Evaluation of a rabbit rectal VX2 carcinoma model using computed tomography and magnetic resonance imaging.
OBJECTIVE
To establish a rabbit rectal VX2 carcinoma model for the study of rectal carcinoma.


METHODS
A suspension of VX2 cells was injected into the rectum wall under the guidance of X-ray fluoroscopy. Computed tomography (CT) and magnetic resonance imaging (MRI) were used to observe tumor growth and metastasis at different phases. Pathological changes and spontaneous survival time of the rabbits were recorded.


RESULTS
Two weeks after VX2 cell implantation, the tumor diameter ranged 4.1-5.8 mm and the success implantation rate was 81.8%. CT scanning showed low-density foci of the tumor in the rectum wall, while enhanced CT scanning demonstrated asymmetrical intensification in tumor foci. MRI scanning showed a low signal of the tumor on T(1)-weighted imaging and a high signal of the tumor on T(2)-weighted imaging. Both types of signals were intensified with enhanced MRI. Metastases to the liver and lung could be observed 6 wk after VX2 cell implantation, and a large area of necrosis appeared in the primary tumor. The spontaneous survival time of rabbits with cachexia and multiple organ failure was about 7 wk after VX2 cell implantation.


CONCLUSIONS
The rabbit rectal VX2 carcinoma model we established has a high stability, and can be used in the study of rectal carcinoma.
Department of Radiology, Sixth People's Hospital of Shanghai Jiaotong University; Institute of Medical Imaging of Shanghai Jiaotong University, No. 600, Yishan Road, Shanghai 200233, China.
Xin-Mei
XM
Liang
Guang-Yu
GY
Tang
Ying-Sheng
YS
Cheng
Bi
B
Zhou
D000818:Animals; D004195:Disease Models, Animal; D006801:Humans; D008279:Magnetic Resonance Imaging; D009368:Neoplasm Transplantation; D011817:Rabbits; D012004:Rectal Neoplasms / Q000473:pathology*; D014057:Tomography, X-Ray Computed