Name : Morteza
Family : Sanei Taheri
Affiliation :Radiology Department,Shohada Tajrish Hospital,SBMU
Academic Degree : Associate Professor of Radiology
Resident : Afarin Sadeghian
Head & Neck Imaging
Gender : Male
Age : 42
42-year-old man with tinnitus
In axial T2-weighted spin-echo images,an area of signal void in posterior aspect of the left internal acoustic meatus is seen which in correlation with post-gad images, there is a tubular enhancing structure in continuity with internal jugular vein .In coronal plane image,extension of the dome of the internal jugular vein above the floor of the internal acoustic canal is clearly depicted.
1.High jugular bulb,2.Asymmetric large jugular bulb,3.Dehiscent jugular bulb
High jugular bulb as normal variant
Discussion (Related Text)
A high riding jugular bulb is distinguished from an asymmetrically large jugular bulb by its dome reaching above the internal acoustic meatus (IAM). It need not be larger than the contralateral bulb, but usually is. A run of the mill high riding jugular bulb has an intact sigmoid plate (a thin plate of bone separating the jugular bulb from the middle ear cavity). This can only be appreciated on thin slice bone algorithm CT, and is too thin to appreciate on MRI. If the sigmoid plate is deficient, the the bulb is free to protrude into the middle ear cavity, and is then known as a dehiscent jugular bulb and is a common cause of a retrotympanic vascular mass.
JD Swatrz, HR Harnsberger "Imaging of the Temporal Bone" Thieme