[Quantitative Assessment for Brain Lesion by Perfusion and Metabolic Imaging]

Advances in neuroimaging have improved the diagnosis and management of structural brain diseases, including cerebrovascular disorders and brain tumors. Although conventional computed tomography and magnetic resonance imaging (MRI) provide essential morphological information, functional and metabolic imaging enables the qualitative assessment of tissue physiology. Integrating morphological and qualitative imaging has become increasingly important for optimizing diagnostic strategies, treatment selection, and therapeutic response evaluation. However, excessive imaging may increase cost and complexity without improving clinical outcomes, thereby necessitating appropriate modality selection. This review summarizes perfusion and metabolic imaging modalities, including MRI-based arterial spin labeling, and nuclear medicine techniques. These techniques enable the evaluation of cerebral blood flow, oxygen metabolism, and tumor metabolic characteristics. Clinical applications include differentiating tumor from non-tumor lesions, predicting glioma grade and infiltration, performing preoperative functional mapping, distinguishing tumor recurrence from radiation necrosis, assessing the ischemic penumbra in acute stroke, evaluating chronic cerebral ischemia, and localizing epileptic foci. Qualitative imaging complements morphological imaging and is crucial in modern neurodiagnostic techniques. Appropriate selection and interpretation of these modalities are crucial in improving patient management in clinical practice.