Visualization of right adrenal vein: Comparison with three phase dynamic contrast-enhanced CT

To evaluate the visualization of the right adrenal vein (RAV) on dynamic contrast-enhanced computed tomography (CT) images in patients with primary aldosteronism.

We evaluated 27 consecutive patients with primary aldosteronism who underwent contrast-enhanced dynamic CT and subsequent adrenal venous sampling. Scan delays were 10-, 20- and 60-s after a bolus-tracking program detected that the threshold of a 100 Hounsfield units (HU) increase in the abdominal aorta had been achieved. RAV visualization for each phase was evaluated by two readers using a four-point scale. The Friedman and McNemar tests were employed to compare the confidence ratings and the RAV visualization rates between the three phase images.

The RAV visualization rates were 20.4%, 83.3%, and 63.0%, for the first, second, and third phase, respectively. The RAV visualization rates were 92.6%, 83.3%, 63.0%, and 92.6% for all three phases combined, the first and second phase image combined, the first and third phase image combined, and second and third phase image combined. The combined second and third phase images had the highest RAV visualization rates compared with all other image combinations (P<0.0001).

RAV visualization was significantly improved by combining the second and third phase images.