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.     

癌症生存者家庭适应相关测量工具的研究进展

介绍家庭适应的相关概念及起源,阐述家庭适应方面常用测量工具的发展历程、内容结构、适用人群、评分方法、信度与效度、应用现状等情况,以期能够指导临床工作者在实践过程中选择合适的家庭适应测量工具,旨在帮助研究者进一步开发适用于我国癌症生存者的特异性家庭适应测量工具。     

免疫抑制儿童感染新型冠状病毒Omicron变异株病毒清除时间的回顾性队列研究

背景：儿童新型冠状（新冠）病毒Omicron变异株流行期间，免疫抑制状态儿童新冠病毒清除时间定量分析研究较少。 目的：探讨新冠病毒Omicron株感染后免疫抑制和非免疫抑制儿童病毒清除的时间差别，为公共卫生政策制定和精准疫情防控措施提供临床数据。 设计：回顾性队列研究。 方法：以新冠病毒Omicron变异株感染住院患儿为队列人群，分为免疫抑制组和非免疫抑制组，免疫抑制分为绝对免疫抑制、相对免疫抑制和实施免疫抑制疗法，以免疫抑制组病例的性别、年龄和新冠病毒感染的分型与非免疫抑制组行1∶3匹配。以鼻咽拭子新冠病毒PCR检测拷贝数阈（Ct）值≥35为队列终点。 主要结局指标：新冠病毒清除时间。 结果：2022年4月12日至2022年5月12日在上海市新冠病毒感染定点收治医院符合本文共同纳入和排除标准的连续病例728例。免疫抑制组33例，其中绝对免疫抑制8例，相对免疫抑制23例，接受免疫抑制疗法2例（不包括绝对和相对免疫抑制患儿）。非免疫抑制组匹配后99例。2组临床症状、新冠病毒感染治疗和疫苗接种次数差异均无统计学意义。免疫抑制组和非免疫抑制组新冠病毒清除时间分别为（16.5±6.8）和（10.3±4.4）d，差异有统计学意义。免疫抑制组和非免疫抑制组新冠病毒感染轻型病例病毒清除时间分别为（14.0 ± 8.3）和（9.7 ± 3.1）d，普通型病例病毒清除时间分别为（18.3 ± 4.9）和（11.2 ± 5.9）d，差异均有统计学意义。2组单日病毒清除率在第9~14天时差异有统计学意义（P为0.005~0.039）。2组普通型病例单日病毒清除率在第10~15天时差异有统计学意义。免疫抑制组新冠病毒感染2周后核酸检测再次呈阳性3例（9%），临床分型均较前轻，3例均未接种新冠疫苗。 结论：Omicron株感染的免疫抑制患儿病毒清除时间较非免疫抑制患儿显著延长，主要反映在第9~14天，免疫抑制患儿病毒复阳风险高，提示需要更长的隔离时间和转阴后严格的病毒监测。