Nasal polyps are benign neoplasms of the nasal area. On a CT scan, they primarily appear as increased density shadows in the nasal cavity and sinus cavity. These shadows have a definite shape, which is why we see nasal polyps as oval-shaped. Secondly, the density of the nasal polyps can be distinctively differentiated from the surrounding densities; the density of the surrounding bone is very high, while the density of the nasal polyps is relatively direct, appearing as a gray density shadow. Thirdly, we observe accompanying inflammatory changes in the nasal cavity and sinus cavity on the nasal polyps, such as thickened sinus cavity mucosa and, in some cases, the presence of purulent secretions due to inflammatory infections, as seen on the CT scan.