CEST MRI of sepsis-induced acute kidney injury
CEST MRI of sepsis-induced acute kidney injury
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脓毒症引起的急性肾损伤的 CEST MRI
DOI：
10.1002/nbm.3942
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发表时间：
2018-08-01
影响因子：
2.9
通讯作者：
Liu, Guanshu
中科院分区：
文献类型：
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作者：
Liu, Jing;Han, Zheng;Liu, Guanshu
脓毒症引起的急性肾损伤（SAKI）是肾脏疾病的主要并发症，与死亡率增加和进展加快有关。因此，开发用于检测脓毒症 AKI 的成像生物标志物具有重大的临床意义。在本研究中，我们旨在表征脂多糖（LPS）诱导的 SAKI 小鼠模型中的内源性化学交换饱和转移（CEST）MRI 对比，并研究使用 CEST MRI 来检测此类损伤。我们使用由 i.p. 生成的 SAKI 小鼠模型。注射10mg/kg LPS。由此产生的肾损伤通过血清肌酐升高和组织学证实。 LPS注射后24小时进行MRI评估，包括不同B-1强度（1、1.8和3T）的CEST MRI、T-1映射、T-2映射和常规磁化传递对比（MTC）MRI。使用 Z 谱分析 CEST MRI 结果，其中标准化水信号饱和度 (S-sat/S-0) 作为饱和频率的函数进行测量。在所有 B-1 功率下，在与水的 3.5 和 -3.5ppm 频率偏移处观察到 CEST 对比度大幅下降，其中在 1.8 T 的 B-1 时获得最显着的差异。受损肾脏和正常肾脏之间的平均 S-sat/S-0 差异为 0.07（0.55 +/- 0.04 与 0.62 +/- 0.04，P=0.0028）和 0.07 （0.50 +/- 0.04 对比 3.5 和-3.5ppm 分别为 0.57 +/- 0.03，P=0.0008)。相比之下，受损肾脏的T-1和T-2弛豫时间以及MTC对比度与正常对照相比没有表现出显着变化。我们的结果表明，CEST MRI 对受损肾脏的病理变化比 T-1、T-2 和 MTC 效应的变化更敏感，表明其在肾脏疾病分子成像方面具有潜在的临床应用价值。
Sepsis-induced acute kidney injury (SAKI) is a major complication of kidney disease associated with increased mortality and faster progression. Therefore, the development of imaging biomarkers to detect septic AKI is of great clinical interest. In this study, we aimed to characterize the endogenous chemical exchange saturation transfer (CEST) MRI contrast in the lipopolysaccharide (LPS)-induced SAKI mouse model and to investigate the use of CEST MRI for detecting such injury. We used a SAKI mouse model that was generated by i.p. injection of 10mg/kg LPS. The resulting kidney injury was confirmed by the elevation of serum creatinine and histology. MRI assessments were performed 24h after LPS injection, including CEST MRI at different B-1 strengths (1, 1.8 and 3 T), T-1 mapping, T-2 mapping and conventional magnetization transfer contrast (MTC) MRI. The CEST MRI results were analyzed using Z-spectra, in which the normalized water signal saturation (S-sat/S-0) is measured as a function of saturation frequency. Substantial decreases in CEST contrast were observed at both 3.5 and-3.5ppm frequency offset from water at all B-1 powers, with the most significant difference obtained at a B-1 of 1.8 T. The average S-sat/S-0 differences between injured and normal kidneys were 0.07 (0.55 +/- 0.04 versus 0.62 +/- 0.04, P=0.0028) and 0.07 (0.50 +/- 0.04 versus 0.57 +/- 0.03, P=0.0008) for 3.5 and-3.5ppm, respectively. In contrast, the T-1 and T-2 relaxation times and MTC contrast in the injured kidneys did not show a significant change compared with the normal control. Our results showed that CEST MRI is more sensitive to the pathological changes in injured kidneys than the changes in T-1, T-2 and MTC effect, indicating its potential clinical utility for molecular imaging of renal diseases.