Endosonography of the adrenal glands: normal size — pathological findings

Abstract

Transabdominal sonography of the adrenal glands frequently is non-successful. It was the aim of this project to improve the imaging of the adrenal glands using high resolution sonography in order to obtain information about even small changes in these organs. Therefore, endosonographic imaging was investigated using an endosonoscope PENTAX FG32UA. The correct identification of the adrenal glands was examined in five human cadavers. A total of 58 patients with 113 adrenal glands (in 3 cases history of unilateral adrenalectomy) were investigated. 109 adrenal glands (97%) were identified and evaluated. Healthy adrenal glands are slightly hyperechoich and regarding their echogeneity comparable to other endocrine organs such as the testes or the thyroid. Adrenal size can be determined as largest cross sectional area and was found to be 216 +/- 93 mm2 right and 231 +/- 98 mm2 left. In the adrenal glands which could be imaged by endosonography, all findings detected by CT (n = 33) or MRI (n = 19) could also be demonstrated endosonographically. Additional information as compared to CT/MRI was obtained in 7 out of 33 and in 6 out of 19 patients. This concerns in particular differentiation between tumor and hyperplasia and detection of small adrenal adenomas. High resolution endosonography of the adrenal glands can provide information about adrenal gland morphology which cannot be obtained by any other diagnostic approach.

Sonografie und Endosonografie der Nebennieren

“…The positioning and complete evaluation of the right adrenal gland from the gastric antrum or the duodenum are significantly more technically difficult [1,4,5,11,12] and were only possible in about one third of the subjects in Dietrich's study [1]. In contrast, the workgroup of Kann et al which investigates EUS of the adrenal glands primarily from an endocrinological standpoint, reported a visualization rate for both adrenal glands of 97 % [3]. The examination technique in a supine position and in a right-lateral position as implemented by this workgroup is more effective for the right adrenal gland but contradicts basic endoscopic rules due to the high risk of aspiration.…”

Adrenal glands transabdominal ultrasonography - pictorial essay

“…On the left side, the presence of the stomach, correlated with the smaller volume of the spleen compared to the liver, decreases the possibility of US visualization of the adrenal gland to 40-50% [3]. Normal adrenal glands have a shape of the letters V, Y or λ or of a seagull, with a central hyperechoic line or thin image (medulla), surrounded by hypoechoic layers corresponding to adrenal cortex and eventually a capsule (fig 1) [4,5]. Endoscopic ultrasonography (EUS) allows examination of the left adrenal in 97% of the cases, but the right side is visible in less cases (30-40%) [5,6].…”

“…Normal adrenal glands have a shape of the letters V, Y or λ or of a seagull, with a central hyperechoic line or thin image (medulla), surrounded by hypoechoic layers corresponding to adrenal cortex and eventually a capsule (fig 1) [4,5]. Endoscopic ultrasonography (EUS) allows examination of the left adrenal in 97% of the cases, but the right side is visible in less cases (30-40%) [5,6]. EUS reveals much better the structure of the glands and smaller lesion as compared to TUS, but this approach is not the subject of this article.…”

Relevance of Endoscopic Ultrasound in Endocrinology Today: Multiple Endocrine Neoplasia Type 1, Insulinoma, Primary Aldosteronism—An Expert’s Perspective Based on Three Decades of Scientific and Clinical Experience

“…Using instruments primarily developed for imaging in gastroenterology, it is now possible to generate ultrasound imaging of the retroperitoneal endocrine organs from the stomach and duodenum in higher quality and resolution than ever before. A then newly developed technical approach solved the problem even of imaging the right adrenal [ 1 ].…”