MRI Head and Internal Auditory Canal With IV Contrast There is no relevant literature to support the use of MRI head and IAC with IV contrast for evaluation of unilateral NPT. The study should be performed without and with IV contrast as described in the next section. MRI Head and Internal Auditory Canal Without and With IV Contrast MRI head and IAC without and with IV contrast can be considered for retrocochlear processes such as vestibular schwannoma or other mass lesions in patients with NPT [71,77]. Tinnitus may occur among patients with vestibular schwannomas (63%-75%) and intralabyrinthine schwannomas [78]. These are readily diagnosed by MRI. Rarely, meningiomas in or around the IAC and cerebellopontine angle cistern can also cause tinnitus and are accurately diagnosed on MRI [79,80]. Vestibular schwannomas cause NPT more commonly than PT [49]. Mass lesions in the IAC and posterior fossa such as schwannomas, meningiomas, and endolymphatic sac tumors are readily diagnosed by MRI. A study of 218 patients with NPT found that 91.8% of patients had an unremarkable MRI [81]. Spontaneous intracranial hypotension can cause tinnitus, probably due to venous engorgement in the IAC [82,83]. Endolymphatic hydrops has an association with Meniere disease, which presents with episodic hearing loss, vertigo, and tinnitus [84-87] and requires special sequences for diagnosis, including heavily T2-weighted 3-D FLAIR (fluid- attenuated inversion recovery) and 3-D real inversion recovery performed 4 hours after injection of the IV contrast [88], best interpreted alongside a routine 3-D heavily T2-weighted sequence. MRV Head With IV Contrast There is no relevant literature to support the use of MRV head with IV contrast for evaluation of unilateral NPT. MRV Head Without and With IV Contrast There is no relevant literature to support the use of MRV head without and with IV contrast for evaluation of unilateral NPT.
Tinnitus. MRI Head and Internal Auditory Canal With IV Contrast There is no relevant literature to support the use of MRI head and IAC with IV contrast for evaluation of unilateral NPT. The study should be performed without and with IV contrast as described in the next section. MRI Head and Internal Auditory Canal Without and With IV Contrast MRI head and IAC without and with IV contrast can be considered for retrocochlear processes such as vestibular schwannoma or other mass lesions in patients with NPT [71,77]. Tinnitus may occur among patients with vestibular schwannomas (63%-75%) and intralabyrinthine schwannomas [78]. These are readily diagnosed by MRI. Rarely, meningiomas in or around the IAC and cerebellopontine angle cistern can also cause tinnitus and are accurately diagnosed on MRI [79,80]. Vestibular schwannomas cause NPT more commonly than PT [49]. Mass lesions in the IAC and posterior fossa such as schwannomas, meningiomas, and endolymphatic sac tumors are readily diagnosed by MRI. A study of 218 patients with NPT found that 91.8% of patients had an unremarkable MRI [81]. Spontaneous intracranial hypotension can cause tinnitus, probably due to venous engorgement in the IAC [82,83]. Endolymphatic hydrops has an association with Meniere disease, which presents with episodic hearing loss, vertigo, and tinnitus [84-87] and requires special sequences for diagnosis, including heavily T2-weighted 3-D FLAIR (fluid- attenuated inversion recovery) and 3-D real inversion recovery performed 4 hours after injection of the IV contrast [88], best interpreted alongside a routine 3-D heavily T2-weighted sequence. MRV Head With IV Contrast There is no relevant literature to support the use of MRV head with IV contrast for evaluation of unilateral NPT. MRV Head Without and With IV Contrast There is no relevant literature to support the use of MRV head without and with IV contrast for evaluation of unilateral NPT.