ENLARGED MEDIASTINAL LYMPH-NODES IN BRONCHOGENIC-CARCINOMA - ASSESSMENT WITH DYNAMIC CONTRAST-ENHANCED MR-IMAGING - WORK-IN-PROGRESS

PURPOSE: To determine whether dynamic contrast material-enhanced magne tic resonance (MR) imaging can help differentiate between malignant an d benign mediastinal lymph nodes (MLNs) in bronchogenic carcinoma. MAT ERIALS AND METHODS: Nine patients with biopsy-proved lung carcinoma un derwent dynamic contrast-enhanced MR imaging before undergoing thoraci c surgery. MR studies included spin-echo, electrocardiographically gat ed axial and coronal sequences and transaxial gradient-echo breath-hol d sequences, which were performed after administration of a bolus of g adoterate meglumine. The enhancement curves were established on the ba sis of mean signal intensities from regions of interest at the level o f tumor and the enlarged MLN. MR images were compared with pathologic specimens obtained at surgical resection. RESULTS: Metastatic MLNs exh ibited their peak enhancement at 60-80 seconds, with a slow decrease u ntil 6 minutes. Granulomatous and anthracotic lymph nodes displayed a slight enhancement, with no peak within 6 minutes (P < .01). CONCLUSIO N: Dynamic contrast-enhanced MR images may provide informative data ab out the nature of enlarged MLNs in the preoperative assessment of lung carcinoma. Further studies are needed to investigate its usefulness i n clinical practice.