The use of the iterative reconstruction technique, such as the Adaptive Statistical Iterative Reconstruction (ASIR) or SAFIRE (Sinogram affirmed Iterative Reconstruction), is mandatory.
The use of dose modulation systems (e.g. Auto mA, smartmA, Care Dose 4D) is mandatory.
A rotation time of less than 0.4s should be used if it is available in your scanner.
This to obtain a reduction in the dose and a faster execution of the examination.
A high pitch is recommended.
Following the use of the contrast medium, the 80kVp protocol and mA modulation are recommended as indicated in the Table 8.
The image quality parameters guarantee the expected levels defined on the Italian regulatory (D.Lgs. 101/2020). The reduction of kV and mA, as expected, causes an increase in noise which is however attenuated by the use of iterative reconstruction.
The recommended protocol is reported in the Table 8.
Regarding the decision of using the mA range in the scans, it is not recommended to select one that is too high as the thorax, considered as an anatomical structure mainly composed of air, does not require an excessively wide dose modulation like that present in the protocols.
Below is the table that demonstrates the noise trend in the scans performed.
Furthermore, the reduction of the mA range (60-100 or 60-300 rather than 100-400 / 500) results in a high reduction of the CTDI.
It is important to remember that the study was performed on a phantom and not on a group of patients, so the considerations made regarding dose modulation are relative.
In conclusion, it is appropriate to exploit more the potential of CT equipment, naturally on the basis of the anatomical district under examination, and try to make greater use of iterative algorithms.
The various exam settings and the choice of different parameters, however, depend on the clinical need, which is why close collaboration between the radiologist and the radiographer is essential.