MRI Head and Neck

Neurocranium

The interhemispheric fissure is centered on the midline. The cerebrum and cerebellum exhibit normal cortical sulcation. The cerebral ventricles are of normal size and symmetrical with normal circulation of CSF. There are no signs of increased intracranial pressure. The cortex and white matter show normal development and normal signal intensity, especially in the periventricular white matter. No abnormalities are seen in the basal ganglia, internal capsule, corpus callosum, or thalamus.

The brain stem and cerebellum show no abnormal changes in signal characteristics.

The sella and pituitary are normal, and parasellar structures are unremarkable.

The cerebellopontine angle area appears normal on each side. The internal acoustic meatus has normal width.

The paranasal sinuses and mastoid air cells show normal development and pneumatization. The orbital contents are unremarkable.

Interpretation

Cranial MRI is normal.

Checklist

Interhemispheric fissure

Cortical sulcation in the cerebrum and cerebellum (arbor vitae)

Centered on the midline No displacement Falx cerebri:

— Signal characteristics

— Flow in the dural sinuses (if the sequence permits flow assessment)

Configuration Number of sulci Width of sulci No coarsening of sulci

Cerebral cortex

Ventricles

White matter

Basal ganglia, internal and external capsule, thalamus Corpus callosum

Brain stem

No circumscribed widening or narrowing Cisterns and cortical markings are well defined Width

Distribution (no ectopic tissue) Signal characteristics (no hyperintense [demy-elination, edema, hemorrhage] or hypointense [calcification, hemorrhage] changes) No areas of separation from the calvarium No abnormal fluid collection (convex or concave) between the cerebral cortex and calvar-ium Shape

Size normal for age (see below) Symmetry (no unilateral or circumscribed enlargement)

Evidence of flow in the (centrally located) aqueduct

Fourth ventricle is tent-shaped and not dilated No signs of increased intracranial pressure (e.g., effaced sulci, narrowed or widened ventricles)

Signal characteristics (maturity appropriate for age; homogeneous signal intensity, especially at periventricular sites; no patchy or circumscribed hyperintense [demyelination, edema, hemorrhage] or hypointense [calcification, hemorrhage] signal changes) Normal width in relation to cortex Position Size

Delineation Signal intensity Anatomy Configuration Size

No circumscribed narrowing or expansion No foci of demyelination No masses Shape

Signal intensity (homogeneous) No focal abnormalities

Cranial nerves (presence, course, width, symmetry)

Cerebellum

Intracranial vessels

Sella and pituitary

Petrous pyramids

Paranasal sinuses •

Anatomy (symmetry)

Cortex (width, sulcation)

White matter (homogeneous signal intensity)

Course

Width

No abnormal dilatation No vascular malformations Size (see below)

Configuration (surface flat or slightly concave, infundibulum centered)

Signal intensity (neurohypophysis and adeno-hypophysis, no circumscribed change in signal intensity before or after contrast administration)

Parasellar structures (optic chiasm, suprasellar CSF spaces, carotid siphon, cavernous sinus) are unremarkable

Cerebellopontine angle area:

— Width of internal auditory canals (see below)

— CSF spaces (symmetrical, fluid intensity)

— Vestibulocochlear nerve clearly defined Mastoid cells, mastoid antrum

— Pneumatization

— Borders (wall thickness, smooth and continuous contours)

— Not fluid-filled

Cochlea and semicircular canals:

— Configuration

— Smooth borders Anatomy Pneumatization

Borders (wall thickness, smooth and continuous contours)

Nasal cavity:

— Pneumatization

— Septum on midline

— Turbinates (presence of superior, middle, and inferior turbinates; width)

Orbit • Configuration of orbital cone

— Globe (position, size, signal intensity, wall thickness)

— Eye muscles (position, course, signal intensity, width)

— Ophthalmic vein (course, width—see below)

Important Data

Vetricular dimensions:

1 Cella media index:

2 Frontal horn of lateral ventricle (at level of foramen of Monro):

3 Width of third ventricle:

• <5 mm in children (slightly more in infants)

Axial image

4 Width of ophthalmic vein:

5 Optic nerve (axial image):

a Retrobulbar segment: 5.5 mm ± 0.8 mm b Narrowest point (at approximately mid-orbit): 4.2 mm ± 0.6 mm

6 Position of globe:

• Posterior margin of globe 9.9 mm ± 1.7 mm behind interzy-gomatic line

7 Internal auditory canal:

• Approximately 5-10 mm, with no more than 1 mm difference between the right and left sides

8 Pituitary:

• Height of pituitary in sagittal plane: 2-6 mm Caution: normal size variations during

— Puberty: up to 10 mm in girls, up to 8 mm in boys

Sagittal image

Pituitary

The size, position, and configuration of the sella are normal. The floor and walls of the sella are smooth and well-defined. The pituitary is normal in size, shape, and position. The pituitary tissue shows normal signal characteristics both before and after contrast injection, with no circumscribed abnormalities of signal intensity. The infundibulum is centered and of normal size. The optic chiasm and suprasellar CSF spaces appear normal. The cavernous sinus and imaged portions of the internal carotid artery and carotid siphon are unremarkable.

Evaluable portions of the neurocranium show no abnormalities. The sphenoid sinus is clear and pneumatized.

Interpretation

The pituitary appears normal.

Checklist Sella

Pituitary

Position Size

Configuration (U-shaped)

Walls steep, not splayed

Borders smooth, sharp, and of normal width

Position (centered in the sella)

Configuration (bean-shaped)

Superior border straight or slightly concave

(convex only during puberty or pregnancy)

Size (see below)

Delineation of adenohypophysis and neurohy-

pophysis (sagittal image)

Pituitary tissue homogeneous on noncontrast images

Homogeneous contrast enhancement No circumscribed hypointense or hyperintense areas (especially on coronal images, no signal difference between left and right halves of pituitary)

Dynamic sequence (if performed) shows no time differential in the enhancement of different pituitary areas

96 MRI: Head and Neck

Infundibulum

Position (centered)

Size (see below)

Optic chiasm

Position

Size (see below)

Symmetry

Suprasellar CSF

Symmetrical

spaces (chias-

Not constricted

matic cistern)

Cavernous

Symmetry

sinuses

Size

No infiltration

Internal carotid

Symmetry

arteries

Size (especially in siphon area)

No circumscribed or generalized narrowing or

expansion

Neurocranium

Temporal lobe

Hypothalamus

Floor of third ventricle

Sphenoid sinus

Smooth margins, normal width (especially of the

roof), clear and pneumatized roof), clear and pneumatized

Important Data Pituitary

1 Sagittal diameter:

2 Height in sagittal plane:

• 2-6 mm (Caution: normal size variations during

— Puberty: up to 10 mm in girls, up to 8 mm in boys

3 Pituitary stalk:

Sagittal image
Coronal image

4 Optic chiasm:

Internal Auditory Canals, Petrous Pyramids

The petrous pyramids appear normal and symmetrical. The internal acoustic meatus is of normal width, and its walls are smooth and sharply defined. The vestibulocochlear nerve on each side shows normal course and diameter. Contrast administration is not followed by abnormal rise of signal intensity within the nerve, especially its in-trameatal portion.

The cochlea and semicircular canals appear normal. The mastoid air cells are clear and pneumatized. The tympanic cavity and external auditory canal are normal.

The cerebellopontine angle area shows normal configuration on each side.

The brain stem shows normal configuration and normal signal characteristics, with normal emergence of the nerves of the auditory canal. The cerebellopontine angle cistern is clear and symmetrical on each side.

The other imaged portions of the neurocranium are unremarkable. Interpretation

The internal auditory canals appear normal.

Checklist

Petrous pyramids

Vestibulocochlear • nerve (cranial • nerve VIII)

Facial nerve • (cranial nerve VII)

Configuration Bilateral symmetry Internal auditory canals:

— Borders (smooth, sharp) Course (straight, continuous)

Width (uniform, no right-left discrepancy, no circumscribed expansion)

Enhancement characteristics (nonenhancing, especially within the meatus)

Course (starts parallel to vestibulocochlear nerve)

Width (uniform, no right-left discrepancy, no circumscribed expansion)

Enhancement characteristics (nonenhancing)

Cochlea and •

Anatomy

semicircular •

Configuration

canals •

Smooth borders

Mastoid cells, •

Anatomy

mastoid antrum, •

Pneumatization

tympanic cavity •

Borders (wall thickness, smooth and continuous

contours)

No masses

Not opacified by material of soft-tissue or fluid

signal intensity

External auditory •

Anatomy

canal •

Course

Width

Borders

Cerebellopontine •

Brain stem:

angle area

— Shape

— Signal intensity (homogeneous)

— No focal abnormalities

Vestibulocochlear and facial nuclei (motor root

in medial eminence on floor of fourth ven-

tricle):

— No demyelination

— No masses

Sites of entry of vestibulocochlear nerve (enters

pons and medulla at lateral extension of medul-

lopontine sulcus) and facial nerve:

— Bilaterally symmetrical

CSF spaces:

— Cerebellopontine angle cistern (symmetrical,

fluid intensity)

— No masses

— Well delineated

— No vascular loops

Rest of neuro- •

Cerebrum (especially the temporal lobe) and

cranium

cerebellum:

— Configuration

— Sulcation

— Cortical markings (arbor vitae) not effaced

— No circumscribed narrowing or expansion

— Homogeneous signal intensity of cortex and white matter (no hypointense or hyper-intense changes)

— No circumscribed narrowing or expansion

— Homogeneous signal intensity of cortex and white matter (no hypointense or hyper-intense changes)

CSF spaces • Prepontine cistern

• Fourth ventricle

Important Data

1 Internal auditory canal:

• Approximately 5-10 mm

2 Difference between right and left internal auditory canals:

• Approximately 1 mm

Axial image

Coronal image

Orbit

The orbits are symmetrical and of normal size, with normal development of the orbital cones. The orbital walls show a normal configuration with smooth, sharp margins. No foci of bone destruction, no circumscribed expansion of the bony or soft-tissue components of the orbital wall are evident.

The globes are symmetrical and of normal size and position, and the ocular contents show normal signal characteristics. The ocular walls are smooth, sharply defined, and of normal thickness. The optic nerve has normal course and caliber on each side.

The eye muscles are normally positioned and display normal course and width. The retrobulbar fat, ophthalmic vein, and lacrimal gland are unremarkable.

Evaluable portions of the neurocranium and paranasal sinuses show no abnormalities.

Interpretation

The orbits and orbital contents appear normal.

Checklist Orbits

Globe

Shape (orbital cone) Size

Symmetry Orbital walls:

— Borders (smooth and sharp)

— No bone destruction

— No circumscribed expansion of bony or soft-tissue components of the orbital wall

Shape (spherical) Size (see below) Position (see below) Symmetry Ocular contents:

— Signal intensity (fluid-equivalent) Ocular wall:

— Borders (smooth and sharp)

— Thickness Retrobulbar fat (clear) No masses

Optic nerve Eye muscles

Ophthalmic vein Lacrimal gland

Neurocranium Paranasal sinuses

Caliber (see below)

Course

Position

Width (see below)

Course

Course

Caliber (see below) Size

Symmetry

No unilateral or bilateral enlargement Position (see below)

No excavation or destruction of adjacent bone

Homogeneous internal structure

No hypointense or hyperintense changes

Smooth borders

Temporal lobes

Frontal lobes

Maxillary sinuses

Ethmoid cells

Axial image through center of orbits

Important Data

1 Diameter of globe:

a Axial image plane: right 28.6 ± 1.2 mm left 29.4 ± 1.4 mm b Sagittal image plane: right 27.8 ± 1.2 mm left 28.2 ± 1.2 mm

Axial image through roof of orbit
Coronal image

2

Position of globe:

• Posterior margin of globe is 9.9 mm ± 1.7 mm behind in-

terzygomatic line

3

Optic nerve (axial image plane):

a Retrobulbar segment: 5.5 mm ± 0.8 mm

b Narrowest point (at approximately mid-orbit): 4.2 mm ±

0.6 mm

4

Eye muscles:

a Lateral rectus: 2.9 mm ± 0.6 mm

b Medial rectus: 4.1 mm ± 0.5 mm

c Superior rectus: 3.8 mm ± 0.7 mm

d Oblique: 2.4 mm ± 0.4 mm

e Inferior rectus: 4.9 mm ± 0.8 mm

f Levator palpebrae superioris: 1.75 mm ± 0.25 mm

5

Ophthalmic vein:

a 1.8 mm ± 0.5 mm (axial image, 4 mm slice thickness)

b 2.7 mm ± 1 mm (coronal image)

6

Lacrimal gland:

• Less than one-half of the gland is anterior to the frontozygo-

matic process

Sagittal image

Paranasal Sinuses

The frontal sinuses are normally developed, clear, and pneumatized with smooth wall contours.

The ethmoid cells show normal development and intact bony walls, with no defects on the orbital side. There are no areas of wall erosion or mucosal thickening.

The sphenoid sinus is normally developed and presents a coarse honeycomb structure. There are no fluid collections or mucosal swelling. The maxillary sinuses are bilaterally symmetrical and have smooth walls of normal thickness. The sinuses are clear and aerated with no foci of bone erosion or destruction. The nasal septum is centered on the midline. The nasal turbinates show a normal arrangement and normal signal intensity.

The nasal cavity, pharynx, and imaged parapharyngeal structures show no abnormalities.

Interpretation

The paranasal sinuses appear normal.

Checklist

Frontal sinuses

Ethmoid cells

Sphenoid sinus

Maxillary sinuses

Anatomy

Wall contours (smooth) Pneumatization Anatomy Pneumatization

Bony structures (especially bordering the orbit:

contours are smooth, sharp, and intact)

No wall erosion

No mucosal thickening

Anatomy (coarse honeycomb structure)

Clear and pneumatized

No fluid collection

No mucosal swelling

Bony structures (smooth, intact walls, no erosion)

No extrinsic wall indentations Anatomy

Size (bilaterally symmetrical)

Bony structures (smooth, intact contours, normal wall thickness, no bone erosion or destruction)

Nasal cavity

Pharynx and parapharyngeal structures

Neurocranium (especially the temporal and frontal lobes) Orbit

Pneumatization

No tooth roots projecting through sinus floor

Anatomy (symmetry)

Size

Aeration (clear)

Septum centered on the midline

Nasal turbinates (three per side: superior, middle, inferior) are normally developed

Signal characteristics

Anatomy (symmetry)

Size

Wall thickness No foreign bodies No masses Cortex

White matter Gyration

Signal characteristics

Eye muscles (width, signal characteristics) Optic nerve (width, course) Globe (shape, size, signal characteristics) Retrobulbar fat (no masses)

Coronal image

Important Data

1 Frontal sinus:

2 Sphenoid sinus:

3 Maxillary sinuses;

Axial image
Sagittal image

Cervical Soft Tissues

The cervical soft tissues show normal configuration. The position of the cervical spine is normal.

The oral floor muscles are normally developed and bilaterally symmetrical. The spaces of the oral cavity and neck are clear and well defined.

Imaged portions of the parotid and submandibular glands show no abnormalities.

The pharynx and larynx show normal boundaries and normal wall thickness.

The thyroid gland shows reasonable symmetry and normal size. The thyroid lobes display normal internal structure.

Cervical vessels that are evaluable with MRI have normal appearance.

The muscular structures of the neck are normal.

There are no signs of cervical lymphadenopathy.

No abnormalities are seen in the cervical spinal cord or cervical plexus.

Interpretation

The cervical soft tissues appear normal.

Retropharyngeal space —

Perivertebral space

(paraspinal portion)

Posterior -

cervical space

Spaces of

Retropharyngeal space —

Perivertebral space

(paraspinal portion)

Posterior -

cervical space

Anterior cervical space Carotid space

Perivertebral space (pre-vertebral portion)

Visceral space

Superficial space

Anterior cervical space Carotid space

Perivertebral space (pre-vertebral portion)

Visceral space

Superficial space

Checklist

Cervical soft tissues

Oral floor muscles

Submandibular and parotid glands

Pharynx and larynx

Cervical spaces

Esophagus

Thyroid gland

Configuration Normal anatomy

Normal position of the cervical spine (see below)

Anatomy

Width

Bilateral symmetry Delineation Internal structure

Spaces of oral floor are clearly defined

Size (symmetry)

Signal characteristics

No dilatation of glandular duct

No hypointense or hyperintense areas within the glandular tissue

Shape (symmetrical)

Size

Smooth walls Normal wall thickness No masses

Retropharyngeal space Parapharyngeal space (visceral space) Carotid space

Anterior and posterior cervical spaces Perivertebral space (prevertebral and paraspinal portions):

— Configuration

— Internal structure

— Width (see below) Position

Wall thickness (see below)

Borders

No masses

Anatomy (consists of two lobes, reasonably symmetrical) Size (see below)

Internal structure (homogeneous) No cysts No nodules

Cervical vessels

Neck muscles

Lymph node stations (if evaluable) Cervical spine (if evaluable)

Cervical plexus

Course

Caliber (see below)

No abrupt caliber changes

Anatomy

Symmetry

Borders

Signal characteristics (internal structure) No lymphadenopathy

Vertebral bodies

Bone marrow signal Intervertebral disk spaces Spinal canal:

— No circumscribed narrowing

Normal width of cervical spinal cord

No masses

No narrowing

No appreciable narrowing

No masses (including lymphadenopathy)

Important Data

Ch = Chamberlain's line (line connecting the posterior part of the hard palate with the posterior rim of the foramen magnum):

• Tip of the dens projects no more than 1 ± 6.6 mm past Chamberlain's line

Prevertebral soft tissues:

1 Retropharyngeal:

2 Retroglottic:

3 Retrotracheal:

Midsagittal image
Sagittal image

Lumina of upper respiratory tract (normal respiration):

4 Laryngeal inlet (hyoid level):

5 Glottis:

6 Trachea:

7 Dimensions of thyroid gland: a Length: 3.5-6 cm b Width: 1.5-2 cm c Depth: 1 -2 cm Vascular calibers (at level of thyroid gland):

8 Common carotid artery:

9 Esophagus:

Axial image
Coronal image

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