Signal intensity values were measured in an operator-defined region of interests (ROIs). The musculoskeletal radiologist (T.T.F.S., with 15 years experience) places the ROIs were placed with the aid of a cursor and a graphic display device, along the border of high-signal-intensity bone marrow on T1 weighted images covered the entire bone marrow of each vertebra. One vertebral body was covered by one ROI measurement. The ROI was measured separately for each of selected lumbar vertebrae (L2, L3 and L4) in each subject. The signal intensity values derived from the ROI measured in each vertebral body were then plotted against time to obtain a time–signal intensity curve (Fig 1) for each vertebral body. The baseline value for signal intensity (SIbase) on a time– signal intensity curve was defined as the mean signal intensity from the first three images. The maximum signal intensity (SImax) was defined as the maximum value of the first rapidly rising part of the time–signal intensity curve. The time to peak contrast enhancement was defined as the time (Trise) between SIbase and SImax. After the peak, which usually occurred about 40 seconds after the start of injection, the time–signal intensity curve entered an equilibrium phase that lasted about 30 seconds. The total 100-second imaging time encompassed both the first rapid rise in the curve and the early equilibrium phase. In our study, the SIbase and SImax were measured only from the first rapidly rising curve. For the semiquantitative analysis, the peak enhancement ratio peak was calculated for each ROI as (SImax – SIbase)/SIbase and average enhancement slope (average slope) was defined as (SImax – SIbase)/ Trise for each ROI. The initial slope was measured as the most steep uprising slope from the early rapid-rising part of time intensity curve. The mean value was calculated from the parameters of the L3, L3 and L4 vertebrae and represented for each subject. In our preliminary study, like others [Moehler et al, 2001], this constructed images performed by dynamic contrast-enhanced MRI, which mimic the perfusion status within bone marrow, had been correlated with distinct clinical outcomes in our acute myeloid leukemia and MM patients in a preliminary study.