title: Principles and Clinical Application of Dual-energy Computed Tomography in the Evaluation of Cerebrovascular Disease.
abstract: Dual-energy computed tomography (DECT) simultaneously acquires images at two X-ray energy levels, at both high- and low-peak voltages (kVp). The material attenuation difference obtained from the two X-ray energies can be processed by software to analyze material decomposition and to create additional image datasets, namely, virtual noncontrast, virtual contrast also known as iodine overlay, and bone/calcium subtraction images. DECT has a vast array of clinical applications in imaging cerebrovascular diseases, which includes: (1) Identification of active extravasation of iodinated contrast in various types of intracranial hemorrhage; (2) differentiation between hemorrhagic transformation and iodine staining in acute ischemic stroke following diagnostic and/or therapeutic catheter angiography; (3) identification of culprit lesions in intra-axial hemorrhage; (4) calcium subtraction from atheromatous plaque for the assessment of plaque morphology and improved quantification of luminal stenosis; (5) bone subtraction to improve the depiction of vascular anatomy with more clarity, especially at the skull base; (6) metal artifact reduction utilizing virtual monoenergetic reconstructions for improved luminal assessment postaneurysm coiling or clipping. We discuss the physical principles of DECT and review the clinical applications of DECT for the evaluation of cerebrovascular diseases.
authors: Department of Medical Imaging, Princess Alexandra Hospital, Brisbane, Queensland, Australia.
authors: Charlie Chia-Tsong
authors: CC
authors: Hsu
authors: Department of Medical Imaging, Princess Alexandra Hospital, Brisbane, Queensland, Australia.
authors: Gigi Nga Chi
authors: GN
authors: Kwan
authors: Department of Medical Imaging, Princess Alexandra Hospital, Brisbane, Queensland, Australia.
authors: Dalveer
authors: D
authors: Singh
authors: Department of Medical Imaging, Princess Alexandra Hospital, Brisbane, Queensland, Australia.
authors: Jit
authors: J
authors: Pratap
authors: Department of Medical Imaging, Princess Alexandra Hospital, Brisbane, Queensland, Australia.
authors: Trevor William
authors: TW
authors: Watkins
keywords: Artifacts; atherosclerotic; carotid stenosis; cerebrovascular disorders; intracranial hemorrhages; multidetector computed tomography; plaque