Stevens H, Van de Wiele C, Santens P, Jansen H M, De Reuck J, Dierckx R, Korf J
Department of Nuclear Medicine, University Hospital Ghent, Belgium.
J Nucl Med. 1998 Mar;39(3):495-8.
Previous studies have shown the usefulness of divalent cobalt isotopes to visualize cerebral damage after stroke. The site of accumulation of cobalt ion is unknown but may be explained by neuronal influx, analogous to that of calcium ion. Additionally, uptake may be due to infiltrating leukocytes or protein-bound cobalt. The aims of this study were to compare 57Co-SPECT with leukocyte SPECT and to compare the SPECT findings with clinical outcome as scored by the Orgogozo scale.
Ten patients with a CT scan positive for middle cerebral artery infarcts were included in the study (7 men, 3 women; mean age 70 yr). Technetium-99m leukocyte and cobalt-SPECT (interval 2-4 days) were made with a double-headed gamma camera, after the injection of 10-15 mCi 99mTc-HMPAO-labeled leukocytes and 0.4 mCi 57Co, respectively. Scans were performed within 5-30 days after onset of the first symptoms. Regions of interest (ROI) containing the area of infarction in the slices displaying enhanced radioactivity or the middle cerebral artery (MCA) region in four successive slices were defined for calculating enhancement ratios. The 99mTc leukocyte enhancement ratio (LER) and cobalt enhancement ratio (CER) were defined as the quotient of radioactivity in the ROI and an identical contralateral ROI. The MCA stroke-scale according to Orgogozo was used to assess neurological deficits at the time of scanning and discharge.
Cobalt-57 and 99mTc-HMPAO showed uptake in the infarcted brain area in five patients; the quantitative uptake in the infarcted brain area of the two tracers correlated significantly (p < 0.05). Both the LER and the CER correlated significantly (p < 0.05) with the Orgogozo score at the time of scanning. Only the LER correlated significantly (p < 0.05) with the Orgogozo score at discharge.
Uptake of cobalt and leukocytes in the peri-infarct tissue suggests that 57Co may visualize a component of the inflammatory response. Divalent 57Co may be convenient to predict clinical prognosis after stroke.
先前的研究已表明二价钴同位素在可视化中风后脑损伤方面的有效性。钴离子的积聚部位尚不清楚，但可能可以用类似于钙离子的神经元内流来解释。此外，摄取可能归因于浸润的白细胞或与蛋白质结合的钴。本研究的目的是比较⁵⁷Co单光子发射计算机断层扫描（SPECT）与白细胞SPECT，并将SPECT结果与用奥尔戈戈佐量表评分的临床结局进行比较。
本研究纳入了10例大脑中动脉梗死CT扫描呈阳性的患者（7例男性，3例女性；平均年龄70岁）。分别注射10 - 15毫居里的⁹⁹ᵐTc - HMPAO标记的白细胞和0.4毫居里的⁵⁷Co后，用双头γ相机进行⁹⁹ᵐTc白细胞和钴SPECT检查（间隔2 - 4天）。在首次症状出现后的5 - 30天内进行扫描。在显示放射性增强的切片中包含梗死区域或在连续四个切片中的大脑中动脉（MCA）区域定义感兴趣区（ROI），用于计算增强率。⁹⁹ᵐTc白细胞增强率（LER）和钴增强率（CER）定义为ROI中放射性与相同对侧ROI中放射性的商。根据奥尔戈戈佐量表的MCA中风量表用于在扫描时和出院时评估神经功能缺损。
5例患者的梗死脑区显示出⁵⁷Co和⁹⁹ᵐTc - HMPAO摄取；两种示踪剂在梗死脑区的定量摄取显著相关（p < 0.05）。LER和CER在扫描时均与奥尔戈戈佐评分显著相关（p < 0.05）。仅LER在出院时与奥尔戈戈佐评分显著相关（p < 0.05）。
梗死周围组织中钴和白细胞的摄取表明⁵⁷Co可能使炎症反应的一个成分可视化。二价⁵⁷Co可能便于预测中风后的临床预后。
