The Value Of Combined Application Of 1H-MRS And Multi B Value Of DWI In The Differential Diagnosis Of High Grade Glioma And Single Brain Metastasis

Objective:To explore the value of Cho/NAA value,Cho/Cr value,NAA/Cr value of proton magnetic resonance spectroscopy(~1H magnetic resonance spectroscopy,~1H-MRS)and the apparent diffusion coefficient(ADC)of multi b value magnetic resonance diffusion weighted imaging(DWI)in the differential diagnosis of supratentorial high-grade gliomas(HGG)(WHO?grade and WHO?grade)and single brain metastases(MET)before operation,and find the best parameters for the differential diagnosis of the two kinds of tumors,and to explore whether the differential diagnosis efficiency of ~1H-MRS combinded with multi b value DWI is better than that of single functional imaging.Materials and methods:Inpatient whose lesion considered as high grade glioma or single brain metastases with routine MR examination(head MR plain scan and head MR enhancement)were collected in our hospital.All cases were adult supratentorial single tumors.~1H-MRS and multi b value DWI were examined respectively.Among them,24 patients with HGG(14 males and 10 females)and 25 patients with single brain MET(19 males and 6 females)were enrolled.Import ~1H-MRS and multiple b value DWI data to Siemens post processing software.The spectral maps of the region of interest and the corresponding ADC maps of each b value(b=1000s/mm~2,b=2000s/mm~2,b=4000s/mm~2,b=6000s/mm~2,b=8000s/mm~2 and b=10000s/mm~2)were obtained.The Cho/NAA value,Cho/Cr value and NAA/Cr value in tumor area,peritumor area and corresponding normal brain area were recorded on ~1H-MRS spectrum respectivly,and the ADC values in tumor area,peritumor area and contralateral normal brain area were recorded on ADC map respectivly.The ROC curves of ~1H-MRS and multi b value DWI in the differential diagnosis of the two kinds of tumors were drawn by SPSS software and the area under the receiver operating characteristic curve(AUC)were calculated.The best ~1H-MRS parameters and multi b value DWI parameters for distinguishing HGG and single MET were found out respectively according to the principle of maximum AUC value,and according to the principle of maximum Jordan index,the critical value and its corresponding sensitivity and specificity were determined.The ROC curves of~1H-MRS,multi b valued DWI and ~1H-MRS combined with multi b valued DWI 3techniques in distinguish the two kinds of tumors were drawn after calculate the the prediction probability of ~1H-MRS combined with multi b valued DWI to distinguish HGG and single brain MET by using binary logistic linear regression method,and their AUC maximum,sensitivity and specificity were compared.Results:1.Some parameters of MRS can be used as the basis for distinguishing HGG from single brain MET,these parameters include the average Cho/NAA value in the tumor area,the average NAA/Cr value,the average Cho/Cr value and the average Cho/NAA value in the peritumor area,the average Cho/NAA value in the peritumor area is the best parameter of them.When the critical value was 0.966,the maximum AUC was0.92,the sensitivity was 100%,and the specificity was 73.9%.2.Some parameters of ADC value of multi b value DWI can be used as the basis for distinguishing HGG from single brain MET,including the corresponding ADC values in the peritumor area of b=1000s/mm~2,b=2000s/mm~2,b=4000s/mm~2,b=6000s/mm~2and b=8000s/mm~2.The corresponding ADC values of b=1000s/mm~2 in the peritumor area is the best parameter of them.When the critical value was 1.488,the maximum AUC was 0.863,the sensitivity was 87%,and the specificity was 78.9%.2.Combinding the best differential parameters of the two techniques,that is,combinding the average Cho/NAA value of the peritumor area with the corresponding ADC value in the peritumor area of b=1000s/mm~2,the maximum AUC was 0.973,the sensitivity was 86.4%,and the specificity was 100%when it was used to distignguish HGG form MET.Conclusion:The Cho/NAA value,Cho/Cr value,NAA/Cr value of ~1H-MRS and ADC value of multiple b value DWI are effective in distinguishing HGG from single brain MET before operation.The most effective differential diagnosis parameter was the Cho/NAA value of the peritumor area and the ADC value of the peritumor area of b=1000s/mm~2 respectively in two functional imaging techniques of ~1H-MRS and multi b value DWI.The differential diagnosis efficiency of the two kinds of tumors of combinding two functional imaging techniques was better than that of the single brain functional imaging technique.