1. Division of Imaging; Diagnostics and Software Reliability; Office of Science and Engineering Laboratories; Center for Diagnostic and Radiological Health; FDA; Silver Spring MD 20993 USA
2. Department of Mechanical Engineering; Department of Computer Science; Carnegie Mellon University; Pittsburg PA 15213 USA
3. Department of Radiology; Carl E. Ravin Advanced Imaging Laboratories; Medical Physics Graduate Program; Department of Biomedical Engineering; Department of Electrical and Computer Engineering; Duke University; Durham NC 27705 USA