Liver enhancement ct with fast in and fast out is not normal, ct with fast in and fast out is the typical imaging manifestation of liver cancer, and it needs to improve the related examination such as liver biopsy combined with hematological examination for comprehensive judgment and clear diagnosis. As most of liver cancer is arterial blood supply, it shows rapid filling state in arterial phase, which is high density compared with normal liver tissues, and low density in venous phase, which is the typical imaging manifestation of fast in and fast out of liver cancer, the imaging manifestation can only play the role of prompting, and it is necessary to improve the relevant examination, combining with ultrasound, magnetic resonance imaging (MRI), hematology examination, tumor markers and so on to make a comprehensive judgment to make a clear diagnosis. It is necessary to improve relevant examinations, combined with ultrasound, MRI, hematology, tumor markers, etc. to make a clear diagnosis. Not all liver cancers have typical imaging manifestations of fast-onset and fast-offset, so it is necessary to improve relevant examinations under the guidance of doctors to make a clear diagnosis and take active treatment.