Chest CT With Contrast for Lingular Mass
Yes, order a chest CT with intravenous contrast for a mass on the lingula. This is the primary imaging modality recommended by the American College of Radiology for evaluating lung masses, as it provides superior tissue characterization, assessment of mediastinal involvement, and evaluation of vascular invasion compared to non-contrast imaging 1, 2.
Rationale for Contrast-Enhanced CT
Contrast administration is essential for evaluating lung masses because it enables:
- Distinction of vascular structures from lymph nodes, which is critical for accurate staging 1
- Detection of enhancing cellular components within the lesion, helping differentiate solid tumors from cystic or necrotic areas 1
- Assessment of chest wall invasion and extent of mediastinal involvement, which directly impacts surgical planning and resectability 1
- Identification of central obstructing tumor versus surrounding atelectasis in cases where the mass abuts airways 1
Why Not Non-Contrast CT
While non-contrast CT is appropriate for evaluating pulmonary nodules (small, incidental findings), it is inadequate for characterizing masses 3. The key distinction is:
- Non-contrast CT cannot reliably assess vascularity or enhancement patterns that differentiate benign from malignant processes 1
- Experienced radiologists may distinguish vascular structures from nodes on non-contrast studies, but this remains suboptimal for N1 nodal assessment and central vessel relationships 1
- For a lingular mass (which is a larger, more concerning finding than a nodule), the additional information from contrast justifies the minimal added risk 1, 2
Technical Considerations
Ensure the CT protocol includes 1:
- Thin-section imaging (≤5 mm slices) for optimal spatial resolution
- Coverage of the adrenal glands if concurrent abdominal imaging is not planned, as lung cancer commonly metastasizes to the adrenals 1
- Multiplanar reconstructions to assess relationship to adjacent structures
When to Consider MRI
Add MRI chest if CT findings are equivocal, particularly for 1, 2:
- Suspected chest wall or diaphragmatic invasion (MRI has superior soft tissue contrast)
- Evaluation of neurovascular involvement
- Distinguishing cystic from solid components when CT is indeterminate
Common Pitfalls to Avoid
- Do not rely on size criteria alone for lymph node assessment—nodes >1 cm in short axis are considered abnormal, but this has limited sensitivity and specificity 1
- Do not skip contrast unless there are absolute contraindications (severe renal insufficiency, documented severe contrast allergy) 3, 4
- Do not assume benignity based on imaging alone—tissue diagnosis is typically required for definitive management 2