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Objective To investigate the diagnostic value of 3.0T MR high field high-b-value diffusion weighted imaging (DWI) in prostate cancer (PCa) and to analyze its correlation with Gleason classification.Methods A total of 78 cases proved by operation and pathology were collected,including 41 cases of benign prostatic hyperplasia(BPH) and 37 cases of PCa.PCa patients were classified according to postoperative pathological scores,and their correlation with ADC values was analyzed subsequently.Parameter scanning was performed in all patients by using Philps 3.0T MR with b value at 0 s/mm2,1 000 s/mm2 and 1 500 s/mm2.The signal intensity and ADC value of PCa and BPH were compared under two kinds of high-b-values,and the correlation between ADC value and Gleason classification was analyzed.Results It was found that the specificity and accuracy of T2WI combined with b value of 1 500 s/mm2 were higher than these of T2WI combined with b value of 1 000 s/mm2 for the diagnosis of PCa.The ranking result of ADC value corresponding to Gleason score of PCa after operation was:2-4 points ＞ 5-6 points ＞7 points ＞ 8-10 points.Besides,the ADC value of the corresponding lesion with b value of 1 500 s/mm2 was lower than that with b value of 1 000 s/mm2,and the difference was statistically significant (P＜0.05).Conclusion High field high-b-value DWI combined with T2WI is of high value in differential diagnosis of PCa and BPH,and the specificity and accuracy of PCa and BPH improve obviously with the increase of the b value.Additionally,the ADC value is negatively correlated with the Gleason score.
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Objective To explore the value of ultra-high b-value diffusion-weighted imaging(DWI) in diagnosis of prostate cancer. Methods According to inclusion and exclusion criteria, 73 consecutive examinees in Chinese PLA General Hospital from June 2014 to May 2015 were screened. Written informed consent was obtained from all patients. T2WI, conventional DWI with b-value of 1 000 s/mm2and ultra-high b-value DWI with 2 000 s/mm2and 3 000 s/mm2were performed in each examinee. Images were interpreted and were corresponding to histological results conducted by ultrasound guided prostate systematic biopsy. Reference biopsy as the gold standard,the sensitivity,specificity, positive predictive value(PPV) and negative predictive value (NPV) were calculated for each image. Sensitivity and specificity differences between ultra-high b-value DWI and conventional DWI were analyzed. The areas under the curves (AUCs) between ultra-high b-value DWI and other modalities were compared. Results The sensitivity and specificity for ultra-high b-value DWI were 92.5 % and 68.8 % with b-value of 3 000 s/mm2, and they were 88.1 % and 53.1 % for 2 000 s/mm2in peripheral zone. The sensitivity and specificity for ultra-high b-value DWI were 88.0 % and 88.2 % with a b-value of 3 000 s/mm2, and they were 80.0 % and 52.9 % for 2 000 s/mm2in transition zone. The values of sensitivity for ultra-high b-value DWI were significantly higher than those for conventional DWI both in peripheral zone and transition zone (all P <0.000 1). The detection of lesions was comparable with ultra-high b-value DWI at 2 000 s/mm2and 3 000 s/mm2in peripheral zone (P >0.05), whereas the value of specificity for 3 000 s/mm2were significantly higher than that for 2 000 s/mm2in transition zone (P<0.000 1). PPV and NPV for 3 000 s/mm2were significantly higher than those for the other three modalities both in peripheral zone(86.1 % and 81.5 %) and transition zone (91.7 % and 83.3 %). In peripheral zone, the AUCs were 0.591, 0.553, 0.698 and 0.806 in T2WI, conventional DWI and ultra-high b-value DWI at 2 000 s/mm2 and 3 000 s/mm2respectively, for the diagnosis of transition zone cancer were 0.693, 0.506, 0.665 and 0.881 respectively, and the AUCs for the ultra-high b-value with 3 000 s/mm2were the largest. Conclusion Ultra-high b-value DWI is an accurate and reliable method in the diagnosis of prostate cancer.
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Objective To investigate the value of DWI high b value and ADC value in the diagnosis of hyperacute cerebral is-chemia.Methods Adult SD rats were selected and divided into the control and ischemic group by adopting the random number table method,the ischemic group was re-divided into 0.25,0.50,2.00,4.00、6.00 h groups according to the ischemic time,6 cases in each group with a total of 42 cases.The ischemic group conducted the right middle cerebral artery occlusion(MCAO)for performing the head T2WI and DWI scanning(b values were 0,400,800,2 000,3 000 s/mm2),the CNR and SNR values were recorded,rs-T2WI, rs-DWI and relative apparent diffusion coefficient(rADC)were measured.Then the imaging change of ischemic area was observed. The sensitivity and specificity were detected.Results In b=2 000 s/mm2and 3 000 s/mm2,the diagnostic rates of DWI for hyper-acute cerebral ischemia were obviously higher than those in b=400 s/mm2and 800 s/mm2,and when the b values were 400,800, 2 000,3 000 s/mm2,the sensitivities were 16.7%,50.0%,100.0% and 100.0% respectively and the specificities were 16.7%, 50.0%,100.0% and 100.0% respectively.The difference of ADC values under different b values had statistical significance(P<0.05).Conclusion High b value DWI in the diagnosis of hyperacute ischemia is significantly better than that of low b value,espe-cially in the aspect of displaying the lesion at 0.25,0.50 h cerebral ischemia.