Léveillé J, Demonceau G, Walovitch R C
Médecine Nucléaire, Hotel-Dieu de Montréal, Canada.
J Nucl Med. 1992 Apr;33(4):480-4.
The pharmacokinetics and quality of planar and SPECT brain imaging of two 99mTc-labeled brain perfusion agents, d,l-hexamethyl propylene amine oxime (HMPAO) and ethyl cysteinate dimer (ECD), were compared in seven healthy, normal subjects. Both radiopharmaceuticals showed rapid brain uptake and had a net brain washout of less than 5% during the first 20 min after drug administration. However, during the same time period, 99mTc-ECD images of the head showed significantly less background facial uptake and retention when compared to 99mTc-HMPAO images. The brain-to-background contrast ratio of 99mTc-ECD (brain/neck) continued to improve over time and by 5 hr postadministration was 17 to 1 versus 2 to 1 for 99mTc-HMPAO. SPECT brain images of both agents show gray/white matter ratios that were unchanged over time and an intracerebral distribution consistent with blood flow. A blind read of these SPECT images also shows 99mTc-ECD to produce images that were "easier to interpret" with less extracerebral activity as compared to 99mTc-HMPAO. Repeat, whole-body planar spot imaging suggests that 99mTc-ECD was cleared more rapidly from the body than was 99mTc-HMPAO.
在7名健康正常受试者中，比较了两种99mTc标记的脑灌注剂，即消旋六甲基丙烯胺肟（HMPAO）和半胱氨酸乙酯二聚体（ECD）的平面和SPECT脑显像的药代动力学及图像质量。两种放射性药物均显示出快速的脑摄取，且给药后最初20分钟内脑内净清除率小于5%。然而，在同一时间段内，与99mTc-HMPAO图像相比，头部的99mTc-ECD图像显示面部背景摄取和滞留明显较少。99mTc-ECD（脑/颈部）的脑与背景对比度随时间持续改善，给药后5小时为17比1，而99mTc-HMPAO为2比1。两种药物的SPECT脑图像显示灰质/白质比值随时间不变，脑内分布与血流一致。对这些SPECT图像的盲法解读还显示，与99mTc-HMPAO相比，99mTc-ECD产生的图像“更易于解读”，脑外活性更低。重复的全身平面点状显像表明，99mTc-ECD从体内清除的速度比99mTc-HMPAO更快。
