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Spinal Hematomas 2007

General Spine

Jason M Asheim, MD,
Rajan Jain, MD, Non ASSR Member
Todd Aho, MD, Non ASSR Member
Jeff Corrigan, MD, Non ASSR Member
Suresh C Patel, MD, Non ASSR Member

Scientific Poster

Exhibit Panels: 2

Purpose

The purpose of this exhibit is to familiarize the reader with the epidemiology, etiologies, and imaging features of spinal hematomas with an emphasis on CT and MR imaging

Methods & Materials

A retrospective review of 12 cases of spinal hematomas was performed. A review of the literature was performed to elucidate and outline the epidemiology and etiologies of subarachnoid, epidural, and subdural spinal hematomas. Case examples are provided to understand the anatomy and the specific features of the three types of spinal hematomas The imaging features are reviewed with an emphasis on CT and MR imaging.

Results

Primary spinal subarachnoid hemorrhage a rare occurrence, representing approximately 1% of all SAHs. The incidence of all SAH is 6/100,000 annually. Trauma is the most common cause of spinal subarachnoid hemorrhage. Spinal subarachnoid hemorrhage may relate to extension of intracranial aneurysm rupture. A variety of other abnormalities are associated including: coagulopathy, traumatic lumbar puncture, vascular malformations, hemorrhagic neoplasms, spinal artery aneurysms, and infection. MR imaging demonstrates variable signal intensities on T1 and T2 depending on the stage of blood break down. Layering of blood within the thecal sac or mass like areas of clot may be seen. T2 GRE imaging is particularly sensitive and will demonstrate low signal from the deoxygenated blood break down products. CT typically demonstrates high attenuation in the subarachoid space. Contrast enhanced imaging may demonstrate mild enhancement of the cauda equine related to inflammatory response. Underlying pathology may enhance.

Spinal epidural hematoma is an accumulation of blood between the dura and the osseous spinal canal. It is a rare entity with an approximately incidence of 1/1,000,000. More common in male patients by a ratio of M:F 4:1. It is often related to trauma. Other sources include: disk herniation, coagulopathy, iatrogenic, vascular malformations, pregnancy, Paget's disease, minor elevations of venous pressure (valsalva, cough, heavy lifting etc.)and idiopathic. MR imaging shows variable signal depending on stage of blood break down. Typically heterogenous but demonstrates progressive T1 hyperintensity as the hemorrhage progresses from acute to subacute. Fat suppressed T1 weighted images are useful to separate hyperintense blood products from epidural fat. T2 GRE shows heterogenous signal with areas of hypointensity related to susceptibility. CT typically demonstates a hyperdense epidural mass, Contrast enhanced images may show peripheral enhancement. Subacute and chronic hematomas may form internal septa which may enhanceme.

A subdural hematoma is an accumulation of blood between the dura and arachnoid. It is a rare occurrence in the spine. Exact incidence is not well described but is considered less common than epidural hematomas. No gender preference has been found. Trauma is the major etiology. Other sources are: coagulopathy, iatrogenic, neoplasm, vascular malformation, and idiopathic. MR imaging usually demonstrates a T1 hyperintense collection which is distinct from the epidural fat and adjacent osseous structures which conforms to the dura. T2 GRE imaging often shows hypointense signal related to blood products. STIR imaging demonstrates hyperintense signal. CT demonstrates a hyperdense intradural collection outlined by cord and epidural fat. There maybe slight enhancement following contrast administration particularly on MR imaging.

Conclusion

Though less common than the intracranial hematomas, hemorrhage does occur in the spine. It is important to recognize and diagnosis spinal hematomas as there may be permanent neurologic deficits if appropriate timely therapy is not instituted The epidemiology and etiologies of the three major types of hemorrhage (subarachnoid, epidural, subdural) was reviewed. The imagings characteristics of CT and MR modalities are demonstrated with multiple case examples to familiarize the reader with the various types of hemorrhage.

References

1. Berlis A. et al. Solitary Spinal Artery Aneurysms as a Rare Source of Spinal Subarachnoid Hemorrhage: Potential Etiology and Treatment Strategy Am J Neuroradiol 26:405-410, February 2005

2. Chang FC et al. Contrast Enhancement Patterns of Acute Spinal
Epidural Hematomas: A Report of Two Cases Am J Neuroradiol 24:366-369, March 2003

3. Fukui MB et al. Acute Spontaneous Spinal Epidural Hematoma Am J Neuroradiol 20:1365-1372, August 1999

4. Holtas S et al. Spontaneous Spinal Epidural Hematoma: Findings at MR Imaging and Clinical Correlation. Radiology Vol 199 No. 2 409-413 May 1996

5. Hung KS et al. Traumatic Spinal Subdural Hematoma with Spontaneous Resolution. Spine Vol 27 E534-E538 Dec 2002

6. Koch C et al. Dural Arteriovenous Fistula of the Lumbar Spine Presenting with Subarachnoid Hemorrhage. Journal of Neurosurgery: Spine Vol. 100 385-391 April 2004.

7. Post MJD et al. Acute Spinal Subdural Hematoma: MR and CT findings with pathologic correlates. Am J Neuroradiol, Vol 15, Issue 10 1895-1905 1994.

8. Ross JS et al. Diagnostic Imaging: Spine. Chapter V:1 30-41 Amirsys Publishing Salt Lake City, Utah 2004