Intravoxel Incoherent Motion Diffusion-weighted Imaging In Clinical Application Of Acute Myeloid Leukemia With Bone Marrow:A Pilot Study

Objective: Using multi-b value DWI technology with the Intravoxel incoherent motion(IVIM) mode, measurement conventional DWI and Multi-b DWI sequence parameters, thus obtained ADCCON, D, D* and f values, in AML patients with lumbar bone marrow before standardized treatment. Combining with the first chemotherapy, analysis the prognostic value of D, D* and f parameter. Then compare with the WBC count、bone marrow blasts and age, and further analyze the pathophysiological significance of the parameters.Material and Methods: Collection of 53 cases of primary AML patients, all patients underwent MR imaging of lumbar vertebral bone marrow. Our MR imaging study included the performance of a routine protocol of sagittal T1-weighted, conventional DWI( b=0,500s/mm2), and Multi-b DWI(b= 0~1200 s / mm2 gradually increased by a total of 11 b values), the traditional ADC value, D value, D* value and f value of lumbar vertebrals( L2–L4, the three vertebraes are in the middle of the visual field, in order to reduce the error)bone marrow were measured;and record the patient’s age and WBC count、bone marrow blasts which were examined at the same time with MRI. 1, 53 patients were divided into CR group and NR group after the first standard chemotherapy, and compared the difference of traditional ADC, D, D* and f values between the two groups. And using the AUC to evaluate the ability of various parameter values in prediction of the prognosis in AML; 2, Analysis the correlation between the WBC count 、bone marrow blasts and age of AML patients and the traditional ADC value, D value, D* value and f value.Results: There was no statistical differences in ADC and D* values between CR group and NR group(P(29)0.05).The D valuess of CR group were higher than NR group, the f valuess of CR group were lower than NR group the difference was statistically significant(P=0.010,0.021); the AUC of the ADC was 0.524, the AUC of D was0. 759 and the AUC of f was 0. 666,there is a certain value in D and f values on the prognosis of AML patients.2, f value was negatively correlated with WBC count(r=-0.373,P=0.027), D value was negatively correlated with the age of AML patients(r=-0.399,P=0.018).There was no correlation between the bone marrow blasts and the parameters of IVIM DWI.Conclusion: 1、Compared with the single exponential model of traditional DWI,Bi-exponential model of DWI based on IVIM has a certain value for evaluating the prognosis of AML patients. When D <0.206×10-3mm2/s, f ﹥21.77%, the treatment effect is poor after the first chemotherapy, and patients with low probability of remission. IVIM DWI is expected to become an effective means to assess the prognosis of AML. 2、The D value can more accurately reflect the diffusion of water molecules in the bone marrow of AML patients than ADC value. 3、The D and f values can reflect the pathological and physiological state of bone marrow of AML patients to some extent, however, it is essential to further adjustment the scanning parameters, and expand the sample capacity to obtain more reliable results.