1. Departments of Imaging Physics The University of Texas MD Anderson Cancer Center Houston TX 77030 USA
2. Department of Medical Physics School of Medicine and Public Health University of Wisconsin‐Madison Madison WI 53705 USA
3. Departments of Diagnostic Radiology The University of Texas MD Anderson Cancer Center Houston TX 77030 USA
4. Department of Diagnostic Radiology and Nuclear Medicine University of Maryland School of Medicine Baltimore MD 21201USA
5. Department of Neurosurgery The University of Texas MD Anderson Cancer Center Houston TX 77030 USA