Spinal epidural space on MRI: Abnormal findings on MRI in patients with spinal haematoma, infection and malignancy.

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1 Spinal epidural space on MRI: Abnormal findings on MRI in patients with spinal haematoma, infection and malignancy. Poster No.: C-1335 Congress: ECR 2011 Type: Educational Exhibit Authors: J. Howard, E. Mc Carthy, K. Cronin, R. Dunne, D. O'Mahony, A. Fagan, N. Sheehy, J. F. Meaney ; Dublin/IE, Galway/IE Keywords: Neuroradiology spine, MR, Diagnostic procedure, Neoplasia DOI: /ecr2011/C-1335 Any information contained in this pdf file is automatically generated from digital material submitted to EPOS by third parties in the form of scientific presentations. References to any names, marks, products, or services of third parties or hypertext links to thirdparty sites or information are provided solely as a convenience to you and do not in any way constitute or imply ECR's endorsement, sponsorship or recommendation of the third party, information, product or service. ECR is not responsible for the content of these pages and does not make any representations regarding the content or accuracy of material in this file. As per copyright regulations, any unauthorised use of the material or parts thereof as well as commercial reproduction or multiple distribution by any traditional or electronically based reproduction/publication method ist strictly prohibited. You agree to defend, indemnify, and hold ECR harmless from and against any and all claims, damages, costs, and expenses, including attorneys' fees, arising from or related to your use of these pages. Please note: Links to movies, ppt slideshows and any other multimedia files are not available in the pdf version of presentations. Page 1 of 24

2 Learning objectives - To illustrate the varied appearance of spinal epidural abnormalities including haematoma, infection and malignancy on multi-sequence MRI imaging. - To highlight the findings which allow for accurate diagnosis. - To describe pitfalls and artefacts that may mimic epidural disease. Page 2 of 24

3 Background Lesions within the epidural space may be subtle, and are frequently missed or underappreciated. Lesions involving the epidural space typically fall into one of three categories: - Malignant Infiltration - Epidural Haematoma - Epidural Abscess An understanding of the MR signal characteristics of different epidural pathologies is essential in making an accurate diagnosis. Page 3 of 24

4 Imaging findings OR Procedure details I - NORMAL ANATOMY OF THE SPINAL CANAL AND EPIDURAL SPACE The epidural space surrounds the dural sac. The epidural space communicates freely with the paravertebral space through the intervertebral foramina. Boundaries of the epidural space: Anterior: The posterior longitudinal ligament and annular ligaments. Posterior: Ligamenta flavum and the periosteum of the laminae. Laterally: Pedicles of the spinal column and the intervertebral foramina containing their neural elements. Superiorly: the space is anatomically closed at the foramen magnum where the spinal dura attaches with the endosteal dura of the cranium. Caudally: the epidural space ends at the sacral hiatus, which is closed by the sacrococcygeal ligament. Contents of the epidural space: Loose areolar connective tissue Adipose tissue Lymphatics, arteries, and an extensive venous plexus Exiting spinal nerve roots as they exit the dural sac and pass through the intervertebral foramina. II - EPIDURAL METASTASIS / MALIGNANCY The spine is an extremely common site for development of metastases. Nearly every malignancy may involve the spine or epidural soft tissues, but myeloma, breast cancer, prostate cancer, lung cancer and lymphoma are most commonly seen. These lesions may extend into the epidural space by either direct extension of the Page 4 of 24

5 vertebral body metastasis or by soft tissue invasion into the spinal canal. This may be associated with impingement of the thecal sac or compression of the spinal cord. MRI is highly sensitive for detection of metastasis in the vertebral bodies or epidural space. Typical MRI characteristics are: T1WI: Low signal intensity TIWI + Gadolinium: High signal intensity T2WI: Varied appearance. Often high signal intensity. Sclerotic lesions may be low signal or iso-intense. 1 Use of fat suppression will increase conspicuity of metastases. Case Presentation 1 This is a case of a 75 year old male with metastatic prostate cancer. He had diffuse bony metastases, including multiple lesions in the lumbosacral spine. He presented with clinical symptoms and signs of acute spinal cord compression. Multiplanar multisequence contrast enhanced spinal MRI was performed, confirming the presence of mulitple bone metastases. In addition, there was soft tissue within the epidural space extending from the level of the L3 vertebra down to the S2 level. There was no significant compression of the conus. Figure 1: Contrast enhanced T1 TSE weighted saggital image of the lumbosacral spine showing en enhancing soft tissue within the epidural space extending from the L3 to S2 levels. Multiple vertebral bone metastases are also present. Page 5 of 24

Fig.: Figure 1. Contrast enhanced T1 TSE weighted saggital image of the lumbosacral spine showing en enhancing soft tissue within the epidural space extending from the L3 to S2 levels.

6 Fig.: Figure 1. Contrast enhanced T1 TSE weighted saggital image of the lumbosacral spine showing en enhancing soft tissue within the epidural space extending from the L3 to S2 levels. Multiple vertebral bone metastases are also present. Figure 2: Axial T2 TSE W image at the level of the L5 vertebral body showing intermediate signal intensity soft tissue in the anterior epidural space, but no significant compression of the conus at this time. Page 6 of 24

Fig.: Figure 2: Axial T2 TSE W image at the level of the L5 vertebral body showing intermediate signal intensity soft tissue in the anterior epidural space, but no significant compression of the

7 Fig.: Figure 2: Axial T2 TSE W image at the level of the L5 vertebral body showing intermediate signal intensity soft tissue in the anterior epidural space, but no significant compression of the conus at this time The signal characteristics of this soft tissue mass were characteristic of malignant infiltration from the neighbouring vertebral metastatic disease: T1WI: Low signal intensity T2WI: Intermediate signal intensity T1WI + Gadolinium: Diffuse enhancement. III: EPIDURAL ABSCESS Extradural spinal infection with formation of abscess. Frequently see findings of infective discitis with an adjacent enhancing epidural phlegmon / collection. Clinical Presentation: Patients frequently present with pyrexia and acute/subacute back pain. Aetiology: Page 7 of 24

8 Staphylococcus aureus - most common pathogen (55-75%) Mycobacterium tuberculosis - 25% Anterior spinal epidural abscess - direct spread from an adjacent discitis or osteomyelitis. Posterior abscess - haematogenous spread from a distant source (GI/GU/Respiratory/ Skin etc). Direct inoculation of epidural space - penetrating trauma,intervention, diagnostic 2. procedure (eg Epidural anaesthesia) Typical MRI Signal Characteristics: T1WI: Iso or Hypo-intense relative to the cord T2WI: High signal intensity STIR: High signal intensity T2 GRE: Intermediate or High signal intensity DWI: High signal intensity T1WI + Gadolinium: Avid enhancement. Optimal Imaging Protocol: Saggital STIR of T2WI with fat saturation in order to increase the conspicuity of the lesion by suppressing the epidural fat and vertebral marrow signal. Case Presentation 2a A 75 year old lady with multiple myeloma presented with increasing back pain and loss of power in both lower limbs. She had a recent history of multiple thoracic vertebral compression fractures affecting T5, 6, 11 and 12 vertebral bodies. Spinal MRI demonstrated a loculated epidural fluid collection surrounding the spinal cord at the T8-T10 levels. This was high signal intensity on T2WI and demonstrated post contrast rim-enhancement, in keeping with an epidural abscess. The collection abuts the spinal cord and caused deviation of the cord to the right side, but no cord compression. Page 8 of 24

Figure 3: Saggital and Axial T2W images illustrating a high signal intensity loculated lower thoracic epidural fluid collection, with associated displacement of the spinal cord to the right. Fig.

9 Figure 3: Saggital and Axial T2W images illustrating a high signal intensity loculated lower thoracic epidural fluid collection, with associated displacement of the spinal cord to the right. Fig.: Figure 3: Saggital and Axial T2W images illustrating a high signal intensity loculated lower thoracic epidural fluid collection, with associated displacement of the spinal cord to the right Figure 4: Post Contrast T1Weighted saggital and axial images displaying avid post contrast enhancement of the epidural fluid collection, in keeping with an epidural abscess. Page 9 of 24

Fig.: Figure 4: Post Contrast T1 Weighted saggital and axial images displaying avid post contrast enhancement of the epidural fluid collection, in keeping with an epidural abscess.

10 Fig.: Figure 4: Post Contrast T1 Weighted saggital and axial images displaying avid post contrast enhancement of the epidural fluid collection, in keeping with an epidural abscess. Aspiration of the epidural abscess was performed under CT guidance at the T9-T10 thoracic disc space level using a 20-gauge spinal needle: Figure 5: Axial CT image showing the tip of the spinal needle within the epidural space during CT guided aspiration. Page 10 of 24

11 Fig.: Figure 5: Axial CT image showing the tip of the spinal needle within the epidural space during CT guided aspiration. Microbiological analysis of this aspirate demonstrated growth of coagulase negative staphylococcous. Case Presentation 2b: An 86 year old male, with a history of emergency abdominal aortic aneursym repair 5 weeks previosuly, complained of increasing back pain and development of foot drop. MRI demonstrated a number of abnormal findings. Figure 6: Page 11 of 24

Saggital T2W image showing abnormal fluid signal within the L3-4 disc, abnormality of the adjacent end-plates, a large abdominal aortic aneurysm and a possible intra-spinal collection. Fig.

12 Saggital T2W image showing abnormal fluid signal within the L3-4 disc, abnormality of the adjacent end-plates, a large abdominal aortic aneurysm and a possible intra-spinal collection. Fig.: Figure 6: Saggital T2W image showing abnormal fluid signal within the L3-4 disc, abnormality of the adjacent end-plates, a large abdominal aortic aneurysm and a possible intra-spinal collection. Figure 7: Page 12 of 24

Axial T2W image further illustrating an eccentric fluid collection within the spinal canal. Fig.: Figure 7: Axial T2W image further illustrating an eccentric fluid collection within the spinal canal.

13 Axial T2W image further illustrating an eccentric fluid collection within the spinal canal. Fig.: Figure 7: Axial T2W image further illustrating an eccentric fluid collection within the spinal canal. Figure 8: Saggital fat saturated T1 weighted images, pre and post gadolinium injection, demonstrating extensive epidural fluid collection. The fluid is bright (pre-contrast) consistent with pus. There is extensive enhancement around the margin of the collection post-contrast and also extensive enhancement within the posterior aneurysm wall. Page 13 of 24

Fig.: Figure 8 Saggital fat saturated T1 weighted images, pre and post gadolinium injection, demonstrating extensive epidural fluid collection. The fluid is bright (precontrast) consistent with pus.

14 Fig.: Figure 8 Saggital fat saturated T1 weighted images, pre and post gadolinium injection, demonstrating extensive epidural fluid collection. The fluid is bright (precontrast) consistent with pus. There is extensive enhancement around the margin of the collection post-contrast and also extensive enhancement within the posterior aneurysm wall. Figure 9: Post contrast saggital and axial T1 weighted images showing extensive enhancement within the aneurysm wall (white arrows), abscess within the left psoas (red arrow) and extensive enhancement around the margin of the vertebra (green arrow). Page 14 of 24

Fig.: Figure 9: Post contrast saggital and axial T1 weighted images showing extensive enhancement within the aneurysm wall (white arrows), abscess within the left psoas (red arrow) and extensive

15 Fig.: Figure 9: Post contrast saggital and axial T1 weighted images showing extensive enhancement within the aneurysm wall (white arrows), abscess within the left psoas (red arrow) and extensive enhancement around the margin of the vertebra (green arrow). IV: EPIDURAL HAEMATOMA Accumulation of blood in the epidural space. Variable aetiology. Commonly associated with: - Trauma - Rupture of epidural venous plexus - Anticoagulation - Coagulopathy - Transient venous hypertension (Sneezing / Coughing / Valsava) - Disc herniation with rupture of adjacent veins. - Pregnancy - 40% are idiopathic Page 15 of 24

16 Clinical presentation: Patients most commonly present with: - Acute onset back pain - Rapid progression of neurologic impairment Typical MRI Findings T1WI: Variable appearance, depending on the age of the haematoma: Acute (within 48 hrs): Iso-intense, > hypo-intense / hyper-intense Sub-acute and chronic: hyper-intense > iso-intense. TI + fat suppression: No signal loss (to distinguish blood from fat) T2WI: High signal intensity. T2 GRE: Blooming 3 T1WI + Contrast: Will see post-contrast enhancement. Case 3 An 86 year old male patient presented with rapidly progressive lower limb weakness over 48 hours. He had been mobilising independently prior to admssion. He was on warfarin for Atrial Fibrillation, and at the time of presentation his INR was 5.6. Spinal MRI demonstrated a number of abnormal findings: - Extensive high signal abnormality of the CSF, on the T1WI, consistent with acute subarachnoid blood. Figure 10: T1 TSE (left) and T1 TSE fat saturated (right) saggital images demonstrating high signal intensity of the CSF, which does not suppress on fat saturated imaging, in keeping with haemorrhage. Page 16 of 24

Fig.: Figure 10: T1 TSE (left) and T1 TSE fat saturated (right) saggital images demonstrating high signal intensity of the CSF, which does not suppress on fat

17 Fig.: Figure 10: T1 TSE (left) and T1 TSE fat saturated (right) saggital images demonstrating high signal intensity of the CSF, which does not suppress on fat saturated imaging, in keeping with haemorrhage. Figure 11: Post contrast T1W saggital image showing enhancement of the conus, consistent with a haematoma. Page 17 of 24

18 Fig.: Figure 11: Post contrast T1W saggital image showing enhancement of the conus, consistent with a haematoma. Follow-up imaging performed 4 weeks later showed resolution of the intra-dural haemorrhage, and partial resolution of the conus haematoma: Figure 12 T1W TSE image (left) showing return to normal low signal intensity of the CSF and Post contrast T1 TSE image (right) showing partial resolution of conus haematoma. Page 18 of 24

19 Fig.: Figure 12: Follow-up imaging performed 4 weeks later. T1W TSE image (left) showing return to normal low signal intensity of the CSF and Post contrast T1 TSE image (right) showing partial resolution of conus haematoma. V: EPIDURAL LIPOMATOSIS Epidural Lipomatosis is an excessive accumulation of intra-spinal adipose tissue, which can cause cord compression and neurological deficit. It is associated with long term exposure to either exogenous steroids, or excessive production of endogenous steroids (such as in Cushings disease). The MRI signal characteristics of epidural lipomatosis are as follows: T1W: High signal intensity T1W with Fat Suppression: Signal loss T2W: Intermediate signal intensity Page 19 of 24

No post-contrast enhancement 4 Case 4: This is a case of a 75 year old lady who presented with low back pain. MRI of the lumbosacral spine was performed.

20 No post-contrast enhancement 4 Case 4: This is a case of a 75 year old lady who presented with low back pain. MRI of the lumbosacral spine was performed. Figure 13: Saggital T1W-TSE (left), T2W (middle) and axial T2W images. There is excessive accumulation of adipose tissue within the epidural space, consistent with epirdural lipomatosis (high signal on T1, intermediate signal intensity on T2). The axial image shows generalised fatty replacement of both psoas and erector spinae muscles, and excessive adipose tissue within the epidural space. This is causing displacement of the cauda equina. Fig.: Figure 13: Saggital T1W-TSE (left), T2W (middle) and axial T2W images. There is excessive accumulation of adipose tissue within the epidural space, consistent with epirdural lipomatosis (high signal on T1, intermediate signal intensity on T2). The axial image shows generalised fatty replacement of both psoas and erector spinae muscles, and excessive adipose tissue within the epidural space. This is causing displacement of the cauda equina. Page 20 of 24

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22 Conclusion Lesions within the epidural space or extending into the epidural space from the adjacent vertebrae represent a diagnostic challenge. Familiarity with the imaging manifestations of the most commonly encountered abnormalities greatly aids diagnostic accuracy Page 22 of 24

23 Personal Information Authors: J.M. Howard, E. McCarthy, K. Cronin, R. Dunne, D. O'Mahony, A. Fagan, N. Sheehy, J. F. Meaney Department of Radiology, St James's Hospital, Dublin, Ireand Page 23 of 24

24 References 1.Metastatic disease of the spine. Andreula C, Murrone M. Eur Radiol Mar;15(3): MR imaging assessment of the spine: infection or an imitation? Hong SH, Choi JY, Lee Jw et al. Radiographics Mar-Apr;29(2): Dorsay TA et al: MR imaging of epidural hematoma in the lumbar spine. Skeletal Radiol. 31(12):677-85, Fassett DR et al: Spinal epidural lipomatosis: a review of its causes and recommendations for treatment. Neurosurg Focus. 16(4):E11, 2004 Page 24 of 24

MR imaging the post operative spine - What to expect!

MR imaging the post operative spine - What to expect! Poster No.: C-2334 Congress: ECR 2012 Type: Educational Exhibit Authors: A. Jain, M. Paravasthu, M. Bhojak, K. Das ; Warrington/UK, 1 1 1 2 1 2 Liverpool/UK