Tinnitus is the perception of sound when no external sound is present. It can be subjective, heard only by the patient, or objective, able to be heard by an examiner. Pulsatile tinnitus is a rhythmic type of tinnitus that is synchronous with the heartbeat. Imaging findings associated with pulsatile tinnitus include aberrant internal carotid arteries, persistent stapedial arteries, high or dehiscent jugular bulbs, sigmoid sinus wall anomalies, and vascular tumors or malformations. A detailed history, physical exam, audiologic evaluation, and imaging are needed to evaluate tinnitus and identify potential underlying causes.

1. BY
DR. AHMED HAMDY
A. LECTURER - ASWAN SCHOOL OF MEDICINE
TINNITUS

2. TINNITUS
 Introduction
 Classification
 Pulsatile tinnitus
 Imaging findings
 Checklist
 Quiz

3. Introduction
The perception of sound in the absence of external stimuli
Tinnire = “ringing” in Latin
 Unilateral or bilateral
 First or only symptom of a disease process or auditory/psychological
annoyance
 40 million affected in the United States… 10 million severely affected …..
Suicide!!!
 Most common in 40-70 year-olds
 The evaluation of a patient with tinnitus requires a detailed history,
neurootologic physical examination with otoscopy, a comprehensive
audiologic evaluation with hearing thresholds, and imaging studies.

4. Classification
 SUBJECTIVE TINNITUS
sound is only perceived by the patient (most common)
 OBJECTIVE TINNITUS
sound produced by paraauditory structures which may be heard by an
examiner, often PULSATILE

5. Subjective TinnitusSubjective Tinnitus
• Most common type of tinnitus.
• Only heard by the patient.
• Associated symptoms depend on cause:
• Vertigo – superior semicircular canal dehiscence &
Meniere’s disease
• Conductive hearing loss – otosclerosis & superior
semicircular canal dehiscence
• Sensorineural hearing loss – vestibular schwannoma,
presbyacusis, & noise induced hearing loss

6. Objective TinnitusObjective Tinnitus
• An actual sound made by the human body.
• Physical explanation for perceived noise.
• Often due to a vascular process.
• Can be due to other physiologic sounds:
• Muscular contractions (palatal
myoclonus – clicking)
• Respiration (patulous Eustachian tube)
• Venous hum (flow murmurs)
• Frequently can be perceived by an observer.

7. PulsatilePulsatile TinnitusTinnitus
• Can be altered with compression of arterial or venous structures.
• Can be perceived by the examiner if stethoscope placed in the right
location.
• Can be venous or arterial.
• Tends to produce whooshing sound.
• Cardiac rhythm synchronous.

8. Pulsatile Tinnitus CausesPulsatile Tinnitus Causes
1- CONGENITAL VASCULAR MALFORMATIONS
**A- Arterial:-
 Aberrant internal carotid artery (ICA)
 persistent stapedial artery,
 lateralised internal carotid artery
 Fibromuscular dysplasia
**B- Venous:-
 High-riding jugular bulb
 Dehiscences jugular bulb
 Jugular venous diverticula
 laterally placed sigmoid sinus
 Abnormal mastoid emissary veins
2- ACQUIRED VASCULAR ABNORMALITIES
 Petrous carotiud aneursm
 Carotico-cavernous fistula
 Dural Artero-venous Malformation
 Vascular loop syndrome
 Carotid artery dissection / occlusion atherosclerosis / stenosis
Sigmoid sinus wall anomalies

9. Pulsatile Tinnitus CausesPulsatile Tinnitus Causes
3- VASCULAR TUMORS:
 Paragangliomas: (glomus tympanicum or glomus jugulare)
 Metastasis
4- NARROWING OF THE TRANSVERSE SINUS
 Pseudotumor cerebri
 Transverse sinus / Jugular thrombosis
5- MISCELLANEOUS
 Superior semicircular canal dehiscence
 Otospongiosis
 Inflammatory hyperemia diseases (mastoiditis - Paget’s disease)

11. Collins RD. Algorithmic diagnosis of symptoms and signs: a cost-effective approach. 2d ed. Philadelphia: Lippincott Williams &
Wilkins, 2003:568-9.
ENT Referral
ENT Referral

12. Imaging Findings Associated withImaging Findings Associated with
Pulsatile TinnitusPulsatile Tinnitus

13. Imaging OptionsImaging Options
• Overall, radiologic imaging is effective in detecting
causes of pulsatile tinnitus in approximately 70% of cases.
• High-resolution contrast-enhanced CT or MRI are
reasonable options and are regarded as the imaging
modalities of choice.
• In the absence of objective pulsatile tinnitus, CTA or MRA
are appropriate initial exams.
• If there is suspicion for arterio-venous fistulas, angiography
should be performed.

15.  A variant of the internal carotid artery (ICA)
 Involution / absence of the normal cervical portion (first
embryonic segment) of the ICA
Enlargement of the usually small collaterals passes lateral
to the cochlear promontory and appears during
otoscopic examination as a retro-tympanic vascular
mass.
Aberrant Internal Carotid ArteryAberrant Internal Carotid Artery
If mistaken for a paraganglioma and biopsied, the
results can be FATAL

16. C2= three sections:
*vertical
* the genu / bend
*horizontal portion.

17. Norm
al C
arotid
canal
A
berrant IC
A

18. Radiographic features
A deficient bony plate along the tympanic portion of the ICA (aberrant
ICA) is a normal variant and can be mistaken with glomus jugulare.

19. Left aberrant
ICA entering
the middle ear
cavity through
an enlarged
inferior
tympanic
canaliculus
(arrows).

20. Failure of regression of the embryonic stapedial artery
The stapedial artery is an embryological vessel arising from the primitive second
aortic arch that divides into a dorsal branch (the future middle meningeal
artery) and a ventral division (future maxillary and mandibular arteries). These
divisions link with branches developing from the external carotid artery during
the third fetal month causing the stapedial artery to regress.
If the stapedial artery persists in postnatal life, the middle meningeal artery arises
from it thus the foramen spinosum (normally containing the middle meningeal) is
absent.
Radiographic features
small canaliculus origniating from petrous segment of internal carotid artery.
linear soft tissue density crossing over cochlear promontory
enlarged facial nerve canal or separate canal parallel to facial nerve
aplastic or hypoplastic foramen spinosum
may be normal variant or in instances where middle meningeal artery arises from
ophthalmic artery
The vessel is important to recognize as it can be confused on examination with
vascular tumours such as glomus tympanicum. It should not be biopsed as it will
The persistent stapedial artery (PSA)The persistent stapedial artery (PSA)

21. Related pathology
may be associated with aberrant ICA, which is
formed when inferior tympanic artery anastomosis
with the caroticotympanic artery; enlarged inferior
tympanic canaliculus is then seen
may be associated with other middle ear anomales

22. Coronal CT image shows the left
internal carotid artery within the
hypotympanum (arrow).
Aberrant Carotid Artery &Aberrant Carotid Artery &
Persistent Stapedial ArteryPersistent Stapedial Artery
Axial CT image shows the stapedial
artery passing through the obturator
foramen (arrow).

23. Lateralised internal carotid arteryLateralised internal carotid artery
The lateralised internal carotid artery is an anatomic variation of the course
of the horizontal internal carotid artery (ICA). It can be visualised on CT by its
more posterolateral entrance to the skull base and protrusion into the anterior
mesotympanum. It may result in pulsatile tinnitus.
Radiographic features
CT
a lateralised ICA passes underneath the cochlea in the hypotympanum
focal thinned or dehiscent lateral wall of the carotid canal
THE INFERIOR TYMPANIC CANALICULUS IS NOT AFFECTED
Differential diagnosis
aberrant internal carotid artery: usually courses across the middle ear along the
cochlear promontory and shows an enlarged inferior tympanic canaliculus

24. the lateralised internal carotid artery is an anatomic variation of the course of the
horizontal internal carotid artery (ICA). It can be visualized on CT by its more
posterolateral entrance to the skull base and protrusion into the anterior mesotympanum.
It may result in pulsatile tinnitus.
Radiographic features
CT
** a lateralised ICA passes underneath the cochlea in the hypotympanum
** focal thinned or dehiscent lateral wall of the carotid canal
** the inferior tympanic canaliculus is not affected

25. Heterogeneous group of vascular lesions
characterized by an idiopathic, non-
inflammatory, and non-atherosclerotic
angiopathy of small and medium-sized arteries.
Fibromuscular Dysplasia is an arteriopathy that may lead to stenosis,
aneurysm, and dissection most common in young females.
Pulsatile tinnitus is a presenting symptom in approximately one-third of
patients and is associated with a pattern of multi-vessel involvement,
increased involvement of the cervical carotid and/or vertebral
arteries, and cervical artery dissection.
The characteristic finding is alternating stenoses and dilatations,
causing a string of beads appearance.
Fibromuscular dysplasiaFibromuscular dysplasia (FMDFMD)

26. Beaded appearance
of the internal carotid
arteries at the C1 to
C2 level greater on
the left than the right.
Finding is typical of
fibromuscular dysplasia
.

27. Coronal MRA MIP image shows a beaded appearance of the right internal carotid artery
(arrow).
Axial MRA MRIP images shows narrowing of the right petrous internal carotid artery
(arrow), due to dissection.

28. The jugular bulb is often asymmetric, with the right jugular bulb usually being
larger than the left.
If it reaches above the posterior semicircular canal or IAM high jugular bulb.
If the bony separation (sigmoid plate) between the jugular bulb and the middle
ear is absent  Dehiscent jugular bulb.
Rarely an outpouching is seen  Jugular bulb diverticulum.
A HIGH RIDING JUGULAR BULB
&
Dehiscent Jugular bulb
&
Jugular bulb diverticulum.

29. Sigmoid Sinus Wall Anomalies
 Pulse-synchronous tinnitus (PST) arises from the abnormal self-
perception of one’s own vascular flow, and can arise from a
number of venous and arterial abnormalities.
 Venous PST is more commonly encountered in clinical
practice than arterial PST.
 Sigmoid wall anomalies (SWA) are an increasingly recognized
cause of venous PST. SWA include sigmoid sinus thinning,
dehiscence, diverticulum and ectasia.
 Sigmoid wall anomalies include attenuation of the sinus plate,
frank dehiscence resulting in exposure of the sinus to the air in
the mastoid air cells, diverticula and segmental sigmoid sinus
ectasia

30. Thin plate of bone
between a
high riding jugular bulb
and the middle ear cavity
or more generally as the
thin bone separating the
sigmoid sinus from
adjacent structures
(especially mastoid air
cells). The wall of the vein
can protrude through a
defect into the middle ear,
creating a
dehiscent jugular bulb.
THE SIGMOID PLATE

31. IAM include: facial nerve, vestibulocochlear nerve,
labyrinthine artery (usually a branch of the AICA or basilar artery)

32. High jugular bulb

33. Dehiscent Jugular bulb

34. Large left jugular bulb. It is not a high riding bulb by definition since it does not
extend cranial to the IAM. But, note the deficient sigmoid plate allowing the jugular
vein to almost protrude into the middle ear.

35. Both jugular bulbs show dehiscence into medial
wall of middle ear with absence of intervening bony
plate. These bulbs are however not high riding.

36. Jugular bulb diverticulum

37. Venous Sinus Dehiscences &Venous Sinus Dehiscences &
DiverticulaDiverticula
Axial and coronal CT images show right sigmoid sinus diverticulum
and dehiscences involving the mastoid air cells and mastoid cortex
(arrows).

38. Venous Sinus Dehiscences &Venous Sinus Dehiscences &
DiverticulaDiverticula
• Sigmoid sinus diverticulum and dehiscence is
perhaps the most common identifiable cause for
pulsatile tinnitus of venous origin, with a
prevalence of 23% in symptomatic patients.
• Dehiscence of the sigmoid sinus can involve erode
into the mastoid air cells or the mastoid cortex, or
both.

39. It passes inferiorly in an S shaped groove posteromedial to the mastoid air-cells
to the jugular foramen, where it ends in the jugular bulb, in the posterior half of
the foramen (pars vascularis). It has connections via mastoid and
condylar emissary veins with pericranial veins.
The jugular foramen courses anteriorly, laterally, and inferiorly as it insinuates
itself between the petrous temporal bone and the occipital bone.
The jugular foramen is usually described as being divided into two parts by a
fibrous or bony septum, called the jugular spine, into:
the pars nervosa: anteromedial and smaller
the pars vascularis: posterolateral and larger

44. Mastoid emissary vein
(MEV).
sending or coming out, as cert
ain veins that pass through
the skull and connect the veno
us sinuses inside with the vein
s outside.

45. Mastoid emissary vein (MEV).
A three-dimensional volume-rendered image (posterior view) (b) shows the
MEV draining into the posterior auricular vein (PAV) and PAV draining into
the suboccipital venous plexus on the left side.
A posterior condylar vein emerges from its canal on the right side.

46. posterior fossa emissary veins
in a patient with a hypoplastic
sigmoid sinus and internal
jugular vein.
External connections of
emissary veins are indicated by
the blue arrows and bold white
letters. DCV, deep cervical vein;
EJV, external jugular vein; IJV,
internal jugular vein; JB, jugular
bulb; LCV, lateral condylar vein;
MEV, mastoid emissary vein;
OEV, occipital emissary vein;
PAV, posterior auricular vein;
PCV, posterior condylar vein;
PSS, petrosquamosal sinus;
RMV, retromandibular vein;
SOVP, suboccipital venous
plexus; SS, sigmoid sinus; SSS,
superior sagittal sinus; TS,
transverse sinus; VAVP,
vertebral artery venous plexus.

47. Para-GangliomaPara-Ganglioma

48. A) Glomus TympanicumA) Glomus Tympanicum
Axial CT images shows a soft tissue opacity in the middle ear, along the cochlear
promontory (arr0w). The coronal post-contrast T1-weighted MRI shows avid enhancement in
the lesion (arrow). Catheter digital subtraction angiography shows marked hypervascularity
in the lesion (arrow).

49. Glomus TympanicumGlomus Tympanicum
• Often apparent on otoscopic examination as a pulsating reddish
mass, the role of imaging is to differentiate these from glomus
jugulotympanicum.
• Most glomus tympanicum tumors arise on the cochlear
promontory.
• CT without contrast is adequate for delineating the extent of the
tumor.
• Avid enhancement and a “salt and pepper” appearance can be
observed on MRI.

50. RT middle ear cavity glomus tympanicum paraganglioma (red arrow
located just anterior to the cochlear promontory (blue arrow).

51. A) Glomus TympanicumA) Glomus Tympanicum

52. Temporal Bone MetastasesTemporal Bone Metastases
Initial presentation of prostate cancer as pulsatile tinnitus due to a
metastasis. The CT, CTA, and post-contrast T1-weighted MRI show a
lytic, enhancing mass (arrows) in the left temporal bone with associated
compression of the left jugular bulb (oval).

53. • Rare cause of pulsatile tinnitus due to vascular
impingement or tumor hyperemia.
• The presence of accompanying new cranial
nerve deficits should raise the suspicion for a
malignancy.
• Serial scanning in patients at high risk of
metastatic disease may be warranted.
Temporal Bone MetastasesTemporal Bone Metastases

54. ARTERIOVENOUS MALFORMATIONS
AND FISTULAS
•Petrous carotiud aneursm
•Carotico-cavernous fistula
•Dural Artero-venous Malformation

55. Petrous Carotid AneurysmPetrous Carotid Aneurysm
Coronal CT image shows an
expansile lesion of the right petrous
carotid canal (arrow).
Catheter angiogram reveals an
aneurysm of the horizontal petrous
carotid artery (arrow).

56. Petrous Carotid AneurysmPetrous Carotid Aneurysm
• Most petrous aneurysms are large and fusiform and believed
to be congenital in origin.
• Other etiologies for petrous aneurysms are radiation injury,
trauma, and infection.
• Otologic manifestations include conductive and sensorineural
hearing loss and tinnitus, with rupture seen in 25% as initial
presentation.
• Endovascular treatment is the mainstay of treatment.

57. Dural Arteriovenous FistulaDural Arteriovenous Fistula
The patient presented with a retroauricular bruit and had a remote
history of temporal bone trauma. The 3D hybrid CTA image shows a
prominent occipital artery (arrow) that drains into the junction of the left
transverse sinus with the sigmoid sinus.

58. Dural Arteriovenous FistulaDural Arteriovenous Fistula
• Related to trauma, prior craniotomy, or dural sinus thrombosis.
• Classified according to direction of flow and presence or absence
of cortical venous drainage
• Most common locations: CAVERNOUS, transverse, & sigmoid
sinuses.
• Findings may be subtle on cross sectional imaging and requires
high index of suspicion.

59. Pseudotumor CerebriPseudotumor Cerebri
Sagittal T1-weighted MRI shows an enlarged partially empty sella in a young
obese female. The MRA MIP shows constriction of the bilateral transverse
sinuses (arrows). The axial T2-weighted MRI shows mild bulging of the bilateral
optic nerve discs (arrows).

60. Coronal FIESTA MRI show a vascular structure (arrow) impinging upon
the right cranial nerve 7 and 8 complex (arrowhead).
Vascular Loop SyndromeVascular Loop Syndrome

61. Vascular Loop SyndromeVascular Loop Syndrome
• Pulsatile tinnitus can be caused by arterial or venous vascular loops
and may be accompanied by vertigo.
• Impingement upon the cranial nerve 7 and 8 complex in the
cerebellopontine angle cistern or internal auditory canal can best be
observed on FIESTA/CISS/DRIVE MRI sequences.
• May be treated successfully by microvascular decompression.

62. Vascular
compression
syndrome in the
cerebellopontine
angle cistern
Axial 3D-FIESTA MR images through the eighth CN show the following: AICA (
Anterior inferior cerebellar artery) loop within the right IAC, vascular loop extending into
>50% of the IAC (Type III).

64. Axial 3D CISS image showing (A) a
linear structure originating from
the basilar artery corresponding
to the left anterior inferior
cerebellar artery (white arrow)
which loops around the cisternal
portion of left VIIth and VIIIth
nerve (white arrow) (B). The VIIth
nerve is not well-visualized as the
vascular loop causes overlapping
of the structure.

65. Pseudotumor CerebriPseudotumor Cerebri
(Idiopathic intracranial hypertension (IIH)(Idiopathic intracranial hypertension (IIH)
( Benign intracranial hypertension)( Benign intracranial hypertension)
Syndrome with signs and symptoms of increased intracranial pressure but where a
causative mass or hydrocephalus is not identified.
The older term benign intracranial hypertension is generally frowned upon due to the
fact that some patients with IIH have a fairly aggressive clinical picture with rapid visual
loss.
Interestingly as it has become evident that at least some patients present with IIH due to
identifiable venous stenosis, some authors now advocate reverting to the older
term pseudotumour cerebri as in these patients the condition is not idiopathic 15
. An
alternative approach is to move these patients into a group termed secondary
intracranial hypertension 15
.
Venous pulsatile tinnitus can result from conditions associated increased intracranial
pressure.
Characteristic neuroimaging findings for pseudotumor cerebri (Idiopathic intracranial
hypertension) include a partially empty sella, constriction of the transverse sinuses, and
optic nerve disc and optic nerve sheath cerebrospinal fluid prominence.

66. Both optic nerves show
flattening of the posterior sclera (dashed lines)
protrusions of the optic nerve heads (red arrows)
prominent subarachnoid space around the optic nerves(yellow arrows)
vertical tortuosity of the optic nerves

67. OPTIC NERVES
prominent subarachnoid space around the optic nerves (~45%)
vertical tortuosity of the optic nerves (~40%)
papilloedema
​flattening of the posterior sclera (~80%)
intraocular protrusion of the optic nerve head
enhancement of the prelaminar (intra-ocular) optic nerves (~50%)
enlarged arachnoid out-pouchings
* partial empty sella turcica (~70%)
*enlarged Meckel cave 9
* prominent arachnoid pits / small meningocoeles typically within
the temporal bone and sphenoid wing
*bilateral venous sinus stenosis
lateral segments of the transverse sinuses
no evidence of current or remote thrombosis 8
*slitlike ventricles (relatively uncommon compared to other
findings) 15
*acquired tonsillar ectopia (mimicking Chiari I malformation)

69. Atherosclerotic DiseaseAtherosclerotic Disease
New pulsatile tinnitus due to new basilar artery steno-occlusive disease (arrow).
Initial MRI MIP MRI MIP 8 years later

70. • Pulsatile tinnitus can be the first manifestation
atherosclerotic disease.
• Most commonly associated with significant
stenosis of the internal carotid arteries.
• Both the head and neck vasculature should be
covered on imaging.
Atherosclerotic DiseaseAtherosclerotic Disease

71. Miscellaneous

72. Superior Semicircular CanalSuperior Semicircular Canal
Dehiscence syndromeDehiscence syndrome
A recently described inner ear abnormality, where a clinical disequilibrium
phenomenon is associated with absence of the bony covering of the superior
semicircular canal (SSC).
Dehiscence of the SSC forms a "third window" into the inner ear, in addition to
the round and oval windows. This allows motion of the endolymph to be
induced by sound and pressure stimuli 2
.
Pulsatile tinnitus results from transmission of the normal pulse-related
pressure changes within the cranial cavity to the inner ear.
Temporal bone CT is the modality of choice for diagnosing superior
semicircular canal dehiscence by the lack of overlying bone, particularly via
Stenver and Pöschl views.

74. Rating of the bone covering the SSC used for the 1-mm-collimated CT scans in the
control subjects with normal temporal bones.
(a)Coronal 1-mm-collimated CT scan through the left temporal bone shows clearly
intact bone (arrow) over the left SSC.
(b) Coronal 1-mmcollimated
CT scan through the left temporal bone demonstrates an area of possible bone
dehiscence (arrow) over the SSC.
(c) Coronal 1-mm-collimated CT scan through the right temporal bone demonstrates a
region of bone dehiscence (arrow) over the SSC.

75. The patient presented with dizziness, pulsatile tinnitus, hyperacusis, otalgia, and
fullness in the right ear. Stenver and Pöschl CT images show deficiency of bone
along the apex of the right superior semicircular canal (arrows).

76. CT scan, sagittal projections showed bilateral dehiscence of posterior semicircular canal
in right ear (3c) and left ear (3d), and unilateral right dehiscence of the superior
semicircular canal (3a white arrow). White arrows in 3b instead show the bone covering
the left superior semicircular canal.

77. OtospongiosisOtospongiosis
Axial CT images shows extensive demineralization of the otic capsule (arrows).

78. OtospongiosisOtospongiosis
• Otospongiosis contains arteriovenous microfistulas which can
lead to pulsatile tinnitus.
• Demineralization in the region of the fissula ante fenestram
and/or otic capsule can be observed on CT.
• The affected areas display enhancement due to the vascular
nature of otospongiosis.

79. Inflammatory andInflammatory and
Hypermetabolic ConditionsHypermetabolic Conditions
Otomastoiditis. The MRI shows
enhancement throughout the right
mastoid air cells and an epidural
abscess (arrow).
Paget disease. Sagittal CT image show
diffuse expansion of the skull diplopic
space and lucency of the otic capsule
(arrow).

80. • Infectious and inflammatory processes in and around the temporal
bone, including mastoiditis and Paget disease, can lead to pulsatile
tinnitus due to increased regional blood flow.
• Otomastoiditis appears opacification on CT and associated
enhancement of the mucosa and sometimes the bone marrow is
apparent on MRI.
• Paget disease has variable imaging manifestations depending upon
the stage of disease, but can appear as bone marrow expansion and
demineralization on CT during the active phase with pulsatile tinnitus,
cranial nerve deficits and Eustachian tube dysfunction.
Inflammatory andInflammatory and
Hypermetabolic ConditionsHypermetabolic Conditions

81. Quiz.. !!

84. 18-year-old male with right pulsatile
tinnitus

85. 34 year-old female with right pulsatile
tinnitus

86. 34 year-old female with right pulsatile
tinnitus

87. 44 year-old female with left pulsatile
tinnitus
Axial CT shows ectatic left sigmoid sinus with thinning of the left sigmoid plate
without a focal diverticulum

88. 41 year-old female with right tinnitus

89. 38 year-old female with right PST.

90. Case seniro…
Transmastoid approach for sigmoid sinus wall
repair: Intraoperative findings
(A) Appearance of a right sigmoid sinus diverticulum during transmastoid
surgery. Yellow lines: outline of normal sigmoid sinus; Blue oval:
diverticulum. (B) Post-reduction of diverticulum. Metal suction tip sitting on
the wall of the sigmoid sinus through a hole in the bone after diverticulum
reduction. (C) Post-repair of sinus wall. Tissue graft reinforcing the wall of
the sigmoid sinus, sitting deep to the bone on the sinus wall, through the
hole in the bone. Following this step, the hole itself is repaired with synthetic
bone cement (Hydroset) and bone pate made from the patient’s own bone.
A B C

91. Postoperative imaging findings: CT
Axial CT image of the temporal bone on soft tissue window (A) demonstrates
relatively hypoattenuating material (arrows) lateral to the hyperattenuating,
contrast enhanced sigmoid sinus. (B) On bone windows, hydroset material is
identified as sharply demarcated hyperdense material (asterisk) conforming
to the size and shape of dehiscence. Bone pate is identified lateral to the
hydroset as amorphous ill-defined hyperdensity (arrow).
*
A B
*

92. CHECKLISTS
of imaging findings in
various anatomical
compartments

93. Epicranium
– Dilatation of branches of the external carotid artery (in dural arteriovenous
fistulas)
Neck
– Vascular stenosis (arteriosclerosis, fibromuscular
dysplasia)
– Vascular dissection
– Aneurysm
– Carotid or vagal paraganglioma
– Jugular vein abnormality

94. Temporal bone
– Aberrant or dehiscent internal carotid artery
– Persistent stapedial artery
– Anatomical variants/abnormalities of the jugular bulb
– Tympanic/jugular paraganglioma
– Other strongly vascularized tumor of the temporal bone
– Otosclerosis
– Otitis
– Semicircular canal dehiscence
– Labyrinth fistula
– Meningocele, meningoencephalocele
– Cholesterol granuloma
Other skull
– Strongly vascularized tumor, vessel-rich metastasis
– Paget’s disease
– Empty sella
– Large emissary vein
– Dilated transossial vascular canals (in dural arteriovenous

95. Dura mater
– Dural arteriovenous fistula
– Sinuvenous thrombosis
– Stenosis or diverticulum of dural sinus
Endocranium
– Space-occupying lesion
– Disturbance of CSF circulation
– Craniocervical transition disorder
– Vascular loops in the internal auditory meatus
– Pial arteriovenous vascular malformation
– Venous congestion (in dural arteriovenous fistulas)

96. Thanks for your time