Purpose: To evaluate the impact of CT scan protocol parameters on patient dose and image quality for optimization of protocols for newborn patients.
Materials and methods: Three anatomical areas (chest, abdomen and combined chest + abdomen area) of a newborn PH-50 Newborn Whole-Body Phantom (Kyoto Kagaku Co, LTD, Japan) were scanned on Ingenuity 128 CT scanner (Philips) using different scan parameters. The values of weighted CT dose index (CTDIvol) and dose length product (DLP) were used as dose characteristics and the noise of CT image was chosen to estimate the image quality. The noise was determined in the soft tissues in the areas of shoulder girdle and diaphragm in images with the reconstruction kernel B, as well as in lung tissue of lung apices for images with the reconstruction kernel YC for chest and chest + abdomen; and in soft tissues (for reconstruction kernel B) in the area of the diaphragm for abdomen.
Results: The analysis of the impact of tube voltage and dose right index (DRI) on dose characteristics and image quality made it possible to determine the optimal parameters of CT protocols for selected CT department: chest – 80 kV at DRI -– 19, abdomen – 100 kV at DRI – 22, chest + abdomen – 120 kV at DRI – 22. These protocol parameters provide an effective dose of newborn patients – 1.4, 1.7 and 2,8 mSv for chest, abdomen and chest + abdomen scans, respectively.
Conclusion: The impact of different scan parameters (tube voltage and DRI) of chest, abdomen and chest + abdomen protocols on patient dose and image noise was evaluated. The study allowed setting optimized protocol parameters to improve the image quality.