High resolution CT literally means high resolution, similar to the commonly used cell phones and digital cameras, but in the CT professional field, high resolution has its own specific parameters, only in these specific parameters of the data obtained from the scan is high resolution CT. specific data, first of all, requires enough thin, layer thickness is basically based on 1mm, there is a specific voltage and milliampere volume. The normal CT voltage for conventional scanning is 120 KV, but in high resolution the voltage used is often 140 KV, and the milliampere amount is also increased accordingly. In addition to this, there is the size of the matrix used to reconstruct the data, high resolution uses a high matrix, for example, the general CT may be 256 × 256 matrix, but in high resolution can be used 2 times or even 4 times the matrix. There is also the post-processing algorithm, conventional high-resolution map in order to achieve this high-resolution effect, often using the bone algorithm, ordinary CT is often used in soft tissue reconstruction method, while high-resolution must use the bone algorithm, here need to emphasize the point, not like digital cameras to pursue very high resolution is the purpose of all CT examination, general high-resolution CT is commonly used in the lung, especially interstitial lesions and Temporal bone, mainly used in these two areas.