Resistance index in mediastinal lymph nodes: a feasibility study

Area of Science:

• Vascular imaging
• Medical diagnostics
• Cardiovascular research

Background:

• Mediastinal lymph nodes are crucial in disease staging and monitoring.
• Assessing lymph node vascularity can provide insights into their physiological state.
• Doppler ultrasonography offers a non-invasive method to evaluate blood flow characteristics.

Purpose of the Study:

• To establish the normal range of Doppler ultrasonographic measurements for the resistance index (RI) in mediastinal lymph node arteries.
• To determine the feasibility and reliability of assessing RI in these vessels.

Main Methods:

• Color Doppler ultrasonography was used to examine mediastinal lymph node arteries in patients with normal CT findings.
• Peak systolic velocity (PSV) and end-diastolic velocity (ESV) were measured to calculate the resistance index (RI).
• Measurements were taken in various lymph node stations, with a focus on interpretable values.

Main Results:

• The study included 89 patients, with interpretable RI values obtained in 50 patients (127 nodes).
• Median PSV was 15.6 cm/s and median ESV was 5.8 cm/s.
• The median resistance index (RI) for mediastinal lymph node arteries was 0.63 (range, 0.52-0.75).

Conclusions:

• Color Doppler ultrasonography effectively quantifies velocities (PSV, ESV) in mediastinal lymph node arteries.
• The calculated resistance index (RI) provides a measure of blood flow resistance.
• Knowledge of the normal RI range is a valuable adjunct for ultrasonic mediastinal assessment.