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Updated: May 1, 2026
Non-invasive Optical Imaging of the Lymphatic Vasculature of a Mouse
Published on: March 8, 2013
Indirect magnetic resonance imaging lymphography identifies lymph node metastasis in rabbit pyriform sinus VX2
Na Shen1, Jun Tan1, Peng Wang1
1Department of Otolaryngology, ZhongShan Hospital, Fudan University, Shanghai, China.
Background:
USPIO is a contrast agent for MRI that can generate T2W images with low signal intensities. After subcutaneous or intravenous injection of USPIO, normal lymph node tissues uptake these nano-particles, but tumor cells do not. Thus, tumor metastasis can be detected using this contrast agent.
Objective:
The aim of this study was to access the feasibility of USPIO enhanced MRI for the detection of cervical lymph node metastasis in a pyriform sinus carcinoma animal model and to investigate the ability of USPIO to enhance images of cervical lymph node metastases.
Methods And Findings:
Twenty New Zealand rabbits were randomly divided into tumor and inflammatory groups, and each group contained 10 rabbits. In the inflammatory group, a 0.5 ml egg yolk emulsion was injected into the sub-mandibular muscle of the rabbits to induce an inflammatory reaction in their cervical lymph nodes. In the tumor group, a VX2 tumor tissue suspension was transplanted into the pyriform sinus sub-mucosa of the rabbits using direct laryngoscope. Four weeks after the tumor or egg yolk injection, MRIs were performed before and after USPIO injection to observe the imaging enhancement features of USPIO. After that, a histo-pathological analysis was performed for all rabbits. We found the metastatic lymph nodes had no signal reduced intensity or irregular signal reduced intensity on T2-weighted image by using USPIO enhancement. In the tumor group,the sensitivity and specificity of plain MRI were 57.6% and 60.7%. The corresponding values of USPIO-enhanced MRl were 96.1% and 85.7%. (P<0.05).
Conclusion:
The features and the extent of the lymph node metastases corresponded to those observed on USPIO-enhanced MR images. USPIO-enhanced MRI is useful for the detection and estimation of lymph node metastasis in this cervical carcinoma animal model.
Insights
Superparamagnetic iron oxide nanoparticles (USPIO) enhance MRI detection of cervical lymph node metastasis in a pyriform sinus carcinoma model. USPIO-enhanced MRI significantly improves sensitivity and specificity for identifying metastatic lymph nodes.
Area of Science:
- Biomedical Imaging
- Oncology
- Nanotechnology
Background:
- Ultrasmall iron oxide particles (USPIO) act as MRI contrast agents, generating low signal intensities on T2W images.
- USPIO are taken up by normal lymph node tissue but not by tumor cells, enabling detection of metastasis.
- This characteristic allows USPIO-enhanced MRI to visualize lymph node involvement in cancer.
Purpose of the Study:
- To evaluate the feasibility of USPIO-enhanced MRI for detecting cervical lymph node metastasis.
- To assess the efficacy of USPIO in enhancing the visualization of lymph node metastases in a pyriform sinus carcinoma animal model.
Main Methods:
- Twenty New Zealand rabbits were divided into tumor and inflammatory groups.
- Tumor group: VX2 tumor implanted in the pyriform sinus; Inflammatory group: egg yolk emulsion injected to induce inflammation.
- MRI performed before and after USPIO injection, followed by histo-pathological analysis.
Main Results:
- USPIO-enhanced MRI revealed metastatic lymph nodes with reduced or irregular signal intensity on T2-weighted images.
- In the tumor group, sensitivity increased from 57.6% (plain MRI) to 96.1% (USPIO-enhanced MRI).
- Specificity improved from 60.7% (plain MRI) to 85.7% (USPIO-enhanced MRI) (P<0.05).
Conclusions:
- USPIO-enhanced MRI accurately reflects the features and extent of lymph node metastases.
- USPIO-enhanced MRI is a valuable tool for detecting and assessing lymph node metastasis in cervical carcinoma models.
