Both MRI and CT have their strengths and weaknesses. In general, MRI provides a higher degree of diagnostic efficacy than CT; lesions/tumors are better characterized and disease processes are better evaluated; this is especially true in the brain. Another added benefit is that MRI produces no ionizing radiation! With this being said, CT is ideal for visualization of the lungs and coronary arteries. For this reason, we image these two parts of the body with low dose, XR-29 compliant CT images.