Intraoperative impedance monitoring during CT-guided stereotactic biopsies

In this study, the relationships among computed tomography (CT) characteristics, intraoperative impedance monitoring, and histologic features were evaluated in 46 patients. Preoperatively, the CT characteristics of the proposed trajectory of the biopsy needle were determined and correlated intraoperatively with the impedance profile as obtained with a monopolar electrode. An excellent correlation between high-resolution CT density characteristics and impedance patterns was seen (r = 0.897). A correlation was also seen between CT patterns/impedance profiles and histologic features. Impedance values were also useful in predicting variation between predicted and actual needle trajectory, determining the proximity of normal structures to the probe tip and detecting loculations within cystic structures.