1. Adrenal Haemorrhage By Andrew McGovern Image: Underwood (2006) The use of different imaging methods in:

2. Introduction PART 1. Adrenal haemorrhage: An overview Pathophysiology PART 2. Imaging in adrenal haemorrhage: Different imaging possibilities Positive and negative aspects of each type Image examples

3. What is adrenal haemorrhage? Uncommon, usually presents as bilateral haemorrhage. (Light, 2006) Can occur at any age. (Light, 2006) Extensive necrosis of all three cortical layers and medulla. (Tritos, 2007) Can cause volume loss and shock in infants and acute adrenal insufficiency unless recognised and treated properly. (Light, 2006) Adrenal haemorrhage at autopsy Image: Underwood (2004)

4. Pathophysiology Causes of adrenal haemorrhage: Coagulopathies: causing thrombosis in renal and adrenal veins. Waterhouse-Friderichsen syndrome: in children and young adults (occurring in 20% of meningitis cases). Trauma: found in 28% of severe trauma cases autopsy. (Sevitt, 1955) Asphyxia: in neonates – at birth the adrenal gland is very large and vascular. Also associated with adrenal tumours. (Light, 2006)

5. Imaging: Computed tomography CT scanning is the preferred method for identifying adrenal haemorrhage in all patients over 6 months old. CT is rapid, widely available and accurate in diagnosis. Useful for the identification of an underlying neoplasm, tumour or large thrombosis. Allows examination of the adrenal glands in trauma patients with other imaging indications. Adrenal haemorrhage is detected as a round or oval mass obliterating the normal chevron shape of the adrenal gland. (Light, 2006)

6. Imaging: Computed tomography CT of normal adrenals several months before the onset of haemorrhage. CT two weeks after the onset of an acute haemorrhage. Images excerpted from: Rao et al. (1989)

7. Imaging: Computed tomography CT of acute bilateral haemorrhage. Image: Hentel (2008)

8. Imaging: Magnetic Resonance In general MRI identifies adrenal abnormalities at a rate which is comparable to CT. Not as widely available as CT. May be preferable in younger people due to CT radiation risk: –1 fatal cancer per 2000 scans. (FDA, 2007) –20% increased lifetime cancer mortality risk. (FDA, 2007) –5 fatal cancers per 6000 scans in under 15s. –May account for up to 2% of cancers in the US. (Brenner, 2007) Evidence for these studies is 25,000 survivors of Hiroshima bombing. Not directly comparable? (BRER, 2006)

9. Imaging: Magnetic Resonance T1 weighted MRI displaying right adrenal infarction without haemorrhage, in a 42-year-old man with anti phospholipid syndrome. Image: Riddell and Khalili (2004)

10. Imaging: Ultrasound US is the standard in neonates for imaging adrenal masses. It is sensitive for enlargements of the adrenal glands. Can differentiate between causes of adrenal mass. Echogenicity is variable with the age of the haemotoma – can estimate age. Widely available. No ionising radiation. But US is operator dependant. (Light, 2006)

11. Imaging: Ultrasound An adrenal haemorrhage as seen on ultrasound. Image: Hentel (2008)

12. Imaging: Ultrasound An adrenal haemorrhage as seen with Doppler ultrasound. This enables the avascular nature of the mass to be identified. Image: Hentel (2008)

13. Imaging: Ultrasound Adrenal haemorrhage in a foetus at 34 weeks gestation caused by a neuroblastoma. Image: Trop and Levine (2001)

14. Imaging: Other modalities Plain radiographs: Acute adrenal haemorrhage is rarely detectable. It may cause mass effect in the upper abdomen. (Light, 2006) Image: Kawashima et al. (1999)

15. Imaging: Other modalities Nuclear medicine studies: Of very little use as the main contrast agents used are not taken up by haematoma or normal adrenal tissue. (Light, 2006) Image: Kawashima et al. (1999)

16. Summary Adrenal haemorrhage is an uncommon but serious condition which causes adrenal insufficiency. CT is the diagnostic method of choice. MRI should be considered as an alternative in children. Ultrasound should be used in neonates.

17. References BRENNER, D. J. (2007) Computed Tomography — An Increasing Source of Radiation Exposure. the New England Journal of Medicine, 357 pp. 2277-2284. BRER (2006) Health risks from exposure to low levels of ionizing radiation — BEIR VII, 1st ed. Washington, DC: The National Academies Press. FDA (2007) What are the Radiation Risks from CT? [online]. Available from: http://www.fda.gov/cdrh/ct/risks.html [accessed: 28 Feb 2008].http://www.fda.gov/cdrh/ct/risks.html HENTEL, B. (2008) Adrenal hemorrhage [online]. Available from: http://www.radswiki.net/main/index.php?title=Adrenal_hemorrhage [accessed: 23 Feb 08]. http://www.radswiki.net/main/index.php?title=Adrenal_hemorrhage KAWASHIMA, A., SANDLER, C. M., ERNST, R. D., TAKAHASHI, N., ROUBIDOUX, M. A., GOLDMAN, S. M. et al. (1999) Imaging of Nontraumatic Hemorrhage of the Adrenal Gland. RadioGraphics, 19 pp. 949-963. LIGHT, D. (2006) Adrenal Hemorrhage [online]. Available from: http://www.emedicine.com/radio/topic15.htm [accessed: 23 Feb 2008].http://www.emedicine.com/radio/topic15.htm RAO, R. H., VAGNUCCI, A. H. and AMICO, J. A. (1989) Bilateral massive adrenal hemorrhage: early recognition and treatment. Annals of Internal Medicine, 110 (3), pp. 227-235. RIDDELL, A. M. and KHALILI, K. (2004) Sequential Adrenal Infarction Without MRI-Detectable Hemorrhage in Primary Antiphospholipid-Antibody Syndrome. American Journal of Roentgenology, 183 pp. 220-222. SEWITT, S. (1995) Post-traumatic adrenal apoplexy. Journal of Clinical Pathology, 8 (3), pp. 184-194. TRITOS, N. A. (2007) Adrenal Hemorrhage [online]. Available from: http://www.emedicine.com/MED/topic3009.htm [accessed: 28 Feb 2008].http://www.emedicine.com/MED/topic3009.htm TROP, I. and LEVINE, D. (2001) Hemorrhage During Pregnancy Sonography and MR Imaging. American Journal of Roentgenology, 176 pp. 607-615. UNDERWOOD, J. C. E. (Ed.) (2004) General and Systemic Pathology, 4th ed. London: Churchill Livingstone.