Distribution of intranodal vessels in differentiating benign from metastatic neck nodes

AIM: Recent studies report high accuracy of power Doppler sonography in the differentiation of benign from malignant cervical lymphadenopathy. This st udy was undertaken to identify which of the parameters used in Doppler sono graphy of cervical lymph nodes is accurate and readily applicable in routin e clinical practice. MATERIALS AND METHODS: We reviewed the power Doppler ultrasound examination s of 50 patients with cytologically proven metastatic nodes from nasopharyn geal carcinoma and 50 patients with proven reactive lymphadenopathy. All th e examinations had been performed by an experienced sonologist, and intrano dal vascular distribution and resistance were evaluated during real-time ul trasound, Twenty metastatic nodes and 40 reactive nodes were less than 10 m m in maximum transverse diameter. The vascular patterns of lymph nodes were classified into three categories: (1) hilar; (2) capsular; (3) hilar and c apsular. The resistive index OU) and pulsatility index (PI) were measured b y spectral Doppler, RESULTS: Although metastatic nodes (RI, 0.81 +/-0.11; PI, 1.89 +/-0.89) ten ded to have higher intranodal vascular resistance than reactive nodes (RT, 0.65 +/-0.08; PI, 1.07 +/-0.26), there was considerable overlap of the resi stance parameters between benign and malignant nodes. Most of the metastati c nodes showed the presence of capsular vascularity (capsular, 16%; capsula r and hilar, 78%), whereas the majority of the reactive nodes showed hilar vascularity (98%), and the difference was significant. CONCLUSION: The distribution of intranodal vascularity appears to be more u seful than RI or PI in differentiating benign from malignant cervical lymph adenopathy, It is also easier to evaluate the distribution and the results are therefore readily applicable in routine clinical practice, (C) 2001 The Royal College of Radiologists.