الفهرس 
ANATOMYOnly 14 pages are availabe for public view
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Abstract
B
eing the most common primary malignant brain tumors, gliomas represent a challenge for radiological diagnosis and therapeutic management. This partly due to the histological heterogeneity of the lesions and the wide range of differential diagnosis in a significant number of patients.
Through the last decades, conventional pre and post contrast MRI sequences proved to be the valuable diagnostic tool for gliomas, yet still inaccuracies and overlap occurred between high and low grades gliomas.
Moreover the contrast-enhanced studies actually estimates the degree of blood-brain barrier disruption rather than the inherent tumoral neovascularity, which is well known to correlate positively with malignancy and its grade. This obstacle necessitated the invention of new MRI diagnostic sequences capable of solving these problems.
With the introduction of MR DTI and PWI, a step towards obtaining radiological base line data, nearly equivalent to the histopathological results was achieved.
This study aimed to assess the role of MR DTI and MR perfusion in grading of brain gliomas and included twenty four patients with MRI study suggestive of brain glioma.
All patients were subjected to the following:
o History taking.
o Pre and post contrast MRI study of the brain.
o MR DTI.
o MR perfusion.
The use of MR DTI and MR perfusion helped for accurate diagnosis of gliomas (100% accuracy) .
All the lesions were histopathologically proven to be gliomas and further sub-divided into two groups:LGG: 6 cases &HGG: 18 cases
MR DTI and PWI for the two groups were analyzed in each patient.
rCBV cuttoff values of (1.2) was considered as sensitive & specific marker to predict high grade gliomas as non of the examined low grade gliomas showed rCBV higher than cutoff.
The use of MR DTI had an important role in the grading of brain gliomas as it was accurate in grading 24 cases of gliomas (sensitivity of 100% and accuracy 100%) regarding,Max &Mean FA values & for Min FA (was with sensitivity 93.3%& accuracy 88.9%) in tumor area which were greater than cutoff values( 0.085, 0.190 & 0.135 ) respectively i.e increasing with high grade .Also significant finding regarding Min&Mean FA in necrotic area,which were decreasing toward high grade because it approaching isotropic movement with more necrosis, with sensitivity (91.7% &75% respectively)& specificity(83.3% &100% respectively ) were below cutoff values (0.035 & 0.051 respectively).Positive correlation between Max FA & histopathological grade could not be established.
Combined use of MR DTI and MR perfusion in this study added to the accuracy of grading of glioma up to 100 %, while the accuracy with the use of conventional MRI alone was only 72.5 %.