The Experimental Correlative Study Of MRI With Pathology On Soft Tissue Involved Of Malignant Bone Tumor

Objective To explore the optimal MRI series for revealing the soft tissue infringement of malignant bone tumors and to improve the knowledge about the tissue changes around the soft tissue masses in the method of MRI with pathologic correlation.Methods25adult outbreed New Zealand white rabbits weighing between2.0and3.0kg were used. VX2carcinoma were implanted into the tibiaes of25rabbits. MRI were repeated including sagittal SE T1-weighted image (SE T1WI),Fat-Sat FSE T2-weighted image (FS FSE T2WI), STIR, gadolinium-enhanced fat-suppressed T1WI (FS SE T1WI-C+). Then histological examinations for the tibiaes with implanted tumors were performed and MRI-pathologic correlation were done. The extents of the infringement of soft tissue masses and the edema both in MRI and histological section were measured separately and analyzed statistically. The pathological changes of soft tissue around tumors were analyzed by comparing the MRI and the histological sections.Result20VX2rabbit models were made successfully and received MRI and pathological examinations.(1) There were no differences among the MRI and the pathological section about the tumor appearance and margin. The infiltration around the tumor was limited.(2)The sequences of the measurement in the extent about infringement in SE T1WI, FS FSE T2WI, STIR, FS SE T1WI-C+and the pathological section were (13.54±3.98) mm (10.88±4.11) mm,(10.78±3.77) mm,(10.04±3.55) mm and (10.45±3.61) mm. There were no differences among the MRI series and the pathological section except the SE T1WI.(3) The sequences of the measurement in the extent about edema around the soft tissue masses in FS FSE T2WI, STIR, FS SE T1WI-C+and the pathological section were (4.49±2.33)mm,(4.48±2.33) mm,(4.99±2.41) mm and (4.83±2.37)mm. There were no differences among the MRI series and the pathological section.(4) The accuracy, sensitivity and specificity of the different MRI series for displaying the tumor margins are (50.0%,22.2%,25.0%),(33.3%,92.9%,75.0%),(40.0%,93.3%,80.0%) and (80.0%,100.0%,95.0%).Conclusion (1). There are no differences among the MRI series and the pathological section about the tumor appearance and margins. There are no tumor cells in the edema areas except some inflammatory cells. The extents about the infringement of the soft tissue masses in the VX2malignant bone tumor models are limited in the margins and interim areas displaying in MRI series.(2). FS FSE T2WI, STIR, FS SE T1WI-C+series can display the margin and infiltration of the soft tissue masses clearly comparing with the SE Tl WI.(3). There are no differences in the ability and accuracy of displaying the edema extent among the FS FSE T2WI, STIR, FS SE T1WI-C+series.(4). The FS SE T1WI-C+series has the best accuracy, sensitivity and specificity for displaying the tumor margin comparing with the FS FSE T2WI, STIR and SE T1WI series.