Published online Mar 28, 2026. doi: 10.4329/wjr.v18.i3.118119
Revised: January 10, 2026
Accepted: January 16, 2026
Published online: March 28, 2026
Processing time: 85 Days and 13.7 Hours
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.
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.
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 mea
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 < 0.001), as was improvement in overall image quality (median difference 1 Hounsfield unit, P < 0.001). Good inter-observer agreement (intraclass correlation coefficient > 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).
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.
Core Tip: Single-energy metal artifact reduction (SEMAR) is a computed tomography (CT) algorithm designed to reduce metal-induced artifacts while preserving vessel contrast. In this retrospective single-center study, lower limb CT angiography examinations in 22 patients with metallic fixation prostheses were reconstructed with and without SEMAR to assess arterial signal-to-noise ratio, contrast-to-noise ratio, artifact burden, and diagnostic confidence. SEMAR significantly reduced metal artifacts, improved signal-to-noise ratio and overall image quality, and restored periprosthetic arterial visualization to levels comparable with the contralateral reference limb, without compromising vascular contrast, thereby enhancing the diagnostic performance of lower limb CT angiography in this challenging patient population.