Abstract: Brain metastasis(BM)are secondary malignant tumors originating from solid organs outside the central nervous system. They represent a severe complication of the incurable advanced stage of systemic cancer, characterized by high diversity, high heterogeneity, and poor prognosis, and are more common than primary brain tumors. The early and precise diagnosis of BM as well as the accurate assessment of their treatment prognosis are of critical importance for clinical decision-making regarding BM. The diagnostic classification of BM primarily relies on imaging data and clinical history. Due to its high sensitivity and specificity, conventional enhanced magnetic resonance imaging(MRI)has become the radiological gold standard for noninvasive diagnosis of BM, offering significant advantages in early diagnosis and treatment planning. Imaging diagnostics have shown great potential in the diagnosis, assessment and treatment of brain BM with the continuous development of MRI technology. Imaging diagnosis has demonstrated enormous potential in the diagnosis, evaluation and treatment of BM with the continuous advancement of MRI technology. Emerging functional MRI techniques are not confined to morphological assessment of BM; functional MRI technologies enable non-invasive evaluation of BM at the molecular and biological levels. This advancement facilitates precise and efficient diagnosis, enhances the accuracy and efficiency of therapeutic efficacy assessment and aids in clinical decision-making. This article reviews the application and latest research progress of MRI in the diagnosis and efficacy assessment of brain metastasis.

Key words: brain metastasis, magnetic resonance imaging, functional magnetic resonance imaging