What should be included in an ultrasound order for a patient with non-specific calcification in the calf?

Ultrasound Order for Calf Non-Specific Calcification

When ordering an ultrasound for non-specific calcification in the calf, request a complete duplex ultrasound (CDUS) that includes compression from the common femoral vein to the ankle, with specific evaluation of the area of calcification to assess for deep vein thrombosis and soft tissue pathology. 1

Key Components to Include in the Order:

Clinical Information:

• Location and characteristics of the non-specific calcification
• Presence of any symptoms (pain, swelling, tenderness)
• Duration of symptoms
• Risk factors for DVT if present
• Previous imaging findings (e.g., X-ray showing calcification)

Specific Ultrasound Protocol:

1. Complete duplex ultrasound examination including:
   • Compression ultrasound from common femoral vein to ankle
   • Evaluation of posterior tibial and peroneal veins in the calf
   • Color and spectral Doppler of common femoral veins bilaterally
   • Color and spectral Doppler of popliteal vein on the symptomatic side
   • Focused assessment of the area with calcification

Clinical Question to Address:

• Rule out DVT
• Characterize the calcification (location, size, relationship to adjacent structures)
• Evaluate for associated soft tissue abnormalities (tendinopathy, bursitis, mass)

Rationale for Complete Duplex Ultrasound:

The Society of Radiologists in Ultrasound consensus recommends complete duplex ultrasound as the preferred venous ultrasound test for comprehensive evaluation 1. Limited protocols that skip the calf are not recommended as they may miss important findings and require follow-up imaging.

Complete duplex ultrasound offers several advantages:

1. Detects both proximal and distal DVT in a single examination
2. Allows for comprehensive evaluation of the calcification and surrounding structures
3. Eliminates the need for follow-up imaging if negative (unlike limited protocols)
4. Provides information relevant to patient outcomes regardless of treatment decisions 1

Importance of Evaluating Calcifications:

Non-specific calcifications in the calf may represent various conditions:

• Hydroxyapatite deposition disease (HADD) if within tendons 2
• Calcium pyrophosphate dihydrate (CPPD) crystal deposition if intra-articular 2
• Vascular calcifications (arterial or phleboliths)
• Soft tissue masses with calcification
• Post-traumatic changes

The American College of Radiology recommends careful characterization of calcification patterns, as diffuse, central, or laminated patterns typically suggest benign etiology, while stippled or eccentric patterns may require further evaluation 3.

Common Pitfalls to Avoid:

1. Ordering limited ultrasound protocols: These miss 5% of isolated calf DVTs and require follow-up imaging 1
2. Failing to specify the area of concern: Ensure the radiologist knows the exact location of the calcification
3. Not providing relevant clinical information: Include symptoms and prior imaging findings
4. Assuming all calcifications are benign: Some soft tissue sarcomas can contain calcifications 3
5. Not requesting Doppler evaluation: Essential for assessing blood flow and potential vascular involvement

By following these guidelines, you'll ensure a comprehensive evaluation that provides the most clinically relevant information for patient management while minimizing the need for additional imaging.