Adaptive Segmentation for Vessels Dynamic Characterization Using High Resolution MR Sequences

Magnetic resonance angiography is a continuously developed technique for vessel and flow mechanical characterization studies. Synchronized high temporal resolution sequences enable obtaining more precise results. We propose an adaptive corrective thresholding (ACT) segmentation principle. The method provides the new feature that it can automatically detect vessel region even while the presence of movement-related phenomena leading to a false segmentation. ACT method is able to approximate vessel contours using the last image in the time series as an elementary corrective structure. For the means of validation, the method is applied on clinical and phantom data sets. Qualitative, quantitative and shape comparisons between manual and automatic results permitted to evaluate segmentation performance. Results demonstrate that ACT overcomes all MRA- related problems with root mean square error as low as 0.18 and 2 mm² respectively on invitro and invivo images with maximal errors Emax of 0.81 and 5.44 mm . The shape error ERR doesn´t exceed 7%.