Department of Nephrology and Hypertension, University Hospital Erlangen, Erlangen, Germany.
Institute of Radiology, University Hospital Erlangen, Erlangen, Germany.
Am J Nephrol. 2021;52(1):69-75. doi: 10.1159/000513665. Epub 2021 Mar 5.
Alteration in kidney perfusion is an early marker of renal damage. The purpose of this study was to evaluate if changes in renal blood flow (RBF) could be detected using MRI with arterial spin labeling (ASL) technique.
RBF as assessed by cortical (CRBF), medullary, and total renal blood flow (TRBF) were measured by MRI with arterial spin labeling (ASL-MRI) using flow-sensitive alternating inversion recovery true fast imaging with steady-state precession sequence. In 11 normotensive healthy individuals (NT) and 11 hypertensive patients (HT), RBF was measured at baseline and after both feet were covered with cold ice packs (cold pressor test) that activates the sympathetic nervous system. In another experiment, RBF was measured in 10 patients with CKD before and after a pharmacological intervention. We compared RBF measurements between the 3 study populations.
A significant reduction in CRBF (p = 0.042) and a trend in TRBF (p = 0.053) were observed in response to the activation of the sympathetic nervous system. A trend toward reduction of CRBF (p = 0.051) and TRBF (p = 0.059) has been detected after pharmacological intervention. TRBF was significantly lower in patients with HT and CKD patients compared to NT individuals (NT vs. HT, p = 0.014; NT vs. CKD, p = 0.004). TRBF was lower in patients with CKD compared to HT (p = 0.047).
Our data indicate that both acute and short-term changes in RBF could be detected using ASL-MRI. We were able to detect differences in RBF between healthy and diseased individuals by needing only small sample size per group. Thus, ASL-MRI offers an advantage in conducting clinical trials compared to other technologies.
肾脏灌注的改变是肾脏损伤的早期标志物。本研究旨在评估磁共振成像动脉自旋标记（ASL）技术是否可以检测到肾血流量（RBF）的变化。
使用磁共振成像动脉自旋标记（ASL-MRI）通过流量敏感交替反转恢复真正快速成像与稳态进动序列评估皮质（CRBF）、髓质和总肾血流量（TRBF）。在 11 名血压正常的健康个体（NT）和 11 名高血压患者（HT）中，在基线时和双脚被冷冰袋覆盖（冷加压试验）后测量 RBF，该试验激活交感神经系统。在另一个实验中，在接受药物干预前后，在 10 例 CKD 患者中测量 RBF。我们比较了这 3 组研究人群之间的 RBF 测量值。
在激活交感神经系统后，观察到 CRBF（p=0.042）和 TRBF（p=0.053）显著降低。在药物干预后，CRBF（p=0.051）和 TRBF（p=0.059）呈下降趋势。HT 患者和 CKD 患者的 TRBF 明显低于 NT 个体（NT 与 HT，p=0.014；NT 与 CKD，p=0.004）。与 HT 患者相比，CKD 患者的 TRBF 较低（p=0.047）。
我们的数据表明，使用 ASL-MRI 可以检测到 RBF 的急性和短期变化。通过每组仅需要少量样本，我们能够检测到健康个体和患病个体之间的 RBF 差异。因此，与其他技术相比，ASL-MRI 在进行临床试验方面具有优势。
