Evaluation of an abbreviated MRI protocol in the screening for brain metastases in the initial staging of lung cancer.

BACKGROUND AND PURPOSE: In the routine clinical practice, only a few key sequences allow positive diagnosis of brain metastasis. The aim of our study was to investigate the diagnostic accuracy of a reduced protocol including only 2 sequences of interest for the detection of brain lesions in lung cancer. MATERIALS AND METHODS: Fifty four patients undergoing MRI in the initial staging of lung cancer were included in this monocentric, retrospective study. Four radiologists reviewed the data from a short protocol with 2 sequences of interest (T2 FLAIR and 3D T1w-SE sequences) and from the standard reference protocol (DWI, T2*, T2 FLAIR, native T1 and post-contrast 3D T1w-GRE and 3D T1w SE sequences). Diagnostic performances were assessed on a per-patient and per-lesion basis. RESULTS: In our population, 35% of patients had brain metastases. The short protocol detected 22 metastatic patients with 3 false positives. The analysis showed excellent diagnostic performance of the short protocol with more than 90% sensitivity and specificity, for both per-patient and per-lesion evaluations. Metastatic classification was not significantly influenced by the reviewer's experience. Seven major secondary findings were identified, including 3 ischemic events and 1 aneurysm that were only detected when the long protocol was used. CONCLUSIONS: A short MRI brain protocol, including only 3D T2 FLAIR and T1w-SE sequences, demonstrated diagnostic accuracy equivalent to standard protocols for BM screening in lung cancer patients. The subsequent reduction in examination time can potentially improve access to MRI.