Each develops from different embryonic tissues, forms different anatomic and functional structures, and combines within a common capsule. The adrenal gland consists of two distinct parts: the cortex and the medulla. 8 Sonographers have a role both in the initial detection of AIs and in gathering diagnostic information regarding newly discovered AIs. Adrenal incidentaloma (AI) has become a common term in the medical literature and represents a diagnostic challenge that includes discovery of masses, which range from benign, nonfunctional lesions to malignant tumors such as pheochromocytomas, adrenocortical carcinomas, or metastases from other primary cancers. The general term for an unexpected mass detected during an imaging procedure being performed for unrelated disease is “incidentaloma.” This term may be applied to any unexpected mass occurring anywhere in the body. Owing to technical improvements in all the diagnostic imaging modalities and the increased use of these modalities, more clinically silent or unexpected masses are being detected. In addition, EUS, IOUS, computed tomography (CT), magnetic resonance imaging (MRI), and associated nuclear medicine imaging procedures are presented as related to adrenal imaging. As a sonographer, it is important to develop critical-thinking and problem-solving skills for sorting out the origin and extent of abdominal masses, including those of suprarenal and retroperitoneal origin. Of the normal gland as well as adrenal pathology. This chapter provides an overview of relevant anatomy, embryology, scanning techniques, functional and morphologic adrenal pathology, and the sonographic appearance 4, 5 As new technologies are introduced for transabdominal imaging, such as three-dimensional/four-dimensional (3D/4D) imaging and elastography, these tools also become available for EUS and IOUS applications. Using a 7.5-MHz transducer positioned 1 to 2 cm from the adrenal gland, EUS and IOUS are particularly useful for detecting adrenal metastases and staging cancer.

1, 2 and 3 In addition, since the mid-1990s, endoscopic ultrasound (EUS) and intraoperative ultrasound (IOUS) have developed as tools for high-resolution sonography evaluation of suprarenal and retroperitoneal masses. However, combining planar flexibility and improved beam-resolution capabilities of modern ultrasound equipment with maneuvering the patient into multiple positions increases the likelihood of producing quality sonographic images of the adrenal glands. Examination of the adrenal glands challenges the skills of novice and experienced sonographers alike and requires a working knowledge of exact adrenal anatomic locations and landmarks. In contrast with other examinations of the abdomen, transabdominal sonographic imaging is not the first-choice imaging modality for screening adrenal glands or detecting adrenal pathology.

Adrenal cortex secretes