A few studies suggested that US can distinguish between metastatic and inflammatory neck nodes [41-47]. Although these results are promising, scans are user dependent. US serves as a powerful tool for image-guided sampling [48], which is beyond the scope of this document. Advantages of US include the ability to be performed at the point of care and to expedite sampling [14]; however, US is limited for comprehensive evaluation of the deep spaces of the neck, and for larger, multispatial, and malignant lesions. US may play a future rule in identifying unknown primary mucosal tumors, notably in the oropharynx [49]. Techniques such as US elastography and contrast-enhanced US are being explored for possible future clinical applications [44,45,50-58]. FDG-PET/CT Skull Base to Mid-Thigh While there is established literature regarding the use of PET using the tracer fluorine-18-2-fluoro-2-deoxy-D- glucose (FDG)/CT for staging and surveillance of head or neck malignancy, FDG-PET/CT is not an initial imaging study for evaluation of a nonpulsatile neck mass. FDG-PET/MRI Skull Base to Mid-Thigh While there is growing literature regarding the use of FDG-PET/MRI for staging and surveillance of head or neck malignancy, FDG-PET/MRI is not an initial imaging study for evaluation of a nonpulsatile neck mass. Arteriography Cervicocerebral There is no evidence to support the use of catheter angiography for evaluation of a nonpulsatile neck mass. Neck Mass/Adenopathy CT Neck Neck CT should be performed with IV contrast. Dual-phase CT imaging (without and with IV contrast) is not usually necessary. CT performed only without IV contrast may be helpful in a small minority of cases. Contrast is useful for distinguishing vessels from lymph nodes and confirming whether a mass is hypervascular as many pulsatile neck masses (especially those in level II or III) are lymph nodes overlying the carotid artery rather than true vascular masses.
Neck Mass Adenopathy. A few studies suggested that US can distinguish between metastatic and inflammatory neck nodes [41-47]. Although these results are promising, scans are user dependent. US serves as a powerful tool for image-guided sampling [48], which is beyond the scope of this document. Advantages of US include the ability to be performed at the point of care and to expedite sampling [14]; however, US is limited for comprehensive evaluation of the deep spaces of the neck, and for larger, multispatial, and malignant lesions. US may play a future rule in identifying unknown primary mucosal tumors, notably in the oropharynx [49]. Techniques such as US elastography and contrast-enhanced US are being explored for possible future clinical applications [44,45,50-58]. FDG-PET/CT Skull Base to Mid-Thigh While there is established literature regarding the use of PET using the tracer fluorine-18-2-fluoro-2-deoxy-D- glucose (FDG)/CT for staging and surveillance of head or neck malignancy, FDG-PET/CT is not an initial imaging study for evaluation of a nonpulsatile neck mass. FDG-PET/MRI Skull Base to Mid-Thigh While there is growing literature regarding the use of FDG-PET/MRI for staging and surveillance of head or neck malignancy, FDG-PET/MRI is not an initial imaging study for evaluation of a nonpulsatile neck mass. Arteriography Cervicocerebral There is no evidence to support the use of catheter angiography for evaluation of a nonpulsatile neck mass. Neck Mass/Adenopathy CT Neck Neck CT should be performed with IV contrast. Dual-phase CT imaging (without and with IV contrast) is not usually necessary. CT performed only without IV contrast may be helpful in a small minority of cases. Contrast is useful for distinguishing vessels from lymph nodes and confirming whether a mass is hypervascular as many pulsatile neck masses (especially those in level II or III) are lymph nodes overlying the carotid artery rather than true vascular masses.