Department of Radiology, University of California, San Diego, San Diego, CA, United States.
Departments of Orthopaedic Surgery, University of California, San Diego, San Diego, CA, United States.
Front Endocrinol (Lausanne). 2020 Sep 29;11:555756. doi: 10.3389/fendo.2020.555756. eCollection 2020.
Bone is comprised of mineral, collagenous organic matrix, and water. X-ray-based techniques are the standard approach for bone evaluation in clinics, but they are unable to detect the organic matrix and water components in bone. Magnetic resonance imaging (MRI) is being used increasingly for bone evaluation. While MRI can non-invasively assess the proton pools in soft tissues, cortical bone typically appears as a signal void with clinical MR techniques because of its short T2*. New MRI techniques have been recently developed to image bone while avoiding the ionizing radiation present in x-ray-based methods. Qualitative bone imaging can be achieved using ultrashort echo time (UTE), single inversion recovery UTE (IR-UTE), dual-inversion recovery UTE (Dual-IR-UTE), double-inversion recovery UTE (Double-IR-UTE), and zero echo time (ZTE) sequences. The contrast mechanisms as well as the advantages and disadvantages of each technique are discussed.
骨由矿物质、胶原有机基质和水组成。基于 X 射线的技术是临床中评估骨的标准方法，但它们无法检测骨中的有机基质和水成分。磁共振成像（MRI）越来越多地用于骨评估。虽然 MRI 可以非侵入性地评估软组织中的质子池，但由于皮质骨的 T2* 较短，临床 MRI 技术通常显示为信号缺失。最近已经开发出了新的 MRI 技术，用于在避免基于 X 射线方法中存在的电离辐射的情况下对骨进行成像。使用超短回波时间（UTE）、单反转恢复 UTE（IR-UTE）、双反转恢复 UTE（双 IR-UTE）、双反转恢复 UTE（双 IR-UTE）和零回波时间（ZTE）序列可以进行定性骨成像。讨论了每种技术的对比机制以及优缺点。
