The MR Research Center, Department of Clinical Medicine, Aarhus University, Aarhus, Denmark.
Department of Renal Medicine, Aarhus University Hospital, Aarhus, Denmark.
J Magn Reson Imaging. 2024 May;59(5):1603-1611. doi: 10.1002/jmri.28983. Epub 2023 Sep 1.
MRI can provide information on kidney structure, perfusion, and oxygenation. Furthermore, it allows for the assessment of kidney sodium concentrations and handling, allowing multiparametric evaluation of kidney physiology. Multiparametric MRI is promising for establishing prognosis and monitoring treatment responses in kidney diseases, but its intraindividual variation during the day is unresolved.
To investigate the variation in multiparametric MRI measurements from the morning to the evening.
Prospective.
Ten healthy volunteers, aged 29 ± 5 without history of kidney disease.
FIELD STRENGTH/SEQUENCE: 3 T/T mapping, blood-oxygen level dependent imaging, arterial spin labeling perfusion imaging, diffusion weighted imaging, and sodium imaging.
A multiparametric MRI protocol, yielding T1, R2*, ADC, renal blood flow and renal sodium levels, was acquired in the morning, noon, and evening. The participants were fasting prior to the first examination. Urine biochemical analyses were performed to complement MRI data. The cortex and medulla were analyzed separately in a semi-automatic fashion, and gradients of total sodium concentration (TSC) and R* gradients were calculated from outer cortex to inner medulla.
Analyses of variance and mixed-effects models to estimate differences from time of day. Coefficients of variation to assess variability within and between participants. A P-value <0.05 was considered statistically significant.
The coefficients of variation varied from 5% to 18% for proton-based parametric sequences, while it was 38% for TSC over a day.
Multiparametric MRI is stable over the day. The coefficients of variation over a day were lower for proton multiparametric MRI, but higher for sodium MRI.
2 TECHNICAL EFFICACY: Stage 2.
MRI 可提供有关肾脏结构、灌注和氧合的信息。此外，它还可以评估肾脏的钠浓度和处理能力，从而实现对肾脏生理学的多参数评估。多参数 MRI 有望用于确定肾脏疾病的预后和监测治疗反应，但目前尚不清楚其在一天内的个体内变化情况。
研究多参数 MRI 测量值从早上到晚上的变化情况。
前瞻性。
10 名健康志愿者，年龄 29±5 岁，无肾脏疾病史。
磁场强度/序列：3T/T1 mapping、血氧水平依赖成像、动脉自旋标记灌注成像、扩散加权成像和钠成像。
在早上、中午和晚上采集多参数 MRI 协议，得到 T1、R2*、ADC、肾血流和肾钠水平。参与者在第一次检查前禁食。进行尿液生化分析以补充 MRI 数据。皮质和髓质分别采用半自动方式进行分析，并从外皮质到内髓质计算总钠浓度（TSC）和 R*梯度。
方差分析和混合效应模型用于估计不同时间点的差异。变异系数用于评估个体内和个体间的变异性。P 值<0.05 被认为具有统计学意义。
质子基参数序列的变异系数在 5%至 18%之间，而 TSC 在一天内的变异系数为 38%。
多参数 MRI 在一天内是稳定的。质子多参数 MRI 的日内变异系数较低，但钠 MRI 的变异系数较高。
2 技术功效：2 级。
