Artificial Intelligence or Human Hand? Evaluating Inferior Vena Cava Imaging for Hydration Status

This observational pilot project is to compare AI-guided sonographic IVC measurements with those of human operators (experienced sonographer, beginner sonographer) in two commonly used views (SC, RI) in healthy, euvolemic participants before and after PLR, which mimics hypervolemia, in order to assess the possible role of AI-guided sonographic IVC measurements by assessing its feasibility and reliability. US assessment will be performed by two sonographers, one beginner (BS) and one experienced (ES), blinded to each other's measurements. The BS is defined as a doctor who has not performed more than 20 US assessments of the IVC and has not performed clinical US of the abdominal region (at least 1x/week) in the past 6 months. The ES is defined as a doctor who has performed at least 20 US assessments of the IVC and uses US at least 1x/week in the past 6 months. Both BS and ES will perform a 2-hour training session in IVC sonography in two views (SC, RI) with a US-experienced doctor and will have full access to the protocol and measurement techniques during the assessments. The study consists of a screening visit and a study visit, which can be performed on the same day, with at least 2 hours interval between the two.

Inclusion criteria

• Healthy adults aged 18 years or older, 50% biological women

Exclusion criteria

• Pregnant or lactating women
• History of thrombosis of the inferior vena cava
• Major cardiovascular event in the last 3 months
• History of peripheral arterial disease of the legs
• History of heart failure of any grade
• History of atrial fibrillation or atrial flutter
• History of severe valvular disease
• History of renal failure
• History of liver cirrhosis
• History of chronic obstructive lung disease (COPD), chronic bronchitis, pulmonary emphysema
• History of diabetes mellitus
• History of arginine-vasopressin (AVP) disturbance
• Abdominal surgery within the last 3 month
• Volume loss (diarrhoea, vomiting, or bleeding) within the past 3 days
• Respiratory distress of any grade
• Any diuretic therapy, angiotensin-converting enzyme (ACE) inhibitors, angiotensin receptor blockers (ARBs)
• Inability to follow procedures or insufficient proficiency in the study language
• Inability to provide informed consent
• Vital signs outside normal limits: tachycardia >100 bpm, systolic blood pressure <85 mmHg, or SpO2 < 92%
• Employees or colleagues in a direct supervisory, subordinate, or collaborative relationship with the study team