Gray-Scale, Color Doppler, Spectral Doppler, and Contrast-Enhanced Renal Artery Ultrasound: Imaging Techniques and Features

Renovascular hypertension - a primer for the radiologist

Renovascular hypertension (RVHT) is an important cause of secondary hypertension, accounting for approximately 75% of cases. This pictorial review describes the imaging modalities used to diagnose RVHT, including ultrasound, computed tomography angiography, and magnetic resonance angiography, provides their benefits and limitations, and explores the imaging findings, diagnostic criteria, and management of multiple causes of RVHT. Atherosclerosis is the most common cause of RVHT, particularly in older individuals, while fibromuscular dysplasia is more prevalent in younger females. Less common discussed etiologies include polyarteritis nodosa, extrinsic compression, Page kidney, dissection, renal artery (RA) thrombus, and RA aneurysms. This paper also highlights the importance of recognizing anatomical variants and rare conditions that can impact diagnosis and management. While RVHT represents a minority of hypertension cases, its potential reversibility makes accurate diagnosis crucial. Treatment approaches vary based on etiology and may include medical management, angioplasty, stenting, or surgical intervention. This review aims to enhance radiologists' understanding of RVHT, facilitating improved diagnosis and patient care.

Renal and Genitourinary Ultrasound Evaluation in Emergency and Critical Care: An Overview

Renal and genitourinary ultrasound are fundamental resources employed by emergency and critical care healthcare providers to make prompt diagnoses and perform ultrasound-guided procedures. At the bedside, ultrasound can aid in the diagnosis of relevant pathologies, such as post-renal obstruction or kidney stones, and life-threatening conditions such as aortic dissection or hemoperitoneum. A narrative overview was performed, providing an updated review of renal and genitourinary ultrasound for emergency and critical care healthcare providers, emphasizing its advantages and the latest advances in the field. A thorough summary that can be utilized as a guide for emergency and critical care healthcare providers is presented. The daily hemodynamic management of critically ill patients involves the implementation of new protocols, such as VexUS or the evaluation of the renal resistance index. The role of ultrasound in managing acute nephropathy and genitourinary issues is increasingly crucial given its bedside availability, thus this imaging modality not only facilitates the initiation of therapeutic interventions but also provides swift prognostic insights that are vital to provide tailored patient care. As further advances in ultrasound will arise, it is important for healthcare providers to foster the use of these technologies capable of improving patient outcomes.

Magnetic Resonance Imaging in Atherosclerotic Renal Artery Stenosis: The Update and Future Directions from Interventional Perspective

Background

Atherosclerotic renal artery stenosis (ARAS) is a condition where the renal arteries become narrowed due to atherosclerosis, leading to reduced blood flow to the kidneys and various renal complications. The effectiveness of interventional treatments, such as renal artery angioplasty and stenting, remains debated, making patient selection for these procedures challenging.

Summary

This review focuses on the diagnosis and management of ARAS, with a particular emphasis on the potential role of functional magnetic resonance imaging (MRI) in evaluating renal function and mechanisms. By summarizing current diagnostic approaches and outcomes of interventional treatments, the review highlights the importance of informed clinical decision-making in ARAS management. Functional MRI emerges as a promising noninvasive tool to assess renal function, aiding in patient stratification and treatment planning.

Key Messages

The efficacy of interventional treatments for ARAS requires further investigation and careful patient selection. Functional MRI holds promise as a noninvasive means to assess renal function and mechanisms, potentially guiding more effective clinical decisions in ARAS management. Advancing research in diagnostic methods, particularly functional MRI, can enhance our understanding and improve the treatment outcomes for ARAS patients.