Assessment of Renal Vasculature and Function with Ferumoxytol-enhanced Magnetic Resonance Imaging

Overview

Conventional contrast-enhanced magnetic resonance imaging is typically performed with extracellular gadolinium chelates, which is often limited in patients with CKD owing to the risk of nephrogenic systemic fibrosis. Ferumoxytol, a novel contrast medium, can be used as an "off-label" contrast agent for magnetic resonance imaging. During the last decade, ferumoxytol has gained appeal as an MRI contrast agent in patients with estimated glomerular filtration rates \<30mL/min and there are reports in the literature for its safe use and utility in both adult and pediatric patients with CKD. The study is designed to evaluate the diagnostic performance of ferumoxytol-enhanced magnetic resonance imaging in patients suspected of renal artery stenosis, investigate the correlation between renal cortical T2\*(T2\*=1/R2\*) and renal function, and develop an automatic algorithms for renal vessel segmentation.

This study is a single-center, prospective, controlled and diagnostic clinical trial to evaluate renal vasculature and renal function with ferumoxytol-enhanced magnetic resonance imaging using domestic polysaccharide superparamagnetic iron oxide injection as the contrast agent. This study will enroll 40 patients with or without renal impairment that are expected to undergo renal artery angiography in China. The investigators will record the baseline data of patients after admission. Patients will receive enhanced renal magnetic resonance imaging with polysaccharide superparamagnetic iron oxide nanoparticle to assess renal vasculature and renal function. The related laboratory indices will be reviewed at 24-72 h after magnetic resonance imaging, and then patients will receive renal angiography. The indices will be reexamined at 1 month and 3 months after magnetic resonance imaging. In order to evaluate the safety of polysaccharide superparamagnetic iron oxide nanoparticle, patients will detect iron levels in peripheral and tissue before and after the examination. The results of MR imaging including image quality, degree of vascular stenosis, and quantitative T2\* values of the renal cortex will be evaluated independently by two experienced radiologists. The degree of stenosis of the same vessels assessed by Quantitative Coronary Analysis (QCA) will be used for comparison with MR results. All clinical adverse events will be recorded by investigators.