Role of metal artifact reduction software in computed tomography angiography of lower limb metallic prosthesis: A retrospective study

BACKGROUND Metal artifacts significantly limit the diagnostic quality of computed tomography (CT) algorithm in patients with lower limb metallic prostheses. Single-energy metal artifact reduction (SEMAR) algorithms have been developed to address this limitation. AIM To evaluate the effects of SEMAR algorithm on image quality characteristics of lower limb CT algorithm (CTA) (artifact reduction, signal-to-noise ratio (SNR) and inter-observer agreement) in patients with metallic prostheses. METHODS Twenty-two patients (14 males, 8 females; median age 54 years) with unilateral or bilateral metal lower limb prostheses or screws underwent lower limb CTA on a 128-slice multi-detector CT scanner. Images were reconstructed with and without SEMAR algorithm. Three radiologists independently assessed subjective image quality using standardized scoring systems. Quantitative analysis included measurement of SNR and contrast-to-noise ratio in arterial and soft tissue regions of interest. RESULTS Application of SEMAR significantly improved SNR in two of three observers (P = 0.009 and P = 0.004), with values approaching those in the contralateral reference limb. Overall artifact reduction was statistically significant (median difference 1.5 Hounsfield unit, P 0.75) was demonstrated for SNR and contrast-to-noise ratio assessment with metal artifact reduction (MAR) and reference images, while poor agreement (intraclass correlation coefficient < 0.5) was noted for non-MAR images. Kendall’s W demonstrated significant concordance among observers (W = 0.899, P < 0.001 for study quality with MAR). CONCLUSION SEMAR algorithm significantly reduces metal artifacts from lower limb fixation prostheses without compromising vessel contrast, improving visualization of periprosthetic vascular structures and enhancing diagnostic capability of CTA examinations.