Dual bolus intravenous contrast injection technique for multiregion paediatric body CT.

objectivesOptimal vascular and parenchymal enhancement for multi-region paediatric body computed tomography (CT) has many challenges. A variety of approaches are currently employed, associated with varying image quality and radiation dose implications. We present a dual bolus intravenous (DBI) contrast technique for single-acquisition imaging of the chest, abdomen and pelvis, with evaluation of multi-compartmental vascular enhancement.

methodsA DBI regime was designed for use with a programmable dual head pump injector. A larger initial bolus (two-thirds volume) is followed by a smaller bolus (one-third volume) before imaging the chest, abdomen and pelvis in a single acquisition, 45-65 seconds from the start of initial injection. Flow rates and second bolus timing were tailored to patient weight and contrast volume, using five weight categories. Multi-compartmental vascular opacification was graded and image quality was assessed in a cohort of 130 patients.

resultsThe DBI technique resulted in concordant multi-compartmental (thoracic aortic, pulmonary arterial, abdominal aortic and portal venous) vascular enhancement. Early splenic parenchymal enhancement artefacts and alterations to renal enhancement were observed.

conclusionWe present a weight-stratified dual bolus intravenous contrast technique to improve image quality in paediatric multi-region body CT. KEY POINTS: • In children, optimal vascular and parenchymal enhancement in multi-region CT is challenging. • A dual bolus contrast technique offers concordant arterial and portal venous opacification. • Adaptation to patient size is achieved by stratification into five weight categories. • Dose penalties of 'overlap' and 'dual phase' imaging techniques can be avoided.