Devous M D, Payne J K, Lowe J L, Leroy R F
Nuclear Medicine Center, University of Texas Southwestern Medical Center, Dallas 75235-9061.
J Nucl Med. 1993 May;34(5):754-61.
Technetium-99m-1,1-ethyl cysteinate dimer (ECD) has been proposed as a "chemical microsphere" for SPECT measurement of regional cerebral blood flow (rCBF). However, its distribution has not yet been compared in humans to an established rCBF measure. Therefore, we compared the uptake and distribution of ECD with rCBF measured by 133Xe SPECT in subjects with mild to moderate flow abnormalities and in normal volunteers. Blood and urine chemistries and vital signs were unchanged from pre-ECD values up to seven days postinjection. Profile plots demonstrated pattern agreement between rCBF ratios (133Xe) and ECD count density ratios. A significant correlation of rCBF ratios to ECD count density ratios was observed (r = 0.77), with a slope of 0.64 and intercept of 0.36. To explore whether or not the relationship between rCBF and ECD was dependent on absolute flow, ECD region of interest data were expressed in units of ml/min/100 g by equating global CBF (133Xe) and ECD global count density. A closer correlation (r = 0.88) was found for these data than for the count ratio data. The slope was closer to one (m = 0.83) and the intercept was closer to zero (b = 8.2). Also, a significant correlation was observed between ECD-derived rCBF and 133Xe rCBF in the lesion area (r = 0.92) for patients with well-demarcated rCBF lesions. The slope (0.80) suggested a slight underestimation of lesion flow by ECD. Finally, ECD clearance from cortical gray matter ROIs derived from high-resolution scans from 1 to 4 hr postinjection was slow (2.4%/hr). In summary, ECD is a safe and effective marker of regional cerebral perfusion. The distribution of ECD is linearly related to rCBF measured by 133Xe SPECT, although our data suggest a mild underestimation of flow at the high end of the normal range.
锝-99m-1,1-乙基半胱氨酸二聚体（ECD）已被提议作为一种“化学微球”，用于单光子发射计算机断层扫描（SPECT）测量局部脑血流量（rCBF）。然而，其在人体中的分布尚未与既定的rCBF测量方法进行比较。因此，我们在轻度至中度血流异常的受试者和正常志愿者中，比较了ECD的摄取和分布与通过133Xe SPECT测量的rCBF。从注射前到注射后七天，血液和尿液化学指标以及生命体征与注射ECD前的值相比没有变化。剖面图显示rCBF比率（133Xe）和ECD计数密度比率之间的模式一致。观察到rCBF比率与ECD计数密度比率之间存在显著相关性（r = 0.77），斜率为0.64，截距为0.36。为了探究rCBF与ECD之间的关系是否依赖于绝对血流量，通过使整体脑血流量（133Xe）和ECD整体计数密度相等，将ECD感兴趣区数据以毫升/分钟/100克为单位表示。与计数比率数据相比，这些数据的相关性更强（r = 0.88）。斜率更接近1（m = 0.83），截距更接近0（b = 8.2）。此外，对于rCBF病变界限清晰的患者，在病变区域观察到ECD衍生的rCBF与133Xe rCBF之间存在显著相关性（r = 0.92）。斜率（0.80）表明ECD对病变血流的估计略有低估。最后，注射后1至4小时高分辨率扫描得出的皮质灰质感兴趣区的ECD清除缓慢（每小时2.4%）。总之，ECD是一种安全有效的局部脑灌注标志物。ECD的分布与通过133Xe SPECT测量的rCBF呈线性相关，尽管我们的数据表明在正常范围高端血流量存在轻度低估。
