Supra- and infrahyoid neck continuation: Anatomy of the oral cavity, pharynx, continuity w suprahyoid neck : Carotid space larynx and infrahyoid neck Retropharyngeal & danger space Perivertebral (prevertebral, paraspinal) Posterior cervical space ECNR Dubrovnik 22.10. 2018 Bernhard Schuknecht Medical Radiological Institutes Zurich Switzerland [email protected]
Infrahyoid only: Visceral space suprahyoid pharyngeal mucosal Anterior cervical space Harnsberger ED. Diagnostic Imaging Head and neck 2nd edition Amirsys 2011
Order of „business“ Infrahyoid level Visceral space = unpaired infrahyoid space Anatomy and imaging issues middle layer of deep cervical fascia The space based approach spatial relationship • Oral cavity retropharyngeal space • Hypopharynx carotid space • Larynx anterior cervical space contents: • Thyroid/ parathyroid gland larynx, hypopharynx trachea, esophagus thyroid, parathyroid- thymus recurrent laryngeal nerve, paratracheal LN
How to approach neck lesions? LN level-classification in the neck space based approach Level I: superior to hyoid Deep cervical fascia IA: submental, IB: submandibular ĺsuperficial ĺPLGGOH Level II: internal jugular -superior to hyoid ĺdeep layer IIA: anteror to SCM, IIB: medial to SCM separate spaces: suprahyoid Level III: int. jugular (inferior hyoid-inf. cricoid) infrahyoid midthird vascular chain – SCM
Level IV: internal jug- inf cricoid- supraclavicular lower vascular chain – SCM
Level V: posterior cervical space – supraclavicular VA : above inf. cricoid level VB: below inf. cricoid
Level VI: prelaryngeal: hyoid- jugulum
+ retropharyngeal, parotid, facial LN Level: VII: jugulum -aortic arch upper mediastinum Fig.Harnsberger Ed. Diagnostic Imaging Head and neck 2nd ed. I1 4,6; Amirsys 2011 Sublingual & submandibular space: Oropharynx content squamous epithelium within the oropharynx derives from endoderm Sublingual space: not fascia lined ĺSURSHQVLW\IRUGHYHORSPHQWRISRRUO\GLIIHUHQWLDWHGDJJUHVVLYHFDCV Sublingual gland, + minor salivary glands submandibular, sublingual duct Subsites lingual, glossopharyngeal, hypoglossal n. • post. 1/3 of tongue, • lingual tonsils, Submandibular space : fascia lined • palatine tonsils, Submandibular gland superficial lobe • soft palate, (deep lobe = partly within SLS) • post. pharyngeal wall Facial artery, vein, digastric muscle (ant. belly) LN: submental IA, submandibular IB Both spaces : extend from side to side from Harnsberger Diagnostic Imaging Head and Neck, Amirsys 2004
Oral cavity deep lobe submandibular & sublingual spaces squamous epithelium of the oral cavity derived from ectoderm ĺWHQGVWRJLYHULVHWRPRUHGLIIHUHQWLDWHGOHVLRQV Sm gland: Superficial lobe in Sm space deep lobe = partly within SLS Subsites sl+ sm VSDFHļabove midline • lips, sm VSDFHļparapharyngeal space • 2/3 of the tongue, superficial lobe • buccal mucosa, • gingiva, • retromolar trigone, • hard palate, • floor of the mouth Oropharynx + oral cavity cancer : incidence 8.5 : 100000 oral cavity to oropharynx 2:1 LQFLGHQFHWUHQGFDQFHURIRUDOFDYLW\ĻRURSKDU\Q[Ĺ
Tongue muscles Anatomic variations
Intrinsic: slong., ilong., transverse, vertical Unilateral agenesis of sm gland Staphne cyst Extrinsic: genioglossus 1, hyoglossus 2, styloglossus 3, palatoglossus 4
1 2
3 Herniation of sl gand 4
Root of tongue Floor of mouth Geniohyoid-genioglossus complex and lingual septum Oral cavity neoplasms Anatomic division of the pharynx: oral tongue ca naso-, oro-, and hypopharynx nasopharynx
skull base soft palate oral tongue mucoepidermoid ca oropharynx soft palate floor of the mouth ca pharyngo-epiglottic fold hypopharynx cricopharyngeus m.
retreomolar adenoidcystic ca lateral buccal mucosa ca squamous cell neoplasms glandular neoplasms
Oral cavity congenital lesions Hypopharynx subsites: piriform sinus, postcricoid region, • Vascular malformations: venous, lymphatic, mixed posterior wall • Germ cell tumours: epi-, dermoid, teratoma dermoid, epidermoid,
venous / lymphatic vascular malformation • aryepiglottic fold anteromedially
• thyroid cartilage laterally
• paraglottic space anteriorly
• hypopharynx esoph. junction @ level of inf. cricoid lamina
Anatomical subdivision of the pharynx: Hypopharynx subsites: piriform sinus, naso-, oro-, and hypopharynx postcricoid region, posterior wall nasopharynx Skull base Soft palate • aryepiglottic fold anteromedially
oropharynx • thyroid cartilage laterally soft palate pharyngo-epiglottic fold • paraglottic space
hypopharynx • hypopharynx esophagus junction cricopharyngeus m. pa @ level of inf. cricoid lamina Sobotta Becher 2nd ed. U&S 1972 Glottis and subglottis Anatomic subdivision of the larynx derived from tracheo-bronchial bud sparse lymphatic drainage ! Glottis level: Vocal cord = medial fibres of thyroarytenoid m. anterior posterior commissure + 5mm below Subglottis : mucosal surface close to cricoid supraglottis Hyoid conus elasticus fibroelastic membrane 5 betw. vocal lig. - cricoid cartilage 5 LN prelaryngeal = Delphian lymph node (s) (VI) glottis Thyroid c Level VI subglottis Cricoid c
M arytenoideus transversus + obliquus
Supraglottis Glottis-level derived from buccopharyngeal anlage How to identify ? rich lymphatic drainage !
laryngeal vestibule thyroid c epiglottis arytenoid c cricoid c pre-epiglottic fat
false vocal cords
ventriculus laryngis
paraglottic space
arytenoid cartilage
3 levels ! Larynx false vocal cord plica vestibularis
epiglottis
pre-epiglottic fat cricoid c false vocal cords arytenoid c. true vocal cord laryngeal ventricle vocal ligament = glottis + 5mm arytenoid cartilage
true vocal cord thyroid c false cord arytenoid c cricoid c. paraglottic space true cord subglottis cricoid c conus elasticus cricoid cartilage Embryology: thyroid- parathyroid Thyroid/visceral space anatomy
• Thyroid lobes and superior parathyroid 4th branchial pouch
• Isthmus thyroid and inferior parathyroid 3rd branchial pouch Inferior parathyroid (35% ectopic hyoid, carotid, intrathyroid, mediastinal) longer course of 3rd branchial pouch
VIBE Gd
Embryology Thyroid anatomic variation: • Thyroid descent via thyroglossal duct Zuckerkandl tubercle Posterior view: two different cases from foramen cecum suprahoid midline infrahyoid off midline to visceral space • thyroglossal duct involutes at 5-6 gest. weeks Thyroglossal duct cyst: 25% suprahyoid, 50% level of hyoid, 25% infrahyoid Black dots = parathyroid glands Posterior thyroid tubercle “ Zuckerkandl tubercle” • surgical landmark (proximity to recurrent laryngeal nerve) • extension of thyroid to tracheo-esophageal sulcus in 87%, • nodular configuration of ZT in 42.1% of patients. • DD: Parathyroid adenoma
Lingual thyroid Lee TC et al. Zuckerkandl Tubercle of the Thyroid: A Common Imaging Finding That May Mimic Pathology. Thyroglossal duct cyst AJNR 2012 33: 1134-1138
Thyroglossal duct cyst Parathyroid gland anatomy fistula continuation o thyroid isthmus
Dynamic CT Dynamic MR VIBE Gd Parathyroid adenoma MR Imaging protocol neck Adenoma > 5mm (10-30mm),
CT Upper: posterior to upper midpole Coverage: orbital roof - below aortic arch Lower: 65% lateral/posterior to lower pole • sagittal T2 TSE 3 mm 20 % ectopic (intrathyroid, carotid, mediastinum..) 2-3% multiple • coronal STIR 4 mm <1% parathyroid carcinoma • axial T2 TSE fs Dixon 3 mm Twist dynamic Tc 99m sestamibi: early + delayed focal enhancement • axial T1 TSE localized 3 mm Cholin PET: under investigation • axial DWI b 0, b 800-1000; ADC 5mm US: homogenous, well defined hypoechoic, hypervascular Dynamic CT/ and – dyn. MR: early enhancement ! • axial VIBE Dixon Gd 3D 0.9 mm
Dynamic ceCT or ceMR arterial phase!! (T1 TSE Gd fs Dixon, T2 Space 0.8-1.0mm)
Specialized examination CT Imaging protocol neck Dynamic ceMR sequence (10s intervall) MDCT (64/128)
Coverage Orbital roof – below aortic arch
• Collimation : 0.6mm • Table feed per rot : pitch 1.0 • Rot. time, duration : 0.3s /16s • Reconstruction slice: thickness/ increm. 1.0/0.7 mm, Fov 180
•MPR 3mm contig. : W/C soft tissue 270 -300/100 baseline 10s 20s 60s W/C HR bone 2mm 3200/700(1700/600 cartilage) Work in progress: improved detection of parathyroid adenoma (?) • 80ml nonionic contrast + 20ml saline 2ml/s; => 50s delay
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