Noninvasive assessment of renal dynamics and pH in a unilateral ureter obstruction model using DCE MR-CEST urography.
Noninvasive assessment of renal dynamics and pH in a unilateral ureter obstruction model using DCE MR-CEST urography.
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DOI：
10.1002/mrm.29436
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发表时间：
2023-01
影响因子：
3.3
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中科院分区：
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通过在注射碘帕醇后同时测量pH值和肾脏摄取/清除率，评估DCE MR CEST尿路造影评估单侧输尿管梗阻（UUO）小鼠肾功能的潜力。9只小鼠的右输尿管通过缝合结扎阻塞。在梗阻后第1、2和3天在11.7T MRI扫描仪上对动物进行成像。收集了4.3和5.5 ppm的96组饱和CEST图像。通过计算这两个频率的信号比并使用pH校准曲线获得肾脏pH值。肾脏时间活性曲线测量为4.3 ppm处注射后CEST信号相对于平均注射前信号的百分比变化。对于健康小鼠，两个肾脏的时间活性曲线几乎相同，并且显示出快速的造影剂排泄。对于UUO小鼠，梗阻肾脏的动态CEST曲线显示与对侧（CL）肾脏相比，达峰时间（TTP）值延长，造影剂排泄延迟。健康动物的肾脏pH图显示两个肾脏的酸性值相似（pH 6.65 ± 0.04 vs 6.67 ± 0.02），而与CL肾脏相比，梗阻肾脏的pH值显著升高（CL和UUO肾脏分别为pH 6.67 ± 0.08 vs 6.79 ± 0.11）。我们的研究结果表明，DCE-MR-CEST尿路造影可以检测肾脏摄取/排泄和pH稳态的变化，并区分梗阻和通畅的肾脏，早在UUO后1天。
To assess the potential of DCE MR CEST urography for assessing renal function in mice with unilateral ureter obstruction (UUO) by simultaneous pH and renal uptake/clearance measurements following injection of iopamidol. The right ureter of nine mice was obstructed via suture ligation. The animals were imaged at day 1, 2, and 3 post-obstruction on an 11.7T MRI scanner. Ninety-six sets of saturated CEST images at 4.3 and 5.5 ppm were collected. Renal pH values were obtained by calculating the signal ratio for these two frequencies and using a pH calibration curve. Renal time activity curves were measured as a percentage change in the post-injection CEST signal at 4.3 ppm relative to the average pre-injection signal. For the healthy mice, the time activity curves of both kidneys were nearly identical and displayed rapid excretion of contrast. For the UUO mice, the dynamic CEST curves for the obstructed kidneys displayed prolonged time to peak (TTP) values and delayed contrast excretion compared with the contralateral (CL) kidneys. Renal pH maps of the healthy animals showed similar acidic values for both kidneys (pH 6.65 ± 0.04 vs 6.67 ± 0.02), whereas in the obstructed kidneys there was a significant increase in pH values compared with the CL kidneys (pH 6.67 ± 0.08 vs 6.79 ± 0.11 in CL and UUO kidneys, respectively). Our findings indicate that DCE-MR-CEST urography can detect changes in renal uptake/excretion and pH homeostasis and distinguish between obstructed and unobstructed kidney as early as 1 day after UUO.