2. Neck anatomy.
Superficial neck structures.
nasopharynx
oropharynx
oral cavity
Deep neck structures.
The deep anatomy is separated by fascial planes into seven
deep compartments of the head and neck:
pharyngeal (superficial) mucosal space
parapharyngeal space
parotid space
carotid space
masticator space
retropharyngeal space
perivertebral space
39. Neck Spaces
• Infrahyoid neck spaces:
– Visceral space
– Posterior cervical space
– Anterior cervical space
– Retropharyngeal space
– Prevertebral space
– Carotid space
63. Fig. 1. Suprahyoid neck anatomy: (A) Sagittal T1-weighted midline image of the neck demarcating the
level of the hyoid bone (blue line), separating the suprahyoid neck above from the infrahyoid neck below.
Other colored lines demarcate the various levels listed below (red line, B; orange line, C; yellow line, D;
green line, E). (B) Axial T2- weighted image at the skull base: the cephaled-most aspect of the masticator
space (red outline) extends superior to the zygomatic arch (arrow). Any disease process that occurs in
this space warrants evaluation superiorly to the aponeurosis of the temporalis muscle (T) along the
calvarium. GS, greater wing of sphenoid; Max, maxillary sinus; m, mandible; asterisk, pterygopalatine
fossa. (C) Axial T1-weighted image more inferiorly at the alveolar ridge: The parapharyngeal space (PPS,
black outline) is readily apparent as a T1 hyperintense region, relating to its fat content. Anterolateral is
the masticator space (red border) containing the masseter (M), lateral pterygoid (lp), and medial
pterygoid (mp) muscles. The buccal space is located just anterior to the masticator space (B, asterisk
border). Lateral to the parapharyngeal space is the parotid space (green border), which encompasses the
isointense gland itself along with the retromandibular vein (v) within the substance of the parotid
parenchyma. The carotid space encompassing the internal carotid artery (IC) and internal jugular vein
(IJ) provides an additional lateral border to the PPS. Note the T1 isointense mucosal space medial to the
PPS, including the torus tubaris (arrow). Posteriorly is the perivertebral space (yellow border) containing
the longus colli muscle. (D) Axial T2-weighted image more inferiorly at the level of the oropharynx: Note
the continuation of the masticator space (red outline) containing the mandible (m) and masseter (M).
The parotid (green border) and parapharyngeal spaces have tapered down. The perivertebral space
(yellow outline) is again noted, located just dorsal to the retropharyngeal space (blue border). Ton,
palatine tonsils; IJ, internal jugular vein; IC, internal carotid artery; v, retromandibular vein; LC, longus
colli. (E) Axial T1-weighted image at the level of the submandibular glands and hyoid bone (labeled): As
the other suprahyoid neck spaces continue to taper down, the submandibular space appears (orange
outline). This is bordered medially and superiorly by the isointense mylohyoid muscle (labeled) and
contains the submandibular gland (labeled) as well as fat. The median raphe of the tongue is denoted by
an arrow and the epiglottic valeculla can be seen posteriorly (v).
66. Fig. 2. Coronal T1-weighted imaging of the suprahyoid neck at several levels. (A) Just dorsal
to the mandibular mentum, the sublingual glands (slg) are present between the mylohyoid
(mylo) and genioglossus (GG) muscles. They are of increased signal intensity in comparison
with muscle. Inferior to the mylohyoid muscle is the anterior belly of the digastric (Dig). The
fatty T1-hyperintense median raphe of the tongue is present superiorly between the
genioglossus muscles (white arrow). Just inferior to the hard palate (white arrowheads),
which is hyperintense because of marrow fat, is the apposed tongue surface with intrinsic
musculature (labeled) noted. The buccal mucosa and buccinator musculature are noted along
the lateral border of the oral cavity (black arrow). Max, maxillary sinus. (B, C) More
posteriorly, the masticator space is noted with the masseter (Masseter) and temporalis
(Temp) muscles now identified (labeled) along with the T1 hyperintense zygomatic arch (Z).
The buccal fat/space is well demonstrated (Buc) and the geniohyoid muscle (GH) is noted
along the floor of the mouth. Stensen duct is present lateral to the buccal mucosa (black
arrowhead) and the parotid gland comes into view (black arrow). (D) At the level of the nasal
choana, the oral cavity structures are again well seen, including the mylohyoid muscle, which
divides the submandibular space inferiorly from the sublingual space superiorly. The
hyoglossus muscle is noted along the lateral margin of the tongue, providing the medial
margin of the sublingual space. Within the masticator space, the medial and lateral
pterygoids are identifiable (mp, lp). The soft palate (labeled) is also now noted. (E) At the
level of the mandibular rami, the submandibular glands (SMG) are visualized inferiorly as are
the parotid glands (PG) superiorly. Posterior and medial to the masticator space is the fat
filled, T1-hyperintense parapharyngeal space (PPS). The longus colli (LC) muscles of the
prevertebral space are well seen, as are the lingual (labeled) and palatine tonsils (PT).
69. Fig. 3. Imaging of the infrahyoid neck. (A) Sagittal T1-weighted image demonstrates
the geniohyoid (labeled) and genioglossus (GG) muscles along the floor of the mouth,
attaching to the T1-hyperintense mandible (M). The intrinsic tongue muscles (ITM) lie
essentially apposed to the hard (black arrow) and soft (SP) palates. The epiglottis (white
arrow) lies posterior to the vallecula (v). The air-filled T1-hypointense trachea (T) is
noted inferiorly. Posteriorly, the vertebrae are noted (C2 and T1 labeled). (B) Coronal T1-
weighted image highlights the false (black arrow) and true (white arrow) vocal cords,
with a small amount of T1-hyperintense fat noted along the false cord. The hyoid bone
is visualized (labeled) and the mylohyoid (MH), mandible (M), and masseter (Mass)
muscle are seen. (C, D) Axial T1-weighted image through the larynx. Superior image (C)
demonstrates the false vocal cords (black arrow) with the paired, air-filled T1
hypointense pyriform sinuses noted posteriorly (asterisk). Subjacent to the
sternocleidomastoid muscle are the common carotid artery (cc), internal jugular vein
(IJ), and jugular chain lymph nodes (N). The vertebral artery (v) is noted traversing the
foramen transversarium, whereas the spinal cord (SC) is noted posteriorly. Inferiorly, (D)
the true cords (v) are noted with a portion of the cricoid cartilage seen posteriorly (C).
(E) Axial T2-weighted fat-suppressed image at the same level. Most of the neck tissues
lose signal. A few small nodes are again present (circled) and a venous plexus is noted
along the spinal column (arrowhead). The T2-hyperintense cerebrospinal fluid surrounds
the spinal cord. (F) Axial T1-weighted image at the level of the thyroid gland (Thy). The
thyroid borders the trachea and the esophagus (E). The brachial plexus (asterisk) is
noted traveling between the anterior (AS) and middle (MS) scalene muscles.
71. Brachial plexus imaging.
Brachial plexus imaging. (A–C) Sagittal T1-weighted imaging of the brachial plexus. (A) Along the lateral aspect of
the cervical spine, the originating nerve roots can be seen as they exit the neural foramina (circles). (B) As the
plexus forms (circled), it can be seen posterior to the anterior scalene muscle (white arrow) and superior to the
subclavian artery (black arrow). (C) Laterally, the plexus (circled) is best seen superior to the axillary artery (black
arrow). (D, E) Coronal T1-weighted (D) and STIR (E) imaging of the plexus. Note the plexus descending through the
thoracic inlet (white arrowheads). (F) Axial T2-weighted image at the thoracic inlet demonstrates bilateral plexi
(white arrows) traveling posterior to the anterior scalene (AS). Midline trachea (T) and esophagus (E) are present
and the spinal cord is noted centrally (black arrow).
72. Contrast-enhanced MR angiogram of the
neck was obtained and presented as MIP
images (A, anteroposterior view; B,
oblique). The aortic arch most commonly
gives rise to 3 great vessels: the
innominate (or brachiocephalic) artery
(IA), the left subclavian artery (LSA), and
the left common carotid artery (LCC). The
right common carotid artery (RCC) arises
off of the innominate distally. Both
common carotids travel anteriorly within
the carotid space of the neck and
bifurcate (white arrows) at
approximately the level of the hyoid bone
into external (black arrowhead) and
internal carotid arteries (ICA, white
arrowhead). The vertebral arteries (black
arrows) are typically the first branches
off of the subclavian arteries and ascend
posteriorly along the transverse
foramina, entering the skull base through
the foramen magnum.