Targeted sonography using an image fusion technique for evaluation of incidentally detected breast lesions on chest CT: a pilot study

Background With increasing use of computed tomography (CT), incidentally detected breast lesions are being encountered more frequently. The aim of our study was to verify the utility of targeted sonography using an image fusion technique, real-time virtual sonography (RVS) that coordinates real-time sonography images with previously obtained CT images using a magnetic position tracking system, for evaluation of incidentally detected breast lesions on chest CT. Methods Eleven lesions in 11 women with no history of breast cancer who were referred to our unit for assessment of breast lesions incidentally detected on CT were enrolled in this study. To assess the efficacy of targeted sonography using RVS, we analyzed the frequency of sonographic detection of incidentally detected breast lesions and the difference between sonography- and CT-determined diameters. Results Using RVS guidance, all 11 lesions were sonographically detected. Ten (91 %) of 11 lesions underwent sonography-guided biopsy, yielding a success rate of 90 % (9/10). The remaining sonography-guided biopsy failure lesion required surgical biopsy for definitive diagnosis; this was performed after RVS was used to mark CT imaging information onto the breast surface. Four (36 %) lesions subsequently proved to be malignant. The mean diameters provided by RVS were 14.9 ± 6.7 mm for sonography and 16.8 ± 7.5 mm for CT ( p = 0.538). Conclusion Using RVS, a sonographic probe was precisely guided to the lesions. Our results suggest that targeted sonography using RVS is a useful technique for identifying incidentally detected breast lesions on chest CT.