HRCT is not enhanced CT, HRCT is high resolution CT, typically scanned in thin layers of 1-2mm. An examination technique that reconstructs images with a high-resolution algorithm, typically usually a bone algorithm. Because this technique requires a thinner layer to be scanned, it usually requires an appropriate increase in tube voltage and tube current. The relative amount of radiation received by the patient increases, and enhanced CT is also enhanced CT, which refers to the CT flat scan, and then intravenous injection of contrast agent, through different tissues to blood, blood flow signal intensity, and then to determine the nature of the lesion.