From the Department of Radiology, Vancouver General Hospital, University of British Columbia, 899 W 12th Ave, Vancouver, BC, Canada V5Z 1M9 (N.M., K.E.D., F.E.W., P.D.M., S.N.); and the Medical Imaging Department, King Saud bin Abdulaziz University for Health Sciences, King Abdullah International Medical Research Center, Ministry of the National Guard, Health Affairs, Riyadh, Saudi Arabia (M.F.M.).
Radiographics. 2019 Jan-Feb;39(1):264-286. doi: 10.1148/rg.2019180087.
Evaluation of the nontraumatic acute abdomen with multidetector CT has long been accepted and validated as the reference standard in the acute setting. Dual-energy CT has emerged as a promising tool, with multiple clinical applications in abdominal imaging already demonstrated. With its ability to allow characterization of materials on the basis of their differential attenuation when imaged at two different energy levels, dual-energy CT can help identify the composition of internal body constituents. Therefore, it is possible to selectively identify iodine to assess the enhancement pattern of an organ, including the identification of hyperenhancement in cases of inflammatory processes, or ischemic changes secondary to vascular compromise. Quantification of iodine uptake with contrast material-enhanced dual-energy CT is also possible, and this quantification has been suggested to be useful in differentiating inflammatory from neoplastic conditions. Dual-energy CT can help determine the composition of gallstones and urolithiasis and can be used to accurately differentiate uric acid urinary calculi from non-uric acid urinary calculi. Moreover, dual-energy CT is capable of substantially reducing artifacts caused by metallic prostheses, to improve the imaging evaluation of abdominopelvic organs. The possibility of creating virtual nonenhanced images in the evaluation of acute aortic syndrome, gastrointestinal hemorrhage and ischemia, or pancreatic pathologic conditions substantially reduces the radiation dose delivered to the patient, by eliminating a true nonenhanced acquisition. Finally, by increasing the iodine conspicuity, contrast-enhanced dual-energy CT can render an area of free active extravasation or endoleak more visible, compared with conventional single-energy CT. This article reviews the basics of dual-energy CT and highlights its main clinical applications in evaluation of the nontraumatic acute abdomen. RSNA, 2019.
多排螺旋 CT 对非创伤性急性腹痛的评估长期以来一直被认为是急性疾病的参考标准，并已得到验证。双能 CT 已成为一种很有前途的工具，其在腹部成像方面的多种临床应用已经得到证实。双能 CT 能够根据物质在两种不同能量水平下的不同衰减特性进行物质特性分析，有助于识别体内物质的组成。因此，可以选择性地识别碘，以评估器官的增强模式，包括在炎症过程中识别高增强，或在血管受损的情况下识别缺血性改变。用对比剂增强的双能 CT 也可以对碘摄取进行定量，并且这种定量已被建议有助于区分炎症和肿瘤性病变。双能 CT 有助于确定胆囊结石和尿路结石的成分，并且可以用于准确地区分尿酸结石和非尿酸结石。此外，双能 CT 能够大大减少金属假体引起的伪影，从而改善对腹盆腔器官的成像评估。在急性主动脉综合征、胃肠道出血和缺血或胰腺病理状况的评估中，通过消除真正的非增强采集，有可能创建虚拟非增强图像，这大大降低了患者的辐射剂量。最后，通过增加碘的对比，可以使对比增强的双能 CT 比常规单能 CT 更清楚地显示游离性主动外渗或内漏的区域。本文综述了双能 CT 的基础知识，并重点介绍了其在非创伤性急性腹痛评估中的主要临床应用。RSNA，2019 年。
