What is the recommended imaging protocol for a patient presenting with neck enlargement, specifically considering the use of a CT (Computed Tomography) scan of the neck?

CT Neck with Contrast is the Recommended Initial Imaging for Neck Enlargement in Adults

For patients presenting with neck enlargement, order a contrast-enhanced CT of the neck as the preferred initial imaging modality, particularly when there is concern for malignancy. 1

Imaging Protocol Recommendation

Primary Imaging Choice: CT Neck with IV Contrast

• Contrast-enhanced CT is the preferred initial imaging modality for nonpulsatile neck masses in adults due to superior spatial resolution and ability to detect head and neck cancer. 1

• Contrast administration is essential for distinguishing vessels from lymph nodes, detecting nodal necrosis, identifying abscesses (especially intramuscular), and clarifying the relationship of masses to major neck vessels. 1

• Single-phase contrast-enhanced CT is sufficient—dual-phase imaging (without and with contrast) is not usually necessary and doubles radiation exposure with minimal added benefit. 1, 2

When to Consider Alternative Imaging

MRI with contrast is an appropriate alternative to CT and should be considered in specific scenarios: 1

• Patients who cannot receive iodinated contrast (severe renal insufficiency or contrast allergy) 1
• When radiation exposure is a concern 1
• Suspected perineural invasion or skull base involvement 3
• Improved soft-tissue characterization is needed 1

Ultrasound has a limited but specific role: 3

• First-line for discrete superficial cystic lesions 1, 3
• Evaluation of thyroid or salivary gland masses 3
• Guiding fine-needle aspiration (FNA) 3
• However, ultrasound cannot adequately assess deep structures, skull base involvement, or the upper aerodigestive tract where primary tumors often arise 3

Clinical Context: Risk Stratification for Malignancy

The decision to order imaging should be based on clinical assessment of malignancy risk: 1

• Perform comprehensive head and neck examination including cranial nerve assessment, visualization of mucosal surfaces (oral cavity, oropharynx, nasopharynx, hypopharynx, larynx), and bimanual palpation of the neck, floor of mouth, and salivary glands 1

• Order CT or MRI with contrast for patients deemed at increased risk for malignancy based on clinical examination findings, patient age, smoking history, alcohol use, or concerning mass characteristics (firmness, fixation, size >2 cm, persistence >2-4 weeks) 1

Diagnostic Pathway After Imaging

If imaging shows suspicious findings and diagnosis remains uncertain, proceed to FNA rather than open biopsy: 1

• FNA is the preferred initial pathologic test for neck masses at increased risk of malignancy 1
• Ultrasound or CT guidance can be used for FNA 3
• Open biopsy should be avoided as initial diagnostic approach due to associated complications 1

Critical Technical Specifications to Include in Order

When ordering CT neck with contrast, specify: 2

• Clinical indication: "Evaluation of neck enlargement" with specific anatomical location and duration 2
• Request contrast administration unless contraindicated 2
• Include relevant clinical information: size, consistency, associated symptoms (dysphagia, hoarseness, cranial nerve deficits), risk factors for malignancy 2

Common Pitfalls to Avoid

• Do not order CT without contrast as initial study—this significantly limits diagnostic information for distinguishing malignant from benign processes 1, 2
• Avoid vague anatomical descriptions in the imaging order, which may lead to incomplete coverage 2
• Do not use PET/CT, CTA, or MRA as initial imaging—these are not appropriate for initial evaluation of nonpulsatile neck masses 1
• Imaging is not a substitute for thorough physical examination including visualization of mucosal surfaces with mirror or endoscopy 1