and CFRp was obtained using a 1-compartment 2K-dynamic volume (DV)-constant kinetic model in Flowquant. During catheterization, simultaneous pressure and flow readings were obtained in 10 vessels (three vessels in one patient, one vessel each in 7 patients) using a dual sensor tipped Combowire, and CFRi, CDP, LFC, and FFR were computed. %AS was obtained using quantitative coronary angiography. CDP was correlated with invasive pressure index (FFR) and CFRp and with FFR and CFRi. LFC was correlated with the %AS, FFR, and CFRp/CFRi, individually and in combination. Correlation analysis was done in SAS; p < 0.05 was used for statistical significance.
The correlations between CDP vs FFR and CFRp (r = 0.62, p = 0.19) in combination, as well as CDP vs FFR and CFRi in combination (r = 0.58, p = 0.24) remained similar. The correlation between LFC vs FFR, CFRp and %AS in combination improved (r = 0.82) with a near-significant p = 0.06, in comparison to the correlation between LFC vs FFR, CFRi and %AS in combination (r = 0.75, p = 0.15). CFRp correlated strongly and significantly (r = 0.82, p = 0.003) with CFRi, and the values were within 11 %.
The novelty of the PET procedure in this study is that the noninvasive CFRp can be used instead of invasive CFRi for the functional diagnosis of CAD. Therefore, a PET scan can reduce procedure time and cost while simplifying the diagnostic protocol for assessing coronary artery disease, thus benefitting both the patients and clinicians.
心脏正电子发射断层扫描（PET）可通过PET冠状动脉血流储备（CFRp：应激血流与静息血流之比）实现血流受损量化，且优于当前标准的单光子发射计算机断层扫描。在本研究中，我们的首要目的是通过比较每个指标与压力和血流综合指数CDP以及功能（压力-血流）和解剖（%面积狭窄，%AS）综合指数LFC的相关性，评估用CFRp替代有创CFR（CFRi）的益处。第二个目的是测试CFRp与CFRi之间的相关性。
进行N-13氨PET扫描，并使用Flowquant中的单室双K动态容积（DV）恒定动力学模型获得CFRp。在导管插入术期间，使用双传感器尖端的Combowire在10条血管（1例患者中的3条血管，7例患者中的每条血管各1条）中同时获取压力和血流读数，并计算CFRi、CDP、LFC和FFR。使用定量冠状动脉造影获得%AS。CDP与有创压力指数（FFR）和CFRp相关，也与FFR和CFRi相关。LFC分别及联合与%AS、FFR和CFRp/CFRi相关。在SAS中进行相关性分析；p<0.05用于统计学显著性。
CDP与FFR和CFRp联合（r = 0.62，p = 0.19）以及CDP与FFR和CFRi联合（r = 0.58，p = 0.24）之间的相关性仍然相似。与LFC与FFR、CFRi和%AS联合（r = 0.75，p = 0.15）的相关性相比，LFC与FFR、CFRp和%AS联合的相关性有所改善（r = 0.82），p值接近显著性，为0.06。CFRp与CFRi强烈且显著相关（r = 0.82，p = 0.003），且值在11%以内。
本研究中PET程序的新颖之处在于，无创CFRp可用于替代有创CFRi进行CAD的功能诊断。因此，PET扫描可减少手术时间和成本，同时简化评估冠状动脉疾病的诊断方案，从而使患者和临床医生均受益。
