Fabrication and evaluation of high-density concrete shields using lead and polypropylene fibres for head computed tomography

Abstract This study developed and evaluated novel high-density concrete shields (HDCS) to protect the radiosensitive ocular lens during head computed tomography (CT). Five formulations with varying polypropylene and lead fibres were tested using anthropomorphic phantoms and clinical patients (n = 35). The lead-free M1 formulation (9.2 kg/m3 polypropylene) was optimal, achieving ~35% reduction in patient ocular lens dose across both CT acquisition protocols. Quantitative American College of Radiology phantom tests confirmed maintained CT number accuracy, uniformity, and spatial resolution. Qualitative radiologist assessment found minimal anterior artefacts that did not affect diagnostic interpretation of central or posterior brain structures. The M1 HDCS is a viable, potentially cost-effective shielding alternative, ideal for routine head CT where orbital detail is not the primary focus.