To perform CT scan examination, a doctor generally sets a scan protocol based on basic information of a patient, such as the gender, a body part to be scanned and a scanning mode. A scan protocol includes a scanning voltage, a scanning current, a scanning duration and a scanning irradiation dose, and the like.
It is especially important to set the irradiation dose parameter in the scan protocol. If a low irradiation dose is applied to both a fat patient and a thin patient, a scan image noise of the fat patient is lager than that of the thin patient; and if a high irradiation dose is applied to both the fat patient and the thin patient, the irradiation dose is wasted for the thin patient and the thin patient is subjected to excessive and unnecessary radiation. Hence, a high irradiation dose should be applied to the fat patient, and a low irradiation dose should be applied to the thin patient.
However, different doctors may have significant subjective difference in determining a scan protocol for a patient due to their different working experiences. The differences between scan protocols set by different doctors for the patient, especially between the irradiation doses in the scan protocols, are significant. In this case, the set irradiation dose may be deficient such that definition of a CT image is negatively affected, or the set irradiation dose may be excessive such that the patient is subjected to redundant radiation.