From the Departments of Radiology (B.G., J.C.M., J.W.U., S.E.S., A.D.S., B.K.) and Orthopedic Surgery (M.J.W.), Brigham and Women's Hospital Emergency Radiology Division, 75 Francis St, Boston, MA 02115.
Radiographics. 2020 May-Jun;40(3):859-874. doi: 10.1148/rg.2020190173.
Dual-energy CT is increasingly being used in the emergency department to help diagnose acute conditions. Its applications include demonstrating bone marrow edema (BME) seen in the setting of occult fractures and other acute conditions. Dual-energy CT acquires data with two different x-ray energy spectra and is able to help differentiate materials on the basis of their differential energy-dependent x-ray absorption behaviors. Virtual noncalcium (VNCa) techniques can be used to suppress the high attenuation of trabecular bone, thus enabling visualization of subtle changes in the underlying attenuation of the bone marrow. Visualization of BME can be used to identify occult or mildly displaced fractures, pathologic fractures, metastases, and some less commonly visualized conditions such as ligamentous injuries or inflammatory arthritis. The authors' major focus is use of dual-energy CT as a diagnostic modality in the setting of trauma and to depict subtle or occult fractures. The authors also provide some scenarios in which dual-energy CT is used to help diagnose other acute conditions. The causes and pathophysiology of BME are reviewed. Dual-energy CT image acquisition and VNCa postprocessing techniques are also discussed, along with their applications in emergency settings. The authors present potential pitfalls and limitations of these techniques and their possible solutions.RSNA, 2020.
双能 CT 越来越多地用于急诊科以帮助诊断急性病症。其应用包括显示隐匿性骨折和其他急性病症中出现的骨髓水肿（BME）。双能 CT 使用两种不同的 X 射线能谱采集数据，并能够基于物质对 X 射线吸收特性的差异来帮助区分物质。虚拟非钙（VNCa）技术可用于抑制小梁骨的高衰减，从而使骨髓内部衰减的细微变化可视化。BME 的可视化可用于识别隐匿性或轻度移位性骨折、病理性骨折、转移瘤以及一些不太常见的可见病变，如韧带损伤或炎性关节炎。作者的主要关注点是将双能 CT 作为创伤的诊断方式，并描述细微或隐匿性骨折。作者还提供了一些双能 CT 用于帮助诊断其他急性病症的场景。本文回顾了 BME 的病因和病理生理学。还讨论了双能 CT 图像采集和 VNCa 后处理技术及其在急诊环境中的应用。作者提出了这些技术的潜在陷阱和局限性及其可能的解决方案。RSNA，2020。
