High-sensitivity power Doppler imaging of normal superficial lymph nodes. 
This study was conducted to describe the various patterns of vascularity of the normal superficial lymph nodes detected using high-sensitivity power Doppler imaging according to the dimension and anatomic location of the nodes.  A total of 712 lymph nodes (416 in the neck, 205 in the groin, and 91 in the axilla) were studied in 118 patients with high-sensitivity Power doppler.  Three categories of vascularity were defined: absence of vascularity (type 1), hilar and perihilar vascularity (type 2), and vascularity in the entire node (type 3).  The 3 types of vascularity were correlated with the anatomic location and the dimension (maximum transverse diameter) of the nodes.  Type 3 vascularity was found in all lymph nodes with a maximum transverse diameter > 6 mm, in the 67.9% (133/196) of lymph nodes between 4 and 6 mm in diameter, and in 45.7% (42/92) of lymph nodes between 2 and 4 mm in diameter.  In lymph nodes with transverse diameters of 2-6 mm, type 3 vascularity was detected in 80.7% (46/57) of the axillary nodes, in 69.0% (87/126) of the inguinal nodes, and in 40.0% (42/105) of the cervical nodes.  Type 2 vascularity was seen in 14.2% (101/712) of all examined lymph nodes.  The absence of vascularity (type 1) was noted in only 1.9% (8/416) of cervical and 2.0% (4/205) of inguinal nodes.  State-of-the-art power Doppler equipment can demonstrate type 3 vascularity in a high percentage of normal superficial lymph nodes.  This pattern of intense, extensive-but harmonious-vascularity must be considered as an indicator of benignity.