Scanning Method — Longitudinal Scanning of the Submandibular Gland (Color Doppler Flow Image): The transducer is positioned longitudinally along the submandibular region, parallel to the long axis of the gland. The probe marker is oriented anteriorly toward the chin. A high-frequency linear transducer (7–15 MHz) is recommended. After acquiring gray-scale images, Color Doppler is activated to assess vascular flow. The scan demonstrates the submandibular gland as an elongated, homogeneous structure with the Wharton’s duct extending anteriorly. Color Doppler highlights vascular landmarks, particularly the facial artery and vein near the gland hilum, and helps in evaluating glandular vascularity, detecting hyperemia in sialadenitis, or identifying abnormal flow patterns within masses or vascular lesions. Gentle angulation superior–inferior and slight medial tilting ensure complete coverage of the gland and duct.
Sectional Structures :
None or a few spots of blood flow Doppler signal
in normal submandibular gland parenchyma.
Sometimes facial artery may be shown running in
the gland.
Doppler Measuring Methods — Submandibular Gland:
Color Doppler — Applied after gray-scale survey to assess overall vascularity of the gland and adjacent structures. Helps detect hyperemia (e.g., sialadenitis), avascular areas (e.g., abscess), or abnormal flow patterns in masses and lymph nodes.
Power Doppler — Used for detecting low-velocity flow in small intraglandular vessels or lymph nodes, providing higher sensitivity than color Doppler.
Spectral (Pulsed-Wave) Doppler — Measurements are obtained by placing a sample gate within a visible vessel (typically the facial artery branch at the gland hilum). Parameters recorded include:
– PSV (Peak Systolic Velocity) — highest velocity during systole.
– EDV (End Diastolic Velocity) — velocity at end-diastole.
– RI (Resistive Index) — calculated as (PSV – EDV) / PSV. Normal: 0.6 – 0.8.
Technique — Align Doppler angle ≤ 60° to the vessel, optimize gain and wall filter, and use appropriate pulse repetition frequency (PRF) to avoid aliasing. Measurements are averaged over at least 3 cardiac cycles for accuracy.
| Parameter | Normal Value | Notes |
|---|---|---|
| PSV (Peak Systolic Velocity) | 20 – 40 cm/s | Measured in facial artery branch at hilum |
| EDV (End Diastolic Velocity) | 8 – 15 cm/s | Stable forward flow in normal state |
| RI (Resistive Index) | 0.6 – 0.8 | RI < 0.6 → hyperemia (acute inflammation); RI > 0.8 → chronic fibrosis or obstruction |
| Venous Flow (Facial / Submandibular Vein) | 5 – 15 cm/s | Low-velocity, monophasic, continuous flow; no turbulence |
Abnormal Color Doppler Findings :
Sialadenitis (Acute) — Marked hyperemia with prominent intraglandular color signals, reflecting increased vascularity.
Sialadenitis (Chronic) — Reduced or sparse parenchymal flow due to fibrosis and atrophy.
Sialolithiasis / Obstruction — Absence of flow within the calculus; increased color flow proximally in the periductal region.
Abscess / Phlegmon — Peripheral rim hyperemia with a central avascular core, creating a “ring of fire” appearance.
Benign Tumors — Mild to moderate internal vascularity, usually regular and organized in pattern.
Malignant Tumors — Chaotic or disorganized intralesional vascularity with high color flow density; possible neovascularity extending beyond gland margins.
Lymph Nodes — Reactive nodes show central hilar vascularity. Suspicious nodes show peripheral or mixed vascular patterns on color Doppler.
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