{'fraction_non_alphanumeric': 0.030257186081694403, 'fraction_numerical': 0.01664145234493192, 'mean_word_length': 5.7846153846153845, 'pattern_counts': {'":': 0, '<': 1, '<?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}}
3D isotropic high‐resolution diffusion‐weighted MRI of the whole brain with a motion‐corrected steady‐state free precession sequence

The main obstacle to high‐resolution (<1.5 mm isotropic) 3D diffusion‐weighted MRI is the differential motion‐induced phase error from shot‐to‐shot. In this work, the phase error is addressed with a hybrid 3D navigator approach that corrects motion‐induced phase in two ways. In the first, rigid‐body motion is corrected for every shot. In the second, repeatable nonrigid‐body pulsation is corrected for each portion of the cardiac cycle. These phase error corrections were implemented with a 3D diffusion‐weighted steady‐ state free precession pulse sequence and were shown to mitigate signal dropouts caused by shot‐to‐shot phase inconsistencies compared to a standard gridding reconstruction in healthy volunteers. The proposed approach resulted in diffusion contrast more similar to the contrast observed in the reference echo‐planer imaging scans than reconstruction of the same data without correction. Fractional anisotropy and Color fractional anisotropy maps generated with phase‐corrected data were also shown to be more similar to echo‐planer imaging reference scans than those generated without phase correction. Magn Reson Med 70:466–478, 2013. © 2012 Wiley Periodicals, Inc.