on call head and neck gladwin hui acknowledgement: special thanks to elissa price
TRANSCRIPT
On Call Head and Neck
Gladwin Hui
Acknowledgement: Special thanks to Elissa Price
CT Head and Neck
• Emergency
• Requests from Emerg or ENT
• Talk to referring physician to make sure airway is secured
• IV Contrast
• Neck vs. C-spine
CT Head and Neck
• Difficult studies
• Not very often (maybe once a month)
• Focus on the urgent issues (will take a long time to learn Head and Neck well)
Technique
• Skull base to below carina, to include top of pericardium
My Approach to CT Neck1) Airway
- Nasopharynx, oropharynx and hypopharynx (whole airway)- Trachea and esophagus
2) Deep neck spaces- Parapharyngeal space- Retropharyngeal space- Masticator space- Carotid space- Perivertebral space- Anterior visceral space- Submandibular/sublingual space
Approach to CT Neck
3) Glands- Parotid- Submandibular- Thyroid
4) Vessels and lymph nodes5) Bones and Soft tissues6) Neuro
- Brain, orbits, paranasal sinuses, mastoid air cells7) Cord8) Chest
- Lung apices - Mediastinum, Pericardial region
Approach to CT Neck
• Bottom Line
– Check your ABC’S– A = AIRWAY– B = BONES– C = CAROTID SHEATH/VESSELS– S = SPINAL CORD/CANAL
Anatomy: Fat Planes & Spaces
• Deep neck spaces
• - Parapharyngeal space
• - Retropharyngeal space
• - Masticator space
• - Carotid space
• - Perivertebral space
• - Anterior visceral space
• - Submandibular/sublingual space
Lateral pterygoid muscle
Masticator space
Pharyngealmucosal space
Nasopharynx
Medial PterygoidMuscle
Parotid
Styloid process
ECA
ICAInternal jugular vein
Parapharyngeal space
Carotid space
Uvula
Nasopharynx Oropharynx
Retropharyngeal space
Posterior bellydigastricmuscle
Perivertebral space
Jugulodigastric lymph node </= 1.5-cm
Lt JDG node
Back edge submandibular gland
Back edge sternocleidomastoid muscle
mylohyoid
ad
ad= ant belly digastric muscle
Epiglottis
Oropharynx Hypopharynx
Vallecula
Submandibular Gland
Submandibular space
Hyoid bone
Hyoid bone
Hyoid bone
Aryepiglottic Folds
Piriform sinus
Cricoid cartilage
Cricoid cartilage
Cricoid cartilage
Cricoid cartilage
Cricoid cartilageThyroid
Anterior Visceral Space
• Extends from hyoid bone to anterior mediastinum
• Sling around the trachea, esophagus
• Contiguous with the retropharyngeal space
Retropharyngeal Space
• Extends from skull base to superior mediastinum
• Limited anteriorly by middle layer of deep cervical fascia, and posteriorly by deep layer of deep cervical fascia
• Extends to mid T-spine, then connects to Danger space and closed off by connective tissue at carina
• Content: Fat, LN
Danger Space
• Extends from skull base to diaphragm in the posterior mediastinum
• Posterior to retropharyngeal space
• Lies between the alar and prevertebral layers of the deep cervical fascia
• Spread of infection from neck to mediastinum
Carotid space – Neurovascular Bundle
• Extends from skull base to mediastinum
• CCA, IJV, Vagus– Dissection, narrowing, aneurysm, rupture– Thrombus– Mass
Parapharyngeal Space
• Key landmark – primarily fat-containing– How is it being effected by a process going on
in the region?
Retropharyngeal space
Parapharyngeal space
Carotid artery
Internal jugular vein
Tonsil
Submedial pterygoid space
Parapharyngeal space
Parotid gland
Neurovascular bundle
Retropharyngeal space
Retropharyngeal space
Neurovascular bundle
Anterior visceral space
Esophagus
Retropharyngeal space
Visceral space
Tonsil
Parapharyngeal space
Submandibular gland
Parapharyngeal space
Submandibular gland
Submandibular space
Medial pterygoid muscle
Submandibular and Sublingual Spaces
• Important regions to evaluate for floor of mouth infections
Pathophysiology
• Cellulitis
• Phlegmon
• Fluid collections
• Abscess
Cellulitis
• Focal or diffuse
• Streaky infiltration of fat planes
• Diffuse enlargement of adjacent muscles
• No focal loculation of fluid
Cellulitis
Phlegmon
• Slightly heterogeneous solid swelling
• May be minimal low density suggestive of fluid loculation developing
• Usually seen in tonsillar/peritonsillar or retropharyngeal locations
Phlegmon
Fluid Collections
• homogeneous or minimally heterogeneous
• no good peripheral margin, no enhancement
• turns the fat planes grey
Fluid Collection
Abscess
• Well-defined capsule
• Little or no cellulitic change in adjacent tissues
• Often adjacent to bone (secondary to osteomyelitis)
Complications
ALWAYS CHECK FOR:• Airway obstruction
• Carotid pseudoaneurysm or rupture
• Internal jugular vein thrombosis
• Mediastinitis/fluid collection/abscess
• Pericarditis
Dental Infections
• Usually mandibular, usually molar
• Submedial pterygoid space
• Floor of mouth
• Anterior visceral space
• Parapharyngeal space
• Neurovascular bundle
• Retropharyngeal space
Ludwig’s Angina
• Cellulitis that involves inflammation of the tissues of the floor of the mouth, under the tongue
• Extremely dangerous• Early airway compromise• Extensive edema of tongue and floor of mouth• +/- Floor of mouth fluid/air• No abscess• Dental origin
Tonsil
• Unilateral swollen tonsil
• Parapharyngeal space
• Floor of mouth
• Neurovascular bundle
• Retropharyngeal space
Iatrogenic
• Post-intubation
• Post-endoscopy
Pharyngeal/Esophageal Perforations
• Air in the fat planes
• Retropharyngeal space
• Neurovascular bundle
• Mediastinum
Salivary Gland Obstruction
• Parotid
• Submandibular
Courtesy: Learning Radiology
Courtesy: Learning Radiology
Epiglottitis on Lateral Xray
My Approach to CT Neck1) Airway
- Nasopharynx, oropharynx and hypopharynx (whole airway)- Trachea and esophagus
2) Deep neck spaces- Parapharyngeal space- Retropharyngeal space- Masticator space- Carotid space- Perivertebral space- Anterior visceral space- Submandibular/sublingual space
Approach to CT Neck
3) Glands- Parotid- Submandibular- Thyroid
4) Vessels and lymph nodes5) Bones and Soft tissues6) Neuro
- Brain, orbits, paranasal sinuses, mastoid air cells7) Cord8) Chest
- Lung apices - Mediastinum
Approach to CT Neck
• Bottom Line
– Check your ABC’S– A = AIRWAY– B = BONES– C = CAROTID SHEATH/VESSELS– S = SPINAL CORD/CANAL
Good resources
• Statdx• http://www.med.wayne.edu/diagRadiology/
Anatomy_Modules/axialpages/Overview.html
Thank you