To Evaluate the Damage of Renal Function in CIAKI Rats at 3T: Using ASL and BOLD MRI

Abstract

Purpose. To investigate noninvasive arterial spin-labeling (ASL) and blood oxygen level-dependent imaging (BOLD) sequences for measuring renal hemodynamics and oxygenation in contrast induced acute kidney injury (CIAKI) rat. Materials and Methods. Thirteen SD rats were randomly grouped into CIAKI group and control group. Both ASL and BOLD sequences were performed at 24 h preinjection and at intervals of 0.5, 12, 24, 48, 72, and 96 h postinjection to assess renal blood flow (RBF) and relative spin-spin relaxation rate (R 2 *), respectively. Results. For the CIAKI group, the value of RBF in the cortex (CO) and outer medulla (OM) of the kidney was significantly decreased (P < 0.05) at 12–48 h and regressed to baseline level (P = NS) at 72–96 h. In OM, the value of R 2 * was increased at 0.5–48 h (P < 0.05) and not statistically significant (P = NS) at 72 and 96 h. Conclusions. RBF in OM and CO and oxygen level in OM were decreased postinjection of CM. ASL combining BOLD can further identify the primary cause of the decrease of renal oxygenation in CIAKI. This approach provides means for noninvasive monitoring renal function during the first 4 days of CIAKI in clinical routine work.

Atherosclerotic renal artery stenosis is associated with elevated cell cycle arrest markers related to reduced renal blood flow and postcontrast hypoxia

“…In a similar pattern, NGAL can be protective against acute ischemic injury, although it is most often utilized as a biomarker for AKI [36]. Our results using BOLD MRI suggest that residual accumulation of deoxyhemoglobin after contrast imaging can persist for at least 24-27 h and extend results observed in experimental rat models that demonstrate renal hypoxia measured by BOLD MRI after injection of iodinated contrast [37]. Studies in the rat suggest that these changes were associated with AKI as measured by NGAL levels [38].…”

Renal Arterial Spin Labeling Magnetic Resonance Imaging

“…ASL correlated with renal volume loss and histological changes [57], while the combined measurement of tissue perfusion and oxygenation [58] seems to improve the possibility of early detection of disease onset [59]. …”

Experimental imaging in orthotopic renal cell carcinoma xenograft models: comparative evaluation of high-resolution 3D ultrasonography, in-vivo micro-CT and 9.4T MRI

“…Furthermore, measurements of renal tumor oxygenation have been performed with this method in mice 24 . In rats, ASL has been used to investigate acute kidney injury induced by intravenous application of x-ray contrast agent 25 . Using DCE- and DWI-MRI, Jeon and colleagues could show that small animal MRI might also be able to assess early therapeutic response to small molecule tyrosine kinase inhibitors in subcutaneous RCC xenograft models 26 .…”