Applied Research On Prostate By MR Diffusion Weighted Imaging

Objective To describe diffusion weighted imaging(DWI) and apparent diffusion coefficient(ADC) map appearance of the normal prostate,benign hyperplasia(BPH) and prostate cancer(PCa),and to evaluate ADC values in differential diagnosis of PCa.Methods 15 cases with normal prostate,48 cases with BPH and 28 cases with PCa, 1 case with tuberculosis of prostate were examined by MRI and DWI,DWI and ADC map findings were reviewed.ADC values of the marked foci of the PCa patients and ADC values of peripheral zone(PZ) and central glands(CG) voxels in BPH and normal prostate,and ADC values of the tuberculosis of prostate were measured.The ADC values of the bladder were also measured to assess the validity of the method. ADC values of cancerous tissue were compared to those of hyperplastic tissue and normal tissue by statistical analysis.Results DWI can display the CG and PZ of the normal prostate.On DWI,PZ of BPH demonstrated homogenous slightly signal intensity(SI),CG appeared heterogeneous SI.The intensity of PCa appeared to be higher in the DWI images while the factor b was greater.The tuberculosis of prostate showed low or high signal intensity on DWI,The mean ADC was(0.659±0.102)X10^-3mm²/s.When the factor b was constant,the ADC values of bladder among 3 groups had no statistical difference.The mean ADC of the PZ,CG of the normal prostate groups was(1.884±0.378)X10^-3mm²/s,(1.602±0.275)X10^-3mm²/s, respectively,and(1.762±0.170)X10^-3mm²/s,(1.485±0.351)X10^-3mm²/s in the BPH groups,respectively,and(1.210±0.217)X10^-3mm²/s,(1.467±0.321)X10^-3mm²/s in the PCa groups.The mean ADC of the PCa was significantly lower than that of PZ and CG of the BPH and the normal prostate.The mean ADC of the PCa was significantly lower(F=67.821,P=0.000) than that of PZ of the normal prostate and the BPH,but the different between the PZ of the normal prostate and the BPH had no statistical significance(P=0.341).Conclusion(1)MR DWI can give quantitative information for pathological changes in BPH and PCa.(2) MR DWI plays an important role in the diagnosis of PCa.DWI map can well display PCa location and area.PCa showed high signal intensity on DWI,the ADC value was lower in cancerous tissue than that in healthy tissue of the prostate and in the tissue of BPH. ADC value measured from DWI can be used to differentiate BPH and PCa,and to diagnosis early PCa.(3)MRI added to DWI can provide the information of morphology and pathological change,which can improve accuracy of diagnosis to PCa.