Diagnostic Value Of Susceptibility-Weighted Imaging And Dynamic Susceptibility Contrast Enhancing In Astrocytomas Grading

Purpose To investigate the diagnostic value of susceptibility-weighted imaging and dynamic susceptibility contrast enhancing perfusion weighted MR imaging in astrocytomas grading.Materials and Methods29patients with astrocytomas pathologically proven were enrolled in this study, include high grade astrocytomas ((WHO Ⅲ(n=12), WHO Ⅳ(n=7))(n=19), low grade astrocytomas (WHO Ⅱ)(n=10). All the patients underwent MRI conventional sequences, SWI, DSC and CE-T1WI. DSC:The perfusion color imaging and time-signal intensity curves (TIC) were analyzed. Maximal relative cerebral blood volume(rCBVmax) within tumor parenchyma and peritumoral edema were calculated comparion contralateral white matter. And analysis the connection between rCBVmax and different pathologic grades. SWI:Analysis the differences of ITSS among different pathologic grades comparion MR conventional sequences. Spearman correlation coeffcients were determined between the degree of ITSS, rCBVmax and astrocytomas grade. Receiver operating characteristic (ROC) curve analysis were performed to determine the diagnostic accuracy of combining with DSC and SWI for astrocytomas grading.Results DSC:high grade astrocytomas show high perfusion, low grade astrocytomas show low perfusion; The maximal relative cerebral blood volume(rCBVmax) within tumor parenchyma of grade Ⅱ, Ⅲ and Ⅳ were1.710±0.628,4.271±1.193,6.200±1.012respectively, statistical differences were observed between grade Ⅱ and grade Ⅲ,Ⅳ, and also between grade Ⅲ and grade Ⅳ(P<0.05); The maximal relative cerebral blood volume(rCBVmax) within peritumoral edema of grade Ⅱ, Ⅲ and Ⅳ were0.081±0.257,0.990±0.662,1.061±0.517respectively, statistical differences were observed between grade Ⅱ and grade Ⅲ, Ⅳ (P<0.05) and no significant differences were found between grade Ⅲ and grade Ⅳ (P>0.05). The decrease extent of time-signal intensity curves within tumor parenchyma and peritumoral edema of grade Ⅲ and Ⅳ astrocytomas were larger than the contralateral white matter, The decrease extent of time-signal intensity curves of grade Ⅱ astrocytomas were larger than the contralateral white matter within tumor parenchyma, light larger than or equal to the contralateral white matter within peritumoral edema; SWI:There were statistically significant differences between the differences degree of ITSS among different pathologic grades (P<0.05). Significant correlation were found between the degree of ITSS and rCBVmax (rs=0.740,P<0.0001). There is significant correlation between rCBVmax and strocytomas grade (rs=0.850,P<0.0001) and between the degree of ITSS and strocytomas grade (rs=0.755,P<0.0001). The AUC of rCBVmax, degree of ITSS and combined with them were0.937,0.918,0.989respectively w h e n c r it e r ia w e re0.776,0.613,0.328r esp e ct i v ely, s e n si t i v it y w e r e84.2%,78.9%,100%r e sp e c ti v e ly, sp e c if ic i t y w e r e100%,100%,90%resp e c t i v e l y.Co n c lu si o n DSC p e r f u si o n-we ig h te d im a g in g sh ow s th e d i st r ib u ti o n o f tu mo r b lo o d v e ss e l sa nd p e r f us i o n in f o r m a t i o n f or a st r o c yt om a gr ad in g; SW I d is p la ys in tr a-tu m o r su sc e pt i b i l i t ysi g n a ls su c h as tu m o r he mo r r h a g e, in tr a v e n ou s to he lp a st r o c yt o ma g r a di n g; co mb in e d w it h SW I a n d D SC im p r o ve th e d ia gn o st i c pe r fo r ma n ce f o r st r o c yt om a s g r a di n g a s im p or t a n ta u x il ia r y se qu e nc es o f c o nv e n ti o na l MR im a g in g, whi c h w a s us e f u l f o r c li n ic al tr eatm e n t a n dp r e d ic ti n g p r o g no si s.