DWI/ADC is a completely non-invasive technique that has been successfully conducted for many years in brain imaging and is currently being studied for the assessment of other organs, such as the abdomen and pelvis and in particular the head and neck structures. Even though DWI and the ADC measurement are able provide tissue information at the cellular level, most imaging centers have not yet adopted them as part of their routine evaluation of the head and neck. DWI has demonstrated usefulness to discriminate specific histological tumor types, especially to differentiate benign solid lesions from malignant masses, to evaluate lymph nodes, particularly to differentiate benign disease from malignancy, to differentiate postradiation changes from residual tumor and potentially to predict therapy success. Moreover DWI seems to be a safer and more affordable method considering the absence of radiation and to the higher cost of FDG-PET to localize tumors and to differentiate benign from malignant masses. Given all these advantages and strengths, DWI will certainly become part of the routine in the MR imaging of the head and neck.
Head and neck; Tumors; Squamous cell carcinoma; Diffusion weighted imaging; Apparent diffusion coefficient map; Exponential diffusion weighted imaging
