Dynamic Contrast-Enhanced MR Imaging of VX2 Carcinomas After X-Irradiation in Rabbits

Publisher Website
Google Scholar
Abstract
To compare enhancement patterns of gadomer-17 with those of gadopentetate dimeglumine in VX2 carcinomas after irradiation on rabbits. Twelve rabbits with VX2 carcinoma in the thigh underwent dynamic contrast-enhanced magnetic resonance (MR) imaging with gadopentetate dimeglumine and gadomer-17 at 24-hour intervals before (n = 12), 3 days (group 1, n = 12), 1 month (group 2, n = 8) and 2 months (group 3, n = 4) after 30 Gy irradiation. After taking postirradiation MR images, 4 rabbits were killed for histopathologic examination at each time interval. The enhancement characteristics in MR imaging and morphology of tumor vessels in histopathologic specimen were assessed. After gadopentetate dimeglumine injection, the enhancement characteristics were not different among tumors before and after irradiation (P > 0.05). For gadomer-17, the enhancement ratios decreased after irradiation. The shape of the curves for tumor enhancement before irradiation was significantly different from curves of group 1(P < 0.05). The specimens from group 3 showed sclerosis and wall thickening in arterioles. Dynamic contrast-enhanced MR imaging with a gadomer-17 reveals increased capillary permeability at an early phase after irradiation and chronic obliterating vasculopathy at delayed phase.