SWI原理及临床应用.pptx (1)

TheFirstAffiliatedHospitalZhejiangChineseMedicalUniversitySWI的原理及临床应用2016-12-02TheFirstAffiliatedHospitalZhejiangChineseMedicalUniversity•SWI成像原理简介•SWI的临床应用TheFirstAffiliatedHospitalZhejiangChineseMedicalUniversitySWI成像原理•SWI是一种利用不同组织间的磁敏感性差异而成像的技术，对小静脉、微出血和铁沉积更敏感。•成像基础：组织间磁敏感度差异TheFirstAffiliatedHospitalZhejiangChineseMedicalUniversitySWI成像原理•以T2*加权梯度回波序列作为序列基础，分别采集强度数据和相位数据的方式，并在此基础上进行数据的后处理，可将处理后的相位信息叠加到强度信息上，更加强调组织间的磁敏感性差异，形成最终的SWI图像TheFirstAffiliatedHospitalZhejiangChineseMedicalUniversity与SWI相关的组织磁敏感性特点•血红蛋白及其降解产物–氧合血红蛋白：Fe2++与氧结合，没有不成对的电子，为反磁性–去氧血红蛋白：带有4个不成对的电子，顺磁性–正铁血红蛋白：血红蛋白进一步氧化为，含5个不成对电子，具有较强顺磁性，但磁敏感性较弱，主要缩短T1弛豫时间–含铁血黄素：高度顺磁性，磁敏感性较强TheFirstAffiliatedHospitalZhejiangChineseMedicalUniversity•非血红蛋白铁及钙化的磁敏感性–非血红蛋白铁在体内以铁蛋白常见，为高度顺磁性。正常人随年龄增加，铁在脑内沉积增加，但在某些神经变性疾病中，如帕金森病、阿尔茨海默病等，铁异常沉积–钙化：在脑内的结合状态是弱反磁性，但大多数情况下可以产生局部磁场，导致信号去相位，造成T2*缩短，信号减低TheFirstAffiliatedHospitalZhejiangChineseMedicalUniversity•SWI的影像对比：用于小静脉显像TheFirstAffiliatedHospitalZhejiangChineseMedicalUniversity•无论顺磁性物质还是反磁性物质，只要能改变局部磁场，导致空间相位的改变，就能产生信号的去相位，造成T2*时间缩短。去相位的结果不取决于物质是顺磁性还是反磁性，而取决于物质在一个体素内能多大程度地改变磁场TheFirstAffiliatedHospitalZhejiangChineseMedicalUniversityTheFirstAffiliatedHospitalZhejiangChineseMedicalUniversitySWI的临床应用•血管源性病变•肿瘤性病变•颅脑外伤•神经退行性疾病•其他TheFirstAffiliatedHospitalZhejiangChineseMedicalUniversity血管源性病变•血管源性病变–海绵状血管瘤–动静脉畸形–毛细血管扩张症–淀粉样脑血管病（CAA）–脑梗死及出血TheFirstAffiliatedHospitalZhejiangChineseMedicalUniversity左侧小脑海绵状血管瘤合并出血TheFirstAffiliatedHospitalZhejiangChineseMedicalUniversity多发出血的海绵状血管瘤TheFirstAffiliatedHospitalZhejiangChineseMedicalUniversity血管畸形TheFirstAffiliatedHospitalZhejiangChineseMedicalUniversity右额叶深部血管发育畸形TheFirstAffiliatedHospitalZhejiangChineseMedicalUniversity右枕叶静脉畸形TheFirstAffiliatedHospitalZhejiangChineseMedicalUniversity左侧顶枕叶动静脉畸形TheFirstAffiliatedHospitalZhejiangChineseMedicalUniversity左侧大脑半球静脉发育畸形TheFirstAffiliatedHospitalZhejiangChineseMedicalUniversity放射性毛细血管扩张症TheFirstAffiliatedHospitalZhejiangChineseMedicalUniversity淀粉样脑血管病TheFirstAffiliatedHospitalZhejiangChineseMedicalUniversity淀粉样脑血管病CAATheFirstAffiliatedHospitalZhejiangChineseMedicalUniversityMIPSWICT左侧基底节区梗死合并微小出血灶TheFirstAffiliatedHospitalZhejiangChineseMedicalUniversity肿瘤性病变•肿瘤性病变–SWI可以显示肿瘤的边界、静脉、出血及钙化等TheFirstAffiliatedHospitalZhejiangChineseMedicalUniversityT1-CEFlairSWITheFirstAffiliatedHospitalZhejiangChineseMedicalUniversitySWIT1-CE胶质瘤合并出血TheFirstAffiliatedHospitalZhejiangChineseMedicalUniversity右侧脑室肿瘤静脉分布和出血灶TheFirstAffiliatedHospitalZhejiangChineseMedicalUniversity颅脑外伤性疾病•颅脑外伤性疾病–弥漫性轴索损伤（DAI）–外伤性脑出血及梗死TheFirstAffiliatedHospitalZhejiangChineseMedicalUniversity颅脑外伤性疾病弥漫性轴索损伤DAITheFirstAffiliatedHospitalZhejiangChineseMedicalUniversity弥漫性轴索损伤DAITheFirstAffiliatedHospitalZhejiangChineseMedicalUniversity弥漫性轴索损伤DAITheFirstAffiliatedHospitalZhejiangChineseMedicalUniversity外伤后右侧额叶微小出血灶TheFirstAffiliatedHospitalZhejiangChineseMedicalUniversity神经退行性疾病•神经退行性疾病以脑内铁质沉积增多为特征–Alzheimer’sdisease–Parkinson’sdisease钙质沉积TheFirstAffiliatedHospitalZhejiangChineseMedicalUniversityAlzheimer’sdisease齿状核铁质含量增高TheFirstAffiliatedHospitalZhejiangChineseMedicalUniversityParkinson’sdisease黒质区燕尾征消失TheFirstAffiliatedHospitalZhejiangChineseMedicalUniversityTheFirstAffiliatedHospitalZhejiangChineseMedicalUniversity钙化性疾病双侧苍白球钙化TheFirstAffiliatedHospitalZhejiangChineseMedicalUniversity钙化性疾病少突胶质细胞瘤钙化斑TheFirstAffiliatedHospitalZhejiangChineseMedicalUniversity其他疾病肝豆状核变性TheFirstAffiliatedHospitalZhejiangChineseMedicalUniversityTheFirstAffiliatedHospitalZhejiangChineseMedicalUniversityThankYou!