| PartⅠ Tumor measurements of quantitative DCE- MRI inprostate cancer:effect of region of intereston measurement consistency ofparametersObjective:To determine the measurement consistencyofquantitative DCE- MRI parametres in prostate cancers basedon different ROI methods.Materials and Methods:A total of 33 patientsconfirmed by biopsy resultswho had prostate routine MRI and DCE-MRI scans were retrospectivly analysedduring 2015 May to December.All patients were post-processed by DCE-MRI quantitative analysis. Two readersmeasured quantitative DCE-MRI parametres accordingto three ROI protocols: whole-volume,single-slice or smallsolid samples.The quantitative DCE-MRI parametres include Ktrans,Kep and Ve value.One doctor Repeat the method after 3 months later. The three protocols werecompared for differences in Ktrans 、 Kep and Ve and introbserverinterobservervariability(measured asthe intraclasscorrelation coefficient,ICC). Bland-Altman plot were used tomeasure the reproducibility of the quantitative DCE-MRI parametres too.Results:The quantitative DCE-MRIparametres of whole-volumemethod and the single slice method showed no significant differences(t = 1.82、1.11、1.66, P value0.78、 2.77、 0.11), butthe quantitative DCE-MRIparametresof smallsolid samples method is higher than the value of whole-volumemethod and the single slice method the difference is statistically significant(t = 4.66、3.55、3.75、4.57、3.73、2.73 respectively,P<0.05). The intra-observer relative ICC Values of quantitative DCE-MRIparametreswere 0.62(0.58,0.66)、0.65(0.57,0.69)、0.48(0.43,0.53)with smallsolid samples method respectively;0.93(0.88,0.96)、0.90(0.85,0.92)、0.75(0.69,0.79) with single slice method respectively and0.98(0.97,0.9)、0.93(0.88,0.96)、0.82(0.77,0.85) with whole-volumemethod. The inter-observer relative ICCValues of quantitative DCE-MRIparametres were 0.49(0.18,0.71)、0.53(0.47,0.60)、0.41(0.37,0.45)with smallsolid samples method respectively;0.88( 0.86,0.91) 、0.82(0.77,0.86)、0.69(0.62,0.74) with single slice method respectivelyand0.92(0.88,0.95)、0.86(0.81,0.90) 、 0.74(0.70,0.77) with whole-volumemethod. Bland-Altman scattered diagram showed that the value of single slice methodand whole-volumemethodisdistribute moreconcentration than smallsolid samples means that the single slice methodand whole-volumemethod have more consistent and reproducibility.Conclisions:Different ROI selection methods have a certaininfluence for the determination of prostate quantitative DCE-MRI parameters, the difference is statistically significant; the quantitative DCE-MRI parameters of single slice methodand whole-volumemethod have more consistent and reproducibility.Part Ⅱ Evaluation of the Histogram analysis of quantitative dynamic contranst enhanced MRI for diagnosing prostate cancerObjective:To investigate the diagnostic efficiency of the quantitative DCE-MRI parameters using whole lesion histogram analysis for prostate cancer and to preliminary correlate the histogram analysis result with histological grade(Gleason score).Materials and Methods: A total of 50 patients confirmed by biopsy results who had prostate routine MRI and DCE-MRI scans were retrospectivly analysed during 2015 May to November.All patients were post-processed by DCE-MRI quantitative analysis, and respectively calculated according to the 3D VOI method and 2D ROI method to determine the Ktrans,Kep and Ve value for Pca area,peripheral zone and the central gland area,histogram analysis was used to the 3D VOI result.The diagnostic ability of the two methods for differentiating PCa from noamal areas were determined by ROC regression. The correlations between the quantitative parameters and Gleason score were assessed with Spearan correlation.Results:The histogram-based Ktrans、Kep(mean,10 th,90th) in the Pca area were higher than those in the peripheral noncancerous region(t value:7.98、5.55、8.56、4.53、3.47、4.39,P<0.05), and the histogram-based Ktrans(mean,10 th,90th) in the Pca region were higher than that in the central gland(t value: 3.19、2.17、3.5,P<0.05). The histogram-based Ktrans(skewness and kurtosis)in the Pca region were lower than that in the peripheral zone(U value 42、51,P<0.05). The histogram-based Ktrans(meas,90th) had dominantly high Az(0.92,0.92) than that of the 2D ROI method(0.85). The histogram-based Ktrans(10th,90 th,skewness) and Kep(mean,10 th,90th) had acorrelation with Gleason score(Spearman coefficient is 0.53, 0.56,0.55 and 0.63 0.66, 0.68 respectively, P < 0.05).Conclusions:The histogram-based Ktrans(mean,10 th,90th) in the Pca area were higher than those in the peripheral and central zone noncancerous region. The histogram-based Kep(mean,10 th,90th) in the Pca area were higher than those in the peripheral zone region The histogram analysis of quantitative DCE-MRI are feasible and have a higher efficiency in diagnosing Pcathan 2D ROI-based approach. And it is feasible to stratify the pathological grade of PCa by quantitative DCE-MRI with histogram metrics. |
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