Power Doppler ultrasonographic assistance in percutaneous ethanol injection of autonomously functioning thyroid nodules

The purpose of this study was to explore the potential role of Power Doppler (PD) in guiding the percutaneous ethanol injection (PEI) of autonomously functioning thyroid nodules. 32 patients affected with pretoxic (PTA) and 15 with toxic adenoma (TA) were submitted to PEI under PD guidance. All patients with PTA and 13/15 patients with TA were successfully treated (normalization of circulating thyroid hormones and TSH levels and disappearance of nodular hyperactivity with complete recovery of extra-nodular tracer uptake at scintigraphy). PD showed the progressive reduction of the intranodular blood flow, until to its extraction after 6-12 months. Nodular shrinkage was obtained in all patients (from 10.85±1.04 to 2.9±0.3 ml in PTA and from 15.4±1.8 to 4.2±0.7 ml in TA). PD sonographic guidance seems to improve PEI outcome allowing to detect blood flow even in very small vessels, to guide ethanol injection towards the main afferent vessels of the nodules and to monitor the diffusion and the effects of ethanol on nodular vascularization.