Introduction to Head & Neck Ultrasound

Learning Objectives To recognize the indications for and clinical utility of H&N ultrasound. To identify normal H&N anatomy To know basic ultrasound machine capabilities and control functions ALSO – How to explain to a patient Proper handling of transducer Anatomy: thyroid, salivary glands, carotid, jugular, trachea

What is Ultrasound? Sound waves: 2-10 MHz Waves are propagated through different tissues at different velocities Boundary of two tissues causes impedance mismatch Sound waves are reflected back at different frequencies Differentiation of tissues MegaHz. Audible sound waves are 2-20 kHz (which is 0.002 - 0.02 MHz) 1MHz = 1000kHz Tissue impedance = measure of resistance of propagation of the sound waves The BOUNDRY of two tissues causes the reflection back

Impedance = density x acoustic velocity Attenuation Resolution 2nd and 3rd princples we cannot go into with time allotted

There are other things to consider like artifact and resolution, but don’t have time.

Piezoelectric Crystals Converts the reflected waves (acoustic echoes) into a grayscale image Converts electrical current into sound waves Conversion done in the transducer Mechanical energy is the sound waves

What can we see? Thyroid gland: nodules, goiter Parotid glands Over 200 nodes in neck, normally do not see Can tell “normal” characteristics What can we see? Thyroid gland: nodules, goiter Parotid glands Submandibular glands Enlarged or pathologic lymph nodes

What can we see? Skin / platysma  Epidermal inclusion cysts Subcutaneous  Lipoma Muscle Soft tissue  Lymph nodes

 Skin Sub-Q  Strap Strap L thyroid R thyroid Trachea CCA CCA Esoph Air is black (total reflection) (has much much less velocity than soft tissue) Fluid is black (near total propagation) Sub Q = adipose layer is dark with bright striations Parenchyma is isoechoic gray

Echogenicity anechoic  hypoechoic  isoechoic  hyperechoic Homogeneous vs Heterogeneous Anechoic = tissue that transmits ultrasound waves Hyperechoic = tissue that transmits and reflects waves

Orientation Sagittal view Transverse view Transverse – think axial cut Sagittal – think sagittal cut

Indications for H&N ultrasound Palpable lymph node or neck mass Lymphadenopathy: malignant versus reactive Salivary gland neoplasm Branchial cleft cyst Thyroid nodules Palpable Incidentally found Essentially no contraindications

Reminder: complete your workshop cards and turn them in at the end of this session. Score cards will be used for admission to workshops and attendance. Credit will only be awarded for completed score cards. Rotate and complete each station. Completion of workshop is NOT contingent on pass/fail

Ultrasound Session Evaluation Score cards will be used for admission to sessions and attendance. Credit will only be awarded for completed score cards. Last Name Session 1 2 3 Scale: 1=NO or LOW, to 5=YES or most likely/most positive Scale 1 to 5 1. Were learning objectives met? 2. Was instruction free of commercial bias? 3. Was there adequate instruction before hands-on practice? 4. Was there adequate supervision during practice? 5. Were training aids useful/realistic in learning desired skill? 6. How likely are you to perform these skills in the future? 7. Did this training improve your skills? ATTENDEE NAME (print) ___________________________________ ATTENDEE SIGNATURE:

Ultrasound Score Card Rotate and complete each station. “Go/No Go” for internal use only. Completion of workshop is NOT contingent on pass/fail. Task Go No Go 1. Identify one indication for US exam. 2. Explain the procedure as you would to a patient. 3. Demonstrate proper handling of the US transducer. 4. Identify one anatomical landmark. Comments Proctor Name Proctor Signature

Ultrasound Las Palmas C 20x31 10 learners per session 16 chairs, 2 6ft tables, 2 smaller tables, AV setup Screen Door Door Station 4 Station 2 US unit Station 1 US unit Projector Speaker Equipment Table Equipment Table Proctors