1. Division of Image Processing Department of Radiology Leiden University Medical Center PO Box 9600 2300 RCLeiden The Netherlands
2. Medical Physics, Department of Radiology Leiden University Medical Center PO Box 9600 2300 RCLeiden The Netherlands
3. Department of Radiology Leiden University Medical Center PO Box 9600 2300 RCLeiden The Netherlands
4. Department of Pulmonology Leiden University Medical Center PO Box 9600 2300 RCLeiden The Netherlands