Cardiovasc Imaging Asia.  2022 Jul;6(3):101-103. 10.22468/cvia.2022.00115.

Residual Contrast Media in the Azygos Vein: An Uncommon Pseudolesion in Computed Tomography Coronary Angiography

• Yew MS
• Kaur R
• Lee WL
• Omar HB
• Lee YS

• KMID: 2532344
• DOI: http://doi.org/10.22468/cvia.2022.00115

Abstract

Contrast reflux from superior vena cava into azygos system may be mistaken for pathology. We report a case occurring during CT coronary angiography (CTCA) causing diagnostic uncertainty. A linear hyperdensity anterior and left of the upper thoracic vertebrae was seen during CTCA and mistaken for abnormal calcification. However, this was not seen on noncontrasted coronary calcium images. The hyperdensity correlated to the location of the unenhanced azygos vein seen on test bolus images. Although reported in CT pulmonary angiography, contrast in the azygos system is less common in CTCAs as the longer scan delay allows contrast washout. However, right arm contrast injection, the default for CTCA, is an association. Moreover, right heart and pericardial diseases are also potential causes. Cardiac imagers should be aware of this potential pitfall.

Keyword

Azygos vein; Contrast; Computed tomography angiography