Comparing Peristaltic and Direct-Drive Contrast Injection Systems for Thoracic Computed Tomography (CT): Effects on Dose, Image Quality, and Pathology

Introduction To compare thoracic vasculature opacification between the direct-drive and the peristaltic drive contrast injection systems and the effect on quantitative and qualitative image quality during computed tomography. Method A retrospective chart review of 88 patients who underwent chest computed tomography (CT) following a direct-drive injector before 2016 (Group A) or a peristaltic injector after 2016 (Group B). Both protocols employed 80mL of iodinated contrast media volume. Quantitative measurements of the thoracic vascular opacification, contrast-to-noise ratio (CNR), effective radiation dose, and arterial venous contrast ratio (AVCR) for each vessel were computed and compared. The measured values of vascular opacification, CNR, and dose length product (DLP) were assessed utilizing paired t-test and Pearson's correlation. Receiver operating characteristic (ROC), visual grading characteristics (VGC), and Cohen's kappa methodology were measured. Results There was no significant difference in the mean opacification of the chest vasculature (p > 0.05). The CNR in Group B was significantly lower than in Group A (p < 0.05) except for the brachiocephalic artery, proximal descending aorta, and the right pulmonary artery. Arterial venous contrast ratio at all anatomic levels demonstrated no statistical significance between groups. There were no differences in ROC, VGC, or kappa values between groups. Conclusion When comparing two contrast media injection systems in chest CT, there was no qualitative difference in image quality or pathology detection. However, quantitatively, direct-drive injectors provided higher CNR. Direct-drive contrast injectors also provided a superior quantitative image quality of chest vasculature compared to peristaltic injectors.