Assessing microvasculature changes using super-resolution ultrasound imaging in preclinical and clinical study

Super-resolution ultrasound (SRU) imaging is an emerging technology that visualizes microvessels with unprecedented high resolution. Acute kidney injury (AKI) is a risk factor for the development of chronic kidney disease (CKD). One mechanism for this phenomenon is renal microvascular rarefaction and subsequent chronic impairment in perfusion. CKD is also common among individuals with sickle cell disease (SCD) and is a major contributor to early mortality in this population. Renal microvascular rarefaction and peritubular vascular congestion are known to be associated with progressive deterioration of renal health in SCD. SRU imaging can, therefore, be a promising diagnostic tool for kidney diseases by evaluating the changes of microvasculature. In this presentation, the feasibility and accuracy of SRU is shown in preclinical studies using mouse models of a ischemia–reperfusion injury and a heme induced CKD under an approved animal protocol. The potential clinical translation is demonstrated using a clinical ultrasound probe by assessing significant reductions in vessel density in CKD individuals compared to non-CKD subjects under the approval of institutional review board. Current technical limitations with 2-D SRU are also discussed and an optimized imaging sequence and algorithm for 3-D SRU using a row-columnarray (6 MHz) to overcome such limitations are introduced.