Neuroimaging (dual-energy CT)
Citation, DOI & article data
Dual-energy CT has a number of clinical applications in neuroimaging particularly in the realm of material composition and virtual non-contrast imaging.
Differentiation of hemorrhage from iodinated contrast
Contrast staining of the brain parenchyma post iodinated contrast can lead to interpretation issues, especially when the density of contrast is similar to that of blood. Virtual non-contrast imaging is an accurate 1 method in differentiating intracranial hemorrhage from iodinated contrast staining following interventional procedures such as endovascular clot retrieval.
Quantification of iodine leak in traumatic hemorrhagic contusions
Using iodine quantification one can measure the amount of iodine leak within a core and the penumbra of hemorrhagic contusions after contrast-enhanced whole-body CT 2.
Conventionally removing bone in was either a manual process or a threshold related algorithm (that often subsequentially involves a manual process). Using three material differentiation, dual-energy CT scans can be post-processed to remove bone which is particularly advantageous in both angiography and venography 3. It isn't perfect and has been found to overestimate stenosis when there is calcification close to the skull, additionally the presence of blooming artefact caused by calcifications can lead to artefacts in the post-processing too 3.
Using monoenergetic image reconstruction one can change the energy levels depending on the region of interest, for example using 75 keV at the posterior fossa to reduce beam hardening artefact 4.
- 1. Phan CM, Yoo AJ, Hirsch JA et-al. Differentiation of hemorrhage from iodinated contrast in different intracranial compartments using dual-energy head CT. AJNR Am J Neuroradiol. 2012;33 (6): 1088-94. doi:10.3174/ajnr.A2909 - Pubmed citation
- 2. Uttam K. Bodanapally, Kathirkamanathan Shanmuganathan, Meghna Ramaswamy, Solomiya Tsymbalyuk, Bizhan Aarabi, Gunjan Y. Parikh, Gary Schwartzbauer, David Dreizin, J. Marc Simard, Thomas Ptak, Guang Li, Yuanyuan Liang, Thorsten R. Fleiter. Iodine-based Dual-Energy CT of Traumatic Hemorrhagic Contusions: Relationship to In-Hospital Mortality and Short-term Outcome. (2019) Radiology. 292 (3): 730-738. doi:10.1148/radiol.2019190078 - Pubmed
- 3. Alida A. Postma, Marco Das, Annika A. R. Stadler, Joachim E. Wildberger. Dual-Energy CT: What the Neuroradiologist Should Know. (2015) Current Radiology Reports. 3 (5): 1. doi:10.1007/s40134-015-0097-9 - Pubmed
- 4. Stuart R. Pomerantz, Shervin Kamalian, Da Zhang, Rajiv Gupta, Otto Rapalino, Dushyant V. Sahani, Michael H. Lev. Virtual Monochromatic Reconstruction of Dual-Energy Unenhanced Head CT at 65–75 keV Maximizes Image Quality Compared with Conventional Polychromatic CT. (2013) Radiology. 266 (1): 318-25. doi:10.1148/radiol.12111604 - Pubmed