Normal and abnormal meningeal enhancement: MRI features Poster No.: C-3381 Congress: ECR 2010 Type: Scientific Exhibit Topic: Neuro Authors: I. Hasni Bouraoui, W. Gamaoun, N. Mama, H. Moulahi, A. Daadoucha, H. Jemni, K. Tlili Graiess; Sousse/TN Keywords: meninges, enhancement, imaging DOI: 10.1594/ecr2010/C-3381 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. www.myesr.org Page 1 of 20
Purpose MRI is the best imaging modality to assess the intracranial and intraspinal meninges. The knowledge of normal meningeal enhancement is necessary for recognize abnormal one and make imaging diagnosis of several diseases Methods and Materials several cases of normal and pathologic meningeal enhancement are presented. MRI was obtained by T1W before and after gadolinium contrast materiel injection, thin slice thickness, optimal plane of section (coronal, axial or sagittal) Results Normal meningeal enhancement Normal dura can be demonstrated on post contrast T1W images, thin, and frequently discontinuous. Linear enhancement of variable thickness, corresponding to the dura mater of the convexity. The dura mater of the falx of the brain and the tentorium cerebelli also appears hyperintense, related to the enhancement(fig1). Abnormal meningeal enhancement Two types of enhancement pattern may be present:dura-arachnoid and pia-subarachnoid enhancement. Both types of enhancement may coexist Pia-subarachnoid enhancement Page 2 of 20
Pia-subarachnoid enhancement was seen in association with inflammatory diseases -pneumococcal meningitis (fig2) - tuberculous meningitis mainly in the suprasellar cistern and sylvian fissures(fig3 and 4), -herpetic meningo-encephalitis(fig5) - neuroborreliosis(fig6) and tumoral disease :glioma, medulloblastoma, breast cancer. dura-arachnoid enhancement -Diffuse linear enhancement secondary to thickening of the arachnoid and dura is consistent with a chronic inflammatory process, this appearance is characteristic of diffuse pachymeningitis. It was noted in tuberculosis with wax associated to tuberculoma(fig7) -Diffuse dura-arachnoid enhancement was noted in several cases: -Infectious disease like tuberculosis and inflammatory like: Sarcoidosis(fig8) - Tumoral thickening : metastases of breast and lung cancer It appeared as an area of linear enhancement along the inner itable of the Cranial convexity. -Focal dural enhancement, associated with focal dural thickening, can often be observed in the setting of local or regional tumoral or inflammatory lesions: meningeal extension of an adjacent tumoral or inflammatory lesion. It was observed in :brain cerebral abscess(fig9), empyema(fig10 and11), spinal metastasis of gastric carcinoma(fig12), meningioma,(fig13), infratemporal extent on rhabdomyosarcoma(fig14)hemangiopericytoma,tuberculoma(fig7), and spinal epidural lymphoma. Both types of meningeal enhancement was noted in tuberculous meningitis and herpetic encephalitis(fig15) Page 3 of 20
Images for this section: Page 4 of 20
Fig. 1: Normal dura mater. The coronal contrastenhanced T1 wi show linear enhancement of variable thickness, corresponding to the dura mater of the convexity. The dura mater of the falx of the brain and the tentorium cerebelli also appears hyperintense, related to the enhancement Page 5 of 20
Fig. 2: Pia-subarachnoid enhancement in pneumococcal meningitis Page 6 of 20
Fig. 3: enhancement on left cranial nerve(ii,iii, V,VI,VII,VIII. prédominant cisternal leptoméningeal and pituitary talk enhancement. Page 7 of 20
Fig. 4: The same case as fig3, tow months later:exaggerated of arachnoid and pial enhancement. Page 8 of 20
Fig. 5: coronal flair showws marked hyperintensity involving the cortical and the subcortical areas of the anterior and medial portion of the right temporal lobeleptomeningeal. Enhancement is noted in the right temporal region. Page 9 of 20
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Fig. 6: periradicular and meningeal enhancement in Lyme disease Fig. 7: tuberculosis with pachmeningitis and tuberculoma of vermis Page 11 of 20
Fig. 8: pituitary talk and meningeal enhancemant in neurosarcoidosis Page 12 of 20
Fig. 9: frontal dural thickning and enhancement associated to brain abscess Page 13 of 20
Fig. 10: dural thickning and enhancement in extradural empyema Fig. 11: dural enhancement in empyema Page 14 of 20
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Fig. 12: vertebral and epidural gastric carcinoma metastasis with meningeal enhancement Fig. 13: Olfactif meningioma with temporal dural tail sign. Page 16 of 20
Fig. 14: infra temporal fossa Rhabdomyosarcoma xith intrcranial extent. Note impotent thickning on right temporal meninges Page 17 of 20
Fig. 15: Both types of meningeal enhancementin herpetic encephalitis Page 18 of 20
Conclusion MRI is valuable to demonstrate the presence of meningeal diseases. Postcontrast T1W images are most sensitive for its detection. The distribution, morphological and MR signal intensity features of the lesions correlated with clinical and paraclinical (CSF analysis) findings frequently allow appropriate differential diagnosis. The diffuse or focal nature of the enhancement and its location are useful for differential diagnosis. References 1-Kioumehr F, Dadsetan MR, Feldman N, et al. Postcontrast MRI of cranial meninges: leptomeningitis versus pachymeningitis. J Comput Assist Tomogr 1995;19:713-20. 2-Meltzer CC, Fukui MB, Kanal E, Smirniotopoulos JG. MR imaging of the meninges. Part I. Normal anatomic fetatures and nonneoplastic disease. Radiology 1996;201:297-308. 3-JL Dietemann, R Correia Bernardo, A Bogorin, M Abu Eid, M Koob, Th Nogueira et al Normal and abnormal meningeal enhancement: MRI features. J Radiol 2005;86:1659-83 Personal Information Page 19 of 20
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