Image Noise - Video Lesson

Hey, everybody. Welcome back. This lesson is about image noise in CT. A noisy CT image is easily detected by a technologist and the radiologist. Image noise refers to the patchy or modeled appearance of the image due to insufficient information in the image. Here's an example. These images were acquired with identical parameters, except the first image on the left was reconstructed with a bone algorithm, and the second image on the right was reconstructed in the standard algorithm. Despite both being displayed with the same window width and the same window level, the first image clearly shows increased image noise. Image noise can be a big problem if it obscures the underlying anatomy or pathology. So what else affects image?