Gadolinium mesoporphyrin as an MR imaging contrast agent in the evaluation of tumors: an experimental model of VX2 carcinoma in rabbits.
OBJECTIVE
We determined the enhancement features of experimentally induced malignant tumors on MR imaging with the use of gadolinium mesoporphyrin, a recently developed MR contrast agent that may be necrosis-specific.


METHODS
VX2 carcinoma was inoculated into 24 rabbit thighs. T1-weighted contrast-enhanced MR imaging with IV gadopentetate dimeglumine (2-min delay) and gadolinium mesoporphyrin (20-hr delay) was performed 3-4 days (n = 6), 6-7 days (n = 6), 10-11 days (n = 5), and 13-14 days (n = 7) after the implantation of VX2 carcinoma. All tumors were sectioned along the same plane of MR images, and a detailed MR imaging-histopathologic correlation was performed.


RESULTS
Pathologically, areas enhanced with gadolinium mesoporphyrin included necrotic tissue, viable tumor, inflammatory granulation tissue, hemorrhage, and fibrosis. On gadopentetate dimeglumine-enhanced MR images, unenhanced areas of the tumor corresponded with intratumoral necrosis and hemorrhage.


CONCLUSIONS
Gadolinium mesoporphyrin enhances tumor necrosis on delayed phase MR imaging; however, it is impossible to specifically depict necrosis with gadolinium mesoporphyrin because it also enhances other parts of lesions, including viable tumor.
Kim
T K
TK
Department of Radiology, Seoul National University College of Medicine, Korea.
Choi
B I
BI
Park
S W
SW
Lee
W
W
Han
J K
JK
Han
M C
MC
Weinmann
H J
HJ
D000818:Animals; D003287:Contrast Media; D008279:Magnetic Resonance Imaging; D008665:Metalloporphyrins; D009374:Neoplasms, Experimental / Q000473:pathology*; D011817:Rabbits
D003287:Contrast Media; D008665:Metalloporphyrins; C112663:gadolinium mesoporphyrin