Frank Peeters1, Dennis Rommel1, Jorge Abarca-Quinones1, Vincent Gregoire2, Thierry Duprez1
1Medical Imaging, Universit Catholique de Louvain, Brussels, Belgium; 2Center for Molecular Imaging and Experimental Radiotherapy, Universit Catholique de Louvain, Brussels, Belgium
The diagnostic accuracy of diffusion MRI related parameters derived from different techniques should be empirically assessed. We have performed a comparative study for the assessment of early effects of radiation therapy in a rodent tumour model (rhabdomyosarcoma in rats). Parameters obtained from DTI (2-points ADC, mono- and bi-exponential fits) and q-space imaging (tensor analysis) were compared. Our study shows that diffusion coefficients were very sensitive to radiation-induced tissue changes. Q-space analysis yielded at least the most sensitive parameter: the excess kurtosis of the distribution. The mean value and anisotropy of the tensors detected different sub-areas within irradiated tissue.