Training cuts radiation, preserves diagnostic image quality in pediatric patients

Radiologic staff training may be an effective way to reduce radiation dose while preserving diagnostic image quality in pediatric head CT examinations, according to a study published in the June issue of the American Journal of Roentgenology.

A balance between radiation dose and image quality must be achieved in pediatric imaging, especially for life-saving diagnostic procedures. “For many years pediatric CT examinations have been performed with adapted adult protocols instead of natively pediatric ones,” wrote lead author Fabio Paolicchi, RT, PhD, of the University of Pisa in Italy, and colleagues. “However, an arbitrary reduction of radiation dose may potentially result in substantial loss of image quality (especially if dose-saving tools compensating for higher image noise and artifacts are not applied), highlighting the need for radiologists and technologists to optimize CT protocols in an effort to balance image quality and radiation dose.”

Paolicchi and colleagues evaluated the radiation dose of pediatric head CT exams performed at three radiologic sites to assess the effect of intensive radiologic staff training on delivered radiation dose and image quality of exams.

Outpatients between one month and 14 years old underwent 215 unenhanced head CT exams before and after intensive training of staff radiologists and technologists in CT optimization technique during the study. The patients were divided into three age groups: those between zero and four, five and nine, and ten to 14. CT dose index, dose-length product, tube voltage and tube current-rotation time product values from before and after the training were acquired from the hospital PACS.

The researchers calculated gray matter conspicuity and contrast-to-noise ratio before and after the training. Additionally, three neuroradiologists evaluated subjective image quality in terms of artifacts, gray-white matter differentiation, noise, visualization of posterior fossa structures and need for repeat CT examination.

Results indicated that the median CT dose index and dose-length product values were significantly lower after the training in all groups: 27 mGy and 338 mGy ∙ cm versus 107 mGy and 1,444 mGy ∙ cm for the zero to four group; 41 mGy and 483 mGy ∙ cm versus 68 mGy and 976 mGy ∙ cm in the five to nine-year-old group; and 51 mGy and 679 mGy ∙ cm versus 107 mGy and 1,480 mGy ∙ cm in the ten to 14-year-old group.

Tube voltage and tube current-time values after training were significantly lower than the levels before training. Subjective post-training image quality was not inferior to pretraining levels for any item except noise. This, however, was never diagnostically unacceptable.

“Substantial dose reduction can be achieved through intensive hands-on training of the entire radiology staff while maintaining diagnostic image quality,” wrote the authors. “Given the higher sensitivity of children to biological damage by ionizing radiation and the continuing evolution of MDCT technology and dose-saving tools, dedicated training can be crucial in reducing and harmonizing radiation dose according to the as low as reasonably achievable principle.”