Fig. 4
From: Cardiac CT blooming artifacts: clinical significance, root causes and potential solutions
Four plaque types (as defined by Qi et al. [13]) are simulated here in 3 sizes (with 4, 3, and 2 mm unobstructed diameters). The calcium (white, 1750 Hounsfield units (HU)) is blurred by the system point spread function such that it obscures much of the lumen (light gray, 600 HU) in many cases. The original (ground truth, high resolution) images are shown in the left panel. The right panel simulates the effects of finite system resolution and noise (W/L = 1000/300 HU)