1. Department of Medicine, Cumming School of Medicine, University of Calgary, Calgary, AB T2N 4N1, Canada
2. Department of Surgery, Cumming School of Medicine, University of Calgary, Calgary, AB T2N 4N1, Canada
3. Alberta Health Services, Foothills Medical Centre, Calgary, AB T2N 2T9, Canada
4. Department of Radiology, Cumming School of Medicine, University of Calgary, Calgary, AB T2N 4N1, Canada