时间依赖扩散MRI的基本原理及其在前列腺癌中的应用

Basic principle of time-dependent diffusion MRI and its application in prostate cancer

前列腺癌(prostate cancer, PCa)是一种具有较高发病率及死亡率和异质性的肿瘤,严重影响老年男性的健康,并带来过度诊断和治疗的社会问题。MRI是前列腺疾病的诊断、指导穿刺活检和监测的首选影像学检查方法,常规扩散加权成像不能获得PCa微结构改变引起水分子细胞尺度扩散的特征,对临床意义显著PCa诊断存在一定的局限性。时间依赖扩散MRI(time-dependent diffusion MRI, TDD-MRI)采用振荡梯度场自旋回波(oscillating gradient spin-echo, OGSE)序列,可以获得水分子细胞尺度扩散的特征,从而在体反映前列腺结节微结构。本文就TDD-MRI的基本原理及其在PCa中的应用予以综述,探讨TDD-MRI是否有望作为在体无创且容易反复获得的影像学生物标记并用于PCa的诊断与风险分层,为临床PCa的个性化诊疗提供决策支持。

Prostate cancer(PCa)is a kind of tumor with high morbidity,mortality and heterogeneity,which seriously affects the health of elderly men and brings social problems of overdiagnosis and excessive treatment.MRI is the preferred imaging method for the diagnosis,guidance of biopsy and monitoring of prostate diseases.Conventional diffusion-weighted imaging can not obtain the characteristics of cellular scale diffusion of water molecules caused by clinical significant PCa microstructure changes,which has some limitations in the diagnosis of PCa.However,time-dependent diffusion MRI(TDD-MRI)using oscillating gradient spin-echo(OGSE)can obtain the characteristics of cell-scale diffusion of water molecules to reflect the microstructure of prostate nodules in vivo,which shows the potential to be a non-invasive and easily available imaging biomarker for the diagnosis and risk stratification of PCa,and to provide decision making support for personalized therapy of PCa.This paper mainly introduces the basic principle of TDD-MRI and its application in PCa,and discusses whether TDD-MRI can be used as a non-invasive and easily obtained imaging biomarker in vivo for the diagnosis and risk stratification of PCa,so as to provide decision support for personalized medical treatment of clinical PCa.