MAGNETIC-RESONANCE RELAXATION-TIMES OF NORMAL TISSUE IN THE COURSE OFCHEMOTHERAPY - A STUDY IN PATIENTS WITH BONE SARCOMA

To study the effect of chemotherapy on normal fat, skeletal muscle, an d bone marrow, T1 and T2 relaxation times were measured in 15 patients with bone sarcoma before and after each cycle of preoperative chemoth erapy. A section plane containing the tumor and if possible the nonaff ected extremity was imaged with combined multiecho spin echo and inver sion recovery pulse sequences. T1 and T2 relaxation times were calcula ted in the normal-appearing tissues. Although some variation was found in the values in the individual patient and between patients, no syst ematic changes of relaxation times of fat, muscle, or bone marrow occu rred in the course of treatment. We conclude that the chemotherapy use d in bone sarcoma has no effect on relaxation times of normal fat, mus cle, and bone marrow, and that therefore these tissues may serve as a reference for the signal intensity of tumor.