Abstract：Objective: To explore the value of multimodal MRI to identify solid benign and malignant splenic tumors. Materials and Methods: The clinical and medical imaging data of 21 cases of benign splenic tumors and 14 cases of malignant tumors were analyzed retrospectively. Scanning sequences included: T1WI, T2WI, liver acquisition with volume acceleration(LAVA), diffusion weighted imaging(DWI) and enhanced T2 star weighted angiography(ESWAN). The phase, magnitude and R2* maps were generated from the original ESWAN data. The signal intensity on T1WI, T2WI, DWI, and in phase, magnitude, R2* maps as well as tumor characteristics on LAVA sequence of the two groups were tested by Chi-square test. The values of apparent diffusion coefficient(ADC), phase and R2* of the two groups were measured by two observers, and the consistency measured by two observers was tested by the intra-class correlation coefficients(ICC). Mann-Whitney U test was used to compare various parameters of the two groups. Receiver operator characteristic(ROC) curve was used to calculate the cut-off value of ADC, phase, R2* and performance of ADC, phase, R2* value for distinguishing these solid benign and malignant tumors. Results: The signal intensity of the solid benign and malignant tumors on T1WI and T2WI had no difference. However, the signal intensity of malignant tumors on DWI, phase, magnitude on ESWAN and R2* maps had more complicated mixed signal intensity; the two groups showed differences in the enhanced pattern on LAVA sequence, but with overlap. The ADC values, phase values and R2* values of the two groups obtained from the two observers were in good consistency(ICC value >0.75. The ADC of the benign and malignant tumors were (1.80±0.44)×10-3 mm2/s and(1.40±0.40)×10-3 mm2/s with phase of 0.071±0.037 and -0.003±0.119, R2* values of (13.46±9.00) Hz and (42.09±19.82) Hz respectively, all showing statistically significant differences(all P<0.05). The AUC of the ADC, phase and R2* values were 0.754, 0.721 and 0.941, and the best cut-off values for ADC, phase and R2* in characterizing benign and malignant tumors were 1.23×10-3 mm2/s, 0.440 and 20.47 Hz, respectively. Conclusion: The solid malignant splenic tumors show more complicated signals than benign tumors on DWI and ESWAN. The ADC, phase and R2* values can be used as quantitative indexes to identify benign and malignant splenic tumors, and R2* values were more valuable.
2014, Vol. 25 
