| Part?The Evaluation of Diagnostic Efficiency of Prostate Cancer with ADC Values Measured by the Reconstruction of ADC Map with Different Low b-Values by using monoexponential model on 3.0 T MR-DWIObjective To investigate the evaluation of diagnostic efficiency of prostate cancer with ADC values measured by the reconstruction of ADC Map with different low b-Values at 3.0 T MR-DWI.Materialsand Methods To retrospectively analyze 184 prostatic patients who undergone prostate mp-MRI and multi b-values DWI(b=0,10,20,50,100,200,500,1000,2000s/mm2)examination and had biopsy results in Second Affiliated Hospital of Soochow University,67 patients were prostate cancer,117 were benign prostatic lesion.The enrolled patientswere divided into prostate cancer group and benign prostate lesion group.In the multib-valuesdiffusion weighted imaging(DWI),by using monoexponential model to reconstruct ADC map by three different low b-values(b=50,100,200 s/mm2)and ultra high b-value(2000s/mm2).It was based on the pathological diagnosis of prostate lesions and PI-RADS v2 diagnostic criteria combined with the Imaging finding on T2 WI,DWI,ADC Map and DCEI to identify the areas of the prostate lesions,select the region of interest and measure the ADC values on the reconstructed ADC Map.The ADC values of the lesions in the reconstructed map were represented by ADC50,ADC100,ADC200 respectively.The differences of the ADC values of malignant tissues and benign tissues under different b-values were compared by using independent samples t-test.It was statistically significant when P<0.05.Receiver operating characteristic(ROC)curves were used to evaluate the efficacy of the ADC values measured by the reconstruction of ADC Map with different low b-values in differentiating prostate cancer from benign prostate lesions.Results In the enrolled patients,the mean values of ADV values(ADC50,ADC100 and ADC200)of prostate cancer group in reconstruction ADC Map of every low b-values were lower than benign prostate lesions,the differentiation between two groups was statistically significant(P<0.05);The area under ROC curve(AUC)of ADC50,ADC100 and ADC200 in differentiation between benign and malignant prostate lesions were 0.906,0.906 and 0.887.And the corresponding cut off ADC are 0.35×103mm2/s and 0.311×103mm2 /s respectively.The sensitivity and specificity for ADC50 and ADC100 are 87.9%,89.6% and 82.8%,94.1% respectively.Conclusion On 3.0T MR-DWI the ADC values measured by the reconstruction of ADC Map with different low b-values by using monoexponential model,the diagnostic efficiency in ADC50 and ADC100 is better.When b=50,100s/mm2 is employed,can improve the diagnostic accuracy of prostate cancer.It is recommended that the low b-values select 50s/mm2 or 100s/mm2 on the multi b-values DWI in prostate Mp-MRI.Part?The Influence of Different Low b-values on the Contrast of ADC Values in Prostatic Lesions at 3.0 T MR-DWI Monoexponential ModelObjective To investigate the influence of the selection of low b-values on the contrast of ADC values in prostatic lesions in ADC Map reconstructed by using monoexponential model on 3.0 T MR-DWI.Materials and Methods 67 patients with prostate cancer and 117 patients with benign prostatic hyperplasia with clinically-and pathologically-proved were enrolled in this study.Mp-MRI was performed in all patients.DWI was scanning with multi b-values(b=0,10,20,50,100,200,500,1000,2000s/ mm2).Select three different low b-values(b=50,100,200 s/ mm2)and ultra high b-value(2000s/mm2)respectively to reconstructing ADC Map by using monoexponential model.It was based on the pathological diagnosis of prostate lesions and PI-RADS v2 diagnostic criteria to divide the patients into prostate cancer group and benign prostate lesion group.ADC values of prostate cancer group(PCa),ADC values of benign lesion group(BL),ADC values of normal tissue of prostate peripheral zone(PZ)and ADC values of normal tissue of prostate transition zone(TZ)were measured separately in ADC Map of the reconstruction of each low b-values.Calculate the contrast of the ADC values between lesions and normal tissues to conclude the contrast between the PCa and the TZ(ADCPCa/TZ),the BL and the TZ(ADCBL/ TZ),the PCa and the PZ(ADCPCa/PZ),the BL and the PZ(ADCBL/PZ),the TZ and PZ(ADCTZ /PZ).The differences of those groups in the contrast of the ADC values,measured by the ADC Map reconstructed with three groups of low b-values,were compared by using t-test.It was statistically significant when P<0.05 racy,sensitivity and specificity were calculated for different.Results In the DWI monoexponential model of 67 prostate cancer patients,the contrast of ADC values of prostate cancer which were measured from reconstruct of ADC maps in different low b-values,the multiple comparisons among ADC50PCa/TZ,ADC100PCa/TZ,ADC200PCa/TZ,the mean values of each were 0.321±0.069?0.330±0.106 and 0.328±0.080,had statistical differences(P<0.05);the same as ADC50PCa/PZ,ADC100PCa/PZ and ADC200PCa/PZ,which mean values were 0.442±0.109,0.447±0.104 and 0.444±0.086 had statistical differences(P<0.05);while that among ADC50TZ/PZ,ADC100TZ/PZ,ADC200 TZ /PZ(0.145±0.123,0.138±0.060 and 0.135±0.123)were not comparable in statistical significance(P>0.05).The multiple comparisons among 117 benign prostate lesions had no differences in statistical significance(P>0.05).Conclusion On 3.0T MR ADC Maps by using monoexponential model,the contrast of prostate cancer and normal tissues is better when b=100s/mm2 is employed than that b=50s/mm2 or b=200s/mm2 is employed,which is good for the display of prostate cancer.Therefore,it is recommended to select 100s/mm2 for DWI low b-values in prostate Mp-MRI.Part? The Influence of the Lesions PI-RADS of the ADC Map Reconstructed by the Selection of Different Low-b-valueson 3.0 T Prostate MR-DWIObjective To investigate the influence of thelesions PI-RADS of the selection of different low b-values in ADC Map by using monoexponential model on 3.0T prostate MR-DWI.Materialsand Methods A total of 184 patients with clinically-and pathologically-proved prostate lesions were enrolled in this study.The prostate lesions included prostate cancer(n=67)and benign prostate lesion(n=117).Prostate Mp-MRI and DWI(b=0,10,20,50,100,200,500,1000,2000s/mm2)scanning was performed in all patients.Select three different low b-values(b=50,100,200s/mm2)and ultra high b-value(2000s/mm2)to reconstructing ADC Map by using monoexponential model respectively.According to PI-RADS v2,the DWI and the corresponding reconstructed ADC map collected by different b-values(b = 50,100,200 s/mm2)were evaluated for the diagnosis of the lesions,and the 5-point standard was adopted.Using biopsy as the gold standard,the accuracy,sensitivity and specificity were calculated for different ADC maps for the diagnosis of clinically significant prostate cancer.The differences among the three were compared by using the Mc Nemar test.It was statistically significant when P<0.05.Results The score of the diagnostic results of patients included in this study by using different low b-values toreconstruct ADC map: The accuracy of the reconstruction of ADC Map for the diagnosis of clinically significant prostate cancer was 77.72%(143/184),when the low b-value selected 50s/mm2.As the same,the accuracy was 79.89%(147/184)when b=100s/mm2 and 79.35%(146/184)when b= 200s/mm2.The sensitivity and specificity for the ADC100 was 75.00% and 82.26%.These values were significantly higher than that in ADC50(71.67%,80.65%)and ADC200(74.58%,81.60%),which was statistically significant(P<0.05).Conclusion To use the PI-RADS on 3.0T prostate MR-DWI ADC Maps by using monoexponential model,the diagnostic accuracy,sensitivity and specificity of thelesions arehigher when b=100s/mm2 is employed than that b=50 or b=200 is employed.Therefore,it is recommended to select 100s/mm2 for DWI low b-values in prostate Mp-MRI. |
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