Objective: To evaluate the sensitivity, specificity and diagnostic accuracy of a cut-off of the resistive index of 0.5 for the differentiation between inflammatory and neoplastic primary lymphadenopathies.
Subjects and methods: We measured the resistive index of superficial enlarged lymph nodes in a total of 50 patients (29 males and 21 females; age range 12-72 years, mean age 41.6 year) using an ATL 5000 HDI. A resistive index greater than or equal to 0.5 indicated an inflammatory lymph node and a resistive index <0.5 was consistent with neoplastic primary lymphadenopathies. The gold standard was either surgical biopsy or lymph-node reduction seen with ultrasound examination after antibiotic therapy.
Results: The sensitivity of the resistive index for distinguishing inflammatory from neoplastic lymphadenopathy was 84.6%, the specificity 100% and the diagnostic accuracy 95.7% (P < 0.001, statistically significant).
Conclusion: The results of this study indicate that power-Doppler using a resistive index cut-off of 0.5 was a valid technique for distinguishing between inflammatory and primary neoplastic lymph nodes in patients with superficial lymphadenopathies.