Frequently Encountered Artifacts in the Application of Dual‐Energy Computed Tomography to Cardiovascular Imaging for Urate Crystals in Gout: A Matched‐Control Study

Abstract

ObjectivesThere is surging interest in utilizing dual‐energy CT (DECT) to identify cardiovascular monosodium urate (MSU) deposits among gout patients. We sought to examine the prevalence and characterization of cardiovascular DECT artifacts using non‐ECG‐gated DECT pulmonary angiograms.MethodsWe retrospectively reviewed non‐ECG‐gated DECT pulmonary angiograms performed on patients with and without gout at a single academic center. We noted the presence and locations of vascular green colorization using the default post‐processing two‐material decomposition algorithm for MSU. The high‐ and low‐energy grayscale images and advanced DECT measurements were used to determine if they were true findings or artifacts. We classified artifacts into five categories: streak, contrast medium mixing, misregistration due to motion, foreign body, and noise.ResultsOur study included CT scans from 48 gout patients and 48 age‐ and sex‐matched controls. The majority of patients were males with a mean age of 67 years. Two independent observers attributed all areas of vascular green colorization to artifact. The most common types of artifacts were streak (56% vs. 57% among cases vs. controls, respectively) and contrast medium mixing (51% vs. 65%, respectively). While some of the default DECT measurements of cardiovascular green colorization were consistent with values reported for subcutaneous tophi, advanced DECT measurements were not consistent with that of tophi.ConclusionArtifacts that could be misconstrued as cardiovascular MSU deposits were commonly identified among patients with and without gout on non‐ECG‐gated DECT pulmonary angiograms. These artifacts can inform future vascular DECT studies in gout patients to minimize false‐positive findings.