CT plain scan and enhancement differences are as follows: 1, CT plain scan does not require contrast injection, while CT enhancement scan requires contrast injection, which is the use of iodine contrast within the blood to indirectly display the lesion blood supply to differentially diagnose lesions benign and malignant; 2, plain scan time is shorter, and enhancement examination is often longer because enhancement examination requires multi-phase scanning, including plain scan, arterial phase, venous phase and even delayed phase, etc.; 3, the lesion information obtained by CT plain scan is much less than that obtained by enhanced CT, which can find the observation of the lesion blood supply and is more accurate than ordinary plain CT. If there is a problem suspected by plain CT or if no problem is found and you want to further confirm the diagnosis, you can have an enhanced CT examination.