Motor cortex hypointensity on susceptibility-weighted imaging: a potential imaging marker of iron accumulation in patients with cognitive impairment

• Published in: Neuroradiology Vol. 61; no. 6; pp. 675 - 683
• Main Authors: Park, Mina, Moon, Yeonsil, Han, Seol-Heui, Moon, Won-Jin
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01.06.2019; Springer Nature B.V
• Subjects: Accumulation; Age; Alzheimer's disease; Brain; Cognitive ability; Confidence intervals; Cortex (motor); Dementia; Diagnostic Neuroradiology; Imaging; Impairment; Informed consent; Iron; Magnetic permeability; Magnetic resonance imaging; Medical imaging; Medicine; Medicine & Public Health; Motors; Neuroimaging; Neurology; Neuroradiology; Neurosciences; Neurosurgery; Patients; Quantitative analysis; Radiology; Regression analysis; Statistical analysis; Visual cortex; Susceptibility-weighted imaging; Iron; Alzheimer’s disease; Magnetic resonance imaging; Cognitive dysfunction; Dementia
• ISSN: 0028-3940; 1432-1920
• DOI: 10.1007/s00234-019-02159-3

Purpose To assess the prevalence and characteristics of motor cortex hypointensity on 3-T susceptibility-weighted imaging (SWI) in patients with cognitive impairment and examine its clinical significance. Methods The institutional review board approved this retrospective study and waived the requirement for informed consent. A total of 127 patients with a clinical diagnosis of probable Alzheimer’s disease (AD) ( n  = 32) or mild cognitive impairment (MCI) ( n  = 95) and 127 age- and sex-matched control subjects underwent 3-T brain magnetic resonance imaging. SWI was analyzed for both subjective visual scoring and the quantitative estimation of phase shift in the posterior bank of the motor cortex. A multivariate logistic regression analysis was performed to identify clinical and imaging variables associated with motor cortex hypointensity on SWI. Results Motor cortex hypointensity on SWI was observed in 94/127 cognitively impaired patients (74.0%) and 72/127 control subjects (56.7%) ( p  = 0.004). Age was the only variable that was significantly associated with motor cortex hypointensity in patients with cognitive impairment (odds ratio, 1.15; 95% confidence interval, 1.065–1.242; p  < 0.001). The quantitative analysis confirmed a significant increase in phase shifting in the posterior bank of the motor cortex in patients with positive motor cortex hypointensity on SWI ( p  < 0.001). Conclusion Motor cortex hypointensity on SWI was more frequently found in patients with cognitive impairment than in age-matched controls and was positively associated with age. Thus, it may be a potential imaging marker of iron accumulation in patients with MCI or AD.