The Diagnostic Value Of Cystic And Peritumoral DTI Of Intracranial Masses

Objective: To probe the differentiation value of DTI of cystic region tointracranial cystic lesions.Methods:9epidermoid cysts,13arachnoid cysts,6brain abscesses and24necrotic-cystic intra-axial tumors confirmed pathologically or clinicallyunderwent conventional MRI and DTI. Mean difusivity（MD） and fractionalanisotropy（FA） values were measured in cystic or necrotic region. Differencesin these values between epidermoid cysts and arachnoid cysts were assessed.Differences in these values between brain abscesses and necrotic-cysticintra-axial tumors were assessed. Receiver operating characteristic （ROC）curve analysis were used to determine the cutoff value of MD and FA that hadthe best combination of sensitivity and specificity for distinguishing betweenepidermoid cyst and arachnoid cyst, brain abscess and necrotic-cysticintra-axial tumor.Results: The value （median, interquartile range） of MD and FA ofepidermoid cysts were （1.09,0.169）×10-3mm2/s and （0.171,0.026）respectively. The value（median, interquartile range） of MD and FA ofarachnoid cysts were（3.32,0.177）×10-3mm2/s and （0.075,0.054） respectively.There were significant difference of MD and FA between epidermoid cystsand arachnoid cysts （P<0.05）. According to ROC curve analysis, thesensitivity of MD（2.238×10-3mm2/s） for the differentiation of epidermoidcyst from arachnoid cyst was100%; specificity,100%. The sensitivity ofFA（0.154） for the differentiation of epidermoid cyst from arachnoid cyst was88.9%; specificity,100%. The value （median,interquartile range） of MD andFA of brain abscesses were （0.655,0.060）×10-3mm2/s and （0.074,0.027） respectively. The value （median,interquartile range） of MD and FA ofnecrotic-cystic intra-axial tumors were （2.877,0.232）×10-3mm2/s and（0.041,0.011） respectively. There were significant difference of MD and FAbetween brain abscesses and necrotic-cystic intra-axial tumors （P<0.05）.According to ROC curve analysis, the sensitivity of MD（0.962×10-3mm2/s）for the differentiation of brain abscesse from necrotic-cystic intra-axial tumorswas100%; specificity,100%.The sensitivity of FA（0.054） for thedifferentiation of brain abscess from necrotic-cystic intra-axial tumor was100%; specificity,83.3%.Conclusion: There was significant distinction of DTI parameters ofcystic region between epidermoid cysts and arachnoid cysts, brain abscessesand necrotic-cystic intra-axial tumors. MD and FA values can play animportant role in differentiating epidermoid cyst and arachnoid cyst, brainabscess and necrotic-cystic intra-axial tumor. Objective: To probe differentiation value of DTI of peritumoral regionbetween high-grade glioma and cerebral metastases.Methods:17high-grade gliomas and12metastases confirmedpathologically underwent conventional MRI and DTI. Mean difusivity（MD）,minimum MD and fractional anisotropy（FA） were measured in the peritumoralregion. To determine whether there were a statistical difference betweenhigh-grade gliomas and cerebral metastases. Receiver operating characteristic（ROC） curve analysis were used to determine the cutoff value of mean MD,minimum MD and mean FA that had the best combination of sensitivity andspecificity for distinguishing between high-grade gliomas and cerebralmetastases. Results: The mean MD value and mean minimum MD value（median,interquartile range） were （1.493,0.409）×10^-3mm²/s and（1.36，0.37）×10^-3mm²/s in high-grade gliomas respectively. The mean MD value andmean minimum MD value （median,interquartile range） were（1.673,0.2）×10^-3mm2/s and （1.55,0.288）×10^-3mm²/s in cerebral metastases respectively.The mean FA value was higher in high-grade gliomas（0.108,0.042） than thoseof cerebral metastases（0.076,0.038）. There were significant difference of meanMD, minimum MD and mean FA between high-grade glioma and cerebralmetastases（P<0.05）. According to ROC curve analysis, a cutoff value of1.41×103mm2/s for the minimum peritumoral MD value generated the bestcombination of sensitivity （70.6%） and specificity （100%） for distinguishingbetween high-grade glioma and cerebral metastases.Conclusion: There was significant distinction of DTI parameters ofperitumoral region between high-grade glioma and cerebral metastases.Peritumoral mean MD and minimum MD value can play an important role indifferentiating high-grade glioma from cerebral metastases. The minimumperitumoral MD value has higher diagnostic values than mean MD value forthe differentiation of high-grade glioma from cerebral metastases.