Optic nerve glioma CT
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Optic nerve glioma Microchapters |
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Diagnosis |
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Treatment |
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Case Studies |
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Optic nerve glioma CT On the Web |
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American Roentgen Ray Society Images of Optic nerve glioma CT |
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]Associate Editor(s)-in-Chief: Simrat Sarai, M.D. [2]
Overview
CT
CT is often the first investigation performed and although not as sensitive as MRI, the diagnosis can often be made, especially if thin slice imaging through the orbits is performed, or coronal and sagittal reconstructions obtained from volumetric data. The optic nerve is variably enlarged, and the mass may either be fusiform or exophytic in appearance. Additionally the nerve may be elongated with kinking or buckling. CT scan is superior for detection of intratumoral calcifications, which suggest low grade histology and for bone details. Following three typical patterns are seen on neuroimaging studies:
- Suprasellar tumor with involvement of optic tract
- Suprasellar tumor with expansion of contiguous optic nerve
- Tubular thickening of the chiasm and the optic nerve
The diagnosis is best made by magnetic resonance imaging (MRI), which allows visualization of the entire course of the optic nerve. MRI also delineates hypothalamic involvement more clearly than computed tomography (CT). However, CT is superior for bone detail and detection of intratumoral calcifications, which suggest low grade histology.