EVALUATION OF IMAGE QUALITY USING 1 1 PITCH AND 1.5/1 PITCH HELICAL CT IN CHILDREN - A COMPARATIVE-STUDY/

Objective. The objective of this study was to compare the quality of 1 : 1 and 1.5 : 1 pitch helical contrast-enhanced thoracic and abdomina l CT images in children who cannot cooperate for breath holding. Mater ials and methods This is a retrospective study of 33 contrast-enhanced CT examinations in 11 children of 0-4 years of age. All children had an initial CT study using 1 : 1 pitch helical scanning followed over t he next 6-36 months by one to four CT examinations with 1.5 : 1 pitch. Radiation dose with the two techniques was measured with a pencil ion ization chamber. Results. The two techniques provided comparable overa ll image quality. There was 33 % less radiation dose with 1.5 : 1 pitc h helical scanning. Conclusion. The 1.5 : 1 pitch helical CT provides comparable quality images and a smaller radiation dose than 1 : 1 pitc h in examining children aged 0-4 years.