White matter anatomy of human brain using DTI based atlas: A pictoral review at 3T

Purpose: DTI is frequently used in the diagnostic radiology in all domains including congenital white matter abnormalities, tumours, infections, demyelination, psychiatric illnesses. To interpret pathology involving white matter, one must be aware of normal appearance of the white matter fibres of the brain. For neurosurgery, awareness of normal appearing white matter tracts on DTI is important as DTI based neuronavigation is increasingly being used. We thus aimed to generate colour coded maps of human brain to delineate white matter anatomy using 3T Diffusion Tensor MRI. Method Five healthy volunteers underwent MRI on a 3T MR scanner (Magnetom skyra) using 20 channel head coil. Apart from basic MR sequences (T1W, T2W images to rule out any gross pathology) multidimensional diffusion weighted images were obtained in 20 non collinear directions using two b values (b value = 0 and 1000 s/mm2). The DTI data was autotransferred to a Siemens’ work station and post-processed with syngovia software (VB30A_HF06) to generate colour coded FA maps. The images were also manually processed using the same syngovia software to generate three dimensional tractography images. Results On DTI, major white fibres that were identified were blue coded (cranio-caudal orientation) projection fibres, red coded commissural fibres (medio-laterally oriented) and green coded association fibres (anteroposteriorly oriented). All major fibres were separately identified and demonstarated using tractography. Conclusion DTI is an effective modality to study the anatomy of white matter tracts of human brain and can help radiologists, neurologists, neurosurgeons as well as anatomists to understand the three dimensional orientation of white matter tracts in brain.