head & neck radiology Flashcards
major regions of the head & neck
- skull base: exits of nerves & vessels, synchondroses, cavernous sinus
- temporal bone: outer - middle - inner ear, sigmoid sinus, relations of dura, internal acoustic meatus, facial canal
- orbit: extra-,intra-conal space, pre-, pro- septal space
- paranasal sinuses: ostiomeatal complex, conchae, pars papyracea, blow-out fracture, lamina cribrosa -> frontal scala
- face: suprahyoid compartments -> parapharyngeal, retropharyngeal (spread to the mediastinum), masticator, parotid, prevertebral spaces, pterygopalatine fossa, buccal space, submandibular space
- neck: pharynx [ epi-, meso-(tonsillar fossa, base of tongue), hypo- pharynx (epiglottic valleculae, piriform sinus)], larynx [supraglottic spase (preepiglottic), glottis (paraglottic space), subglottic space], lymphatics, thyroid / parathyroid glands, cervical & brachial plexus)
compartments of head & neck
A. above hyoid bone: pharyngeal mucosal space, masticator space, parapharyngeal space (prestyloid - poststyloid comp), sublingual space, submandibular space, buccal space, parotid space
B. below hyoid bone: anterior cervical space, anterior visceral space, posterior cervical space
C. complete extension: retropharyngeal space, danger space, carotid sheath, perivertebral space (prevertebral, paraspinal)
modalities
- ultrasonography
- conventional x-ray (+ fluoroscopy): plain radiograph or contrast-enhanced -> water soluble or non-soluble
- CT (spiral, multislice, cone-beam) / MRI
- angiography: DSA (digital subtraction angiography), CT-, MR- angiography
- nuclear medicine: scintigraphy, SPECT, PET, PET-CT
ultrasonography: indications
- face
- floor of the mouth
- superficial tissues of neck
- superficial to bones
- most lymphatic regions
ultrasonography: patient preparation
- no jewels
- no bandage (if possible)
- no tracheostomy canule (if possible)
- before contrast-enhanced examination: consent & empty stomach
conventional x-ray -> unenhanced (GENERAL)
- image: shadow of the atom’s electron shell
- radiopaque/dark: high atomic number -> bones, calcified tissues
conventional x-ray -> unenhanced (INDICATIONS)
- panoramic view / tooth x-ray
- fracture suspicion on the face
- inflammation of paranasal sinus
- mastoid cell
- no jewels
conventional X-ray -> with CM (POSSIBILITIES)
- advantage of fluoroscopy: functional information -> moving of calcified lesions (eg. nodule in thyroid gland)
- swallow examination: hypopharynx (eg. tumorous stricture, Zenker-diverticulae)
- sialography (refill of salivary gland and duct) -> stones
conventional X-ray -> with CM (INDICATION)
- blockage by foreign body
- suspicion of perforation
- diverticule
- calcified lesion on the neck
- tumor - stricture
- no jewel
- empty stomach
- good cooperability
CT (GENERAL)
- technique based on x-ray
- better resolution of soft tissues
- worse spatial resolution
- higher dose of radiation exposure
CT (INDICATIONS)
- tumor TNM classification
- regions coveres by bones (deep face)
- to assess bony relations (fracture, detailed relations of paranasal sinuses)
- suprahyoid region: CT instead of MRI
- infrahyoid region (bc the fatty tissues separate well the compartments)
- no metal objects
- empty stomach
- IV CM - DM (metformin)
HRCT -> temporal bone
unenhanced ultrathin slices (0.3 mm).
increased exposure.
conebeam CT (GENERAL)
- unenhanced
- 2D flat panel detector
- less radiation exposure
conebeam CT (INDICATIONS)
- implantology
- maxillo-facial surgery
- impactation
- TMJ evaluation
- airway study
- spinal examination
- orthodontics
MRI (GENERAL)
- map of H atoms in tissues
- best soft tissue contrast
- non-ionizing radiation
- more expensive
- less available
- low temporal resolution
