| Objective: To explore the feasibility of diffusion tensor imaging(DTI) and diffusion tensor tractography(DTT) in normal prostate with 3.0 Tesla magnetic resonance imaging system. To investigate the characteristics of fractional anisotropy(FA) and apparent diffusion coefficient(ADC) on PZ and CZ, and to analyze the differences of age-related changes. Thus, to establish the normal reference range which will be helpful in the diagnosis of prostate disease.Methods: 50 healthy volunteers with no history of prostate disease were divided into 3groups according to different age: group A(15~30 years, n=14),group B(31~50 years,n=24),group C(51~63 years, n=12). T2-weighted images with fat saturation and DTI with single-shot echo planar imaging of the normal prostate were obtained. The measurements of FA and ADC values in PZ and CZ, the reconstruction of prostate fibers were performed using Neuro 3D software. Differences between parameters of the PZ and CZ were assessed.The DTT map was reconstructed, which can visualize the prostate fibers. Professional software(SPSS) was used for statistical analyse. The differences of FA and ADC values on PZ and CZ of normal prostate were analysed by paried t test. The differences of the FA and ADC values on PZ and CZ of normal prostate in each group were analysed by paried t test also. The correlation of FA and ADC values and with age was studied using Pearson correlation analysis.Results: ① The measurements of FA and ADC values, the reconstruction of prostate fibers were performed successfully of 50 healthy volunteers. The orientions of fibers on PZ were right to left and anterior to posterior mainly. The oriention of fibers on CZ was head to foot mostly. ② The FA values on PZ and CZ were 0.175±0.031, 0.239±0.032. The ADC values on PZ and CZ were(1.691±0.144)×10-3mm2/s,(1.450±0.113)×10-3mm2/s. There were significant differences of the FA and ADC values on PZ and CZ(P<0.05). ③ There was no significant difference of the FA and ADC values between the left and right of PZ(P>0.05). ④ There were significant differences of the FA and ADC values on PZ and CZ in each group(P < 0.05). The FA and ADC values on PZ in different age groups were0.186±0.028, 0.173±0.025, 0.166±0.030;(1.548±0.107)×10-3mm2/s,(1.723±0.024)×10-3mm2/s,(1.802±0.125)×10-3mm2/s, respectively. There were significant differences of FA and ADC values on PZ between these groups(P<0.05). The FA and ADC values on CZ in different age groups were 0.238±0.288, 0.232±0.026, 0.224±0.033;(1.405±0.115)×10-3mm2/s,(1.439±0.119)×10-3mm2/s,(1.483±0.102) ×10-3mm2/s respectively. There was no significant difference of FA and ADC values on CZ among these groups(P > 0.05). ⑤ Pearson analysis suggested that the FA values on PZ were negative correlation with age(r=-0.498, P < 0.05), and the ADC values on PZ were positive correlation with age(r=0.682,P<0.05). There was no correlation between the changes of FA and ADC values and age on CZ.Conclusions: 3.0 Tesla DTI of normal prostate is feasible. The values of FA and ADC can reflect the differences of fine structure organization and the age-related changes. DTT can show the spatial structural characteristics of normal prostate fibers.Objective: To explore the characteristics of parameters value and parameters map of DTI in benign prostatic hyperplasia(BPH). To evaluate the value of apparent diffusion coefficient(ADC) and fractional anisotropy(FA) in prediction the histotype of benign prostatic hyperplasia(BPH).Methods: A retrospective analysis of fifty patients with pathologically confirmed BPH underwent T2-weighted images with fat saturation and DTI scanning. The measurements of FA and ADC values in BPH, the reconstruction of parameters map were performed using Neuro 3D software. Differences of FA and ADC values between different types of BPH were assessed by Indepent-Samples t test. The diagnostic efficacy of the FA and ADC values in distinction grandular BPH and stromal were assured using receiver operating characteristic curve(ROI). Differences of parameters map between different types of BPH were observed.Results: There were thirty grandular BPH and twenty stromal BPH. ① The signal characteristic of DTI parameters map: on T2WI-FS imaging、FA map、ADC map, the signal was better uniform in stromal BPH than in grandular BPH. DTT maps showed the prostatic fiber was rule, dense and without break in stromal BPH. While in grandular BPH,the partial fiber was disorder and break. ②In grandular BPH and stromal BPH, the FA values were 0.257±0.037, 0.294±0.012 respectively. There were significant differences between the two groups(t=5.188, P < 0.05). The ADC values were(1.377±0.056)×10-3mm2/s,(1.197±0.092)×10-3mm2/s respectively. There were significant differences between the two groups(t=-7.860,P<0.05). ③ According to ROC analysis,the FA and ADC values have a high diagnostic efficacy to identify different types of BPH.When the appropriate cut off value of FA value was 0.275, the sensitivity was 100% and the specificity was 83.3%. When the appropriate cut off value of ADC value was1.323×10-3mm2/s, the sensitivity was 100% and the specificity was 86.7%.Conclusions: The DTI parameter values and maps play an important part in prediction the histotype of benign prostatic hyperplasia, which can help doctors chose appropriate therapy methods and drugs before clinical treatment.Objective: To explore the differences of diffusion tensor imaging(DTI) quantitative parameters(FA value and ADC value) in the normal prostate of peripheral zone and central gland, benign prostatic hyperplasia(BPH) and prostatic carcinoma(PCa) by the 3.0 Tesla magnetic resonance imaging system. To investigate the FA and ADC values for diagnosing PCa, as well as to the relationship between FA and ADC values with the Gleason score.Methods: Each 50 cases of normal prostate(same with partⅠ), BPH(same with partⅡ),and PCa underwent scanning with conventional MRI and DTI. Post DTI processing was done using Neuro 3D software to measure the FA and ADC values. The 50 cases of prostate cancer were divided into three groups: low, intermediate and high grade according to the Gleason score. The differences of FA and ADC values among normal prostate, BPH,and PCa were investigated using single factor analysis of variance(ANOVA). The diagnostic efficacy of the FA and ADC values in distinction BPH and PCa were assured using receiver operating characteristic curve(ROI). The differences of FA and ADC values among different groups of PCa were explored using ANOVA. The correlation of FA and ADC values with Gleason grade were studied using Pearson correlation analysis.Results: ① The FA value of normal prostate of peripheral zone and central gland, BPH and PCa was 0.175±0.031, 0.239±0.032, 0.272±0.034, 0.326±0.043 respectively. There were statistically significant differences among the four groups(F=157.344,P<0.05) and between each group(P<0.05). ② The ADC value of normal prostate of peripheral zone and central gland, BPH and PCa was 1.691±0.144×10-3, 1.450±0.113×10-3,1.305±0.114×10-3and 0.987±0.122×10-3respectively. There were statistically significant differences among the four groups(F=282.739,P<0.05) and between each group(P<0.05)。③ According to ROC analysis, the area under the ROC curve of the FA value was0.842. The threshold was 0.285 according to the maximum Youden index. The diagnostic sensitivity and specificity was 96% and 66%. The area under the ROC curve of the ADC value was 0.964. The threshold was 1.117±0.113×10-3according to the maximum Youden index. The diagnostic sensitivity and specificity was 92% and 88%. The area under the ROC curve of the ADC value combined with FA value was 0.967, slightly higher than ADC value only. ④ The ADC value of low grade, intermediate grade and high grade was1.070±0.072×10-3, 0.961±0.081×10-3, and 0.821±0.048×10-3respectively. There were statistically significant differences among the three groups(F=49.987, P < 0.05) and between each group(P < 0.05). The FA values were 0.284±0.313, 0.293±0.347,0.369±0.347 respectively. There were statistically significant differences among the three groups(F=234.533,P<0.05) and between each group(P<0.05). ⑤ The correlation of FA value and ADC value with Gleason score: The FA value of PCa was positively with Gleason score(r=0.884,P<0.05). The ADC value of PCa was negatively with Gleason score(r=-0.810,P<0.05).Conclusions: DTI parameters can delineate the microstructure of the normal and pathological prostate, and can provide quantitative diagnostic information. There is a certain value of FA and ADC values for PCa, which could be used to evaluate the grading and prognosis of PCa. |
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