A 60 yr old female with history 8 blood transfusions in 2yrs.Her Hb-60g/I , TLC-5800, platelet-3.4 Iakhs, MCV-60, RBC-2.1 lakhs/mm3. She is having hypochromic mierocytic anemia. Which investigation is not needed?-

Idiopathic pulmonary hemosiderosisis a rare disease characterized by repeated episodes of bleeding into the lungs, which can cause anemia and lung disease. The body is able to remove most of the blood from thelungs, but a large amount of iron is left behind. Ref Robbins 9/e pg 419