Enlarged mediastinal lymph nodes in bronchogenic carcinoma: assessment with dynamic contrast-enhanced MR imaging. Work in progress

Abstract

Purpose: To determine whether dynamic contrast material-enhanced magnetic resonance (MR) imaging can help differentiate between malignant and benign mediastinal lymph nodes (MLNs) in bronchogenic carcinoma.

Materials and methods: Nine patients with biopsy-proved lung carcinoma underwent dynamic contrast-enhanced MR imaging before undergoing thoracic surgery. MR studies included spin-echo, electrocardiographically gated axial and coronal sequences and transaxial gradient-echo breath-hold sequences, which were performed after administration of a bolus of gadoterate meglumine. The enhancement curves were established on the basis of mean signal intensities from regions of interest at the level of tumor and the enlarged MLN. MR images were compared with pathologic specimens obtained at surgical resection.

Results: Metastatic MLNs exhibited their peak enhancement at 60-80 seconds, with a slow decrease until 6 minutes. Granulomatous and anthracotic lymph nodes displayed a slight enhancement, with no peak within 6 minutes (P < .01).

Conclusion: Dynamic contrast-enhanced MR images may provide informative data about the nature of enlarged MLNs in the preoperative assessment of lung carcinoma. Further studies are needed to investigate its usefulness in clinical practice.