Abstract :
Context/Background: Advanced neuro-imaging like Diffusion Tensor Imaging (DTI) is a non-invasive technique with enormous potential in glioma grading.
Aims and Objectives: To assess the diagnostic accuracy of DTI metrics for differentiating low grade from high grade gliomas.
Materials and Methods: This is a diagnostic accuracy study of 38 patients with glioma. DTI was performed on Siemens 3T MRI machine. Post- processing of data was done by placing circular ROI of 30 mm2 on tumor (T), peritumoral edema (PT) and normal appearing white matter (WM) in the corresponding contra lateral hemisphere, avoiding cystic/necrotic/hemorrhagic regions. ROIs were then automatically transferred to corresponding ?1, ?2, ?3 and FA maps. FA, ADC, AD, RD, Cp, Cs and Cl were obtained. DTI parameters and histopathological tumor grades were analyzed statistically.
Results: An independent-samples t-test showed a significant difference between low grade and high grade tumours in eight out of 21 DTI parameters of which ADC (T), AD (T) and RD (T) showed a sensitivity of 100%. 72% and 12%; specificity of 76.9%, 100%, and 100%; PPV of 89.3%, 100% and 100%; NPV of 100%, 65% and 34.32% respectively. Diagnostic Accuracy was highest for ADC (T), ADC (PT), AD (T), RD (T), Cl (T), Cp (T).
Conclusion: DTI is recommended as part of glioma imaging for optimizing patient outcome as this study reveals high diagnostic accuracy and sensitivity for ADC, AD, RD, Cl and Cp of solid tumoral part and ADC, Cl of peritumoral region to differentiate High from Low Grade tumours.
Keyword :
DTI, Glioma grading, ADC, FA, MRI, GBM.