Department of Radiology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College.
J Magn Reson Imaging. 2010 Jun;31(6):1428-34. doi: 10.1002/jmri.22190.
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.
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.
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.
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.
通过兔肿瘤和炎症模型的组织学发现，确定超顺磁性氧化铁（USPIO）增强磁共振成像（MRI）中淋巴结误诊的原因。
36 只兔子随机分为炎症组和肿瘤组。USPIO 给药前后行腘窝 MRI。根据专门的标准评估腘窝淋巴结的诊断，并与组织学和电子显微镜检查结果进行比较。
有 46 个炎症性和 26 个转移性淋巴结。淋巴结转移诊断的灵敏度、特异性、阳性和阴性预测值分别为 84.6%、87.0%、78.6%和 90.9%。有 4 个假阴性（包膜下转移灶）和 6 个假阳性（皮质和皮质旁增生为主）。电子显微镜显示，在炎症性淋巴结中，吞噬泡含有许多 USPIO 颗粒，而在转移性淋巴结中，吞噬泡主要含有细胞残留物。
淋巴结恶性肿瘤的诊断主要取决于转移性肿瘤细胞的位置和数量。深入了解具有肿瘤负荷的淋巴结中巨噬细胞的生理作用将有助于更好地进行临床应用诊断。
