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Recent developments in image analysis have enabled an individual’s brain network to be evaluated and brain age to be predicted from gray matter images. Our study aimed to investigate the effects of age and sex on single-subject gray matter networks using a large sample of healthy participants. We recruited 812 healthy individuals (59.3 ± 14.0 years, 407 females, and 405 males) who underwent three-dimensional T1-weighted magnetic resonance imaging. Similarity-based gray matter networks were constructed, and the following network properties were calculated: normalized clustering, normalized path length, and small-world coefficients. The predicted brain age was computed using a support-vector regression model. We evaluated the network alterations related to age and sex. Additionally, we examined the correlations between the network properties and predicted brain age and compared them with the correlations between the network properties and chronological age. The brain network retained efficient small-world properties regardless of age; however, reduced small-world properties were observed with advancing age. Although women exhibited higher network properties than men and similar age-related network declines as men in the subjects aged < 70 years, faster age-related network declines were observed in women, leading to no differences in sex among the participants aged ≥ 70 years. Brain age correlated well with network properties compared to chronological age in participants aged ≥ 70 years. Although the brain network retained small-world properties, it moved towards randomized networks with aging. Faster age-related network disruptions in women were observed than in men among the elderly. Our findings provide new insights into network alterations underlying aging.

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We prospectively evaluated thin-slice coronal turbo spin-echo (TSE) diffusion-weighted imaging (DWI) covering a larger area with the recently-developed techniques on a 3T MRI scanner, compared with echoplanar imaging (EPI)-DWI in patients undergoing routine hand MRI. Visual score assessment and apparent diffusion coefficient (ADC) measurement were performed for patients with suspected hand tumors. TSE-DWI was superior to EPI-DWI, with less image distortion. The visual score and ADC comparison assessments proved that the image noise of TSE-DWI was acceptable.breast and lung cancers, and spinal cord infarction. 1,5-10 To the best of our knowledge, however, there have been no TSE-DWI studies evaluating musculoskeletal lesions of the hand or foot. In addition, only one previous case report evaluated middle ear cholesteatoma using 2-mm-thick single-shot TSE-DWI, but ADC measurement was not performed and the acquisition time was not presented. 6 TSE-DWI using the recently-developed parallel imaging and single-shot technique on 3T MRI might yield a superior image quality and is already used clinically. However, the image quality of thin-slice TSE-DWI for the assessment of small musculoskeletal lesions has not yet been clarified. Thus, the purpose of this study was to prospectively examine whether the 2-mm-thick coronal TSE-DWI covering a larger area and small lesions could substitute for conventional EPI-DWI in patients undergoing routine hand MRI on a 3T scanner. Materials and Methods Study designThis prospective study was performed in accordance with the ethical standards of our Institutional Review Board. Written informed consent was obtained from the patients and their privacy was completely protected. Eligibility criteria for entry were: (1) adult patients suspected of having or being followed for a musculoskeletal tumor of the hand or finger, (2) patient agreement to cooperate, and (3) examination on a Philips 3T MRI scanner (Ingenia; Philips Medical Systems, Eindhoven, The Netherlands). The exclusion criteria were:(1) contraindications to MR (incompatible metal implants or pacemakers), and (2) motion artifacts and artifacts from unsuppressed fat on the images. The primary endpoint of the