Cross sectional anatomy of neck spaces

anatomy of neck , cross sectional anatomy ,radi0logy of neck

1. CROSS SECTIONAL ANATOMY OF NECK SPACES Dr Raman Ghimire Resident Radiology NAMS

2. INTRODUCTION The neck is composed of : Cervix(anteriorly )-means “neck ”: cylinder of soft tissue Nucha (posteriorly) :vertebral column and its associated musculature Extent: Superior: line connecting the occiput and the tip of the chin Inferior : course of the first rib at the thoracic inlet . The neck has a complex anatomy where many critical anatomic structures are compartmentalized into a small space. The traditional classification of the head and neck into nasopharynx , oropharynx and hypopharynx is useful in the evaluation of superficial mucosal lesions but is much less helpful in localizing deep-seated head and neck lesions. Clinicians divide the superficial structures of the neck into anterior and posterior triangles using superficial musculature as landmarks. cross sectional anatomy of neck spaces 2 8/27/2021

3. Sagittal T2-weighted image of the extracranial head and neck showing the division of the anatomical and functional units of the upper aerodigestive tract cross sectional anatomy of neck spaces 3 8/27/2021

4. cross sectional anatomy of neck spaces 4 8/27/2021

5. cross sectional anatomy of neck spaces 5 8/27/2021

6. FASCIA AND SPACES Anatomists pioneered the work on fascial anatomy and spaces. With the advent of cross-sectional imaging clinicians, surgeons and radiologists adopted the spatial organization of the head and neck into fascial compartments. The basis for dividing the neck into spaces and compartments is the arrangement of the superficial and deep layers of the cervical fascia . The importance of these spaces is that they limit to some degree the spread of most infections and some tumors. This concept can be used to formulate differential diagnosis, determine the extent of disease and facilitate surgical and therapy planning. cross sectional anatomy of neck spaces 6 8/27/2021

7. FASCIAE OF NECK cross sectional anatomy of neck spaces 7 8/27/2021

8. Superficial cervical fascia (SCF) L ayer of fatty loose connective tissue that encircles the neck like a collar. Encircles the deep fascia. Contains: P latysma muscles Muscles of facial expression Subcutaneous nerves and lymphatics P ortions of the anterior and external jugular veins cross sectional anatomy of neck spaces 8 8/27/2021

9. Deep cervical fascia (DCF) Made up of thinner but denser, better-defined layers. Superficial layer (SLDCF) Middle layer (MLDCF) Deep layer (DLDCF) All three layers contribute to the carotid sheath. cross sectional anatomy of neck spaces 9 8/27/2021

10. S uperficial layer of deep cervical fascia (SLDCF )/ Investing layer F orms a complete collar around the neck and envelops the sternocleidomastoid, trapezius and attaches to the skull base, mandible, hyoid, clavicle , sternum and scapula . Capsule : parotid and submandibular gland Spaces: Masticator space (including Buccal space ) Submandibular space (sub mental,sub lingual , submaxillary sapce ) Parotid space cross sectional anatomy of neck spaces 10 8/27/2021

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12. Caudally in the midline the SLDCF splits into two layers enclosing the manubrium. This creates the variably sized suprasternal space of Burns (or Gruber ). Contains fat and a communicating vein between the left and right anterior jugular veins. cross sectional anatomy of neck spaces 12 8/27/2021

13. Middle layer of deep cervical fascia (MLDCF ) /Visceral/Pre-tracheal layer The MLDCF encloses the anterior neck. Extent: IHN: from hyoid bone to superior mediastinum. SHN: continues as buccopharyngeal fascia and encloses naso /oropharynx Muscular part: encases the infrahyoid strap muscles Visceral part : envelops the trachea, larynx, pharynx, esophagus, and the thyroid gland cross sectional anatomy of neck spaces 13 8/27/2021

14. Spaces: Pharyngeal mucosal space . Parapharyngeal space . Visceral space Retropharyngeal space (along with DLDCF) cross sectional anatomy of neck spaces 14 8/27/2021

15. Deep layer of deep cervical fascia (DLDCF) / Prevertebral layer DLCF extends from the skull base to the T4 vertebra where it fuses with the anterior longitudinal ligament in the posterior mediastinum. The deep layer encircles the vertebrae , paravertebral and paraspinal muscles, vertebral artery and vein, phrenic nerve and trunks of the brachial plexus . The vertebrae are completely enclosed by this layer which attaches firmly to the transverse processes dividing the space into an anterior prevertebral and posterior paraspinal portion. Anteromedial to the scalene muscles, the deep layer splits into two leaves; the ventral leaf being the alar fascia , and the dorsal leaf being the prevertebral fascia   Alar layer blends with the visceral layer along the posterior margin of the esophagus at the level between the C6 and T4 vertebrae ; the prevertebral layer extends from the skull base to the coccyx. cross sectional anatomy of neck spaces 15 8/27/2021

16. This fascia separates the lower neck from the thorax and is called Sibson’s fascia. Spaces : Perivertebral space Danger space Retropharyngeal space (MLDCF+DLDCF) Carotid space . (all 3 layers) cross sectional anatomy of neck spaces 16 8/27/2021

17. SPACES OF NECK cross sectional anatomy of neck spaces 17 8/27/2021

18. SPACES OF SUPRAHYOID NECK cross sectional anatomy of neck spaces 18 8/27/2021

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20. SPACES OF INFRAHYOID NECK cross sectional anatomy of neck spaces 20 8/27/2021

21. MASTICATOR SPACE Paired Suprahyoid space Enclosed within SLDCF Contains : Ramus and body of mandible Trigeminal nerve(mandibular division) Muscles of mastication . MS PPS PS cross sectional anatomy of neck spaces 21 8/27/2021

22. Contents Pathology Muscle Rhabdomyosarcoma CN V3 Schwannoma,neurofibroma Mandible Dental tumors ,cysts ,abscesses and osteomyelitis. Vessels Hemangiomas , lymphangiomas Fat Lipoma Extension of SCC 8/27/2021 cross sectional anatomy of neck spaces 22 Masticator space malignancy or infection can spread perineurally via the foramen ovale and along the course of the mandibular division of the trigeminal nerve into the middle cranial fossa. 

23. PAROTID SPACE Paired Suprahyoid space Enclosed within SLDCF cross sectional anatomy of neck spaces 23 8/27/2021

24. Contents Pathology Parotid Parotitis , Hemangiomas ,Calculi Benign tumors:pleomorphic adenomas, Warthin’s tumors Malignant tumors: Mucoepidermoid carcinoma CN VII Nerve sheath tumor Embryological First branchial cleft cysts Fat Lipoma Lymph node Lymphoma 8/27/2021 cross sectional anatomy of neck spaces 24

25. 8/27/2021 cross sectional anatomy of neck spaces 25 SUBMANDIBULAR SPACE Paired Suprahyoid space Enclosed within SLDCF   S ubmental space and sublingual space also considered within SMS as these spaces communicate freely Anatomy of the submandibular and sublingual spaces in the coronal plane: picture illustration and T2-weighted MR image

26. Contents Pathology Submandibular gland Sialolithisis and  sialadenitis Benign: pleomorphic adenomas, malignant masses : mucoepidermoid and adenocystic carcinomas Sub mental Ia /submandibular Ib Lymph nodes Lymphoma , Metastasis,TB Facial artery /vein Vascular malformations Embryological Branchial cleft cysts, cystic hygromas , dermoids , epidermoids and thyroglossal duct cysts Fat Lipoma,liposarcoma Ranula Abscess, ludwig angina Squamous cell carcinoma extension cross sectional anatomy of neck spaces 26 8/27/2021

27. PHARYNGEAL MUCOSAL SPACE(PMS) Single midline Suprahyoid space Enclosed within MLDCF PMS is the area of nasopharynx and oropharynx on the inner side of the buccopharyngeal fascia. M ore inferior hypopharynx is in the visceral space of the infrahyoid neck , which is an inferior continuation of the PMS cross sectional anatomy of neck spaces 27 8/27/2021

28. PMS PPS RPS cross sectional anatomy of neck spaces 28 8/27/2021

29. Contents Pathology Squamous mucosa SCC Tornwaldt cyst lymphoid tissue of Waldeyer's ring Tonsillitis , Peritonsillar abscess non-Hodgkin’s lymphoma (NHL) Minor salivary glands Benign and malignant tumor Pharyngeal constrictor muscle Cartilaginous portion of the  Eustachian tube Juvenile Angiofibroma cross sectional anatomy of neck spaces 29 8/27/2021

30. 8/27/2021 cross sectional anatomy of neck spaces 30 PARAPHARYNGEAL SPACE(PPS) Paired Suprahyoid space Enclosed within MLDCF Its a inverted pyramid space from inferior surface of petrous bone to the hyoid bone

31. CONTENTS Pathology Fat Lipoma Vessels: pharyngeal venous plexus, internal mammary artery and ascending pharyngeal artery Branch of mandibular nerve Trigeminal schwannoma Minor or ectopic salivary gland/rests Salivary gland tumor pleomorphic adenoma Embryological Cystic hygroma / lymphangioma second branchial cleft cyst Parapharyngeal abscess cross sectional anatomy of neck spaces 31 8/27/2021

32. cross sectional anatomy of neck spaces 32 VISCERAL SPACE The visceral space includes all structures within the confines of the MLDCF . The visceral space extends from the hyoid bone superiorly to the superior mediastinum (level of aortic arch / T4 Infrahyoid continuation of PMS 8/27/2021

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34. RETROPHARYNGEAL SPACE Boundaries: Anterior: MLDCF P osterior:DLDCF (alar) Extends from the skull base upto T4 level . Contents: Suprahyoid RPS : N odes and fat Infrahyoid RPS : fat cross sectional anatomy of neck spaces 34 8/27/2021

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36. DANGER SPACE (DS) The DS is formed by the splitting of the deep layer into an anterolateral alar slip and a posterior prevertebral portion. Boundaries : Anterior : Alar fascia Posterior: Prevertebral fascia Superior:   clivus I nferior:  posterior  mediastinum at the level of the diaphragm Contents :Small amount of loose fatty connecctive tissue In healthy patients, it is indistinguishable from the retropharyngeal space cross sectional anatomy of neck spaces 36 8/27/2021

37. cross sectional anatomy of neck spaces 37 8/27/2021

38. PERIVERTEBRAL SPACE(PVS) P osterior midline space Enclosed by DLDCF Extends from the base of the skull to the level of coccyx (SHN+IHN) Prevertebral space: prevertebral and scalene muscle, roots of brachial plexus ,vertebral bodies and pedicles, phrenic nerve,the vertebral arteries and veins . P araspinal Space: paraspinal musculature, vertebral laminae and spinous processes. cross sectional anatomy of neck spaces 38 8/27/2021

39. cross sectional anatomy of neck spaces 39 8/27/2021   A.Contrast -enhanced axial CT shows fluid in RPS and posterior displacement of the longus capitis muscles (B) Axial contrast-enhanced axial CT shows anterior displacemnet of longus capitis muscles with fluid collection within the prevertebral space

40. Prevertebral soft tissue thickness(PVST): RPS and PVS should not exceed >7 mm at C2 for adult and children C6 soft-tissue space should no be >4 mm (children) and >22 mm for (adults) A 24-year-old patient after a motor vehicle crash with closed head injury; no fracture was identified in the cervical spine or craniocervical junction.  A , Midsagittal MDCT image of the cervical spine demonstrates abnormal PVST thickening at C1 and C2 ( asterisks ).  B , Correlation with midsagittal short τ inversion recovery MR image obtained the next day confirms the presence of extensive PVST edema and/or hematoma in this region ( arrowheads ). cross sectional anatomy of neck spaces 40 8/27/2021

41. cross sectional anatomy of neck spaces 41 8/27/2021

42. CAROTID SPACE   Carotid space is a paired space defined by the carotid sheath. Carotid sheath is formed by all three layers of DCF. This space extends from the skull base to the aortic arch at the thoracic inlet/T4. The suprahyoid CS is also known as the poststyloid PPS . Contents: SHN: CN IX-XII, ICA,IJV I HN : CN X , CCA,IJV cross sectional anatomy of neck spaces 42 8/27/2021

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44. POSTERIOR CERVICAL SPACE   Fat filled deep spaces of the neck located posterolaterally . P osterolateral part of the neck extending from the mastoid tip and base of skull to the  clavicles M ost of the volume is in the infrahyoid neck, with some extension into the suprahyoid neck  . B etween   SLDCF and DLDCF Lesion in PCS typically cause anteromedial displacement of the carotid space and posteromedial displacement of the prevertebral space cross sectional anatomy of neck spaces 44 8/27/2021

45. cross sectional anatomy of neck spaces 45 8/27/2021

46. ANTERIOR CERVICAL SPACE The  anterior cervical space  is a small infrahyoid compartment of the head and neck . It is a fat containing space and is not enclosed by fascia. Content : Fat Pathology : lipoma , second branchial cleft cyst cross sectional anatomy of neck spaces 46 8/27/2021

47. REFERENCES CT AND MR IMAGING OF THE WHOLE BODY;6 TH EDITION GRAINGER & ALLISON’S DIAGNOSTIC RADIOLOGY; 6 TH EDITION https:// radiologyassistant.nl/head-neck/infrahyoid-neck https://radiopaedia.org/articles/deep-cervical-fascia cross sectional anatomy of neck spaces 47 8/27/2021

48. THANK YOU cross sectional anatomy of neck spaces 48 8/27/2021