Rai Pranjal, Janu Amit Kumar, Shetty Nitin, Kulkarni Suyash
Department of Radiology, Tata Memorial Hospital, Homi Bhabha National Institute, Mumbai, India.
Department of Radiology, Advanced Centre for Treatment, Research and Education in Cancer (ACTREC), Kharghar, Navi Mumbai, India.
J Magn Reson Imaging. 2025 Apr 21. doi: 10.1002/jmri.29776.
Conventional MRI is limited in imaging tissues with short T2 relaxation times, such as bone, ligaments, and cartilage, due to their rapid signal decay. This limitation has spurred the development of specialized MRI techniques designed specifically for short-T2 tissue imaging. Traditional pulse sequences, including three-dimensional gradient echo (3D-GRE), susceptibility-weighted imaging (SWI), and Fast Field Echo Resembling a CT using Restricted Echo-Spacing (FRACTURE), initially addressed some of these challenges but often lacked sufficient resolution or contrast differentiation. Recent advancements, such as ultrashort echo time (UTE), zero echo time (ZTE), 3D-Bone, and synthetic computed tomography (sCT), have significantly enhanced the diagnostic capabilities of MRI by providing high-quality, CT-like visualization without exposure to ionizing radiation. These innovations have substantially improved MRI's ability to depict bone morphology, assess joint pathology, identify subtle fractures, and characterize bone tumors with higher accuracy. Beyond musculoskeletal applications, these techniques have demonstrated emerging clinical utility in additional domains, including pulmonary and dental imaging. This review article evaluates conventional pulse sequences alongside emerging MRI innovations, highlighting their clinical applications, current limitations, and technical considerations. Continued optimization of these techniques promises broader clinical adoption, potentially reducing dependence on invasive and radiation-intensive imaging modalities. Evidence Level: N/A Technical Efficacy: Stage 3.
传统的磁共振成像(MRI)在对T2弛豫时间短的组织(如骨骼、韧带和软骨)进行成像时存在局限性,因为这些组织的信号衰减很快。这一局限性促使了专门为短T2组织成像设计的MRI技术的发展。传统的脉冲序列,包括三维梯度回波(3D-GRE)、磁敏感加权成像(SWI)以及使用受限回波间距的类似CT的快速场回波(FRACTURE),最初解决了其中一些挑战,但往往缺乏足够的分辨率或对比度区分能力。最近的进展,如超短回波时间(UTE)、零回波时间(ZTE)、3D-骨成像和合成计算机断层扫描(sCT),通过提供高质量的、类似CT的可视化且无需暴露于电离辐射,显著增强了MRI的诊断能力。这些创新极大地提高了MRI描绘骨形态、评估关节病变、识别细微骨折以及更准确地表征骨肿瘤的能力。除了肌肉骨骼应用外,这些技术在其他领域,包括肺部和牙科成像中也展现出了新的临床应用价值。这篇综述文章评估了传统脉冲序列以及新兴的MRI创新技术,强调了它们的临床应用、当前局限性和技术考量。这些技术的持续优化有望在临床上得到更广泛的应用,可能减少对侵入性和辐射密集型成像方式的依赖。证据水平:无。技术效能:3级。