Department of Neuroradiology, Hospital Dona Estefânia e São José, Centro Hospitalar Universitario de Lisboa Central, Lisbon, Portugal
- Publicação sob a forma de poster electrónico no 44th ESNR Annual Meeting, 29 setembro a 3 outubro de 2021, Geneva, Switzerland
- Neuroradiology 2021 Sep; 63(Suppl 1): 1-93. doi: 10.1007/s00234-021-02791-y
Introduction: A wide variety of conditions may present as intraspinal cystic lesions. Clinical presentation is usually non-specific and imaging studies are frequently key in the diagnosis and treatment planning of these lesions. This pictorial review focuses on intradural extramedullary cystic lesions.
Methods: We provide a pictorial review of spinal intradural extramedullary cystic lesions and depict the key and occasionally distinctive imaging findings that can guide the neuroradiologist towards an accurate diagnosis.
Results: Intradural extramedullary cystic lesions include congenital/developmental disorders, such as intradural arachnoid cyst, dermoid and epidermoid cyst and neuroenteric cyst, post-traumatic/post-surgical collections, such as subdural hematoma or abscess, infectious diseases, such as neurocysticercosis, spinal tumors such as cystic schwannoma, and other miscellaneous lesions, such as subdural collections in CSF hypotension. While imaging features may be overlapping, clinical background, concurring abnormalities and MR signal characteristics provide important clues for diagnosis. T1 hyperintensity occurs in the presence of fatty tissue in lipoma and teratoma and occasionally in dermoid cyst, as well as in subacute hemorrhage. Diffusion restriction on DWI is more likely in epidermoid and is also present in subdural abscess. Contrast-enhancement of the cystic walls raises suspicion for infectious or tumoral lesions. Additionally, the widened CSF space and focal spinal cord indentation present on dorsal thoracic arachnoid webs and spinal cord herniation (scalpel sign) may be difficult to distinguish from CSF isointense space-occupying lesions. Cord tissue protrusion through a dural defect may be appreciated at high-resolution thin-section MR imaging. Unimpeded CSF pulsation artifacts within a widened CSF space helps to exclude a space-occupying lesion, while a filling defect at CT myelography can help support a space-occupying lesion.
Discussion&Conclusion: Several conditions present as spinal intradural extramedullary cystic lesions, frequently with overlapping imaging characteristics. A confident imaging diagnosis is often challenging. Nonetheless, knowledge of the most common causes and awareness for the key imaging features can guide the neuroradiologist in the differential diagnosis. MR imaging is the technique of choice in presurgical evaluation, providing an accurate location and lesion characterization, as well as in post-surgery follow-up. High-resolution MR imaging and CT myelography may also provide important distinctive information in specific cases.
Keywords: CT myelography; Intradural extramedullary lesions; MR imaging; Spinal tumors