Savolainen S
Department of Physics, University of Helsinki, Finland.
Nucl Med Commun. 1992 Oct;13(10):757-63.
The splenic uptake of thrombocytes and spleen size were studied in 25 patients with idiopathic thrombocytopenic purpura (ITP) using two methods: anterior/posterior scintigraphy and single photon emission computed tomography (SPECT). Various factors (acquisition and reconstruction protocols) influencing the quality of 111In SPECT were studied. The splenic uptake, measured by SPECT, was found to be significantly higher in patients with a high level of autoantibodies in the blood than in patients without such antibodies (37 +/- 6%, n = 8 vs 22 +/- 3%, n = 11, P = 0.04, t-test). The correlation between the spleen SPECT volume and the geometric mean size in anterior and posterior images was 0.80 (P < 0.001). However, the spleen size calculated as geometric mean of anterior and posterior images differed by more than 50% from the SPECT volume in some patients. Based on these observations and on the results of phantom studies it is concluded that a reasonable estimate of the spleen:liver uptake ratio may be obtained using planar imaging, but to estimate the spleen volume and the absolute splenic uptake of platelets SPECT imaging is needed, in spite of the present technical limitations of SPECT.
采用两种方法对25例特发性血小板减少性紫癜（ITP）患者的脾脏对血小板的摄取情况及脾脏大小进行了研究：前后位闪烁显像和单光子发射计算机断层扫描（SPECT）。研究了影响铟-111 SPECT质量的各种因素（采集和重建方案）。通过SPECT测量发现，血液中自身抗体水平高的患者脾脏摄取明显高于无此类抗体的患者（37±6%，n = 8 vs 22±3%，n = 11，P = 0.04，t检验）。脾脏SPECT体积与前后位图像几何平均大小之间的相关性为0.80（P < 0.001）。然而，在一些患者中，以前后位图像几何平均值计算的脾脏大小与SPECT体积相差超过50%。基于这些观察结果和体模研究结果得出结论，尽管SPECT目前存在技术局限性，但使用平面显像可能获得脾脏与肝脏摄取率的合理估计值，但要估计脾脏体积和血小板的绝对脾脏摄取量则需要SPECT显像。
