How do I order a CT scan of the left neck?

How to Order a CT Scan of the Left Neck

To order a CT scan of the left neck, you should request a CT neck with intravenous (IV) contrast, specifically indicating that the area of interest is the left side of the neck.

Appropriate CT Protocol Selection

When ordering a CT scan of the left neck, follow these guidelines:

1. Imaging Study Type:

   • Request: "CT neck with IV contrast" 1
   • Specify: "Left neck" as the area of interest
   • Do NOT order "CT with and without contrast" as this doubles radiation exposure without added benefit 1

2. Protocol Details:

   • Ensure the scan extends from the skull base to the thoracic inlet to capture all relevant structures 1
   • IV contrast is essential for:
     • Distinguishing vessels from lymph nodes
     • Characterizing masses (cystic vs. solid)
     • Mapping lesion borders
     • Identifying potential primary sites in the upper aerodigestive tract 1

3. CPT Code:

   • For professional component only (radiologist interpretation): Use CPT code with "-26" modifier 2

Clinical Considerations

Advantages of CT with Contrast for Neck Imaging:

• Superior spatial resolution
• Readily available in most facilities
• Short scanning time (<5 minutes)
• Better tolerated by patients (larger scanner bore compared to MRI)
• Acceptable radiation dose in adults (approximately 3 mSv) 1

When to Consider Alternative Imaging:

• MRI may be preferred if:
  • Suspected nasopharyngeal tumor
  • Cranial nerve abnormalities on exam
  • Perineural spread concerns
  • Skull base involvement 1
  • Patient has contraindication to iodinated contrast

Contraindications to IV Contrast:

• Contrast allergy
• Renal insufficiency
• Pregnancy (requires risk-benefit assessment) 1, 3

Common Pitfalls to Avoid

1. Ordering Errors:

   • Avoid ordering dual-phase CT (without and with contrast) as this doubles radiation exposure 1
   • Don't limit the scan field - ensure coverage from skull base to thoracic inlet

2. Clinical Context Errors:

   • Failing to communicate relevant clinical information to the radiologist
   • Not specifying the side of interest (left neck in this case)

3. Patient Preparation:

   • Ensure patient is not wearing metal objects in the scan area
   • Check for contraindications to contrast before ordering

Special Situations

If the patient has contraindications to IV contrast, consider:

• Non-contrast CT (limited value but may help with bony structures)
• Ultrasound (for superficial structures)
• MRI without contrast (better soft tissue characterization than non-contrast CT) 1

Following these guidelines will ensure appropriate imaging of the left neck while minimizing radiation exposure and optimizing diagnostic yield.