Clinical Significance
Perforators connect the superficial venous system to the deep system through the muscular fascia. Incompetent perforators allow outward flow, contributing to ambulatory venous hypertension. Clinically significant: outward flow >0.5 seconds and diameter >3.5mm at the fascia level.
Scanning Technique
Scan in transverse orientation along the medial calf and thigh. Key locations: Cockett perforators (medial calf, 7-13cm above the medial malleolus), Boyd perforator (medial knee), and Dodd/Hunterian perforators (medial thigh).
Use a high-frequency linear probe (10-14 MHz) with depth set to include the deep fascia (3-5cm). Color Doppler at low PRF (500-1000 Hz). Augment with distal calf squeeze to provoke outward flow.
- MX7/M8 Elite: Low PRF color Doppler with low wall filter. Distal calf squeeze to provoke outward flow.
- Resona i9T: Ultra Micro Angiography (UMA) detects flow below conventional Doppler thresholds. V Flow visualizes direction without angle dependence.
- Consona N9: Standard color Doppler with low PRF and manual augmentation.
Documenting Perforators
For each incompetent perforator, record: location, diameter at the fascial level, reflux duration, depth from skin, and relationship to the GSV or tributary.