Contrast-enhanced ultrasonography reveals a lower cortical perfusion and a decreased renal flow reserve in hypertensive patients

Abstract

Background Microvascular structural alteration and dysfunction is a hallmark of arterial hypertension. So far, the visualization and the quantification of renal microcirculation in humans has been hampered by the lack of non-nephrotoxic and non-invasive radiologic techniques. Contrast-Enhanced ultrasonography (CEUS) is an alluring method to investigate renal microcirculation and has not been investigated in this setting. We aimed to compare renal microcirculation in normotensives (NT) and hypertensive (HT) participants using CEUS at rest and during a sympathetic stress test. Methods We measured the renal perfusion index (PI, primary outcome), the renal resistive index (RRI), beat-to-beat systemic hemodynamics and plasma catecholamines before and during a 2-minute cold pressor test (CPT) in NT and HT participants. Linear mixed model analysis was used to compare the effect of the CPT on the variables of interest. Results 73 participants (32 HT) with normal kidney function were included. HT participants had a lower baseline PI compared to NT participants [1476(959–2155) arbitrary unit (a.u.) vs 2062(1438–3318) a.u., p < 0.001]. The CPT increased blood pressure, heart rate and catecholamines in all participants. The increase in PI observed in NT during the CPT was blunted in HT (+504(117–920) a.u. vs + 1159(678–2352) a.u in NT, interaction p = 0.013). Age, sex and body mass index did not modify these results. Conclusions HT patients had a lower basal renal cortical perfusion. During the cold pressor test, HT participants had a smaller increase in the PI, suggesting that renal cortical flow reserve is impaired.

Evaluation of the efficacy of rat renal ischemia-reperfusion injury after itaconic acid and its isomers treatment by contrast-enhanced ultrasound(CEUS)

“…At present, the main component of clinically used ultrasound contrast agents is sulfur hexa uoride (SF6) microbubbles, which are not affected by glomerular ltration rate and tubule absorption, have no metabolic burden on the kidney, and do not increase the risk of kidney injury [9,10]. Therefore, compared with enhanced computed tomography or enhanced magnetic resonance imaging, CEUS has great advantages in the diagnosis of kidney disease, and can safely assess renal perfusion and microcirculation in critically ill patients [11,12]. In addition, the time-intensity curve (TIC) and quantitative parameters(i.e.…”