rely on indirect evidence of nodal metastases. These include nodal enlargement, three or more borderline–sized nodes in a primary drainage pathway, and a nodal morphology showing a change from an elliptical to a spherical shape. The development of accurate radiologic criteria is important since 25% or more of patients presenting with head and neck cancer and no clinically palpable neck disease ...

The detection of an enlarged echogenic size ("hyperechogenicity") of the substantia nigra on transcranial sonography is increasingly used for the early and differential diagnosis of Parkinson disease. However, the diagnostic value of substantia nigra sonography depends on the quality of its execution. This article with an accompanying video presents a step-by-step description and demonstration ...