3.0TMRIIVIM-DWI Applied In The Evaluation Of Staging Diagnosis And Treatment Of Nasopharyngeal Carcinoma

Part I :The Value of IVIM-DWI of 3.0T MR Imaging for Clinical Staging in Nasopharyngeal CarcinomaObjective To discuss the application of intravoxel incoherent motion (IVIM) of diffusion weighted imaging in the clinical stage of NPC.Materials and Methods Ninety-seven newly diagnosed NPC patients who received routine MRI examination and Reduced Field-of-View(r-FOV)IVIM-DWI examination and clinical stage was decided based on Chinese 2008 staging system.Analyse the correlations between IVIM parameters(ADCstand?ADCslow?ADCfast?f) and clinical stage.Compare the scores of T2WI alone and r-FOV IVIM-DWI combined with T2WI for the nasopharyngeal lesions with 3 points evaluation methodology.Resultsl 1.ADCstand and ADCslow showed significant differences in differentoverall stage, T stages(P<0.05).ADCfast showed significant differences in different overall stage, T stages and N stage(P<0.05).f showed not any differences in different overall stage, T stages and N stage.2.ADCstand showed lowly negative correlation with different overall stage(r=-0.215,P=0.034),and moderate negative correlation with T stage(r=-0.496,P=0.000). ADCslow showed lowly negative correlation with different overall stage(r=-0.297, P=0.003),and moderate negative correlation with T stage(r=-0.604, P=0.000).ADCfast showed unconspicuous correlation with different overall stage(r=0.356,P=0.000), T stage(r=0.273,P=0.007) and N stage(r=0.326,P=0.001).3.The delineation scores of r-FOV IVIM-DWI combined with T2WI(2.79 ± 0.05) was significantly to that of T2WI alone(2.43 ±0.08) ,P<0.05.Conclusion r-FOV IVIM-DWI can clearly shows the nasopharyngeal lesions,and it parameters of primary NPC lesions have significant correlation with different overall stage, T stage and N stage, maybe helpful in T stage of NPC.Part ?: The Research on the Prediction of IVIM-DWI of 3.0T MR Curative Effect of Radiochemotherapy in Nasopharyngeal CarcinomaObjective To discuss the value of based on the application of intravoxel incoherent motion (IVIM) of diffusion weighted imaging on predicting curative effect of radiochemotherapy in nasopharyngeal carcinoma.Materials and Methods 33 patients with confirmed nasopharyngeal carcinoma were examed before and after treatment within 1 week by MRI and IVIM-DWI,.Measured the IVIM parameters (ADCstand ADCslow, ADCfast and f) which were before and after treatment, and calculate the rate of tumor regression after treatment. The subjects were classified into tree groups according to the tumor regression rate after treatment as group sensitive,moderate,and resistant curative effect.Analyse the correlation between pretherapeutic IVIM-DWI parameters value and tumor regression rate.Compare the volume (V) and the IVIM-DWI parameters of the nasopharyngeal lesions before and after the treatment using independent sample t test.The comparison of the effect between every group using.Use variance analysis to compare the IVIM-DWI parameters values between every group. Moreover, receiver operating characteristic curve (ROC) was applied for the evaluation of ADC values on predicting curative effect of radiochemotherapy in nasopharyngeal carcinoma.Resultsl l.The ADCstand and ADCslow values showed significant differences in all patients before and after treatment(P<0.05).The numerical value of ADCstand and ADCslow before treatment were different in statistical between different group(P<0.05).2.The numerical values of ADCstand before treatment showed lowly negative correlation to tumor regression rate of after treatment(r=-0.152,P=0.000).The numerical values of ADCslow before treatment showed moderate negative correlation to tumor regression rate of after treatment(r=-0.319,P=0.000).3.The areas under ROC curve of ADCstand and ADCslow numerical values in the two groups were 0.808 and 0.846 respectively. The best diagnostic cutoff values were 1.035 × 10-3mm2/s?and 0.970 × 10-3mm2/s respectively .The diagnostic sensitivity, specificity and accuracy were 100.00%and 100.00% ,65.40% and 73.1% , 75.76% and 78.79% respectively. The difference between the two ROC curve of ADCstand and slow ADC had no statistical significance (Z=0.046, P=0.654)Conclusion IVIM based on the technology multi-b-value DWI bi-exponential model ADCslow value and traditional DWI mono-exponential ADCstand value have higher diagnostic value on predicting curative effect in nasopharyngeal carcinoma., and ADCslow carries better sensitivity, specificity and accuracy when compared with ADCstand value.