Nodal shape (S/L) and its combination with size for assessment of cervicallymphadenopathy: Which cut-off should be used?

The short axis to long axis (Sn) ratio is commonly used to assess cervical lymphadenopathy; however, the cut-off value used has been limited to 0.5. T he accuracy of the combination of Sn ratio and nodal size has not been docu mented previously, We evaluated 1143 normal cervical nodes from 95 healthy subjects, and 1441 nodes from 290 patients with proven cervical lymphadenop athy, The optimum cut-off value of the Sn ratio was determined in different regions of the neck: submental (0.5), submandibular (0.7), parotid (0.5), upper cervical (0.4), middle cervical (0.3) and posterior triangle (0.4). I n the submandibular and parotid regions, the combination of the S/L ratio a nd short axis shows substantial improvement in diagnostic accuracy when com pared to the Sn ratio alone. (C) 1999 World Federation for Ultrasound in Me dicine & Biology.