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

• Published in: Arthritis care & research (2010) Vol. 76; no. 7; pp. 953 - 963
• Main Authors: Yokose, Chio, Eide, Sterling Ellis, Huber, Florian A., Simeone, F. Joseph, Ghoshhajra, Brian B., Shojania, Kamran, Nicolaou, Savvas, Becce, Fabio, Choi, Hyon K.
• Format: Journal Article
• Language: English
• Published: Boston, USA Wiley Periodicals, Inc 01-07-2024; Wiley Subscription Services, Inc
• Subjects: Aged; Aged, 80 and over; Cardiovascular system; Case-Control Studies; Colorization; Computed tomography; Computed Tomography Angiography - methods; Contrast media; Crystals; EKG; Electrocardiography; Female; Gout; Gout - diagnostic imaging; Humans; Male; Middle Aged; Retrospective Studies; Tomography; Tomography, X-Ray Computed - methods; Uric acid; Uric Acid - analysis
• ISSN: 2151-464X; 2151-4658; 2151-4658
• DOI: 10.1002/acr.25312

Objective
There is surging interest in using dual‐energy computed tomography (DECT) to identify cardiovascular monosodium urate (MSU) deposits in patients with gout. We sought to examine the prevalence and characterization of cardiovascular DECT artifacts using non–electrocardiogram (EKG)‐gated DECT pulmonary angiograms.
Methods
We retrospectively reviewed non–EKG‐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 postprocessing two‐material decomposition algorithm for MSU. The high‐ and low‐energy grayscale images and advanced DECT measurements were used to determine whether they were true findings or artifacts. We classified artifacts into five categories: streak, contrast medium mixing, misregistration due to motion, foreign body, and noise.
Results
Our study included CT scans from 48 patients with gout and 48 age‐ and sex‐matched controls. The majority of patients were male with a mean age of 67 years. Two independent observers attributed all areas of vascular green colorization to artifacts. The most common types of artifacts were streak (56% vs 57% between patients and controls, respectively) and contrast medium mixing (51% vs 65%, respectively). Whereas 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.
Conclusion
Artifacts that could be misconstrued as cardiovascular MSU deposits were commonly identified in patients with and without gout on non–EKG‐gated DECT pulmonary angiograms. These artifacts can inform future vascular DECT studies on patients with gout to minimize false‐positive findings.