Weight-based contrast media volume reduction in lower limb computed tomography angiography: a prospective feasibility...

Computed tomography lower-limb angiography (CT LLA) is widely used to evaluate peripheral arterial disease, in which adequate arterial enhancement is essential for accurate diagnosis. Conventional protocols typically use fixed contrast volumes, which may result in unnecessary iodine exposure. This study aimed to evaluate whether a weight-based contrast protocol can maintain image quality compared with a standard fixed-dose protocol.

In this prospective study, 105 patients underwent CT LLA using a weight-based contrast protocol (80-100 mL of 350 mg I/mL) and were compared with 25 patients who received a standard fixed volume (120 mL). Objective image quality parameters, including arterial attenuation, image noise, signal-to-noise ratio (SNR), and contrast-to-noise ratio (CNR), were assessed. Subjective image quality was independently evaluated using a five-point Likert scale. Between-group comparisons were performed using the Mann-Whitney U test.

Subjective image quality scores were higher in the standard protocol group (all P < .001). There was no significant difference in arterial attenuation (P = .090) or SNR (P = .703), while CNR was modestly higher in the standard group (P = .010). All examinations in both groups were diagnostically adequate. Correlation analysis demonstrated that contrast volume did not significantly influence SNR or CNR, whereas arterial attenuation and image noise were the main determinants of image quality.

Weight-based contrast protocols achieve significant contrast volume reduction while maintaining diagnostically acceptable image quality, with a 16.7%-33.3% reduction in contrast-related costs. This approach is a feasible alternative to fixed-dose strategies in routine lower-limb CT angiography.