Postoperative imaging of vestibular schwannomas

Abstract

<jats:p>Symptomatic vestibular schwannomas can be treated with resection (translabyrinthine, retrosigmoid [suboccipital], or middle cranial fossa approaches) or stereotactic radiosurgery. When appropriate, auditory brainstem stimulators can also be implanted in patients with current or impending hearing loss due to bilateral vestibular schwannomas. Imaging plays a prominent role in determining management following these procedures. In this article, the expected postoperative imaging appearances are depicted. The radiological features of complications are also reviewed, including recurrent tumor, fat graft necrosis, CSF leakage, infection, hydrocephalus, cerebral infarction, venous sinus thrombosis, hemorrhage, and temporal lobe and cerebellar contusions.</jats:p>

Imaging Review of the Temporal Bone: Part II. Traumatic, Postoperative, and Noninflammatory Nonneoplastic Conditions

“…The translabyrinthine and the retrosigmoid approaches can be used for all tumor sizes, while the middle cranial fossa approach is most useful for removal of intracanalicular tumors (46). However, hearing preservation can be achieved only by means of the retrosigmoid and middle cranial fossa approaches (47).…”

“…However, hearing preservation can be achieved only by means of the retrosigmoid and middle cranial fossa approaches (47). MR imaging is routinely performed following surgical resection, mainly to assess for residual or recurrent tumor, but also to evaluate for suspected com plications (33,46,48 (46). The use of fat suppression is use ful for distinguishing enhancing tumor from the intrinsic high signal intensity of the fat grafts, which are commonly implanted in the surgical beds during tumor resection to minimize CSF leak age (Fig 20).…”

Cross Sectional Imaging of the Ear and Temporal Bone

“…A fat-suppressed T1-weighted sequence is useful for diagnosis of a lipoma in the IAC or CPA. Fatsuppressed post-contrast T1-weighted sequences are used in post-operative patients in assessing for recurrence of vestibular schwannoma, as there is often fat-packing in the CPA placed during surgery that may be confused for enhancing tumor in the absence of fat signal suppression [60,61].…”

Diagnosis and Management of Dural Sinus Thrombosis following Resection of Cerebellopontine Angle Tumors

“…However this can be negotiated by review of three-dimensional time-of-flight MRV that reveals loss of flow-related enhancement and thus confirms the diagnosis. 16 All of our patients subsequently proceeded to CTV or MRV to confirm sinus thrombosis. In our series no false-positive initial CT images were identified.…”