Optimization of pediatric CT brain protocol to achieve reduced patient dose

The number of CT scans have increased and the usage of CT in children is also rapidly increasing. As children are more prone to the effects of radiation, it is necessary to optimize the dose received by the patient. The purpose of this study was to develop a low dose, age-specific protocol for pediatric CT brain without jeopardising image quality. A total of 69 Subjects referred for routine CT brain were included in the study and categorized into three groups according to their age [1-4, 5-9, 10-16 years]. All the scans were performed in a 64 slice brilliance CT Philips using a newly developed brain protocol. The mAs used was adjusted for the different age groups. Effective dose was estimated from the Dose length product utilizing age-specific conversion factors, and the image quality was evaluated qualitatively using a 4 point scoring system by a radiologist. The effective dose was found to be 1.3±0.3 mSv for 1-4 years, 1.2±0.2 mSv for 5-9 years and 1.63 ±0.09mSv for 10-16 years resulting in a dose reduction up to 71 %, 59 % and 35 % respectively. None of the low dose CT- head studies was rated diagnostically unacceptable, however, for age groups [1-4, 5-9 years], the noise and image acceptability was graded suboptimal quality. There was a significant reduction in radiation doses imparted to patients undergoing CT examination of the brain without much loss of diagnostic information. Advanced technologies in newer CT models can be used in combination with age/size specific protocols resulting in significant reduction of radiation dose.