Visualization of Right Adrenal Vein in Non-Contrast-Enhanced MDCT and Its Guiding Role for Right Adrenal Venous Sampling

This study aimed to evaluate the visualization of right adrenal vein (RAV) in non-contrast-enhanced multi-detector computed tomography (MDCT) and its guiding role for right adrenal venous sampling (AVS) in patients with primary aldosteronism (PA). A total of 237 patients diagnosed with PA who underwent successful AVS procedures from January 2020 to March 2021 were retrospectively analyzed. The non-contrast-enhanced MDCT image features of RAV included the degree of visualization and the position of RAV orifice. Subsequently, the concordance degree between RAV in non-contrast-enhanced MDCT and AVS images was calculated to evaluate its guiding effect for right AVS. The visualization rate of RAV in non-contrast-enhanced MDCT was 81.9% (n = 194), with 73.7% (n = 143) clearly displayed and 26.3% (n = 51) generally displayed. In 6.2% (n = 12) of patients who can display RAV, RAV formed a common trunk with the accessory hepatic vein and then merged into the inferior vena cava. Non-contrast-enhanced MDCT revealed that RAV orifice was located between the 10th thoracic vertebra (T10) and the 1st lumbar vertebra (L1), with 85.1% (n = 165) located from the lower 1/3 of T11 to the lower 1/3 of T12. The concordance of imaging anatomy of RAV between non-contrast-enhanced MDCT and AVS image was found to be at a high rate of 94.3% (n = 183). Non-contrast-enhanced MDCT provides excellent visualization of RAV and clearly depicts its anatomical characteristics. Furthermore, RAV images obtained from non-contrast-enhanced MDCT are highly consistent with those from AVS, indicating that interpretation of non-contrast-enhanced MDCT before AVS can reduce the failure rate of RAV cannulation.