Head and neck CT scan may be helpful in the diagnosis of tongue cancer. Findings on CT scan suggestive of tongue cancer include soft tissue attenuation of lesions, bony erosions, and increased attenuation of involved nodes.

• CT is the most commonly used modality for assessment of tongue squamous cell carcinoma
• Lesions typically appear more attenuating than normal tongue musculature (on account of the keratin) and enhance following contrast administration.
• Non-contrast scans of the neck may demonstrate increased attenuation of involved nodes due to keratin production by tumor deposits.^[1]
• CT is better for the evaluation of bone destruction.
• Assessment of cartilage invasion.^[2]
• Detection of extracapsular spread of tumor. 
• Pathologic lymph nodes are 10 to 11 mm and contains central necrosis. Size criteria based on measurement of minimal axial diameter are considered the most accurate and effective.^[3]
• Pathological lymph nodes show: loss of normal fatty hilum, increased or heterogeneous contrast enhancement, lymph node clustering.^[4]
• Sensitivity is 83% and specificity is 83%.^[5] 

• PET appears to be as sensitive and specific as CT and MRI in detecting primary head and neck tumors.^[6]
• PET is superior to both CT and MRI for detecting regional nodal metastases, as well as distant metastases and second primary tumors.^[7]
• False negatives of PET may be seen in lymph nodes less than 5 mm, necrotic or cystic lymph nodes, and tumors of low metabolic activity. [56]
• PET/CT is sensitive and superior for evaluation of deep lesions. [78]

• 
  CT of squamous cell carcinoma of the tongue showing axial bone window ^[8]
• 
  CT of squamous cell carcinoma of the tongue showing coronal bone window^[8]

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