Dynamic Contrast-enhanced CT Lymphangiography to Quantify Thoracic Duct Lymphatic Flow

Area of Science:

• Medical Imaging
• Lymphatic System Physiology
• Quantitative Analysis

Background:

• CT lymphangiography is used for lymphatic imaging but lacks thoracic duct (TD) flow quantification.
• Accurate measurement of TD lymphatic flow is crucial for assessing lymphatic abnormalities.

Purpose of the Study:

• To develop and validate a technique for measuring TD lymphatic flow rate using dynamic contrast-enhanced CT lymphangiography.
• To compare novel CT-based flow measurement techniques against a surgical US flow probe reference standard.

Main Methods:

• Two techniques, first-pass analysis and thresholding, were developed to quantify TD lymphatic flow from CT images.
• Measurements were validated in a swine model using dynamic contrast-enhanced CT lymphangiography.
• CT-derived flow rates were compared to US flow probe measurements and assessed for repeatability.

Main Results:

• Both CT techniques demonstrated high correlation (r=0.99 and 0.91) and good agreement with the US flow probe.
• Mean differences were small (0.04 and 0.05 mL/min), indicating accurate flow quantification.
• Repeatability analysis showed good agreement for repeated measurements (r=0.94 and 0.90).

Conclusions:

• Dynamic contrast-enhanced CT lymphangiography enables accurate and noninvasive quantification of TD lymphatic flow.
• The developed first-pass analysis and thresholding techniques provide reliable methods for lymphatic flow assessment.