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Updated: Jul 8, 2026
Non-invasive Optical Imaging of the Lymphatic Vasculature of a Mouse
Published on: March 8, 2013
Detection of small inflammatory and metastatic lymph nodes in rabbits by sonography: evaluation with the resistive
Ying Huang1, Steven Bing Hu, Rong Wu
1Department of Ultrasound in Medicine, Shanghai Jiaotong University Affiliated Sixth People's Hospital, Shanghai, China.
Objective:
The aim of this prospective study was to determine whether the resistive index (RI) ratio based on high-resolution spectral Doppler sonography would be useful in the differential diagnosis of small inflammatory and metastatic lymph nodes in rabbit models.
Methods:
The infected and metastatic lymph node models we used were created by subcutaneously inoculating methicillin-susceptible Staphylococcus aureus and VX2 tumor cells respectively into the left hind limbs of 10 New Zealand White rabbits. High-resolution sonography was performed to investigate the popliteal fossa lymph nodes 2 weeks after the inoculation. The sizes, long-/short-axis ratios, and RI ratios (defined as the value of the peripheral RI relative to the central RI) of the nodes were evaluated with sonography and then compared with the histopathologic findings.
Results:
No statistical differences were found between the volumes (mean +/- SD, 104 +/- 41 versus 87 +/- 24 mm(3); P > .05) and the long-/short-axis ratios (1.97 +/- 0.28 versus 2.03 +/- 0.26; P > .05) of 15 inflammatory and 14 metastatic lymph nodes. On spectral Doppler sonography, the RI ratio was higher in the metastatic lymph nodes than in the inflammatory lymph nodes. With an RI ratio higher than 1.2 as a diagnostic criterion for a metastatic lymph node, the sensitivity, specificity, and positive and negative predictive values of sonography were 71% (10/14), 80% (12/15), 76% (10/13), and 75% (12/16), respectively, with an area under the receiver operating characteristic curve value of 0.824.
Conclusions:
This experimental study confirms that RI ratio changes based on high-resolution spectral Doppler sonography are associated with histopathologic changes of metastatic and inflammatory lymph nodes during the initial stage in rabbits.
Insights
The resistive index (RI) ratio using spectral Doppler sonography can help differentiate between inflammatory and metastatic lymph nodes in rabbits. This imaging technique shows potential for diagnosing small lymph node changes.
Area of Science:
- Medical Imaging
- Oncology
- Veterinary Medicine
Background:
- Accurate differentiation of small lymph nodes is crucial for diagnosis.
- Inflammatory and metastatic lymph nodes can present similar morphological features.
- High-resolution spectral Doppler sonography offers detailed vascular information.
Purpose of the Study:
- To evaluate the utility of the resistive index (RI) ratio in distinguishing small inflammatory from metastatic lymph nodes.
- To assess the diagnostic performance of RI ratio in rabbit models.
Main Methods:
- Created inflammatory (Staphylococcus aureus) and metastatic (VX2 tumor cells) lymph node models in rabbits.
- Performed high-resolution spectral Doppler sonography on popliteal lymph nodes.
- Analyzed lymph node size, long-/short-axis ratio, and RI ratio, comparing with histopathology.
Main Results:
- No significant differences in lymph node volume or long-/short-axis ratio between inflammatory and metastatic groups.
- The RI ratio was significantly higher in metastatic lymph nodes compared to inflammatory ones.
- An RI ratio > 1.2 demonstrated 71% sensitivity and 80% specificity for metastatic lymph nodes (AUC=0.824).
Conclusions:
- The RI ratio derived from high-resolution spectral Doppler sonography is a valuable tool for differentiating initial-stage inflammatory and metastatic lymph nodes in rabbits.
- This sonographic parameter correlates with histopathologic findings, aiding in differential diagnosis.
