Ultrasound Evaluation of the Abdominal Aorta and Mesenteric Arteries.

The authors review ultrasound (US) imaging findings of the abdominal aorta and mesenteric arteries, with a focus on screening for abdominal aortic aneurysm (AAA) and posttreatment follow-up. US is the primary imaging modality used to screen for AAA and for surveillance of aneurysms for growth after initial diagnosis. US and contrast-enhanced US may play a greater role in patient follow-up status post-endovascular aneurysm repairs.

Achieving and Maintaining Excellence: A Roadmap for Ultrasound Practices.

This article outlines a roadmap to achieving and maintaining excellence in an ultrasound (US) practice. We present constructive advice on how US practices can achieve and maintain quality, patient and referring physician satisfaction, and efficiency in the setting of rising examination volumes. Accreditation, sonographer and resident/fellow physician training, advanced practice sonographers, and Picture Archiving and Communication System/Artificial Intelligence in US are discussed.

Hemodialysis Access: US for Preprocedural Mapping and Evaluation of Maturity and Access Dysfunction.

Patients with kidney failure require kidney replacement therapy. While renal transplantation remains the treatment of choice for kidney failure, renal replacement therapy with hemodialysis may be required owing to the limited availability and length of time patients may wait for allografts or for patients ineligible for transplant owing to advanced age or comorbidities. The ideal hemodialysis access should provide complication-free dialysis by creating a direct connection between an artery and vein with adequate blood flow that can be reliably and easily accessed percutaneously several times a week.

US Quantification of Liver Fat: Past, Present, and Future.

Fatty liver disease has a high and increasing prevalence worldwide, is associated with adverse cardiovascular events and higher long-term medical costs, and may lead to liver-related morbidity and mortality. There is an urgent need for accurate, reproducible, accessible, and noninvasive techniques appropriate for detecting and quantifying liver fat in the general population and for monitoring treatment response in at-risk patients. CT may play a potential role in opportunistic screening, and MRI proton-density fat fraction provides high accuracy for liver fat quantification; however, these imaging modalities may not be suited for widespread screening and surveillance, given the high global prevalence.

Contrast-enhanced US Evaluation of Endoleaks after Endovascular Stent Repair of Abdominal Aortic Aneurysm.

Ruptured abdominal aortic aneurysm (AAA) carries high morbidity and mortality. Elective repair of AAA with endovascular stent-grafts requires lifetime imaging surveillance for potential complications, most commonly endoleaks. Because endoleaks result in antegrade or retrograde systemic arterialized flow into the excluded aneurysm sac, patients are at risk for recurrent aneurysm sac growth with the potential to rupture.

Microvascular Flow Imaging: A State-of-the-Art Review of Clinical Use and Promise.

Vascular imaging with color and power Doppler is a useful tool in the assessment of various disease processes. Assessment of blood flow, from infarction and ischemia to hyperemia, in organs, neoplasms, and vessels, is used in nearly every US investigation. Recent developments in this area are sensitive to small-vessel low velocity flow without use of intravenous contrast agents, known as microvascular flow imaging (MVFI).

Pulse-Echo Quantitative US Biomarkers for Liver Steatosis: Toward Technical Standardization.

Excessive liver fat (steatosis) is now the most common cause of chronic liver disease worldwide and is an independent risk factor for cirrhosis and associated complications. Accurate and clinically useful diagnosis, risk stratification, prognostication, and therapy monitoring require accurate and reliable biomarker measurement at acceptable cost. This article describes a joint effort by the American Institute of Ultrasound in Medicine (AIUM) and the RSNA Quantitative Imaging Biomarkers Alliance (QIBA) to develop standards for clinical and technical validation of quantitative biomarkers for liver steatosis.

Ultrasound Is Not Useful in Monitoring Lipedematous Alopecia: A Clinical, Trichoscopic, Histologic, and Ultrasound Analysis of 2 Cases.

Introduction: Lipedematous scalp (LS) is a rare condition characterized by thickened adipose tissue in the subcutaneous layer of the scalp resulting in a soft, spongy, or thick consistency of the scalp. When associated with hair loss, this condition is called lipedematous alopecia (LA). Various imaging modalities have been used to diagnose LS and LA along with histopathology.

Feasibility of Creation of an Endovascular Arteriovenous Fistula in Patients Undergoing Preoperative Vascular Mapping.

Background: The first endovascular arteriovenous fistula (endoAVF) device (WavelinQ), a novel percutaneous technique of AVF creation, was approved by the Food and Drug Administration in 2018 and has been placed in a small number of United States patients on hemodialysis. It is unknown how often patients with advanced CKD have vascular anatomy suitable for WavelinQ creation. The goal of this study was to determine the proportion of patients with vascular anatomy suitable for WavelinQ creation and to assess patient characteristics associated with such suitability.

Improved Detection of Gallbladder Perforation Using Ultrasound Small Vessel Slow Flow "Perfusion" Imaging.

Gallbladder (GB) perforation is a potentially fatal cause of acute abdomen. Higher morbidity and mortality are associated with this entity due to delayed diagnosis and treatment. Ultrasound with color/power Doppler and contrast sonography can detect wall discontinuity; however, sometimes it can be subtle or unavailable.

Thyroid Ultrasound: Diffuse and Nodular Disease.

Thyroid ultrasound with gray-scale and color Doppler is the most helpful imaging modality to differentiate normal thyroid parenchyma from diffuse or nodular thyroid disease by evaluating glandular size, echogenicity, echotexture, margins, and vascularity. The various causes of diffuse thyroid disease often have overlapping sonographic imaging features. Thyroid nodules may be hyperplastic or neoplastic, with most due to benign hyperplastic changes in architecture and benign follicular adenomas; only a small percentage are malignant.

Three-dimensional US for Quantification of Volumetric Blood Flow: Multisite Multisystem Results from within the Quantitative Imaging Biomarkers Alliance.

Background Quantitative blood flow (QBF) measurements that use pulsed-wave US rely on difficult-to-meet conditions. Imaging biomarkers need to be quantitative and user and machine independent. Surrogate markers (eg, resistive index) fail to quantify actual volumetric flow.

Early Predictors of Arteriovenous Fistula Maturation: A Novel Perspective on an Enduring Problem.

Background: Preoperative ultrasound mapping is routinely used to select vessels meeting minimal threshold diameters for surgical arteriovenous fistula (AVF) creation but fails to improve AVF maturation rates. This suggests a need to reassess the preoperative ultrasound criteria used to optimize AVF maturation.

Methods: We retrospectively identified 300 catheter-dependent patients on hemodialysis with a new AVF created between 2010 and 2016.

Prediction of Arteriovenous Fistula Clinical Maturation from Postoperative Ultrasound Measurements: Findings from the Hemodialysis Fistula Maturation Study.

Background: The utility of early postoperative ultrasound measurements in predicting arteriovenous fistula (AVF) clinical maturation is uncertain.

Methods: We investigated the relationships of ultrasound parameters with AVF clinical maturation in newly created AVF, measured at 1 day and 2 and 6 weeks, in 602 participants of a multicenter, observational cohort study. A backward elimination algorithm identified ultrasound measurements that independently predicted unassisted and overall AVF maturation.

Postoperative Ultrasound, Unassisted Maturation, and Subsequent Primary Patency of Arteriovenous Fistulas.

Background And Objectives: Postoperative ultrasound is commonly used to assess arteriovenous fistula (AVF) maturation for hemodialysis, but its utility for predicting unassisted AVF maturation or primary AVF patency for hemodialysis has not been well defined. This study assessed the predictive value of postoperative AVF ultrasound measurements for these clinical AVF outcomes.

Design, Setting, Participants, & Measurements: We queried a prospective vascular access database to identify 246 patients on catheter-dependent hemodialysis who underwent AVF creation between 2010 and 2016 and obtained a postoperative ultrasound within 90 days.

Relationships Between Clinical Processes and Arteriovenous Fistula Cannulation and Maturation: A Multicenter Prospective Cohort Study.

Background: Half of surgically created arteriovenous fistulas (AVFs) require additional intervention to effectively support hemodialysis. Postoperative care and complications may affect clinical maturation.

Study Design: Hemodialysis Fistula Maturation (HFM) Study, a 7-center prospective cohort study.

Practical advantages of contrast-enhanced ultrasound in abdominopelvic radiology.

Computed tomography (CT) and magnetic resonance imaging (MRI) are two of the workhorse modalities of abdominopelvic radiology. However, these modalities are not without patient- and technique-specific limitations that may prevent a timely and accurate diagnosis. Contrast-enhanced ultrasound (CEUS) is an effective, rapid, and cost-effective imaging modality with expanding clinical utility in the United States.

Comparison of postoperative ultrasound criteria to predict unassisted use of arteriovenous fistulas for hemodialysis.

Introduction: Arteriovenous fistulas (AVF) frequently fail to mature. Postoperative ultrasounds provide objective measurements to predict unassisted AVF use for hemodialysis (unassisted use) and guide interventions to salvage nonmaturing AVFs. The optimal ultrasound criteria to assess AVF maturation are uncertain.

Contrast-enhanced ultrasound of benign liver lesions.

Liver lesions are often incidentally detected on ultrasound examination and may be incompletely characterized, requiring further imaging. Contrast-enhanced ultrasound (CEUS) was recently approved by the Food and Drug Administration in the United States for liver lesion characterization. CEUS has the ability to characterize focal liver lesions and has been shown to be superior to color Doppler and power Doppler ultrasound in the detection of tumor vascularity.

Focal Liver Lesions: Computer-aided Diagnosis by Using Contrast-enhanced US Cine Recordings.

Purpose To assess the performance of computer-aided diagnosis (CAD) systems and to determine the dominant ultrasonographic (US) features when classifying benign versus malignant focal liver lesions (FLLs) by using contrast material-enhanced US cine clips. Materials and Methods One hundred six US data sets in all subjects enrolled by three centers from a multicenter trial that included 54 malignant, 51 benign, and one indeterminate FLL were retrospectively analyzed. The 105 benign or malignant lesions were confirmed at histologic examination, contrast-enhanced computed tomography (CT), dynamic contrast-enhanced magnetic resonance (MR) imaging, and/or 6 or more months of clinical follow-up.

Intimal Hyperplasia, Stenosis, and Arteriovenous Fistula Maturation Failure in the Hemodialysis Fistula Maturation Study.

Intimal hyperplasia and stenosis are often cited as causes of arteriovenous fistula maturation failure, but definitive evidence is lacking. We examined the associations among preexisting venous intimal hyperplasia, fistula venous stenosis after creation, and clinical maturation failure. The Hemodialysis Fistula Maturation Study prospectively observed 602 men and women through arteriovenous fistula creation surgery and their postoperative course.