Study On The Relationship Between Quantitative Parameters Of Magnetic Resonance Diffusion Kurtosis Imaging And Ki-67 Expression In Nasopharyngeal Carcinoma

Objective:.To explore the correlation between the quantitative parameters of magnetic resonance diffusion kurtosis imaging and the expression of Ki-67 in nasopharyngeal carcinoma,and to provide a new idea for non-invasive evaluation of tumor cell proliferative activity.Methods:(1)54 newly diagnosed patients with nasopharyngeal carcinoma confirmed by pathological biopsy and containing immunohistochemical index Ki-67 were collected from the affiliated Hospital of Youjiang Medical College for nationalities from September 2019 to December 2020.3.0T MRI was used to scan nasopharynx DKI sequence.(2)The values of DKI 8 parameters and DTI 4 parameters in the parenchyma of nasopharyngeal carcinoma patients were delineated and recorded by two surveyors.According to the expression of Ki-67in patients with NPC,the patients were divided into two groups:Ki-67 expression index<30%as low expression group,≥30%as high expression group,Ki-67 high expression group(n=37)and Ki-67 low expression group(n=17).(3)All the data were analyzed by SPSS22.0 statistical software.The parameter values of DKI and DTI of nasopharyngeal carcinoma lesions were tested by Kolmogorov-Smirnov to see if the data conformed to the normal distribution,and the metrological data were expressed by (?)±s.The intra-group correlation coefficient(ICC)was used to test the consistency of the parameters measured by the two surveyors.Take the average of the measurement results of the two surveyors.Independent sample t-test was used to compare the differences of DKI and DTI parameters between Ki-67 high expression group and low expression group.Independent sample t-test was used to compare the differences of DTI and DKI parameters between nasopharyngeal carcinoma and contralateral lateral pterygoid muscle.The differential diagnostic efficacy of the two groups of lesions was evaluated by the(ROC)curve of the subjects’working characteristics,and the area under the curve(AUC),and its corresponding sensitivity and specificity were calculated.Pearson correlation was used to analyze the correlation between the parameter values of DTI,DKI and the expression of Ki-67 in nasopharyngeal carcinoma.The difference was statistically significant(P<0.05).Results:(1)At 0s/mm~2and 1000s/mm~2,the correlation coefficients of DKI and DTI measured by the two surveyors are ICC≥0.75,which is in good agreement.(2)At b=0s/mm~2and b=1000s/mm~2,the DKI parameters FA,MD,Da,Dr and FAK of nasopharyngeal carcinoma lesions were lower than those of the contralateral lateral pterygoid muscle group,while the values of MK,Ka and Kr of nasopharyngeal carcinoma lesions were higher than those of the contralateral lateral pterygoid muscle group,and the DTI parameters FA,MD,Da and Dr values of nasopharyngeal carcinoma lesions were lower than those of the contralateral lateral pterygoid muscle group.(3)At b=0s/mm~2and b=1000s/mm~2,among the DKI parameters,the values of MD,Da and Dr in Ki-67 high expression group were significantly lower than those in low expression group(P<0.001).The Ka value in Ki-67 high expression group was higher than that in Ki-67 low expression group,and the difference was significant(P<0.001).There was no significant difference in FA,FAk,MK and Kr between the two groups.Among the DTI parameters,the values of MD,Da and Dr in the group with high expression of Ki-67 were lower than those in the group with low expression of Ki-67,and the difference was statistically significant(P<0.05).There was no significant difference in FA between the group with high expression of Ki-67 and the group with low expression of Ki-67.(4)At 0s/mm~2and 1000s/mm~2,the values of MD,Da and Dr were negatively correlated with the high expression of Ki-67,while the values of Ka were positively correlated with the high expression of Ki-67.There was no correlation between the high expression of FA,FAK,MK,Kr and Ki-67.In the parameters of DTI,MD,Da,Dr value was negatively correlated with the high expression of Ki-67,and there was no correlation between FA and Ki-67 high expression.(5)At b=0s/mm~2,the values of MD,Da,Dr and Ka in the parameters of DKI were estimated to be 0.953,0.871,0.830 and 0.783,respectively,when the values of MD,Da,Dr and Ka were estimated to be over-expressed in DKI parameters.The values of MD,Da and Dr in DTI parameters predicted that the overexpression AUC of Ki-67 were 0.803,0.814 and 0.804,respectively.At b=1000s/mm~2,The values of MD,Da,Dr and Ka in DKI parameters predicted that the overexpression AUC of Ki-67 was 0.806,0.825,0.725 and 0.795,respectively.The values of MD,Da and Dr in DTI parameters predicted that the overexpression AUC of Ki-67 were 0.759,0.773 and 0.743,respectively.Conclusion:(1)Among the DKI parameters,MD,Da and Dr values were negatively correlated with the high expression of Ki-67 in NPC patients,while Ka value was positively correlated with the high expression of Ki-67.Among the DTI parameters,MD,Da,Dr values were negatively correlated with the high expression of Ki-67 in NPC patients.DKI and DTI parameters can effectively evaluate and predict the level of Ki-67 expression and reflect the degree of proliferation of nasopharyngeal carcinoma cells.(2)when the parameters of DKI and DTI were used to evaluate the expression level of Ki-67,when b=0s/mm~2,the MD value of DKI parameter was the best for the diagnosis of high expression of Ki-67,and when b=1000s/mm~2,the value of DA was the best for the diagnosis of high expression of Ki-67.Among the DTI parameters,when b=0s/mm~2or b=1000s/mm~2,the Da value is the best for the diagnosis of high expression of Ki-67.(3)when b=1000s/mm~2,the diagnostic efficacy of Da value in DKI for high expression of Ki-67 is better than that of DA value in DTI.