MRI Head and Internal Auditory Canal Without and With IV Contrast Vascular loops in contact with cranial nerve (CN) VIII are a normal variant and may be seen in up to one-third of normal patients. However, they may contribute to otological symptoms due to neurovascular compression. Patients with PT are 80 times more likely to have vascular loops in contact with CN VIII than patients without PT [60]. Heavily T2-weighted thin-section sequences of MRI head can detect the neurovascular loops in patients with PT [61,62]. Typewriter tinnitus is described as paroxysmal attacks of staccato sounds, thought to be caused by neurovascular compression of the cochlear nerve, and responds well to carbamazepine. MRI can be helpful for detection and evaluation of the extension of the glomus jugulare in the internal jugular vein. Mass lesions in the IAC and posterior fossa such as schwannoma, meningioma, and endolymphatic sac tumor, are readily diagnosed by MRI. Vestibular schwannomas cause NPT more commonly than PT. Other masses can rarely cause tinnitus [49,63,64]. Postgadolinium 3-D images through the brain show detailed anatomy of the transverse and sigmoid dural venous sinuses and can be used to detect the transverse sinus stenosis. The sigmoid sinus diverticulum can also be seen on these images. MRI 4-D flow can detect abnormal flow patterns in the transverse sinuses in patients with venous PT [65]. It was able to detect increased blood flow and blood velocity in patients who had markers of venous PT such as SSWA and transverse sinus stenosis [43]. Tinnitus MRI Head and Internal Auditory Canal Without IV Contrast Vascular loops in contact with CN VIII are a normal variant and may be seen in up to one-third of normal patients. However, they may contribute to otological symptoms due to neurovascular compression. Patients with PT are 80 times more likely to have vascular loops in contact with CN VIII than patients without PT [60].
Tinnitus. MRI Head and Internal Auditory Canal Without and With IV Contrast Vascular loops in contact with cranial nerve (CN) VIII are a normal variant and may be seen in up to one-third of normal patients. However, they may contribute to otological symptoms due to neurovascular compression. Patients with PT are 80 times more likely to have vascular loops in contact with CN VIII than patients without PT [60]. Heavily T2-weighted thin-section sequences of MRI head can detect the neurovascular loops in patients with PT [61,62]. Typewriter tinnitus is described as paroxysmal attacks of staccato sounds, thought to be caused by neurovascular compression of the cochlear nerve, and responds well to carbamazepine. MRI can be helpful for detection and evaluation of the extension of the glomus jugulare in the internal jugular vein. Mass lesions in the IAC and posterior fossa such as schwannoma, meningioma, and endolymphatic sac tumor, are readily diagnosed by MRI. Vestibular schwannomas cause NPT more commonly than PT. Other masses can rarely cause tinnitus [49,63,64]. Postgadolinium 3-D images through the brain show detailed anatomy of the transverse and sigmoid dural venous sinuses and can be used to detect the transverse sinus stenosis. The sigmoid sinus diverticulum can also be seen on these images. MRI 4-D flow can detect abnormal flow patterns in the transverse sinuses in patients with venous PT [65]. It was able to detect increased blood flow and blood velocity in patients who had markers of venous PT such as SSWA and transverse sinus stenosis [43]. Tinnitus MRI Head and Internal Auditory Canal Without IV Contrast Vascular loops in contact with CN VIII are a normal variant and may be seen in up to one-third of normal patients. However, they may contribute to otological symptoms due to neurovascular compression. Patients with PT are 80 times more likely to have vascular loops in contact with CN VIII than patients without PT [60].