CT anatomy of Neck Spaces RV

CT anatomy of neck spaces describing suprahyoid and infrahyoid neckspaces

1. Dr Roshan Valentine PG Resident Dept of Radiodiagnosis St Johns Medical College CT ANATOMY OF NECK SPACES

2. NORMAL ANATOMY Neck has a complex anatomy Compartmentalisation of anatomic structures Superiorly : Mandible & mylohyoid anteriorly Skull base posteriorly Inferiorly: Thoracic inlet centrally Scapula posteriorly

3. INTRODUCTION Clinicians : anterior and posterior triangles Anatomists : pioneered the work on fascial spaces and anatomy Cross sectional imaging helped clinicians , anatomists and surgeons in dividing it into fascial compartments

4. Basis for dividing neck into spaces and compartments : arrangement of superficial and deep layers of cervical fascia The i mportance of this spaces is that they may limit to some degree the spread of most infections and some tumors A proper understanding of their anatomy will also aid in the diagnosis of various conditions INTR0DUCTION

5. NECK SPACES Described in relation to the hyoid bone. Suprahyoid Spaces. Infrahyoid Spaces. Spaces extending up to the entire length of the neck.

6. SUPRAHYOID SPACES Sublingual Space. Submandibular Space. Buccal Space. Masticator Space. Parotid Space. Pharyngeal mucosal Space. Parapharyngeal Space

7. INFRAHYOID SPACES Visceral Space. Anterior cervical Space. Posterior cervical Space.

8. SPACES COMMON TO BOTH Carotid Space. Retropharyngeal Space. Prevertebral Space. Danger Space.

9. CERVICAL FASCIAE

10. SUPERFICIAL FASCIA Composed of subcutaneous tissues that encircle the neck like a collar. Encircles the deep fascia Components: Platysma and muscles of facial expression. Subcutaneous veins , nerves and fat Superficial lymph nodes.

11. SUPERFICIAL LAYER/INVESTING LAYER Complete collar around the neck Attachments Splits to cover SCM and Trapezius Capsule : parotid and Submandibular gland Spaces : Masticator space ,parotid space, submandibular space and sublingual space. DEEP CERVICAL FASCIAE

12. SUPERFICIAL LAYER/INVESTING LAYER

13. MASTICATOR SPACE Formed by splitting of the SLDCF. Extends from skull base to the inferior edge of the mandible. Contents: mandible, muscles of mastication, and mandibular division of the V th nerve.

14. MASTICATOR SPACE M T L

15. PAROTID SPACE Boundary : Investing fascia(SLDCF) splitting at the angle of mandible. Extends : Superiorly external acoustic meatus Inferiorly up to the mandible. Contents : Parotid Gland, proximal part of the parotid duct, intraparotid lymph nodes and vessels. Parotid gland is divided by facial nerve into superficial and deep. Division identified on imaging by retromandibular vein.

16. PAROTID SPACE

17. PAROTID SPACE

18. PAROTID SPACE

19. SUBMANDIBULAR SPACE Extend : Mylohoid superiorly & hyoid bone inferiorly. C ommunicates freely with sublingual space. Contents : superficial portions of the Submandibular gland,submental and submandibular LNs, facial artery and vein, fat and ant belly of digastric.

20. SUBMANDIBULAR SPACE

21. SUBMANDIBULAR SPACE

22. Extent : Above the m ylohyoid muscle Contents : Sublingual gland and their ducts , LNs, hypoglossal muscle , lingual artery and vein , hypoglossal N and deeper portion of submandibular gland. SUBLINGUAL SPACE

23. SUBLINGUAL SPACE

24. Visceral / pretracheal layer Extent: Hyoid bone to sup mediastinum SHN : Continues as buccopharyngeal fascia(BPF) Contents : Trachea, esophagus , larynx , thyroid and parathyroid gland Spaces : Pharyngeal mucosal space , retropharyngeal space , parapharyngeal space and buccal space MIDDLE LAYER OF DCF

25. MIDDLE LAYER OF DCF

26. MIDDLE LAYER OF DCF- SPACES

27. PHARYNGEAL MUCOSAL SPACE Located on the airway side of the Buccopharyngeal fascia in the nasopharynx and oropharynx . No fascial boundaries on the airway side. Extend from skull base to the Cricoid cartilage. Contents : Mucosa, lymphoid tissue of Waldeyer’s ring, minor salivary glands, and pharyngeal constrictor muscles .

28. PHARYNGEAL MUCOSAL SPACE

29. PARAPHARYNGEAL SPACE Central fat filled spaces in lateral SHN. Extends on the either side of neck from the skull base to the submandibular space inferiorly Surrounded by PMS , MS , PS , CS AND RPS.

30. Contents : Mainly fat , pharyngeal venous plexus , Mandibular N , Int mammary A , ascending pharyngeal artery. Direction of displacement of PPS – space of origin of the lesion PARAPHARYNGEAL SPACE

31. PARAPHARYNGEAL SPACE

32. BUCCAL SPACE Extent : Medially - Buccinator and max alveolar ridge Post Laterally : Masticator space Contents: Buccal fat pad

33. BUCCAL SPACE

34. Extent : Skull base to T4 level 2 parts Ant : True RPS Post : Danger space Contents : SHN : LN and fat IHN : Fat pathway for spread of infections / tumors into the mediastinum from the neck . RETROPHARYNGEAL SPACE

35. RETROPHARYNGEAL SPACE

36. RETROPHARYNGEAL SPACE

37. DANGER SPACE Posterior to the RPS. Bounded by the Alar fascia anteriorly and Prevertebral portion proper posteriorly . Extend s from the skull base up to the diaphragm. Content : loose areolar tissue which provides easy pathway for the spread of infections.

38. Extent : skull base to superior mediastinum T4 level. Encircles : Paravertebral and paraspinal muscles, vertebral body , vertebral A and Vn , phrenic nerve and brachial plexus trunk Spaces : involve both SHN and IHN – CS , RPS, DS , PVS and posterior cervical space. : Involving only IHN - Visceral spaces and anterior cervical space DEEP LAYER OF DCF( Prevertebral fascia)

39. Paired tubular structure traversing SHN and IHN Skull base to superior mediastinum Lateral to RPS Enveloped by carotid sheath : all 3 layers of DCf Contents : SHN – ICA IJV , CN9-12, :IHN - CCA, IJV , CN10 trunk ( vagus ) CAROTID SPACE

40. CAROTID SPACE

41. CAROTID SPACE IHN SHN

42. CAROTID SPACE

43. Posterior midline space of SHN and IHN Enclosed by deep layer of DCF Extent : base of skull to level of coccyx 2 compartments : Prevertebral and Paraspinal PERIVERTEBRAL SPACE

44. PERIVERTEBRAL SPACE- CONTENTS

45. CERVICAL SPACES ANTERIOR CERVICAL SPACE : Hyoid to clavicle Content : Only fat POSTERIOR CERVICAL SPACE : Extend from the skull base to the clavicles . Deep and posterior to sternocledomastoid Content : fat, spinal accessory nerves and spinal accessory chain of deep cervical lymph nodes.

46. CERVICAL SPACES

47. CERVICAL SPACES

48. SUPRAHYOID SPACES INFRAHYOID SPACES

49. INFRAHYOID SPACES