骨肿瘤骨膜异常的MRI表现与病理对照实验研究

Comparison of MRI and pathology of periosteal change in experimental bone tumor

目的研究兔VX2骨肿瘤模型中各种骨膜改变的MRI表现及其病理基础，评价MRI显示骨膜改变的价值。方法制作32只兔VX2骨肿瘤模型，并设36只阳性对照和4只阴性对照。制作模型后每5d对所有肿瘤模型进行X线及MR检查，每次影像检查之后随机处死4只实验兔，取材后制作病理切片，进行影像与病理对照观察。结果肿瘤模型制作后第5～15天，发现32只兔实验侧胫骨骨膜水肿；第20天，发现19只实验侧胫骨骨膜增厚；第25天，发现11只实验侧胫骨骨膜新生骨并骨膜增厚；第30天，发现11只实验侧胫骨被肿瘤掀起的骨膜新生骨；第35—40天，骨膜新生骨及骨膜被肿瘤破坏。结论兔VX2骨肿瘤中骨膜改变依次包括骨膜水肿、骨膜增厚、骨膜新生骨、骨膜新生骨破坏、骨膜破坏。MRI能够显示各种骨膜改变，对骨膜改变的评价有重要价值。

Objective To study MRI features and pathologic basis of various periosteal changes in rabbit VX2 bone tumor and to evaluate the role of MRI in the change of periosteum in bone tumor. Methods Bone tumor models were induced by injection of VX2 carcinoma cell suspension into the medullary cavity of right tibias in 32 rabbits. Thirty-six positive contrast cases and 4 negative contrast cases were established. Serial plain films and MRI examinations were performed at an interval of 5 days following the implantation. Every 4 rabbits were sacrificed immediately after imaging. The findings of periosteal changes were compared between imaging features and pathologic results. Results From the 5th to 15th day after implantation of VX2 carcinoma, periosteal edema was demonstrated in 32 tibias. On the 20th day, periosteal thickening was revealed in 19 tibias. On the 25th day, periosteal new bone with the thickened periosteum attaching to its outer surface was found in 12 tibias. On the 30th day, periosteal new bone with the thickened periosteum were elevated by the tumor in 11 tibias. On the 35th to 40th day, destruction of periosteal bone and periosteum were revealed. Conclusions The progress of periosteal changes in rabbit VX2 bone tumor included periosteal edema, periosteal thickening, periosteal new bone, destruction of periosteal new bone and destruction of periosteum. Various periosteal changes could be demonstrated on MRI and MRI is useful in evaluating periosteal changes.