Quantitative Assessment Of High Resolution SWI At3T In Recurrent Glioma And Posttreatment Effect

Objective：To investigate the value of quantitative measurement of intralesionalsusceptibility singnal intensity（ILSS）in differentiation of recurrent glioma fromposttreatment effect using susceptibility weighted imaging(SWI)， as well asDSC-MRI and MRS.Material and Methods：22cases(13men,9women, mean age±SD:42.32±11.58)who have been underwent surgery and diagnosed as high-grade glioma and gliomaWHOII were randomly enrolled in the study. They were all followed up withconventional contrast-enhanced MRI, DSC-PWI, SWI and MRS. Total of22newenhanced lesion were found, and were divided into recurrent group(11cases) andpost-treatment group(11cases) which were confirmed by re-surgery or clinicalfollow-up. The ILSS and ILSS area were quantitatively measured, and the perfusionvalues such as r CBV、r CBF、Peak Height(PH)、rPH、Percentage of Signal-intensityrecovery(PSR), rPSR and D-value of Signal-intensity(B-A) were also measured, aswell as MRS values’ratio. The difference between two groups was analyzed, and theSpearman correlation was used to analyze the relationship between perfusion andSWI. Receiver operating characteristic（ROC） was used to determine the optimumthreshold in the differential diagnosis. The level of significant was0.05.Results： ILSS and ILSS area were significantly higher in recurrent group (P=0.019and0.002respectively). ILSS area had much better ability in differentiation of thesetwo group, with an optimum threshold of149.6mm2，the sensitivity and specificitywas85.7%and100%respectively. ILSS and ILSS area had moderate correlation with PH （Spearman coefficient0.575， P=0.013and0.567， P=0.014）,andmild-moderate correlate with B-A(0.498,P=0.036and0.525,P=0.025). rCBV wassignificant (P=0.016) and PH, rPH and B-A was extremely significant elevated (P＜0.01) within recurrent tumor. The PH had the best performance in differentialdiagnosis, the sensitivity and specificity was100%and81%at an optimum cutoffvalue of46.989; B-A also had a good efficacy in differential diagnosis at an optimumthreshold of15.029, the sensitivity and specificity was90.9%and81.8%respectively.Among MRS values，The difference of Cho/NAA between the two groups wassignificant（P=0.029＜0.05）;the sensitivity and specificity was81.8%and100%atan optimal cut-off value of2.03。Conclusion： ILSS and ILSS area could distinguish recurrent glioma andpost-treatment effect, and might be used as indice of microvessel perfusion.Compared with other perfusion values，PH and B-A more accurately differentiatedrecurrent glioma form post-therapy effect. ILSS area and PH might be the best valuein differential diagnosis.