Vascular attenuation and volumetric lung iodine density in dual-layer spectral CT pulmonary angiography: a randomized controlled trial comparing three contrast doses

Question Do low doses of iodinated contrast medium for spectral CT pulmonary angiography achieve diagnostic vascular attenuation, and do they allow detection of perfusion defects in pulmonary embolism? Findings All three protocols achieved diagnostic pulmonary artery attenuation in low-energy virtual monoenergetic images and detected perfusion defects in all pulmonary embolism cases. Clinical relevance Spectral CT pulmonary angiography enables diagnostic pulmonary vascular enhancement and reliable perfusion defect detection with reduced contrast material doses, supporting safer and more efficient pulmonary embolism imaging protocols.