Combined Dual-Energy and Single-Energy Metal Artifact Reduction Techniques Versus Single-Energy Techniques Alone for Lesion Detection Near an Arthroplasty.

Abstract

<b>OBJECTIVE.</b> The purpose of this study was to compare a combined dual-energy CT (DECT) and single-energy CT (SECT) metal artifact reduction technique with a SECT metal artifact reduction technique for detecting lesions near an arthroplasty in a phantom model. <b>MATERIALS AND METHODS.</b> Two CT phantoms with a cobalt chromium sphere attached to a titanium rod, simulating an arthroplasty, within a background of soft-tissue attenuation containing spherical lesions (range, 10-20 mm) around the head and stem of different attenuations from the background (range of attenuation, 10-70 HU) were scanned with a single CT scanner individually (unilateral) and together (bilateral) with the following three dose-equivalent techniques: the currently used clinical protocol (140 kVp, 300 Reference mAs); 100 kVp; and DECT (100 kVp and 150 kVp with a tin filter). Three radiologists reviewed the datasets to identify lesions. Nonparametric AUC was estimated for each reader with each technique. Multireader ANOVA was performed to compare AUCs. Multiple-variable logistic regression analysis was used to identify factors affecting sensitivity and specificity. <b>RESULTS.</b> Accuracy was lower (<i>p</i> < 0.001) for the DECT 130-keV technique than for the 100-, 70-, and 140-kVp techniques. Sensitivity was higher with unilateral arthroplasties (<i>p</i> = 0.037), with greater contrast differences from background (<i>p</i> < 0.001), and with the SECT 100-kVp technique versus other techniques (<i>p</i> < 0.001). The difference in specificities of modalities was not statistically significant (<i>p</i> = 0.148). <b>CONCLUSION.</b> Combining DECT and SECT techniques does not provide additional benefits for lesion detection as opposed to using SECT alone.