MRI Research On Nasopharynx Skull Base Structure Of Normal Rabbits And Rabbit Models With Rabbit VX2Carcinoma

Objective To evaluate the consistence between MRI of normal rabbit nasopharynx skull base structure and general specimens, and research the MRI diagnosis and the pathology foundation of rabbit VX2nasopharyngeal carcinoma model. Further comprehensively evaluate the diagnostic application value of the MRI in rabbit VX2nasopharyngeal carcinoma model.Materials and methods This study was approved by the animal ethics committee before study participation according to institutional and native guidelines. Firstly,10normal New Zealand rabbits were received MRI inspection and specimen measured on nasopharynx skull base structure, and evaluate the consistence between MR of normal rabbit nasopharynx skull base structure and general specimens. Then,25rabbits were received the CT scans, and were punctured, and injected the carcinoma cell suspension after rabbits were anesthetized. The size and the intensity change of the skull base were recorded in the conventional MRI. The characters of VX2cacinoma cell, sizes of tumor, and information on invasion of the skull base were observed on the microscopy examinations.Results There was no significant difference between MRI and pathology measurement in nasopharynx skull base structure of the10normal New Zealand Srabbits (P>0.05). In MRI examination, the80%(20/25) rate of rabbit VX2nasopharyngeal carcinoma models were made successfully. In microscopy examinations, there were16cases with destruction of trabecula bone and bone marrow,2cases with fibrosis and hyperplasy, and2normal skull bases.100%sensitivity and50%specificity of MRI diagnosing the rabbit VX2nasopharyngeal carcinoma invading the skull base were calculated according to pathological criteria. The MRI diagnosing showed a good agreement with pathology in the number and location of the lesions of skull base.There was no significant difference between MRI and pathology measurement [(2.3±0.7) cm and (2.1±0.6) cm]in VX2carcinoma sizes (P>0.05) in the T test.among the18rabbit models whose MRI results indicate abnormal signals of the skull base,4cases have singal-bone signal change,14cases with multi-bone signals change, this is consistent with the pathological results。Conclusion MRI examination can reflect the specific anatomical structure of normal rabbit nasopharynx with accuracy, and can also reflect the size and components of the tumor and the lesions of basion. But it can not dertermine the pathology of basion.