PICTORIAL ESSAY Adrenal injuries: spectrum of CT findings Received: 20 December 2002 / Accepted: 26 February 2003 / Published online: 29 March 2003 Ó ASER 2003 Abstract Injury to the adrenal gland is often incidentally diagnosed with Computed Tomography (CT) following blunt abdominal trauma. In a high percentage of cases, it is accompanied by other intra-abdominal, retroperi- toneal or intrathoracic injuries. Although not usually clinically significant, adrenal traumatic lesions can be a source of infection, as well as a cause of acute adrenal insufficiency. We discuss and illustrate typical and less common CT findings of adrenal injuries. Keywords Retroperitoneal space Æ Injuries Æ Adrenal injuries Æ Computed tomography Introduction Adrenal injury secondary to trauma is quite rare because of the position of the adrenal deep within the abdomen, well cushioned by surrounding soft tissue structures. Adrenal injury is noted in approximately 2–3% of blunt abdominal trauma cases [1, 2]. Post-traumatic adrenal hemorrhage is unilateral in more than 90% of cases and with a strong predominance of involvement of the right gland [3]. No specific signs or symptoms are noted rel- ative to the adrenal gland, although associated abdom- inal injuries are seen in more than half of cases. Although not usually clinically significant, adrenal traumatic lesions can be a source of infection, as well as a cause of acute adrenal insufficiency. In this pictorial essay we discuss and illustrate typical and less common CT findings of adrenal injuries. Mechanism of injury Injury to the adrenal gland is often incidentally diag- nosed with CT following blunt abdominal trauma. In a high percentage of cases, it is accompanied by other intra-abdominal, retroperitoneal, or intrathoracic inju- ries. The exact mechanism of traumatic adrenal injury is still unknown. Adrenal glands are susceptible to massive intraglandular bleeding due to their complex vascular supply. Three or more suprarenal arteries arise from branches of the inferior phrenic artery, aorta, and renal artery; however, a single central vein drains each adrenal gland. Pathologic studies show that adrenal hemorrhage occurs in the medulla and juxtamedullary cortex because of rupture of small vessels, many sinusoids, and venules [4]. Three possible mechanisms have been proposed for traumatic adrenal hemorrhage [5, 6, 7]: (1) violent compression and de- compression of the gland between the spine and the surrounding viscera, (2) an acute rise of intra-adrenal venous pressure as a result of severe compression of the inferior vena cava during the abdominal impacting force, and (3) shearing of small vessels as a result of deceleration forces. Hemorrhage occurs in the right adrenal gland in up to 90% of cases. Post-traumatic adrenal hemorrhage is being diagnosed more frequently with the increased use of CT in the evaluation of abdominal trauma. In most cases it is unilateral and on the right side (85%) [8]. Bilateral adrenal hemorrhage is a potentially fatal con- dition which may need immediate treatment with corti- costeroids. On the other hand, unilateral adrenal injuries have limited clinical significance. Nevertheless they are important as sources of delayed hemorrhage, and also sources of possible infection causing post-trau- matic sepsis like any other hematoma. Furthermore, if Emergency Radiology (2003) 10: 30–33 DOI 10.1007/s10140-003-0275-6 Antonio Pinto Æ Mariano Scaglione Æ Fabio Pinto Nicola Gagliardi Æ Luigia Romano A. Pinto (&) Æ M. Scaglione Æ F. Pinto Æ N. Gagliardi L. Romano Department of Radiology, Cardarelli Hospital, Via A. Cardarelli 9, 80131 Naples, Italy E-mail: r-pinto@iol.it Tel.: +39-081-2466150 Fax: +39-081-406833 A. Pinto Via Pontano 7, 80122 Naples, Italy