彩色与能量多普勒评价超声造影在兔实验性肾肿瘤中的诊断价值

Contrast enhanced color doppler flow imaging and power doppler imaging in the evaluation of experimental rabbit renal VX2 tumors

目的 探讨自制超声微泡造影剂在兔实验性肾肿瘤灰阶对比以及血流显像中的作用。方法 新西兰兔14只,手术植入法建立VX2 肿瘤肾荷瘤模型。常规条件与造影条件下分别行二维超声、SonoCT、CDFI和PDI检测肾肿瘤。经耳缘静脉注射自制声学造影剂,随即以1ml生理盐水冲洗。以磁光盘记录声学造影前后的声像图变化,视频密度定量分析肾脏肿瘤结节中心、边缘与临近正常肾皮质的灰阶差值。观察造影前后肿瘤病灶的血流灌注、血管形态及半定量方法计数血管的数目。结果 超声造影后肾皮质灰阶信号显著增强,病灶呈低于肾皮质的负显影,轮廓清晰,形态较规则,内部回声不均质,病灶检出率由89.5 % (17/19)提高到10 0 % (19/19)。造影后CDFI主要是2级血流显示率增高达78.9% (15 /19) ,但总的血流显示率仍为89.4% (17/19) ;PDI则主要是3级血流改变巨大,由无升到5 7.9% (11/19) ,总的血流显示率则由89.4% (17/19)上升到10 0 % (19/19)。此种变化表现为血管由点显示变化为短棒状显示,可见多达11个病灶出现短暂的贯穿性血流。而造影前不能观察到血流的两个病灶也发现有点状的血流信号。结论 使用超声造影剂有助于提高肾脏微小病灶的检出率,深入了解病灶周边与内部的血流供应情况。造影PDI成像比CDFI成像具有更高的敏感性。

Objective The study is designed to investigate the intravenous injection of a echo-contrast agent in grayscale and Doppler flow enhancement of experimental renal VX2 tumors.Methods Vital VX2 tumor tissues were surgically implanted into the kidneys of fourteen New Zealand rabbits to set up animal model of kidney tumor. Conventional and contrasted enhanced ultrasonography were performed using gray scale, color Doppler flow imaging (CDFI) and power Doppler imaging (PDI) modalities. A self-made contrast agent was bolus injected through the ear veins, immediately followed by 1ml saline flash. The baseline and post-contrast images were recorded by magnetic optical disks (MO), and then the gray scale value of the central, peripheral and surrounding normal renal cortex were respectively analyzed by video intensity. The blood perfusion and vascular morphology were observed, and the vessel numbers were also hemi-quantitatively measured pre and post contrast injection.Results It showed that the gray scale images increased significantly after contrast administration, and the lesions demonstrated as hypoechoic nodules with clear margin, regular shape and heterogeneous internal echo. The detection sensitivity of focal lesions increased from 89.5% (17/19) to 100% (19/19). After contrast agent injection, CDFI showed that grade 2 flow increased up to 78.9%(15/19), but its total display rate remained 89.4%(17/19). However, PDI showed a significant increase at grade 3 from zero to 57.9% (11/19), and so the total sensitivity increased from 89.4% (17/19) to 100% (19/19). The color signals were enhanced from dots to lines, and a central penetrated flow signal was found in eleven lesions. Two focal lesions, in which no flow signals were found at baseline, showed dot color flow. Conclusion Intravenous injection of the echo contrast agent helped to increase the delectability of small focal renal lesions, and further investigate the peripheral and internal blood flows of the lesions. Contrasted PDI might be more sensitive than contrasted CDFI.