BACKGROUND AND PURPOSE Changes in the brain composition of anorexics could potentially be expected, opening the door to new imaging approaches where quantitative and qualitative MRI have a role. Our purpose was to investigate anorexia‐related brain dehydration and myelin depletion by analyzing T1, T2, and T2* relaxation times of different brain structures in anorexics and controls. METHODS Thirty‐eight anorexic female patients (mean age, 26.2 years; age range, 16.2‐48.7 years; mean BMI, 14.5 kg/m2; BMI range, 10.0‐18.4 kg/m2) underwent brain MRI between August 2014 and August 2018. Controls were 16 healthy females (mean age, 28.0 years; age range, 22.3‐34.7 years; mean BMI, 20.9 kg/m2; BMI range, 18.4‐26.6 kg/m2). T1, T2, and T2* relaxation times were obtained for different brain structures in anorexics and controls as part of this retrospective case‐control study. RESULTS The T1 relaxation times of gray and white matter were significantly lower in anorexics (P = .009), whereas the T2 relaxation times of gray matter were higher (P < .001). There were no statistically significant differences in gray matter T2* relaxation times or in white matter T2 and T2* relaxation times between anorexics and controls. Occipital lobe gray matter showed the shortest T1, T2, and T2* relaxation times of all brain regions (P < .05). CONCLUSIONS T1 shortening in anorexics suggests both dehydration and myelin loss, whereas T2 prolongation points toward myelin loss (myelin water has lower T2), which seems to be less discernible in white matter. Shorter overall relaxation times in the most posterior regions of the brain suggest higher iron content.

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Background and Purpose: This study aimed to highlight anorexia nervosa-related metabolic changes in different brain regions with different gray and white matter contents. Methods:In a prospective study, 25 anorexic patients with mean body mass index (BMI) of 14.79 kg/m 2 (range 10.04-20.58) were compared with 15 healthy controls with mean BMI of 21.08 kg/m 2 (range 18.36-27.34). Two-dimensional magnetic resonance spectroscopic imaging was acquired in the axial plane above the corpus callosum, including frontal, precentral, postcentral, cingular, and parietal regions, as well as the precuneus, each voxel containing gray and white matter. Results:In the anorexic group, a significant increase of choline/creatine was observed in all brain regions except the precuneus: frontal (p = 0.009), cingulate (p = 0.001), precentral (p = 0.001), postcentral (p = 0.001), and parietal (p = 0.002); and in white and gray matter (p< 0.001). Macromolecules09/creatine was decreased in the following regions: frontal (p = 0.003), cingulate (p< 0.001), precentral (p = 0.004), and precuneus (p = 0.007), and in white and gray matter (p< 0.05). We observed significantly lower values of N-acetyl aspartate/creatine in the frontal (p < 0.001) and precentral (p< 0.001) regions and in voxels containing more than 50% white matter (p = 0.001); and significantly lower values of myo-inositol/creatine in the precentral (p = 0.006), postcentral (p< 0.001), and precuneus (p = 0.006) regions. Conclusions:We observed an increase in choline/creatine in anorexics, possibly reflecting increased cell turnover; a decrease in macromolecules, which was particularly low in the cingulate and precuneus the former being known to be altered in eating disorders; and a decrease in N-acetyl aspartate/creatine considered as a marker of neuronal density and function.