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Updated: Jun 12, 2026
High-frequency Ultrasound Imaging of Mouse Cervical Lymph Nodes
Published on: July 25, 2015
Possible pathological basis for false diagnoses of lymph nodes by USPIO-enhanced MRI in rabbits
Jing Lei1, Hua Dan Xue, Zhuo Li
1Department of Radiology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College.
Purpose:
To determine the cause of misdiagnosis of lymph nodes in ultrasmall superparamagnetic iron oxide (USPIO) enhanced magnetic resonance imaging (MRI) using histological findings in rabbit tumor and inflammatory models.
Materials And Methods:
Thirty-six rabbits were randomly divided into inflammatory and tumor groups. MRI of the popliteal fossa was performed before and 24 hours after USPIO administration. Diagnoses of popliteal lymph nodes were evaluated based on dedicated criteria and were compared with histological and electronic microscopic findings.
Results:
There were 46 inflammatory and 26 metastatic lymph nodes. Sensitivity, specificity, and positive and negative predictive values of the diagnosis of nodal metastasis were 84.6%, 87.0%, 78.6%, and 90.9%, respectively. There were four false-negatives with subcapsular metastatic foci and six false-positives with predominant cortex and paracortex hyperplasia. Electron microscopy showed that in inflammatory nodes, cytophagic bubbles contain many USPIO particles, while in metastatic nodes they contained predominantly cellular residues.
Conclusion:
Diagnosis of lymph node malignancy is largely determined by the location and number of metastatic tumor cells. A profound understanding of the physiological role of macrophages in nodes with tumor burden will contribute to better diagnoses for clinical application.
Insights
Misdiagnosis in ultrasmall superparamagnetic iron oxide (USPIO) enhanced MRI of lymph nodes can occur due to metastatic cell location and macrophage activity. Understanding these factors improves diagnostic accuracy for lymph node malignancy.
Area of Science:
- Oncology
- Radiology
- Pathology
Background:
- Ultrasmall superparamagnetic iron oxide (USPIO) enhanced magnetic resonance imaging (MRI) is utilized for lymph node assessment.
- Misdiagnosis in USPIO-enhanced MRI can impact clinical decision-making for cancer staging.
Purpose of the Study:
- To investigate the causes of misdiagnosis in USPIO-enhanced MRI of lymph nodes.
- To correlate MRI findings with histological and electron microscopic results in rabbit models.
Main Methods:
- Thirty-six rabbits were studied in tumor and inflammatory models.
- Popliteal lymph node MRI was performed before and after USPIO administration.
- Diagnoses were compared against histological and electron microscopic findings.
Main Results:
- Histopathology revealed 46 inflammatory and 26 metastatic lymph nodes.
- Diagnostic accuracy metrics included 84.6% sensitivity and 87.0% specificity.
- False-negatives were linked to subcapsular metastases; false-positives to hyperplasia. USPIO particle distribution differed between inflammatory and metastatic nodes.
Conclusions:
- Lymph node malignancy diagnosis depends on metastatic cell distribution and quantity.
- Understanding macrophage function in tumor-burdened nodes is crucial for improving clinical diagnosis.