title: Material Separation Using Dual-Energy CT: Current and Emerging Applications.
abstract: Dual-energy (DE) computed tomography (CT) offers the opportunity to generate material-specific images on the basis of the atomic number Z and the unique mass attenuation coefficient of a particular material at different x-ray energies. Material-specific images provide qualitative and quantitative information about tissue composition and contrast media distribution. The most significant contribution of DE CT-based material characterization comes from the capability to assess iodine distribution through the creation of an image that exclusively shows iodine. These iodine-specific images increase tissue contrast and amplify subtle differences in attenuation between normal and abnormal tissues, improving lesion detection and characterization in the abdomen. In addition, DE CT enables computational removal of iodine influence from a CT image, generating virtual noncontrast images. Several additional materials, including calcium, fat, and uric acid, can be separated, permitting imaging assessment of metabolic imbalances, elemental deficiencies, and abnormal deposition of materials within tissues. The ability to obtain material-specific images from a single, contrast-enhanced CT acquisition can complement the anatomic knowledge with functional information, and may be used to reduce the radiation dose by decreasing the number of phases in a multiphasic CT examination. DE CT also enables generation of energy-specific and virtual monochromatic images. Clinical applications of DE CT leverage both material-specific images and virtual monochromatic images to expand the current role of CT and overcome several limitations of single-energy CT. (©)RSNA, 2016.
authors.affiliation: From the Division of Abdominal Imaging, Department of Radiology (M.P., A.P., M.D.A., F.J.S., R.G., D.V.S.), and Department of Abdominal Imaging and Intervention (P.F.H.), Massachusetts General Hospital and Harvard Medical School, 55 Fruit St, Boston, MA 02114.
authors.forename: Manuel
authors.initials: M
authors.lastname: Patino
authors.affiliation: From the Division of Abdominal Imaging, Department of Radiology (M.P., A.P., M.D.A., F.J.S., R.G., D.V.S.), and Department of Abdominal Imaging and Intervention (P.F.H.), Massachusetts General Hospital and Harvard Medical School, 55 Fruit St, Boston, MA 02114.
authors.forename: Andrea
authors.initials: A
authors.lastname: Prochowski
authors.affiliation: From the Division of Abdominal Imaging, Department of Radiology (M.P., A.P., M.D.A., F.J.S., R.G., D.V.S.), and Department of Abdominal Imaging and Intervention (P.F.H.), Massachusetts General Hospital and Harvard Medical School, 55 Fruit St, Boston, MA 02114.
authors.forename: Mukta D
authors.initials: MD
authors.lastname: Agrawal
authors.affiliation: From the Division of Abdominal Imaging, Department of Radiology (M.P., A.P., M.D.A., F.J.S., R.G., D.V.S.), and Department of Abdominal Imaging and Intervention (P.F.H.), Massachusetts General Hospital and Harvard Medical School, 55 Fruit St, Boston, MA 02114.
authors.forename: Frank J
authors.identifier: http://orcid.org/0000-0003-2779-7534
authors.initials: FJ
authors.lastname: Simeone
authors.affiliation: From the Division of Abdominal Imaging, Department of Radiology (M.P., A.P., M.D.A., F.J.S., R.G., D.V.S.), and Department of Abdominal Imaging and Intervention (P.F.H.), Massachusetts General Hospital and Harvard Medical School, 55 Fruit St, Boston, MA 02114.
authors.forename: Rajiv
authors.initials: R
authors.lastname: Gupta
authors.affiliation: From the Division of Abdominal Imaging, Department of Radiology (M.P., A.P., M.D.A., F.J.S., R.G., D.V.S.), and Department of Abdominal Imaging and Intervention (P.F.H.), Massachusetts General Hospital and Harvard Medical School, 55 Fruit St, Boston, MA 02114.
authors.forename: Peter F
authors.initials: PF
authors.lastname: Hahn
authors.affiliation: From the Division of Abdominal Imaging, Department of Radiology (M.P., A.P., M.D.A., F.J.S., R.G., D.V.S.), and Department of Abdominal Imaging and Intervention (P.F.H.), Massachusetts General Hospital and Harvard Medical School, 55 Fruit St, Boston, MA 02114.
authors.forename: Dushyant V
authors.initials: DV
authors.lastname: Sahani
mesh_terms: D000465:Algorithms; D003287:Contrast Media; D006801:Humans; D011829:Radiation Dosage; D011857:Radiographic Image Interpretation, Computer-Assisted / Q000379:methods*; D015900:Radiography, Dual-Energy Scanned Projection / Q000379:methods*; D012680:Sensitivity and Specificity; D013382:Subtraction Technique; D014057:Tomography, X-Ray Computed / Q000379:methods*
chemical_list: D003287:Contrast Media