| Background and purpose:Prostate cancer (Pca) is one of the most common malignant tumors in elderly man, which has a high incidence in Europe. In China, the incidence of prostate cancer raised obviously for an aging population, lifestyle changes and improvement of medical treatment. Therefore, it' s one of the hot medical research that searching of new technologies and new methods for the diagnosis of prostate disease. Nowadays, with development of the hardware and software of magnetic resonance equipment, a growing number of new technologys have been used in the diagnosis of prostate disease, in which Hydrogen 1 Proton Magnetic Resonance Spectroscopy (~1H-MRS ) and Diffusion-Weighted Imaging (DWI) are important methods. In this study, we analyzed conventional MR, MR Spectroscopic and Diffusion-Weighted MR to discuss the diagnostic value of them in prostate carcinoma and relationship between the ~1H-MRS metabolic ratio , ADC value and Gleason scale.Materials and methods:Forty-eight male patients of elevated PSA values, abnormal in digital rectal examination or (and) transrectal ultrasound had undergone SIEMENS Magnetom Trio Tim 3 Tesla (T) superconductive MR examination, including MRI, ~1H-MRS and DWI examination. The mean age was 71.3±5.6 years (range 53～87 years). Transrectal ultrasound guided biopsy or surgery were operated in one month after the examination.MR images were analyzed and staging by two experienced physicians independently MR imaging of the prostate was performed with conventional turbo spin echo(TSE) T1-weighted and T2-weighted axial, sagittal and cronal pulse sequences. After the data acquisition, the Cho/Cit and (Cho+Cr)/Cit ratios were calculated on the basis of the ~1H-MRS metabolic maps. DWI was scanned by using echo-planar imaging (EPI) sequence, b-value (diffusion coefficient) was set as 0,400, 800 and 1000 s/mm~2, and calculated the area of interest apparent diffusion coefficient (ADC). All prostate cancer cases were scored by experienced diagnosticians from pathologic department. According to Gleason grading, 1 on behalf of the best differentiation, when 5 on behalf of the worst. Statistical data was analyzed by SPSS 15.0 version statistical analysis soft-ware, two group's classified information was compared by Chi-square test (X~2- test) , multi-variable numerical was compared by one-way ANOVA and two sets of numerical data was compared by Student's t-test, the data were presented as mean values plus or minus standard deviation (SD). Significant level was set as a= 0.05. Receiver operating characteristic (ROC) analysis was used to find out the best Cho/Cit, (Cho +Cr)/Cit ratio and ADC values for diagnosis prostate cancer.Results:A total of 48 patients including 18 prostate cancers and 30 benign prostate hyperplasias (BPH), which proved by histopathologic findings. Staging of the prostate cancer cases according to the conventional MR imaging: stage A of one case(6%), stage B of four cases (22%), stage C of four cases (22%), stage D of nine cases (50%). the sensitivity and specificity of diagnosis prostate cancer by conventional MRI were 77.78% and 73.33%. The mean Cho/Cit, (Cho +Cr)/Cit ratio of the prostate cancer were significantly higher than that of peripheral zone of normal part and BPH. The mean ADC value of the prostate cancer were significantly lower than that of peripheral zone of normal part and BPH. There was statistically difference of the mean Cho/Cit, (Cho +Cr)/Cit ratio and ADC values between the prostate cancer located in central zone and BPH. Under the ROC curve, when Cho / Cit value of 0.43, the sensitivity and specificity of diagnostic were 88.9% and 70%, Cho / Cit value of 0.62, the diagnostic sensitivity and specificity were 83.3% and 96.7%; (Cho+Cr)/Cit values were 0.79 and 0.84, the diagnostic sensitivity and specificity were 88.9%, 73.3% and 83.3%, 86.7%. 18 cases of prostate cancer were divided into two groups: poorly differentiated and middle-differentiated group. There was statistically difference of the mean Cho/Cit, (Cho +Cr)/Cit ratio and ADC values between them.Conclusion:1. MRI plays an important role in detection and diagnosis of the prostate cancer lesion. 2. ~1H-MRS will be combined metabolic imaging with anatomical imaging. There was statistically difference of the mean Cho/Cit, (Cho +Cr)/Cit ratio of prostate cancer and peripheral zone of BPH. 3. Combination of DWI and conventional MRI can improve the diagnostic specificity of prostate cancer obviously. There was statistically difference of the mean ADC value of prostate cancer and peripheral zone of BPH. 4.~1H-MRS and DWI have an great help for the diagnosis of central zone prostate cancer. 5. The sensitivity and specificity of right Cho/Cit, (Cho+Cre)/Cit ratio and ADC value to diagnosis of prostate cancer are much higher than that of conventional MRI. 6. MRI functional imaging chould reflect the degree of differentiation of prostate cancer. |
PDF Full Text Request