{'fraction_non_alphanumeric': 0.023307436182019976, 'fraction_numerical': 0.0, 'mean_word_length': 5.352112676056338, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Directional assessment of fiber integrity in Q-ball imaging

Q-ball imaging (QBI) is a diffusion imaging technique that provides unique microstructural information and outperforms diffusion tensor imaging (DTI) in areas of fiber crossings. The generalized fractional anisotropy (GFA) is a widely accepted quantitative measure of fiber integrity for QBI. In this paper we demonstrate a major drawback of the GFA occuring in crossing fiber regions: the fiber integrity is heavily underestimated here. We present a new, directional anisotropy measure and compare it to the GFA using custom-designed fiber phantoms and Monte Carlo simulations. Furthermore, we present in-vivo data of the measure. With the expense of reduced CNR, the new measure allows a better quantification of fiber bundles in crossing regions and potentially yields additional information regarding non-dominant tracts within a voxel.