Assessment of vascular patterns of small liver mass lesions: Value and limitation of the different Doppler ultrasound modalities

OBJECTIVES: This study aimed to investigate the value and limitation of the different Doppler ultrasound modalities (spectral analysis, color, and pow er Doppler imaging) in the differential diagnosis of small liver tumors to identify the optimal diagnostic approach with the presently available Doppl er technology. METHODS: Presence and distribution of color and power Doppler signals, Dopp ler peak frequency, resistive index, and systolic acceleration time were ex amined in 133 liver nodules (less than or equal to4 cm). RESULTS: Color and power Doppler did not identify specific diagnostic vascu lar patterns. By discriminant analysis, peak frequency (cut-off 1320 Hz) di fferentiates small hematocellular carcinoma (less than or equal to2 cm) fro m macroregenerative nodules and hemangiomas (accuracy 92.6%); resistive ind ex (cut-off 0.65) differentiates malignancies from benign lesions (accuracy 83.8%); and systolic acceleration time (cut-off 105 ms) differentiates hep atocellular carcinoma from metastases (accuracy 80.9%). CONCLUSIONS: Power Doppler imaging is able to assess vascularity in the maj ority of small liver nodules, but the pattern distribution of tumoral vascu lar signals does not provide reliable differential diagnostic criteria. Usi ng conventional Doppler technology, power Doppler should be used to detect vascular signals and spectral analysis, and subsequently to measure quantit ative parameters such as high peak frequency and resistive index (which ide ntify malignancy) and prolonged systolic acceleration time (which identifie s primary from metastatic liver tumors). (C) 2000 by Am. Cell. of Gastroent erology.