Thyroid Ultrasound

1. 1

   Patient supine with neck slightly extended (pillow under shoulders). High-frequency linear probe (10–18 MHz).

2. 2

   Transverse sweep: start at the right lobe superior pole, sweep inferiorly to isthmus. Repeat for left lobe.

3. 3

   Measure right lobe in transverse (width + AP) at the largest dimension, and longitudinally (length).

4. 4

   Measure isthmus AP in transverse. Measure left lobe in same planes.

5. 5

   For each nodule: document location, size (3 planes), composition (cystic/solid/mixed), echogenicity, shape, margins, and echogenic foci.

6. 6

   Apply ACR TI-RADS scoring: assign points for each feature. Total determines FNA threshold.

7. 7

   Color Doppler: note vascularity pattern (peripheral, internal, or absent). Survey central and lateral neck nodes.

• Right lobe — transverse sweep (superior to inferior)
• Right lobe — longitudinal (length measurement)
• Isthmus — transverse (AP diameter)
• Left lobe — transverse sweep
• Left lobe — longitudinal
• Nodule(s) — 3 planes with measurements
• Vascularity — color/power Doppler
• Lymph nodes — bilateral central and lateral

• Lobe dimensions and volume
• Isthmus thickness
• Nodule size, echogenicity, composition
• Nodule margins and orientation
• Echogenic foci (microcalcifications, comet-tail)
• Lymph node morphology

• TI-RADS scoring requires correct classification of composition (cystic >50% drops score)
• Comet-tail artifacts = benign colloid; microcalcifications = high-risk feature
• Posterior shadowing from calcification obscures deeper nodule assessment

Use ACR TI-RADS: score each nodule for composition, echogenicity, shape, margin, echogenic foci. TR1/TR2 = no FNA; TR3 ≥1.5cm; TR4 ≥1.0cm; TR5 ≥0.5cm.