MYOCARDIAL VIABILITY--POSITRON EMISSION TOMOGRAPHY

延迟FDG成像改善心肌/血池对比度 在某些CAD患者中，使用F-18进行心肌成像 在注射后30 - 60分钟通过PET的脱氧葡萄糖（FDG）产生图像 心肌和血池之间的对比度低。 我们假设 在以后的时间成像可能会提高FDG图像的质量 通过增加心肌摄取和清除FDG， 血 我们在7例CAD患者中检验了这一假设：6例男性，1例女性， 年龄66 +/-11; 3名糖尿病患者。 在30 - 60 min采集PET图像 注射5 - 10 mCi FDG后（葡萄糖负荷后1小时）， 135 - 165分钟。对于每例患者，整个LV分为41个 近似相等的线段。绝对值（nCi/cc/mCi）和标准化值 (to峰值铊活性）FDG摄取进行分析。 所有 数据衰减校正到注射时间。 早期正常化， 晚期FDG值高度相关（斜率= 1.26，截距=-0.25， r = 0.92，SEE = 0.05），这意味着早期和晚期图像提供类似的 临床信息。在215个节段中，208个节段（97%）与 早期和晚期成像之间的可行性。 绝对衰减校正 心肌FDG摄取在晚期成像中增加（早期77 +/-27 vs 116 +/- 晚期57例，p <0.05）。 在所有患者中，晚期影像学检查与 降低血池活性（早期34 +/-6.6 vs晚期18 +/-7.1，p <0.01）， 导致改善的晚期心肌/血池对比率（2.3 早期与晚期相比，P <0.01）。 心肌对比度的改善是 糖尿病患者（从2.1到6.5）和非糖尿病患者（从2.5到6.5）相似。 7.6），并且与显著的视觉改善一致。这些数据 这表明，尽管心肌计数略有下降， 衰减，增加心肌FDG摄取结合减少血液 池活动提高了后期图像质量。早-晚FDG 相关性表明，改善不改变FDG 临床分布，但这需要在更大的 患者人数。

Delayed FDG Imaging Improves Myocardial/Blood Pool Contrast In some patients with CAD, imaging of the myocardium with F-18 deoxyglucose (FDG) at 30-60 min post injection by PET produces images with low contrast between myocardium and blood pool. We hypothesized that imaging at a later time might improve the quality of FDG images both by increasing myocardial uptake and clearance of FDG from the blood. We tested this hypothesis in 7 pts with CAD: 6 men, 1 woman, age 66+/-11; 3 diabetics. PET images were acquired both at 30-60 min post injection of 5-10 mCi of FDG (1 hr after glucose load) and at 135-165 min. For each pt, the entire LV was divided into 41 approximately equal segments. Both absolute (nCi/cc/mCi) and normalized (to peak thallium activity on stress) FDG uptake were analyzed. All data were decay corrected to time of injection. Normalized early and late FDG values were highly correlated (slope = 1.26, intercept =-0.25, r=0.92, SEE =0.05), implying early and late images provide similar clinical information. Of 215 segments, 208 (97%) were concordant for viability between early and late imaging. Absolute decay corrected myocardial FDG uptake increased on late imaging (77+/-27 early vs 116+/- 57 late, p<0.05). In all pts, late imaging was associated with decreased blood pool activity (34+/-6.6 early vs 18+/-7.1 late, p<0.01), resulting in improved late myocardium/blood pool contrast ratio (2.3 early vs 7.1 late, p<0.01). This improvement in myocardial contrast was similar for diabetics (from 2.1 to 6.5) and non diabetics (from 2.5 to 7.6), and was consistent with marked visual improvement. These data suggest that despite a slight decrease in myocardial counts due to decay, the increased myocardial FDG uptake combined with decreased blood pool activity improves late image quality. The good early-late FDG correlation suggests that the improvement does not alter the FDG distribution clinically, but this needs to be verified in a larger number of patients.