The magnitude of liver parenchymal opacification depends on patient-related factors and injection-related factors such as body weight, cardiac output, contrast media volume, contrast media concentration, injection rate, and saline chaser. Optimal liver opacification during CT is affected by many contrast media techniques such as a single bolus compared to split bolus injection techniques that can be with or without a saline chaser. Optimal liver parenchymal opacification varies significantly in literature, with limitations in the clinical setting due to contrast media injection parameters, patient selection and scanner parameters during liver CT.
A current study by researchers, at the American University of Beirut – Faculty of Health Sciences, Graduate Public Health Program, demonstrated that there was no significant difference in total liver, functional or segmental parenchymal opacification between each contrast media injection system with mean opacification from 93 – 96 HU (which was higher than reported in the literature for all liver segments). For the total number of patients being scanned in each contrast media and injector group the same population but underwent two injection techniques with a time duration of approximately 1 year apart. The study showed that peristaltic drive had increased quantitative image quality, pathology detection, cost saving with lower radiation doses and contrast volume compared to direct drive injection systems.