P05.03: Antenatal neuronal fiber tracking with diffusion tensor MRI in humans

Abstract

The primary aim of this study was to calculate, based on a mathematically modelled decision tree the cost effectiveness of the RM as an intervention for improving fetal medicine specialist’s decisions. Methods: 106 cases of fCNS were prospectively followed up until either termination of pregnancy (TOP) or postnatal follow up (PF). All of them underwent dedicated ultrasonographic (US) assessment and MR, at least once during prenatal evaluation. Neurological postnatal outcome and anatomo-pathology records were registered as gold standards. Positive and negative likelihood ratios (LR) were calculated for four specific regions: posterior fosa (PF), ventricular zone (VZ), cortex and subcortical region (CSC) and middle line (ML). After refinement of univariate analysis, a discriminative likelihood ratio (LR) was calculated for every region and technique, based on direct and indirect cost and calculated post-test probability a Markov’s chain was designed to modelate the real effectiveness of each test. Results: Table 1 summarizes LR results for region and technique, based on post test probabilities and costs, the probability of improving diagnosis with MR before 22 weeks is 15% for PF, 18,5% for VZ, 11% for CSC, 23% for ML, once modified the model for gestational age, the probability at 33 weeks increases to 53%, 78%, 65% and 42% respectively.