^99Tc^m-DMP444肺动脉血栓与下肢深静脉血栓显像的实验研究

Detection of experimental pulmonary thrombosis and deep venous thrombosis by ^99Tc^m-DMP444

目的探讨小分子多肽血栓显像剂^99Tc^m-邻苯二甲酸二甲酯（DMP）444在PE和下肢深静脉血栓（DVT）动物模型中的显像效果。方法选5条杂种犬，制备左下肺动脉血栓和右股静脉血栓动物模型。注射显像剂后即刻（30s）、2、3、4、5、10、15、30、60、90和120min分别取静脉血1ml，测质量及放射性计数。以注射后即刻的血液放射性计数为100％，计算各时间点的^99Tc^m-DMP444血液清除率。注射后15、30、60、90和120min，分别进行胸部及双后肢平面显像。应用ROI方法，分别计算肺血栓／肺本底（P／L）、股静脉血栓／对侧股静脉血（D／B）和股静脉血栓／肌肉本底（D／M）的放射性比值。显像结束后，取出血栓分别测定肺动脉血栓和股静脉血栓摄取^99Tc^mDMP444的％ID／g。不同时间点均数之间的差异采用单向重复测量方差分析。结果^99Tc^m-DMP444注射后120min的血液清除率为（65．4±3．9）％。左下肺动脉及右股静脉血栓部位放射性摄取随时间逐步增强，注射后15至120min，P／L，D／B和D／M比值分别从2．41±0．28、1．67±0．33、2．20±0．14增加至3．96±0．64、2．56±0．57、3．90±0．95，差异均有统计学意义（F=14．57、7．68和9．37，P均〈0．05）。PE和后肢DVT的％ID／g分别为0．085±0．023和0．054±0．018。结论^99Tc^m-DMP444能无创性地早期检测急性PE和下肢DVT，是较为理想的小分子多肽血栓显像剂。

Objective To evaluate ^99Tc^m-dimethyl pathalate （DMP）444 scintigraphy for detection of PE and deep venous thrombosis （DVT） in animal models. Methods The experimental PE and DVT were induced in 5 dogs. Venous blood samples （ 1 ml ） were collected at 30 s, 2 min, 3 min, 4 min, 5 rain, 10 min, 15 min, 30 rain, 60 rain, 90 min and 120 rain respectively after the tracer injection. The collected blood samples were weighed and counted for radioactivity in a ,y-counter. The radioactivity was expressed as a percentage of the initial （30 s） activity. The blood clearance rate at each time point was obtained. The im-ages of lungs and legs were acquired at 15, 30, 60, 90 and 120 min alter the injection. ROI was drawn on PE, DVT, lung, contralateral femoral vein and lateral thigh for calculating the radioactivity ratios of PE/ lung （P/L）, DVT/blood （D/B） and DVT/muscle （D/M）. PE and DVT were removed, weighed and counted for radioactivity ex vivo to determine the % ID/g. Data at different time points were compared by one-way repeated measures analysis of variance. Results Blood clearance rate of^99Tc^m-DMPd44 was （65.4±3.9 ） % at 120 min after the injection. The radioactivity ratios of PE and DVT increased over time, and the radioactivity ratios of P/L, D/B and D/M increased from 2.41 ±0.28, 1.67± 0.33, 2.20± 0.14 at 15 min to 5.96±0. 64, 2.56±0.57, 3.90±0.95 at 120 min, after the injection respectively （ F = 14. 57,7.68,9.37, all P 〈 0.05）. The % ID/g of PE and DVT was 0.085 ± 0. 023 and 0. 054 ± 0.018 respectively. Conclusion ^99Tc^m-DMP444 may become a potential radiopharmaceutical agent for noninvasively detecting PE and DVT.