Multimodal Diagnostic Ultrasound for Congestion, Perfusion, and Ultrafiltration Tolerance in Maintenance...

Maintenance hemodialysis is characterized by repetitive changes in fluid distribution, blood pressure, and organ perfusion. Conventional clinical examination, empirical dry-weight adjustment, and biomarkers do not fully resolve the compartment-specific nature of congestion in this population. This narrative review reframes ultrasound-based volume assessment as a multimodal diagnostic problem involving pulmonary congestion, intravascular filling, systemic venous congestion, cardiac reserve, tissue response, and perfusion vulnerability.

We synthesized clinically relevant evidence indexed in PubMed and Google Scholar for studies published between January 2016 and April 2026, prioritizing dialysis-specific randomized trials, prospective cohorts, systematic reviews, consensus statements, and methodological studies related to diagnostic ultrasound, Doppler-based congestion assessment, contrast-enhanced ultrasound, elastography, artificial intelligence, point-of-care ultrasound, and remote ultrasound monitoring.

Lung ultrasound currently has the strongest dialysis-specific evidence for detecting and tracking pulmonary congestion. Inferior vena cava ultrasound provides adjunctive information on intravascular filling and right-sided pressure but is not a surrogate for total body water. Echocardiographic parameters help characterize filling pressure and cardiac tolerance to fluid removal, whereas venous Doppler and the Venous Excess Ultrasound Score provide an emerging approach to systemic venous congestion. Elastography and contrast-enhanced ultrasound remain investigational tools for tissue characterization and perfusion vulnerability, while AI-assisted analysis, handheld point-of-care ultrasound, and tele-ultrasound may improve standardization, automated B-line quantification, and scalability.

Different ultrasound modalities answer different diagnostic questions in maintenance hemodialysis. A compartment-specific framework integrating congestion, perfusion, and cardiac-reserve domains may better support individualized ultrafiltration planning, hemodynamic risk assessment, and future outcome-oriented research.