Detection of the adrenal glands by endoscopic or transabdominal ultrasound

The value of transabdominal and endoscopic ultrasound (EUS) in detecting normal adrenal glands is not yet established. The aim of our study was to evaluate whether these techniques can be routinely used to visualize the adrenal glands in patients without suspected adrenal pathology.

Transabdominal ultrasound was validated by examination of 10 corpses and was performed in 80 healthy volunteers (3.5 and 5 MHz). EUS of the left adrenal gland was performed in 154 consecutive patients referred for various other reasons. In 20 patients we attempted to visualize the right adrenal gland as well.

Both adrenal glands were correctly identified in all of the 10 corpses once they were opened. In healthy volunteers, the right adrenal gland was visualized by transabdominal ultrasound in 79/80 patients (99 %) and the left adrenal gland in 55/80 patients (69 %). EUS allowed detection of the left adrenal gland in 151/154 patients (98%). In three patients EUS failed because of grossly distorted anatomy. In 6/20 patients we were also able to detect the right adrenal gland by EUS, which was obvious in two cases because of incidentalomas.

Visualization of the right adrenal gland is almost always possible by transabdominal ultrasound, while its detection by EUS is successful only in some cases. The left gland is more difficult to detect by transabdominal ultrasound, while it can nearly always be seen using EUS. Therefore, a combined transabdominal and endoscopic ultrasonographic approach is useful for visualization of the adrenal glands and may enable diagnosis of even small adrenal masses.