Coronary heart disease (CHD), lung cancer, and chronic obstructive pulmonary disease (COPD) are most prevalent in the general population, and are expected to cause three quarters of deaths by 2050. For this so-called Big-3, early disease detection by CT screening may allow early treatment that can prevent, delay or stop progression of disease. With the use of a new ultra-low-dose CT technique, early imaging biomarkers of CHD, lung cancer, and COPD can be evaluated in one CT scan. 12,000 healthy individuals of the LifeLines cohort will undergo ultra-low-dose CT of the chest.