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Objective To evaluate the utility of apparent diffusion coefficient (ADC) values from DWI in identifying intermediate and high grade prostate cancer (patients harboring Gleason 4 and/or 5 components in their radical prostatectomy specimens). Methods We retrospectively analyzed the DWI of 54 patients with biopsy-proven prostate cancer and biopsy Gleason score (GS)≤3+3=6. These patients were divided into two groups, intermediate and high grade prostate cancer (patients harboring Gleason 4 and/or 5 components in their radical prostatectomy specimens) and low-grade prostate cancer (patients not harboring Gleason 4 and/or 5 components in their radical prostatectomy specimens). ROIs were drawn on areas of the most suspicious lesion on T2WI and the ADC values were calculated. The ADC values of the two groups were compared to determine whether there were differences between them with independent-sample t test. Receiver operating characteristic (ROC) curve was used to determine the ability of ADC values in differentiating intermediate/high grade prostate cancer from low-grade prostate cancer. Results Twenty-eight patients had intermediate and high grade prostate cancer while the other twenty-six ones had low-grade prostate cancer. Significant differences were found for the ADC values of these two groups [(0.905±0.162)×10-3mm2/s vs. (1.143±0.165)×10-3mm2/s, t=5.361,P<0.01]. The area under the ROC curve of ADC in differentiating intermediate and high grade prostate cancer from low-grade prostate cancer was 0.861, with sensitivity of 88.5% and specificity of 67.9% at the cut-off of 1.000 × 10-3mm2/s. Conclusion The ADC values of suspicious areas in prostate contribute to identify intermediate/high grade prostate cancer in patients with a GS≤3+3=6 on biopsy.
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Objective To retrospectively evaluate the utility of apparent diffusion coefficient (ADC) values in predicting aggressiveness of prostate cancer.Comparison was made with transrectal ultrasound-guided biopsy Gleason scores (GS) and prostatectomy GS.Methods Diffusion weighted images of 51 patients with biopsy-proven prostate cancer were obtained using 1.5 T MR with a pelvic phased-array coil.Regions of interest (ROIs) were drawn on areas of the suspicious lesion and the ADC values were calculated.The correlations between the ADC values and prostatectomy GS were assessed with Pearson correlation.The relationship between biopsy GS and prostatectomy GS were also evaluated.Meanwhile,receiver operating characteristic (ROC) curves were used to determine the ability of ADC values and biopsy GS in differentiating low-grade prostate cancer from intermediate/high grade prostate cancer.Results The accuracy of transrectal ultrasound-guided biopsy in predicting prostatectomy GS was 41.2％(21/51).Compared with prostatectomy GS,up to 11.8％ of the patients (n =6) was overestimated by biopsy,while 47.0％ (n =24) were underestimated.These 51 patients had a mean ADC value of (0.974 ±0.194) × 10-3 mm2/s.The mean ADC value of intermediate/high-grade tumors (n =35) was (0.907 ±0.160) ×10-3 mm2/s while that of low-grade tumors was (1.121 ±0.185) × 10-3 mm2/s (n =16).A significant negative correlation was found between mean ADC values of suspicious lesions and their prostatectomy GS (r =-0.761,P ＜ 0.01).No significant correlation was found between biopsy GS and prostatectomy GS (r =0.187,P =0.189).The area under the ROC curves of ADC and biopsy GS was 0.827 and 0.689,respectively.Conclusion The ADC values of cancerous areas in prostate perform better than biopsy GS in predicting aggressiveness of prostate cancer.
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Objectives To investigate the feasibility of the quantitative analysis parameters of dynamic contrast-enhanced MRI (DCE-MRI) in the diagnosis of prostate cancer and to correlate Ktrans, Ve and kep with histological grade (Gleason score) and serum prostate specific antigen (PSA). Methods MR examinations were performed in 38 patients confirmed by biopsy. ROI were drawn on areas of cancerous foci,noncancerous foci in the peripheral zone and central gland to measure the values of Krans, Ve and kep. The values of the three parameters in different tissue were compared with ANOVA. The correlations between the pharmacokinetic parameters and Gleason score, PSA were assessed with Pearson correlation. Results The Ktrans, Ve, kep values of cancerous foci were (0. 35 ± 0. 26 )/min, ( 0. 185 ± 0. 080 ), ( 1.42 ± 0. 53 )/min,respectively, while (0. 07 ± 0. 05 )/min, ( 0. 040 ± 0. 024 ), (0. 50 ± 0. 18 )/min for noncancerous foci in the peripheral zone and (0. 19 ±0. 06)/min, (0. 161 ± 0. 062), (0. 94 ±0. 25) /min for noncancerous foci in the central gland, respectively. The differences between the three parameters of cancerous foci,noncancerous foci in the peripheral zone and central gland were statistically significant ( F = 16. 267,44. 084, 36. 095, respectively; P ＜ 0. 01 ). No significant correlations were found between any parameter and either Gleason score or PSA (r =0. 279,0.069, 0. 109, -0. 175, -0.067,0. 137, respectively;P ＞0. 05). Conclusion Quantitative analysis parameters of DCE-MRI are feasible in diagnosing prostate cancer. They may be useful in differentiating prostate cancer from benign prostatic diseases.
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Objective To investigate the clinical value of MR elastography in the diagnosis of prostate cancer at 3.0 T, and to assess the elasticity and viscosity of prostate cancer and benign prostatic diseases. Methods Eight patients (63±7years old) with 12 foci of prostate cancer and 10 patients(59±3 years old) with 14 foci of prostatitis in the peripheral zone were evaluated by MR elastography.MR elastography was performed by transmitting low-frequency longitudinal mechanical waves of 100 Hz into prostate with a transducer placed above the pubic bones. The phase images were reconstructed to acquire viscoelastic mapping. T test was used to compare the mean elasticity and viscosity of prostate cancer and prostatitis. The correlation of elasticity and Gleason scores between prostate cancer and prostatitis were also retrospectively analyzed with Pearson Correlation. Results The mean elasticity and viscosity were significantly higher in prostate cancer[(6.55±0.47)kPa,(6.56±0.99)Pa·s,respectively]than in prostatitis[(1.99±0.66)kPa,(2.13±0.21)Pa·s,respectively],and the difference was statistically significant (t=19.392,16. 372; P ＜ 0.01). In 8 patients with prostate cancer, the Gleason scores were 5 (2 cases), 6 (3 cases), 7 (2 cases) and 8 (1 case), respectively. The mean elasticity for the cases with different Gleason scores was 5.83,6.02,7.45 and 8.05 kPa, respectively. There was a positive correlation between Gleason scores and elasticity of the prostate cancer( r = 0. 913, P ＜ 0. 01 ) in this study.Conclusion MR elastography can be used to visualize the difference in stiffness between prostate cancer and benign prostatic disease, it is a new imaging method with great potential in grading of prostate cancer.
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Twenty patients with prostate cancer and 20 patients with benign prostate hyperplasia (BPH) in the transitional zone underwent magnetic resonance imaging (MRI) /magnetic resonance spectroscopic imaging ( MRSI ) examinations. The choline + creatine/citrate (CC/Ci) ratio and the choline/creatine (Cho/Cr) ratio were evaluated in each voxel with cancer or BPH confirmed by pathological results.Discriminant analysis was used to determine the power of the two ratios in differentiation between cancer and BPH. The CC/Ci ratio and Cho/Cr ratio for cancer voxels were significantly higher than those in the voxels with BPH in the transitional zone (CC/Ci: 2.26 ± 1.35 vs. 0.81 ±0.22, t =5.17, P ＜0. 01, Cho/Cr:4. 12 ± 1.65 vs. 1.25 ±0. 35, P＜0. 01 ). As for the discriminant function with the CC/Cr ratio and the Cho/Cr ratio, the specificity, sensitivity, and accuracy were 99%, 86%, 93% respectively for the differentiation between cancer and BPH.
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Objective To explore the clinical utility of arterial spin-labeling (ASL) magnetic resonance(MR)imaging for the detection of cerebral blood flow (CBF) abnormalities in patients with Alzheimer disease(AD). Methods Twenty-two subjects with probable AD and twenty normal control subjects underwent ASL and structural MR imaging. Among them, 16 AD patients and 11 control subjects were also examined with single photon emission computed tomography(SPECT). The CBF images were obtained by processing ASL perfusion data. The CBF values of bilateral frontal lobe, temporal lobe, temporoparietal junction, parietal lobe, occipital cortices and hippocampal areas were measured by CBF images. And the CBF values of cerebral structures between AD and control subjects were compared. Results ASL perfusion imaging in AD revealed marked hypoperfusion mainly in temporal lobe (72.7%), temporoparietal junction (54.5%), parietal lobe(45.5%). The brain regions involved were similar to those seen with SPECT. The CBF values of bilateral frontal lobe, temporal lobe, temporoparietal junction, parietal lobe and hippocampal areas were significantly decreased compared with control subjects (all P<0.05). The CBF values of right frontal lobe, left temporoparietal junction, left parietal lobe in patients with AD were positively correlated with the mini-mental state examination score (r= 0.49, 0.54, 0.64, all P<0.05). Conclusions ASL MR imaging can show regional hypoperfusion in AD patients, which is similar to that seen with SPECT. The results suggest ASL MR imaging is an useful tool for assessment of cerebral blood flow in patients with AD.