Dynamic contrast-enhanced MR imaging of VX2 carcinomas after X-irradiation in rabbits: comparison of gadopentetate dimeglumine and a macromolecular contrast agent.
OBJECTIVE
To compare enhancement patterns of gadomer-17 with those of gadopentetate dimeglumine in VX2 carcinomas after irradiation on rabbits.


METHODS
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.


RESULTS
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.


CONCLUSIONS
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.
Kim
Young Hoon
YH
Department of Radiology, Inje University Sanggye Paik Hospital, Seoul, Korea.
Choi
Byung Ihn
BI
Cho
Woo Ho
WH
Lim
Sungjig
S
Moon
Woo Kyoung
WK
Han
Joon Koo
JK
Weinmann
Hanns-Joachim
HJ
Chang
Kee-Hyun
KH
D000818:Animals; D002199:Capillary Permeability / Q000528:radiation effects; D003287:Contrast Media; D005682:Gadolinium; D019786:Gadolinium DTPA; D008279:Magnetic Resonance Imaging; D009374:Neoplasms, Experimental / Q000175:diagnosis* / Q000473:pathology; D011817:Rabbits
D003287:Contrast Media; C402765:gadomer 17; D005682:Gadolinium; D019786:Gadolinium DTPA