Acoustic neuroma CT
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Acoustic neuroma Microchapters | |
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Diagnosis | |
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Treatment | |
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Case Studies | |
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Acoustic neuroma CT On the Web | |
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American Roentgen Ray Society Images of Acoustic neuroma CT | |
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [3]Associate Editor(s)-in-Chief: Simrat Sarai, M.D. [4]
Overview
Head CT scan may be diagnostic of acoustic neuroma. Findings on CT scan diagnostic of acoustic neuroma include erosion, and widening of the internal acoustic canal.[1]
CT
- CT scans with bone windows can also be of prognostic significance as the extent of widening of the IAC and the extent of tumor growth anterior and caudal to the :IAC are predictive of postoperative hearing loss.
- If MRI cannot be done on patient, high resolution CT scanning with and without contrast is an alternative. On MRI and CT scans, vestibular schwannoma can be seen as :enhancing lesions in the region of the internal auditory canal with variable extension into the cerebellopontine angle. CT scans with bone windows can also be of :prognostic significance.
- CT may show erosion and widening of the internal acoustic canal. The density of these tumors on non-contrast imaging is variable, and often they are hard to see, :especially on account of beam hardening and streak artifact form the adjacent petrous temporal bone. Contrast enhancement is present, but can be underwhelming, :especially in larger lesions with cystic components.[1]
- Well-performed scanning can demonstrate tumors 1-2 mm in diameter. However, even with intravenous contrast enhancement thin-cut CT scanning can miss tumors as large as :1.5 cm even. Fine-cut CT scanning of the internal auditory canal with contrast can detect medium-size or large tumor but are not reliable imaging techniques to detect a :tumor smaller than 1-1.5 cm.
References
- ↑ 1.0 1.1 Acoustic Schwannoma. Radiopedia(2015) http://radiopaedia.org/articles/acoustic-schwannoma Accessed on October 2 2015
- ↑ Image courtesy of Dr Frank Gaillard. Radiopaedia (original file [1]).[http://radiopaedia.org/licence Creative Commons BY-SA-NC
- ↑ Image courtesy of Dr Prashant Mudgal. Radiopaedia (original file [2]).[http://radiopaedia.org/licence Creative Commons BY-SA-NC