{"entity":{"id":"dual-energy-spectral-ct","kind":"technology","name":"Dual-energy and spectral CT","aka":[],"tldr":"CT scanned at two X-ray energies at once, so the scanner can tell iodine contrast from calcium and soft tissue, show exactly how much a tumour enhances, and remove the contrast digitally to save a second scan.","summary":"Because tissues absorb low- and high-energy X-rays differently, scanning at two energies lets software separate materials. Vendors reach this in different ways: two tube and detector pairs at different voltages (Siemens dual-source), one tube that switches voltage thousands of times a second (GE), a two-layer detector that sorts photons by energy (Philips), or a split filter or two sequential spins (Canon and others). The outputs are iodine maps that quantify tumour enhancement, virtual non-contrast images that replace a separate unenhanced scan, virtual monoenergetic images that boost contrast or suppress metal artefacts from hip implants and spinal hardware, and material-specific images such as virtual bone removal or calcium subtraction to reveal marrow disease.\n\nIn oncology it helps characterise kidney and adrenal masses, distinguish bland from tumour thrombus, detect hypervascular liver and pancreatic tumours at lower contrast doses, and see myeloma in the marrow. Photon-counting CT gives the same information natively; dual-energy remains the way most installed scanners obtain it.","status":"established","asOf":"2026-09-17","links":[{"label":"McCollough et al., Dual- and multi-energy CT: principles, technical approaches and clinical applications (Radiology 2015)","url":"https://doi.org/10.1148/radiol.2015142631"}],"tags":["machines-wave"],"related":["radiomics"],"cancers":["rcc","hcc","pancreatic","multiple-myeloma","adrenocortical"],"sections":["imaging"],"technologies":["ct","photon-counting-ct"],"targets":[],"drugs":[],"companies":["siemens-healthineers","ge-healthcare","philips","canon-medical"],"institutions":[],"pathways":[],"terms":[],"trials":[],"people":[],"bottlenecks":[],"keyPapers":[],"journals":[],"dependsOn":[],"notes":[],"principle":"Attenuation measured at two X-ray energy spectra is decomposed into material basis pairs (for example water and iodine), yielding iodine maps, virtual non-contrast and virtual monoenergetic images.","strengths":["Quantifies tumour enhancement and iodine uptake","Virtual non-contrast saves a scan and dose","Reduces metal artefact near implants"],"limitations":["Vendor-specific methods and protocols","Some approaches lose temporal or spatial resolution","Adds reading time and data"],"since":2006},"route":"/technologies/dual-energy-spectral-ct/","neighbours":{"technology":[{"id":"contrast-enhanced-mammography","kind":"technology","name":"Contrast-enhanced mammography","route":"/technologies/contrast-enhanced-mammography/"},{"id":"ct","kind":"technology","name":"CT (computed tomography)","route":"/technologies/ct/"},{"id":"photon-counting-ct","kind":"technology","name":"Photon-counting CT","route":"/technologies/photon-counting-ct/"},{"id":"radiomics","kind":"technology","name":"Radiomics","route":"/technologies/radiomics/"}],"cancer":[{"id":"adrenocortical","kind":"cancer","name":"Adrenocortical carcinoma","route":"/cancers/adrenocortical/"},{"id":"hcc","kind":"cancer","name":"Hepatocellular carcinoma","route":"/cancers/hcc/"},{"id":"multiple-myeloma","kind":"cancer","name":"Multiple myeloma","route":"/cancers/multiple-myeloma/"},{"id":"pancreatic","kind":"cancer","name":"Pancreatic ductal adenocarcinoma","route":"/cancers/pancreatic/"},{"id":"rcc","kind":"cancer","name":"Renal cell carcinoma","route":"/cancers/rcc/"}],"section":[{"id":"imaging","kind":"section","name":"Imaging","route":"/fronts/imaging/"}],"company":[{"id":"canon-medical","kind":"company","name":"Canon Medical Systems","route":"/companies/canon-medical/"},{"id":"ge-healthcare","kind":"company","name":"GE HealthCare","route":"/companies/ge-healthcare/"},{"id":"philips","kind":"company","name":"Philips","route":"/companies/philips/"},{"id":"siemens-healthineers","kind":"company","name":"Siemens Healthineers","route":"/companies/siemens-healthineers/"}]}}