Infographics / Digital Radiography

Dual-Energy Radiography

A low-kVp (about 60 kV) and a high-kVp (about 120 kV) chest acquisition are shown. At low kVp the photoelectric effect dominates so bone attenuates strongly and ribs are bold; at high kVp bone and soft tissue differ less. Weighted subtraction of the two combines them into three outputs: a soft-tissue-only image (bone removed, revealing a lung nodule), a bone-only image, and a standard mixed image.

Dual-energy radiography: two kVp acquisitions decomposed into material-selective images A low-kVp (about 60 kV) and a high-kVp (about 120 kV) chest acquisition are shown. At low kVp the photoelectric effect dominates so bone attenuates strongly and ribs are bold; at high kVp bone and soft tissue differ less. Weighted subtraction of the two combines them into three outputs: a soft-tissue-only image (bone removed, revealing a lung nodule), a bone-only image, and a standard mixed image. low kVp (~60 kV) high kVp (~120 kV) photoelectric dominant — bone attenuates strongly more Compton scatter — bone–soft-tissue contrast falls weighted subtraction soft-tissue-only bone removed — nodule revealed bone-only soft tissue suppressed mixed standard-radiograph look Bone (photoelectric) changes attenuation with energy more than soft tissue (Compton). Weighted subtraction of the two exposures yields three material-selective outputs.
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