Magister en Física Médica

Facultad de Física

Calculation of the vascular fraction per voxel in experimental tumours using magnetic resonance imaging (MRI).

Francisco Lagos, PUC


Diffusion-weighted magnetic resonance imaging (DW-MRI) using HASTE diffusion sequence was used to determinate the vascular fraction per voxel in two experimental tumour models. Intravoxel incoherent motion (IVIM) model was employed to determinate this parameter estimating the perfusion contribution of DW-MRI data by maximum likelihood estimator (MLE). In

neuroblastoma mouse tumour model, more than 57% of the tumour area obtained a vascular fraction value between 0.2 and 0.5 in a well distributed fashion. In bone metastases rat tumour model, a spatial description of this parameter was obtained with less defined distribution. Dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) and histological analysis were performed as verification techniques for DW-MRI results for this latter model. Artefacts in DW-MRI data e.g. low SNR and increment of signal in the low b-values range are noted to produce an inaccuracy in the estimation of this parameter. Besides, a new biological understanding of IVIM model applied in tumours should be performed to assess the desirable parameter.

18 de marzo de 2015


Auditorio Prof. J. Krause