时间依赖扩散加权MRI在前列腺癌诊疗中的研究现状及进展

Time-dependent diffusion MRI in prostate cancer:current status and future prospects

前列腺成像报告和数据系统(PI-RADS)在前列腺癌的诊断中已在国际范围内广泛应用,但前列腺癌的早期精准诊断仍然存在一定的挑战性。现阶段PI-RADS评分中重要的参考序列扩散加权成像(DWI)仍存在一定的局限性。原因在于,传统的DWI存在长扩散时间的限制,其可探测的扩散受限范围约为一个细胞直径大小,反映的是组织细胞整体的综合扩散受限情况,无法进一步在亚细胞空间尺度上表征前列腺病变组织的微观病理学变化。如能突破这一局限性,或将增加前列腺癌早期诊断的准确度。而新型DWI技术即时间依赖扩散磁共振成像(td-dMRI)近年来备受关注。td-dMRI是一种基于振荡梯度自旋回波和脉冲梯度自旋回波的组合序列及有限光谱编辑扩散显微结构参数成像模型的磁共振成像方法,通过采集短及长扩散时间内的扩散信号,可以表征组织亚细胞尺度上的微观结构变化情况,在疾病诊疗方面展现出较大的应用潜能。本文对td-dMRI技术在前列腺癌诊疗中的应用技术原理、优势、应用价值以及所面临的挑战进行综述,分析该技术在临床显著性前列腺癌的早期检测、诊断及治疗方面的应用价值。

The Prostate Imaging Reporting and Data System(PI-RADS)of MRI has been applied in the international medical community for diagnosing prostate cancer.However,early detection and accurate diagnosis of prostate cancer remain challenging.At present,application of diffusion weighted imaging(DWI)is still limited in the PI-RADS scoring system despite its importance as a pivotal sequence.The limitations stem from the conventional DWI’s reliance on long diffusion times,which restrict its detection capabilities to approximately one cell diameter.This limitation results in an assessment of overall tissue diffusion restriction,rather than detailing the micropathological changes within prostate lesions at the intracellular spatial scale.Overcoming this limitation could enhance the early diagnostic accuracy of prostate cancer.In recent years,a novel diffusion MRI technique known as time-dependent diffusion MRI(td-dMRI),has garnered significant interest.Td-dMRI combines oscillating gradient spin echo and pulsed gradient spin echo and utilizes imaging microstructural parameters with limited spectrally edited diffusion model,which is capable of capturing diffusion signals over both short and long diffusion timescales to characterize tissue microstructural changes.It has demonstrated remarkable application potential in the diagnosis and therapeutic realms of various diseases.This article aims to provide a comprehensive review of td-dMRI,and discusses its technical principles,advantages,clinical application value,and the challenges it faces in the context of prostate cancer diagnosis and treatment.Specifically,we will explore its potential for early detection,diagnosis,and management of clinically significant prostate cancer.