Diffusion-weighted magnetic resonance imaging in rat kidney using two-dimensional navigated,interleaved echo-planar imaging at 7.0 T

The purpose of this study was to investigate the feasibility of two-dimensional (2D) navigated, interleaved multishot echo-planar imaging (EPI) to enhance kidney diffusion-weighted imaging (DWI) in rats at 7.0 T. Fully sampled interleaved four-shot EPI with 2D navigators was tailored for kidney DWI (Sprague–Dawley rats, n = 7) on a 7.0-T small bore preclinical scanner. The image quality of four-shot EPI was compared with T₂-weighted rapid acquisition with relaxation enhancement (RARE) (reference) and single-shot EPI (ss-EPI) without and with parallel imaging (PI). The contrast-to-noise ratio (CNR) was examined to assess the image quality for the EPI approaches. The Dice similarity coefficient and the Hausdorff distance were used for evaluation of image distortion. Mean diffusivity (MD) and fractional anisotropy (FA) were calculated for renal cortex and medulla for all DWI approaches. The corticomedullary difference of MD and FA were assessed by Wilcoxon signed-rank test. Four-shot EPI showed the highest CNR among the three EPI variants and lowest geometric distortion versus T₂-weighted RARE (mean Dice: 0.77 for ss-EPI without PI, 0.88 for ss-EPI with twofold undersampling, and 0.92 for four-shot EPI). The FA map derived from four-shot EPI clearly identified a highly anisotropic region corresponding to the inner stripe of the outer medulla. Four-shot EPI successfully discerned differences in both MD and FA between renal cortex and medulla. In conclusion, 2D navigated, interleaved multishot EPI facilitates high-quality rat kidney DWI with clearly depicted intralayer and interlayer structure and substantially reduced image distortion. This approach enables the anatomic integrity of DWI-MRI in small rodents and has the potential to benefit the characterization of renal microstructure in preclinical studies.     

特纳综合征患者骨质疏松的研究进展

特纳综合征(TS)是女性常见的性染色体异常疾病,与多种疾病共存。越来越多的证据表明TS患者有较高的骨质疏松患病率,本文就近年来TS中骨质疏松的危险因素及管理治疗的相关研究进展做一综述。     

基于蒙医白脉理论探析帕金森病＊

帕金森病是以多巴胺能神经元减少导致的以静止性震颤、肌强直、运动迟缓和姿势步态障碍为主要临床症状的疾病。此病是蒙医白脉病的一种，又称彻彻热乎病。蒙医将人体的脉络分为白脉和黑脉。白脉病是白脉系统遭受致病因素的影响后所致的一系列疾病的总称，临床上很多疾病归属于“白脉病”。为更好的实现对蒙医优势单病种的规范化研究，本文基于白脉理论，探析蒙医对帕金森病的认识，以期为未来的研究提供理论支持。