1. Department of Hematology, Faculty of Medicine, and
2. Department of Diagnostic Imaging, Graduate School of Medicine, Hokkaido University, Sapporo, Japan;
3. Blood Disorders Center, Aiiku Hospital, Sapporo, Japan;
4. Department of Hematology, Sapporo Hokuyu Hospital, Sapporo, Japan;
5. Department of Radiology, Central CI Clinic, Sapporo, Japan; and
6. Department of Radiology, Keiyukai Sapporo Hospital, Sapporo, Japan