Altered diffusion tensor imaging (DTI) parameters in brain parenchyma after traumatic brain injury

Abstract

Abstract Aim of study To evaluate the role of diffuse tensor imaging (DTI) in detecting structural alterations following TBI with persistent symptoms without findings on conventional structural imaging. Methods This was a prospective study that enrolled a total of 30 individuals (12 females and 18 males), 6 control with no history of trauma and 24 with previous history of trauma. All subjects underwent conventional brain MRI and DTI. The eigenvalues of the genue and splenium of corpus callosum (CC), superior longitudinal fasciculus (SLF), inferior longitudinal fasciculus (ILF), corticospinal tract (CS), arcuate fasciculus (AF) were measured bilaterally in all cases using suitable region of interest and the fraction anisotropy (FA), mean diffusivity (MD), were calculated. FA and MD values were compared between patients and control subjects. Diagnostic accuracy was calculated for FA, MD and combined. Sensitivity and Specificity were determined from the curve and PPV, NPV and accuracy underwent calculation through cross-tabulation. Result As compared with controls, FA was significantly decreased and MD was significantly increased in genue and splenium of CC and CS. For the Combined FA & MD in differentiating cases with trauma there was statistically significant difference in SLF, AF, genue, splenium, ILF and CS as p value < 0.05. Conclusions DTI parameters is a promising tool in the detection of subtle brain parenchymal changes in patients with TBI who have persistent symptoms and no evident abnormalities on conventional MRI. Furthermore combined use of FA and MD shows better diagnostic accuracy in differentiation between control and trauma patient.

Keywords

• DTI (diffusion tensor imaging)
• TBI (traumatic brain injury)
• FA (fractional anisotropy)
• MD (mean diffusivity)