“…Nowadays, brain tumors inside the complex central nervous system remain one of the most challenging cancers to diagnose . This urges the emergence of novel brain‐imaging modalities and the corresponding contrast agents, which work together to offer outcomes with good sensitivity and specificity, deep penetration, high spatial and temporal resolution . Conventional brain‐imaging techniques like positron emission tomography (PET), computed tomography (CT), ultrasound imaging (US), single‐photon emission computed tomography (SPET), and magnetic resonance imaging (MRI) have unlimited penetration, but show certain drawbacks, such as being hazardous to both patients and operators with the ionization energy source (for CT, PET, and SPECT), poor‐soft tissue contrast (for CT), limited spatial resolution (for US, MRI, and PET), and long acquisition time (for MRI and CT) .…”