{'fraction_non_alphanumeric': 0.03961456102783726, 'fraction_numerical': 0.008029978586723769, 'mean_word_length': 5.209302325581396, 'pattern_counts': {'":': 0, '<': 2, '<?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}}
Quantitative MR phase-corrected imaging to investigate increased brain iron deposition of patients with Alzheimer disease.

PURPOSE
Brain iron deposition has been proposed to play an important role in the pathophysiology of neurodegenerative diseases. The aim of this study was to investigate the correlation of brain iron accumulation with the severity of cognitive impairment in patients with Alzheimer disease (AD).


MATERIALS AND METHODS
This study was approved by the institutional review board of Tongji Hospital (Wuhan, China) and written informed consent was obtained from all participants. Fifteen patients with AD, 15 age-and sex-matched healthy controls, and 30 healthy volunteers underwent high-resolution magnetic resonance (MR) phase-corrected imaging. The phase shift and iron concentrations of the bilateral hippocampus (HP), parietal cortex (PC), frontal white matter, putamen (PU), caudate nucleus (CN), thalamus, red nucleus, substantia nigra, and dentate nucleus (DN) of the cerebellum were examined for correlation with severity of dementia by using a two-tailed Student-Newman-Keuls t test (analysis of variance) and linear correlation test.


RESULTS
Regional phase shifts on phase-corrected images were negatively correlated with regional brain iron concentration in healthy adults (r = -0.926, P = .003). Iron concentrations in the bilateral HP, PC, PU, CN, and DN subregions of patients with AD were significantly higher than the controls (P < .05), Moreover, these brain iron concentrations, especially those in the PC at the early stages of AD, were positively correlated with the severity of patients' cognitive impairment (P < .05).


CONCLUSION
Iron concentration in the PC was positively correlated with the severity of AD patients' cognitive impairment, indicating that it may be used as a biomarker to evaluate the progression of AD.