Work

Real-world data on the impact of dose reduction measures on radiation exposure in CT perfusion of the brain

Year: 2026

Type: article

Abstract: Background CT perfusion (CTP) imaging is a valuable tool for assessing cerebral blood flow. However, it is associated with high radiation doses, often exceeding those of non-contrast cranial CT. We evaluated the impact of different dose reduction approaches in CTP. Methods We retrospectively included patients who underwent CTP in a stroke referral center. Imaging was performed using four different scanners. The protocols were iteratively optimized by decreasing the tube current time product through lowering the tube current while maintaining a constant tube rotation time. Additionally, the temporal sampling interval was increased from 1.5 to 3.0 s. Volume CT dose index (CTDI vol ) was compared across the optimization steps. Effective doses were calculated and the theoretical lifetime cancer risk was estimated. Results Radiation doses from 3812 cases with CTP (47.5% female, mean age 73 ± 14 years) were evaluated. Reducing the tube current by one third resulted in a dose decrease of 33.1%. Doubling the temporal sampling interval significantly reduced the dose by approximately half (47.3%-51.7%) across all scanners (all p < 0.001). Combining both adjustments on the same scanner led to an overall dose reduction of 67.7%. The lowest mean CTDI vol and effective dose across all scanners were 69.2 ± 0.2 mGy and 0.61 ± 0.08 mSv, respectively. The estimated additional lifetime cancer risk was reduced by up to 67.7%, with greater absolute benefits in younger patients. Conclusion Dose reduction measures allow for scanning CTP with exposure levels close to those of standard non-contrast CT.

Source: European Journal of Radiology Open

DOI: 10.1016/j.ejro.2026.100759