One of the striking novel findings in the BioImage study was the prevalence of subclinical atherosclerotic disease in the carotid arteries as determined by a novel 3D ultrasound method. 3D carotid imaging was used to identify lesions located in the cervical part of the common carotid arteries (CCA) and internal carotid artery. 3D carotid imaging was initially performed using a high- resolution, linear array 2-dimensional transducer and scanning the artery in cross-section, slowly moving the transducer manually in the cranial direction from the proximal CCA into the distal internal carotid artery (i.e., from the clavicle to jawbone). The resulting 10-s digital video clip of this "manual 3D" cross-sectional sweep was examined in the core ultrasound laboratory for the presence and quantification of plaque. In the second phase of the study an electromechanical transducer was used to accomplish a similar sweep, replacing the manual sweep with a controlled movement of the transducer.