Dual-Energy CT: Clinical Applications in Various Pulmonary Diseases

RadioGraphics 2010; 30:685-698

Dual-Energy CT: Clinical Applications in Various Pulmonary Diseases

Mi-Jin Kang, MD2, Chang Min Park, MD , Chang-Hyun Lee, MD Jin Mo Goo, MD, Hyun Ju Lee, MD

The dual-energy computed tomographic (CT) technique allows the differentiation of materials with large atomic numbers such as iodine and xenon. The basic principle of dual-energy CT is material decom­position based on attenuation differences at different energy levels. By using dual-energy CT angiography for the evaluation of perfusion defects in cases of pulmonary embolism, and using xenon CT for the evaluation of ventilation defects, it may be possible to replace perfu­sion and ventilation scanning. An iodine map from dual-energy CT can demonstrate the distribution of pulmonary perfusion, whereas xenon ventilation CT can be used to generate a ventilation map. Furthermore, the virtual nonenhanced dual-energy CT technique can be used for the evaluation of pulmonary nodule characteristics with­out acquisition of true nonenhanced CT images. Knowledge of the applications of dual-energy CT and the typical images produced may lead to wider use of dual-energy CT for pulmonary applications and better interpretation of the results.