Ni Yicheng, Chen Feng, Mulier Stefaan, Sun Xihe, Yu Jie, Landuyt Willy, Marchal Guy, Verbruggen Alfons
Department of Radiology, University Hospitals, Catholic University of Leuven, Herestraat 49, 3000 Leuven, Belgium.
Eur Radiol. 2006 May;16(5):1031-40. doi: 10.1007/s00330-005-0094-0. Epub 2006 Jan 21.
We exploited a necrosis-avid contrast agent ECIV-7 for magnetic resonance imaging (MRI) in rodent liver tumors after radiofrequency ablation (RFA). Rats bearing liver rhabdomyosarcoma (R1) were randomly allocated to three groups: group I, complete RFA, group II, incomplete RFA, and group III, sham ablation. Within 24 h after RFA, T1-weighted (T1-w) MRI was performed before and after injection of ECIV-7 at 0.05 mmol/kg and followed up from 6-24 h. Signal intensities (SIs) were measured with relative enhancement (RE) and contrast ratio (CR) calculated. The MRI findings were verified histomorphologically. On plain T1-w MRI the contrasts between normal liver, RFA lesion, residual and/or intact tumor were vague. Early after administration of ECIV-7, the liver SI was strongly enhanced (RE=40-50%), leaving the RFA lesion as a hypointense region in groups I and II. At delayed phase, two striking peri-ablational enhancement patterns appeared (RE=90% and CR=1.89%), i.e., "O" type of hyperintense rim in group I and "C" type of incomplete rim in group II. These MRI manifestations could be proven histologically. In this study, tissue components after RFA could be characterized with discernable contrasts by necrosis-avid contrast agent (NACA)-enhanced MRI, especially at delayed phase. This approach may prove useful for defining the ablated area and identifying residual tumor after RFA.
我们利用一种坏死亲和性造影剂ECIV-7，对接受射频消融（RFA）后的啮齿动物肝肿瘤进行磁共振成像（MRI）检查。将患有肝横纹肌肉瘤（R1）的大鼠随机分为三组：第一组，完全RFA组；第二组，不完全RFA组；第三组，假消融组。在RFA后24小时内，于注射0.05 mmol/kg的ECIV-7之前和之后进行T1加权（T1-w）MRI检查，并在6 - 24小时进行随访。测量信号强度（SIs），并计算相对增强（RE）和对比率（CR）。MRI结果通过组织形态学进行验证。在普通T1-w MRI上，正常肝脏、RFA病灶、残余和/或完整肿瘤之间的对比度模糊。在给予ECIV-7后早期，肝脏SI显著增强（RE = 40 - 50%），在第一组和第二组中，RFA病灶表现为低信号区。在延迟期，出现了两种明显的消融周围增强模式（RE = 90%，CR = 1.89%），即第一组的“O”型高信号边缘和第二组的“C”型不完整边缘。这些MRI表现可以通过组织学得到证实。在本研究中，坏死亲和性造影剂（NACA）增强MRI可以通过可辨别的对比度来表征RFA后的组织成分特点，尤其是在延迟期。这种方法可能对界定消融区域和识别RFA后的残余肿瘤有用。
