Fig. 2.

: Photograph of the different types of synthetic nodules used in this study. Each column contains nodules in three sizes, and each row contains the five nodule shape categories. From left to right, spherical, elliptical, lobulated, spiculated, and irregular shapes are shown. The three sizes shown here (with the exception of the irregular shapes on the right) were manufactured to have the equivalent nominal volumes of spherical nodules with diameters of 5, 10, and 20 mm.