Quantitative Comparison of Virtual and True Noncontrast Lung Images in Photon-counting CT: Global and Regional Attenuation Assessment

In thoracic photon-counting CT, virtual noncontrast images demonstrated close agreement with true noncontrast images for attenuation measurements within the lung parenchyma, supporting accurate lung densitometry; inspiratory depth, rather than reconstruction method, was the dominant source of attenuation variability.