MR study of N2 disease in lung cancer: contrast-enhanced method using gadolinium–DTPA

Abstract

OBJECTIVE: In several previous studies, including one of our own, CT andMRI provided similar information on N2 detection in the staging of lungcancer. Both imaging techniques can be considered effective in detectingenlarged mediastinal lymph nodes but the results are often inaccurate whenconfronted with pathological findings. The purpose of this study was toassess the diagnostic accuracy of gadolinium-DTPA enhanced MRI in thedetection of mediastinal lymph nodes in lung cancer. METHODS: A prospectivestudy to compare standard unenhanced MRI and Gd-DTPA enhanced MRI wascarried out in patients with diagnosed lung cancer. The study focused onthe status of mediastinal lymph nodes. Gd-DTPA was administered at a dosageof 0.2 mmol2/KG before T1 weighted sequences. Qualitative visual analysesof both standard and contrast enhanced MRI images were performed on eachpatient by 2 independent radiologists. The imaging results were thencompared to pathological findings obtained after surgical operation.RESULTS: In the identification of mediastinal lymph node metastasesstandard MRI was 62% sensitive, 100% specific and 74% accurate whereasGd-DTPA enhanced MRI was 100% sensitive, 91% specific and 97% accurate.CONCLUSIONS: Gd-DPTA enhanced MRI was more accurate than standard MRI inthe detection of metastatic lymph nodes in patients with lung cancer. Theseinitial results can be considered encouraging especially with regards tothe reduction of false negative findings although further confirmation is,understandably, required.