Advanced imaging techniques for neuro-oncologic tumor diagnosis, with an emphasis on PET-MRI imaging of malignant brain tumors

Abstract

Purpose of review: This review will explore the latest in advanced imaging techniques, with a focus on the complementary nature of multiparametric, multimodality imaging using magnetic resonance imaging (MRI) and positron emission tomography (PET).

Recent findings: Advanced MRI techniques including perfusion-weighted imaging (PWI), MR spectroscopy (MRS), diffusion-weighted imaging (DWI), and MR chemical exchange saturation transfer (CEST) offer significant advantages over conventional MR imaging when evaluating tumor extent, predicting grade, and assessing treatment response. PET performed in addition to advanced MRI provides complementary information regarding tumor metabolic properties, particularly when performed simultaneously. 18F-fluoroethyltyrosine (FET) PET improves the specificity of tumor diagnosis and evaluation of post-treatment changes. Incorporation of radiogenomics and machine learning methods further improve advanced imaging. The complementary nature of combining advanced imaging techniques across modalities for brain tumor imaging and incorporating technologies such as radiogenomics has the potential to reshape the landscape in neuro-oncology.

Keywords: Advanced MRI; Amino acid PET; Brain tumor; Chemical exchange saturation transfer; Diffusion-weighted imaging; FET; Glioblastoma; Glioma; High-grade malignancy; Hybrid PET/MRI; MR spectroscopy; Metastasis; Perfusion-weighted imaging; Progression; Pseudoprogression; Pseudoresponse; Radiation necrosis; Radiogenomics; Radiomics; Treatment-related change; Tumor grading.