Can a patient with hemolytic anemia be injected with gadolinium?

Depends. Certain patients with hemolytic anemia can have increased risk of allergic reactions to contrast used in scans. However, gadolinium has been used commonly in MRI scans in patients with inherited hemolytic anemias such as sickle cell anemias and thalasemias.
Yes. I was not able to find any contraindication for gadolinium that pertains to hemolytic anemia.