囊性脑转移瘤的CT和MRI诊断

目的探讨囊性脑转移瘤的CT、MR I表现特点。方法经临床或病理证实的囊性脑转移瘤26例,男13例,女13例,平均年龄52.7岁。15例行CT平扫,13例行MR平扫,11例行增强CT和/或增强MR I扫描。结果26例共48个囊性脑转移灶,囊壁CT平扫呈等或稍高密度,MR T1W I和T2W I呈等或稍低信号,根据囊壁的形态将其分为3种类型:不均型、结节型、均匀型。MR T1W I囊液信号强度略高于、T2W I高于脑脊液信号强度,而CT密度与之相似或略高。增强扫描肿瘤呈环形强化,部分病灶可见强化壁结节。结论囊性脑转移瘤形态多样,需与脑脓肿及其他肿瘤性囊性病变相鉴别,MR I多方位增强扫描对诊断很有帮助。

CT and MRI Diagnosis of Cystic Brain Metastases

Objective To study the CT and MRI features of cystic brain metastases. Methods 26 cases of cystic brain metastases proved by clinicopathology were presented.There were13 males and 13 females with an average age of 52.7 years.CT studies were obtained in 15 cases,while MR studies were done in 13 cases.11 cases had CT and/or MRI contrast enhancement studies. Results According to the shape of the wall of cystic brain metastases,48 tumors in 26 cases were classified into three types: irregular,nodular,regular type.The wall demonstrated iso-or slightly high density on CT and iso-or slightly low intensity on MR T_1WI and T_2WI,while the hydatid fluid showed slightly high intensity on MR T_1WI and high intensity on T_2WI and iso-or slightly high density on CT compared to CSF.The tumors showed circular reinforcement on enhanced CT or MRI,with nodular enhancement in some cases. Conclusion Cystic brain metastases have mutiple types and should be differentiated from brain abcess and other cystic brain parenchamal tumors.Multi-direction enhanced MRI is helpful to diagnosis.