^(18)F-FDG SPECT显像纵隔病变病灶/本底比值测定方法研究

Clinical study on accurate measurement of mediastinum region L/B in ^(18)F-FDG SPECT imaging

目的 探讨1 8F 脱氧葡萄糖 (FDG)SPECT显像纵隔病变病灶 本底比值 (L B)的准确测定方法。方法 对临床确诊的 2 3例纵隔病变患者行胸部1 8F FDGSPECT显像 ,应用同机融合CT图像和三维定位技术 ,在相应1 8F FDG显像中依次选择气道区、脂肪区、间隙区、血管区和心脏区作为本底区 ,分别测定 2 9处良、恶性病灶的L B ,并进行统计学分析。结果 应用不同本底区测定的L B对纵隔内良、恶性病变的诊断准确性不同。其中以血管区和间隙区作为本底区的诊断灵敏度 (分别为82 4 %和 75 6 % )和特异性 (分别为 83 3%和 75 0 % )较高。结论 1 8F FDGSPECT显像同机融合CT图像和三维定位技术可为纵隔内病灶L B的准确测定提供条件。

Objective To study the method for measuring lesion/background ratio (L/B) accurately by selecting appropriate background to mediastinal lesions in 18 F-fluorodeoxyglucose (FDG) SPECT imaging. Methods Twenty-three patients with mediastinal lesions were selected, whose clinical diagnoses were confirmed by thoracic 18 F-FDG imaging and other examinations. Combined CT imaging fusion and three-dimension location technique were used. According to tissue density and local structure on CT images, airway region (A), fat region (F), vessel region (V), space region (S) and heart region (H) were selected as background respectively for L/B measurement on correspondent 18 F-FDG images. So 5 groups were differentiated by different L/B values (L/B_A, L/B_F, L/B_V, L/B_S and L/B_H). Measurement of L/B_S in the mediastinum of 23 patients (11 benign lesions and 18 malignant lesions), and statistical analysis of quantitative data were performed. Results When different background regions were selected to measure L/B, the diagnostic accuracy rates for the mediastinal lesions were also different. Among them, both sensitivity and specificity in vessel group and space group were relatively high. Conclusion The clinical study on 18 F-FDG imaging indicates that L/B of mediastinal lesions can be measured more accurately with combined CT imaging fusion and three-dimension location technique supplied by SPECT.