IS Case 62: Bilateral Adrenal Hemorrhage
Imaging Sciences URMC 2008
Publication Date: 2009-05-19
A 64-year-old woman with lupus anticoagulant, status post recent hip replacement, presented with progressive weakness, nausea and hyponatremia. Cosyntropin stimulation test was preformed and was suggestive of adrenal insufficiency.
See figure legends.
Adrenal hemorrhage is an uncommon but potentially catastrophic event observed in patients of all ages and usually occurs as a complication of trauma, systemic anticoagulation therapy, sepsis, or stress such as surgery . In this case, it is believed that adrenal hemorrhage was related to an episode of post-operative hypotension following elective hip repair and subsequent low molecular weight heparin use. Adrenal insufficiency (Addison Disease), as seen in this case, is an extremely unusual complication of bilateral adrenal hemorrhage .
Depending on the acuity of the adrenal hemorrhage, CT and MRI findings may vary. Typical acute CT findings include a non-enhancing hyperdense mass (50-90 HU) that distorts the normal shape of the adrenal gland . There may also be thickening of the adjacent diaphragmatic crura and streakiness of periadrenal fat. Areas of enhancement raise the possibility for underlying tumor, such as adrenal carcinoma or metastatic lung cancer. Chronic adrenal hematomas become low density, may become cystic and/or may calcify. Post-hemorrhage adrenal cysts are termed adrenal pseudocysts.
MRI is useful to confirm the presence and chronicity of adrenal hemorrhage. Because of intracellular deoxyhemoglobin, in the acute stages (<7 days), adrenal hemorrhage may show iso-intense to hypo-intense on T1WI and markedly low signal on T2WI .
During the subacute phase (1-8 weeks), the clot begins to evolve. Due to the paramagnetic effects of free methemoglobin T1WI images show hyperintense signal . This hyperintense T1 signal initially is seen only at the rim of the mass, as seen in our case, and then gradually fills in the mass over a period of weeks. Occasionally, with large hemorrhages, irregular clot lysis can be observed. T2WI images show hyperintensity from the presence of serum and clot lysis products. This can be seen in the right adrenal gland in our case.
In the chronic phase, both hemosiderin and calcification result in low signal on T1WI and T2WI images . Calcification is often eggshell or rim-like and the characteristic dark ring is identifiable.
MRI may also be used to demonstrate adrenal vein thrombosis, another cause of adrenal hemorrhage. Adrenal vein thrombosis has the appearance of a non-enhancing mass in the adrenal vein that extends into the IVC (right side) or renal vein (left side) .
Unilateral adrenal hemorrhage is rarely of clinical significance. Deaths from adrenal hemorrhage are frequently attributed to massive blood loss in the neonate and adrenal insufficiency in the adult. Adrenal insufficiency has not been reported until at least 90% of adrenal tissue is destroyed; thus, the precipitating hemorrhage is nearly always bilateral and rare. In the context of trauma, adrenal hemorrhage may be a marker for multiple organ system injury. The prognosis of a patient with adrenal hemorrhage is more strongly related to the primary etiology than to the extent of adrenal hemorrhage.
- Burks DW, Mirvis SE, Shanmuganathan K. Acute adrenal injury after blunt abdominal trauma: CT findings. AJR Am J Roentgenol. 1992 Mar;158(3):503-7. [PMID: 1738984]
- Mayo-Smith WW, Boland GW, Noto RB, Lee MJ. State-of-the-art adrenal imaging. Radiographics. 2001 Jul-Aug;21(4):995-1012. [PMID: 11452074]
- Dunnick NR. Hanson lecture. Adrenal imaging: current status. AJR Am J Roentgenol. 1990 May;154(5):927-36. [PMID: 2108567]
- Kawashima A, Sandler CM, Ernst RD, et al. Imaging of nontraumatic hemorrhage of the adrenal gland. Radiographics. 1999 Jul-Aug;19(4):949-63. [PMID: 10464802]
- Ryan MF, Murphy JP, Jay R, Callum J, MacDonald D. MRI diagnosis of bilateral adrenal vein thrombosis. Br J Radiol. 2003 Aug;76(908):566-9. [PMID: 12893701]