What is the difference between cat scan with constrast and one without contrast?

A CT scan with contrast involves the use of a contrast agent, typically an iodine-based dye, injected into a vein or taken orally to enhance the visibility of certain tissues or blood vessels in the images. This helps to provide clearer and more detailed images, making it easier to identify abnormalities. In contrast, a CT scan without contrast captures images without any enhancement, which may be sufficient for certain conditions but might miss subtle issues that the contrast could reveal. The choice between the two depends on the specific medical question being addressed.