The 18F-fluorodeoxyglucose lumped constant determined in human brain from extraction fractions of 18F-fluorodeoxyglucose and glucose
The 18F-fluorodeoxyglucose lumped constant determined in human brain from extraction fractions of 18F-fluorodeoxyglucose and glucose
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DOI：
10.1097/00004647-200108000-00012
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发表时间：
2001-08-01
影响因子：
6.3
通讯作者：
Paulson, OB
中科院分区：
文献类型：
--
作者：
Hasselbalch, SG;Holm, S;Paulson, OB
使用正电子发射断层扫描和F-18-氟脱氧葡萄糖（PET-FDG）定量局部脑葡萄糖代谢（CMRglc）需要了解FDG和葡萄糖净清除率之间的校正因子，即FDG集总常数（LC）。由于LC的数值不同，作者通过测量脑动静脉测量的FDG（E*）和葡萄糖（E）的脑净提取分数的比值重新评价LC。研究了30例受试者（平均年龄= 25 +/- 4岁）：12例在FDG程控输注期间，18例在FDG推注后。在输注研究中，LC计算为比值E*/E。在推注研究中，根据Patlak-Gjedde图的斜率计算E*。与推注研究相比，输注研究中的集总常数显著较小（0.48 +/- 0.16 vs. 0.81 +/- 0.27，P < 0.001）。在连续FDG输注2.5小时期间研究的4名受试者中，LC降至0.36 +/- 0.11。这些结果表明，“稳态”方法低估了LC，因为E* 持续下降，因为显着的标记产品。此外，作者还提供了LC向更大值重置的证据。CMRglc的后续重置提供了生理上更有意义的估计，并允许比较不同方法之间的CMRglc值。
Quantification of regional cerebral glucose metabolism (CMRglc) using positron emission tomography and F-18-fluorodeoxyglucose (PET-FDG) requires knowledge of the correction factor between FDG and glucose net clearance, the FDG lumped constant (LC). Because diverging values for LC have been obtained, the authors reevaluated LC by measuring the ratio of the cerebral net extraction fractions of FDG (E*) and glucose (E) from arteriovenous cerebral measurements. Thirty subjects were studied (mean age = 25 +/- 4 years): 12 during a programed infusion of FDG and 18 after a bolus injection of FDG. In the infusion study, LC was calculated as the ratio E*/E. In the bolus study, E* was calculated from the slope of a Patlak-Gjedde plot. Lumped constant was significantly smaller in the infusion study as compared with the bolus study (0.48 +/- 0.16 vs. 0.81 +/- 0.27, P < 0.001). In 4 subjects studied during continuous FDG infusion for 2.5 hours, LC decreased to 0.36 +/- 0.11. These results suggest that the "steady-state" method underestimates LC because E* continues to decline because of significant labeled product. Further, the authors provide evidence for resetting of LC toward a greater value. The subsequent resetting of CMRglc provides a physiologically more meaningful estimate and allows for comparison of CMRglc values between different methodologies.