MYOCARDIAL VIABILITY--POSITRON EMISSION TOMOGRAPHY

延迟FDG成像改善心肌/血池对比 在一些冠心病患者中，用F-18进行心肌显像 PET在注射后30-60分钟的脱氧葡萄糖(FDG)成像 心肌与血池对比度低。我们假设 以后的成像可能会提高FDG图像的质量 通过增加心肌对FDG的摄取和清除 血。我们在7名冠心病患者中测试了这一假设：6名男性，1名女性， 年龄66+/-11；3例糖尿病患者。在30-60分钟内采集两组PET图像 在注射5-10mci的FDG后(葡萄糖负荷后1小时)和 135-165分钟。对于每个PT，整个LV被分成41个 大致相等的线段。绝对(nci/cc/mci)和归一化 (在应激状态下使铊的活性达到峰值)FDG摄取分析。全 数据经衰减校正至注射时间。很早就正常化了 晚期FDG值高度相关(斜率=1.26，截距=-0.25， R=0.92，SEE=0.05)，这意味着早期图像和晚期图像提供了类似的 临床信息。在215个节段中，208个节段(97%)符合 早期成像和晚期成像之间的生存能力。绝对衰变已更正 晚期显像显示心肌FDG摄取增加(77+/-27早期VS 116+/- 57迟到，p&lt；0.05)。在所有的患者中，晚期成像与 血池活动减少(早期34+/-6.6对晚期18+/-7.1，p&lt；0.01)， 从而改善晚期心肌/血池对比度(2.3 早盘vs7.1晚盘，p&lt；0.01)。心肌造影剂的这种改善是 糖尿病患者(从2.1%到6.5%)和非糖尿病人(从2.5%到6.5%)相似 7.6)，与明显的视力改善相一致。这些数据 提示尽管心肌计数略有下降，但由于 衰变，心肌FDG摄取增加与血液减少相结合 泳池活动改善了后期的图像质量。好的早晚FDG 相关性表明，这种改善不会改变FDG 临床分布，但这需要在更大的 病人数量。

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.