[Quantitative magnetic resonance (MR) imaging of bone marrow in leukemia]

There were many studies on the relationship between magnetic resonance (MR) imaging of bone marrow and clinical laboratory variables of the patients with leukemia; however, few of them had separated lymphoid leukemia (LL) from myeloid leukemia (ML). The current study was designed to investigate the role of signal intensity ratio (SIR) of MR Imaging in the characteristic diagnosis and tumor burden evaluation in leukemia by separately measurement of spinal marrow SIR in LL and ML.

Spinal marrow in 20 LL patients and 10 ML patients in initial consultant were examined with MR imaging. The diagnosis of leukemia in all the patients was proved by iliac marrow cytological examination. MR imaging of spinal marrow was performed with 0.5T super-conducting system. T1-weighted imaging with spin-echotechniques and T2-weighted imaging with turbo spin-echo techniques were performed. The SIR of spinal marrow to spinal cord in leukemia was calculated on midline sagittal T1-weighted imaging. Meanwhile,peripheral blood routine examination and bone marrow cytological examination was performed.

The SIR of spinal marrow in 20 LL patients and 10 ML patients were 0.72+/-0.11 and 0.73+/-0.11, respectively. There was no statistically significant difference between LL and ML(P=0.836). The SIR of spinal marrow in LL negatively correlated with the percentage of blast lymphocyte in marrow(r =-0.836,P= 0.000),while the SIR of spinal marrow in ML negatively correlated with the percentage of blast myelocyte in marrow (r=-0.673,P= 0.033).

The SIR of spinal marrow is limited in the characteristic diagnosis of leukemia because of its inability to differential LL from ML. The SIR of spinal marrow can be used to evaluate tumor burden in leukemia.