Mark Drakesmith1, John Evans1, Anthony David2, Derek Jones1
1CUBRIC, Cardiff University, Cardiff, Wales, United Kingdom; 2Institute of Psychiatry, Kings College London, London, United Kingdom
The effect of false positives on the performance of blind tract clustering is unclear. From an idealised dataset of 6 pre-defined bundles, various distance metrics and clustering methods were tested across varying FP-rates by substituting a random proportion of true tracts with FPs. Most methods deteriorate gradually with noise. Affinities computed from maximum (Hausdorff) and endpoint distances were most robust to noise. These methods showed FP misclassification were concentrated on the smallest fibre bundle while other methods showed more diffuse misclassification across adjacent bundles. These two distance metrics are therefore best for clustering noisy tractography datasets.