Application Of Dynamic Contrast Enhanced Magnetic Resonance Imaging(DCE-MRI) And Three Dimensional Arterial Spin Labeling(3D-ASL) In Brain Glioma And Primary Central Nervous System Lymphoma

Objectives:1.To study the value of dynamic contrast enhanced magnetic resonance imaging?DCE-MRI?and three dimensional arterial spin labeling?3D-ASL?quantitative parameters in predicting preoperative glioma grading and tumor cell proliferation.2.To evaluate the diagnostic performance of DCE derived permeability parameters and 3D-ASL quantitative parameter to differentiate primary central nervous system lymphoma?PCNSL?from high-grade glioma?HGG?and brain metastasis.Methods:1.The data of 60 patients with glioma diagnosed by pathologically and the ki-67labeling index was proved by immunohistochemical method after operation were analyzed,including 27 patients with low-grade glioma?27 with?grade gliomas?and 33 patients with high-grade glioma?12 with?grade gliomas and 21 with?grade gliomas?.All patients were scanned on a 3.0T MRI system using conventional sequences,gadolinium-enhanced sequence,ASL and DCE sequences.DCE-MRI parameters such as volume transfer constant(K^trans),fractional volume of the extravascular-extracellular space?V_e?,fractional volume of the intravascular compartment?V_p?,the rate constant(K_ep),cerebral blood flow?CBF?and cerebral blood volume?CBV?were measured and analyzed in different grades of glioma by corresponding software.Relative CBV?rCBV?and relative?rCBF?were obtained based on normalized mirror region,also the quantitative parameters CBF and rCBF of arterial spin labeling?ASL?are obtained.T test of two independent samples was used to analyze whether there is a statistical difference between the LGG and HGG,The value of every parameters and Ki-67 labeling index?LI?were also acquired and the correlation was done using the Spearman test.The diagnostic accuracy for glioma grading of the two techniques was determined by ROC curve.2.8 patients with PCNSL,25 patients with HGG and 7 patients with brain metastasis underwent preoperative 3.0T MR imaging including conventional,DWI,ASL and DCE sequences.Quantitative parameters including relative cerebral blood flow?rCBF?of ASL,fractional volume of the extravascular-extracellular space?V_e?of DCE and the volume transfer constant(K^trans)of DCE among PCNSL,HGG and metastasis were compared with a one-way analysis of variance.When statistical differences existed,the post-hoc test was further performed using Dunnett tests treating PCNSL and metastasis as the control and comparing all other groups against it.The area under the receiver-operating characteristic?ROC?was constructed to evaluate the differentiation diagnostic performance of each parameter.Results:1.All quantitative parameters from DCE,ASL and Ki-67 were statistically different between the LGG and HGG?P<0.05?.The K^trans,V_e,K_ep,rCBV and rCBF values of DCE were all associated with Ki-67 LI?r=0.775,0.691,0.564,0.640 and 0.562,P<0.001?.The V_p value was not associated with Ki-67 LI?r=0.252,P=0.052?.The rCBF value of ASL associated with Ki-67 LI?r=0.716,P<0.001?.In the ROC analysis,the area under the receiver operating characteristic curve?AUC?of K^trans,V_e,ASL-rCBF and Ki-67 LI were0.966,0.911,0.927 and 0.962,respectively.The cut-off values were 0.030,0.113,1.901and 17.50%.The sensitivity were 90.9%,84.8%,84.8%and 84.8%,and the specificity were 100%,92.6%,92.6%and 96.3%,respectively.The AUC of V_p was 0.633.2.The PCNSL demonstrated significantly higher K^trans and V_e,but lower rCBF,compared with HGG and brain metastasis.All parameters were statistically significant among the groups.For the ROC analyses,both K^trans and rCBF had good diagnostic performance for distinguishing PCNSL from HGG and metastasis,with the AUC were0.859 and 0.898,the cut-off values were 0.429 and 1.202,the sensitivity were 93.7%and84.4%,and the specificity were 75.0%and 100%,respectively.The combination of K^transrans and rCBF improved the diagnostic performance with AUC of 0.973.Conclusions:1.All the quantitative parameters from DCE and ASL were useful to distinguish LGG from HGG.The values of K^trans,V_e,K_ep,rCBV and rCBF were significantly associated with Ki-67 LI,and the parameters could non-invasively evaluate the preoperative degree of glioma cell proliferation.2.Both K^trans of DCE and rCBF of ASL can distinguish PCNSL from HGG and brain metastasis.The combined application of the two parameters can improve the diagnostic performance of PCNSL.