1. Head and Neck Anatomy
Jake Pickering MS IV

2. Suprahyoid Neck Skull Base to Hyoid Bone (the different spaces)
Parapharyngeal Space
Pharyngeal Mucosal Space
Masticator Space
Parotid Space
Carotid Space
Retropharyngeal Space
Perivertebral Space
Posterior Cervical Space

3. Suprahyoid Spaces

4. Suprahyoid Spaces

5. Suprahyoid Spaces

6. Lateral Neck

7. CT of Suprahyoid Spaces

8. CT of Suprahyoid Spaces

9. CT of Suprahyoid Spaces

10. CT of Suprahyoid Spaces

11. Parapharyngeal Space Internal structures Fat Minor salivary glands
Internal maxillary artery
Ascending pharyngeal artery
Pterygoid venous plexus

12. Parapharyngeal Space

13. Parapharyngeal space

14. Parapharyngeal Space

15. Parapharyngeal Space Clinical implications
Direct extension from neoplasm
From pharyngeal mucosal space (see neoplasm differential for pharyngeal mucosal space)
From masticator space (see neoplasm differential)
From parotid space (see neoplasm differential)
Direct extension from abscess
Tonsillar abscess
Acute Parotiditis
Primary lesion
Lipoma
Venolymphatic malformation

16. Pharyngeal Mucosal Space
Internal structures
Minor salivary glands
Torus tubarius: Cartilaginous end of eustachian tube
Muscles
Superior, middle and inferior constrictor muscles
Salpingopharyngeus muscle
Levator palatini muscle
Lymphatic ring (Waldeyer ring)
Nasopharynx: Adenoids
Oropharynx: Palantine tonsil
Oropharynx: Lingual tonsil

17. Pharyngeal Mucosal Space

18. Torus tubarius
Pharyngeal mucosal space
Adenoids

19. Lingual tonsil
Pharyngeal muscoal space
Palantine tonsil

20. Axial T1 MR

21. Nasopharyngeal mucosal space
Oropharyngeal mucosal space
Hypopharyngeal mucosal space

22. Pharyngeal Mucosal Space
Clinical Implications
Differential diagnosis of lesion in Nasopharyngeal space
Adenoid inflammation
Tornwaldt cyst
Retention cyst
Nasopharyngeal carcinoma
Non-Hodgkin lymphoma
Benign mixed tumor (uncommon)
Post-radiation mucositis (uncommon)
Minor salivary gland malignancy (rare)
Rhabdomyosarcoma (rare)
Extraosseous chordoma (rare)

23. Pharyngeal Mucosal Space
Clinical implications
Differential diagnosis of lesion in oropharynx space
Squamous cell carcinoma
Non-hodgkin lymphoma
Retention cyst
Palantine tonsil abscess
Tonsillar inflammation
Thryoglossal duct cyst (uncommon)
Post-radiation mucositis (uncommon)
Vallecular cyst (uncommon)
Minor salivary gland malignancy (uncommon)
Rhabdomyosarcoma (rare)

24. Masticator Space Internal contents Muscles of Mastication
Masseter
Temporalis
Medial pterygoid
Lateral pterygoid
Mandibular division, trigeminal nerve (V3)
Masticator nerve branch
Mylohyoid nerve branch
Lingual nerve
Inferior alveolar nerve branch
Ramus and posterior body of mandible
Pterygoid venous plexus

25. Masticator Space

26. Masseter muscle
Masticator Space
Temporalis muscle
Lateral pterygoid muscle
Medial pterygoid muscle

27. Axial T1 MR

28. Masticator Space Clinical Implications Trismus
Differential diagnosis of masticator space lesion
Abscess
Benign masticator muscle hypertrophy
Metastasis
Sarcoma
Osteosarcoma
Chondrosarcoma (uncommon)
Perineural tumor CNV3 (uncommon)
Schwannoma (uncommon)
Odontogenic keratocyst (uncommon)
Osteoradionecrosis (uncommon)
Pigmented villonodular synovitis (rare)
Synovial chondromatosis (rare)
Dentigerous cyst (rare)

29. Parotid Space Internal structures Parotid Gland Facial Nerve (CN7)
External carotid artery
Retromandibular vein
Intraparotid lymph nodes
Parotid Duct
Accessory parotid glands (20% of population)

30. Parotid space (green)

31. Parotid Space

32. External carotid artery
Parotid space
Retromandibular vein
Parotid gland

33. Axial T1 MR

34. Parotid Space Clinical Implications Other masses in parotid space
Parotid Tumors benign mixed tumor (75%)
Warthin tumor (5%)
Adenoid cystic carcinoma (5%)
Mucoepidermoid carcinoma (5%)
Other (10%)
Other masses in parotid space
Salivary gland malignancies (uncommon)
Non-Hodgkin lymphoma (uncommon)
Schwannoma (uncommon)
Infantile hemangioma (uncommon)
Lipoma (uncommon)
Oncocytoma (rare)
Venous malformation (rare)
Lymphatic malformation (rare)
1st Branchial cleft cyst (rare)
Rhabdomyosarcoma (rare)

35. Carotid Space Internal structures Suprahyoid Internal carotid artery
Internal jugular vein
Cranial nerves 9-12
Sympathetic plexus

36. Carotid Space

37. Carotid Space

38. External carotid artery (not in carotid space)
Internal carotid artery
Carotid space
Internal jugular vein

39. Carotid Space Clinical implications
Differential diagnosis of carotid space lesion
Reactive lymph nodes
Atherosclerosis of carotid artery
Thrombosis of jugular vein
Squamous cell carcinoma
Dissection of carotid artery
Paraganglioma of carotid body
Schwannoma
Neurofibroma (uncommon)
Hodgkin and Non-Hodgkin lymphoma (uncommon)
Meningioma (rare)
Pseudoaneurysm of carotid artery (rare)
Metastases (rare)
Acute Idiopathic carotidynia (rare)
CN 9-12 neuropathy
Vagus Nerve injury- vocal cord paralysis

40. Retropharyngeal Space
Internal Structures
Suprahyoid
Fat
Lymph nodes (none below hyoid)
Lateral group (nodes of Rouviere)
Medial group

42. Retropharyngeal space

43. Retropharyngeal space

44. Retropharyngeal Space
Clinical Implications
Differential diagnosis of focal lesion
Reactive adenopathy
Suppurative adenopathy
Squamous cell carcinoma
Metastatic node
Non-Hodgkin lymphoma
Tortuous carotid artery
Multinodular goiter (uncommon)
Lipoma (uncommon)
Schwannoma (rare)
Ectopic parathryoid adenoma (rare)

45. Retropharyngeal Space
Clinical Implications
Differential diagnosis of diffuse space lesion
Abscess
Effusion
Longus colli tendonitis (uncommon)
Venous malformation (uncommon)
Lymphatic malformation (uncommon)
Multinodular goiter (uncommon)
Lipoma (rare)

48. Perivertebral Space Internal structures
Prevertrebral muscles-longus colli and capitis
Scalene muscles
Phrenic nerve
Vertebral artery and vein
Vertebral body
Paraspinal muscles
Brachial plexus

49. Perivertebral Space

50. Perivertebral space
Prevertebral portion of the perivertebral space
Paraspinal portion of the perivertebral space

51. Perivertebral Space

52. Perivertebral Space Clinical implications
Differential diagnosis of perivertebral space lesion
Vertebral body metastasis
Infection
Schwannoma of brachial plexus
Longus colli tendinitis
Chordoma (uncommon)
Venous malformation (uncommon)
Lipoma (uncommon)
Non-Hodgkin lymphoma (uncommon)
Lymphatic malformation (rare)
Fibromatosis (rare)
Hemangiopericytoma (rare

53. Posterior Cervical Space
Internal structures
Fat is primary occupant
Accessory nerve (CNII)
Spinal accessory lymph node chain
Pre-axillary brachial plexus
Dorsal scapular nerve

54. Posterior Cervical Space

55. Posterior Cervical Space

56. Posterior cervical space

57. Posterior Cervical Space
Clinical implications
Differential diagnosis of cervical space lesion
Reactive lymph nodes
Squamous cell carcinoma
Non-hodgkin lymphoma
Suppurative lymph node
Thyroid carcinoma
Abscess (uncommon)
Metastases (uncommon)
Sarcoidosis (uncommon)
Tuberculosis (uncommon)
Lipoma (uncommon)
Venous Malformation (uncommon)
Schwannoma (rare)
Liposarcoma (rare)
Sinus histiocystois
3rd Branchial cleft cyst
Giant lymph node hyperplasia

58. References
Harnsberger HR, Osborn AG, Ross JS. Diagnostic and Surgical Imaging Anatomy: Brain, Head and Neck, Spine. 1st edition. Salt Lake City: Amirsys, 2006.
Harnsberger HR, Koch BL, Phillips CD. EXPERTddx: Head and Neck. 1st edition. Salt Lake City: Amirsys, 2009.
Neck CT. Retrieved Sept