To investigate the relationship between RDW and the shape of the blood flow profile in carotid arteries, blood flow was measured by 9 Tesla MRI in distinct animal models of high RDW: mice with induced anemia (n = 9), mice with implanted murine colon cancer CT26 cells (n = 8), mice treated with erythropoietin (n = 6) and transgenic mice thalassemic Hbb homozygotes. The gene discussed is EPO; the disease is colonic neoplasm.