Changes in T₁ relaxation processes in the bone marrow following treatment in children with acute lymphoblastic leukemia - A magnetic resonance imaging study

Magnetic resonance imaging (MRI) and T₁ relaxation time measurements of the vertebral bone marrow were performed in 11 children with acute lymphoblastic leukemia (ALL) at diagnosis. Nine of the children were re-examined after chemotherapeutic treatment. The results were compared with histological data from bone marrow biopsies obtained in close association to the MR examinations. Ten age matched children were examined as a control group. A 1.5 Tesla whole body scanner was used for the measurements. The pretreatment T₁ relaxation times of the bone marrow were significantly prolonged, compared to the age matched controls. After chemotherapy the T₁ relaxation times of the children with ALL decreased significantly towards or into the normal range. A significant correlation was found between the T₁ relaxation time and the content of malignant blast cells in the bone marrow.