Is It Intracranial Hemorrhage? A Case-Based Approach to Confident Determination Using Dual-Energy CT

Differentiating acute hemorrhage from hyperattenuating mimics remains a common problem in neuroradiology practice. High atomic number materials such as iodine, calcium, and silicone oil can be similar in attenuation to acute blood products, depending on their concentration. Dual-energy CT allows differentiation of hemorrhage from these high atomic number materials because of the differential absorption of x-ray photons at different incident energies. The primary purpose of this case review is to illustrate how to confidently and efficiently use 190-keV virtual monoenergetic images and material decomposition maps in routine neuroradiology practice when the differential diagnosis includes hemorrhage versus a high atomic number hyperattenuating mimic. We review the underlying physics of dual-energy CT, the primary output of dual-energy postprocessing, as well as pitfalls.Learning Objective: To learn how to use dual-energy CT to confidently and efficiently differentiate acute hemorrhage and hyperattenuating mimics (eg, calcification or iodinated contrast)