A Comparison Study between Compound Imaging and Conventional Ultrasonography in Subareolar Area

Purpose: The subareolar area is often difficult to evaluate ultrasonographically due to tissue shadowing, which obscures visualization of ducts and parenchymal tissue. The purpose of this study is to determine if real-time compound imaging improves evaluation of normal subareolar tissue and solid nodules in subareolar area compared to conventional ultrasonography. Methods: 190 images of the subareolar area were obtained from 135 patients from March 2001 to July 2002. Thirty-three of 190 images showed solid nodules, extraductal nodules in 30 and intraductal nodules in three. We scanned both conventional and compound imaging with a stationary probe, to maintain an identical projection and tissue pressure. We used two compound techniques; survey mode (S) is made by 3 coplanar images and target mode (T) by 9 coplanar images. The evaluating points were 1) reduction in the density of shadowing, 2) resolution of duct wall, 3) resolution of duct lumen, 4) margin of nodule, and 5) internal echoes of nodule. In a blinded fashion, three radiologists graded the quality of images on a 5-point scale. Results: For reviewer 1/2/3, S showed grade improvements in 1) reduction in the density of shadowing (0.4±0.6/1.1± 0.6/0.5±0.5), 2) resolution of duct wall (0.9±0.2/1.5± 0.6/1.0±0.5), 3) resolution of duct lumen (0.9±0.2/1.6± 0.6/0.7±0.6), 4) margin of nodule (1.0±0.3/1.5±0.5/1.2± 0.5), and 5) internal echoes of nodule (1.1±0.3/1.5±0.5/1.2 ±0.4) and T showed grade improvements in 1) reduction in the density of shadowing (0.4±0.6/1.2±0.6/0.7±0.7), 2) resolution of duct wall (1.0±0.3/1.5±0.6/1.1±0.5), 3) resolution of duct lumen (0.9±0.3/1.6±0.6/0.8±0.6), 4)