Multimodal and multifunctional probes are cutting-edge technologies in which the advantages of
nanoparticles are maximized. The use of MRI has prompted the development of a variety of multimodal
probes based on T2 contrast agents. SPION is considered an ideal vehicle for multimodal and
multifunctional applications. The theranostic agents based on SPION are crucial in cancer detection
and the delivery of therapeutic payloads, such as chemotherapeutic drugs and genes. New research is
dedicated to developing multifunctional and multimodal theranostic agents, which form the ultimate
weapon against cancer. However, there are several challenges facing multimodal and multifunctional
techniques, including the standardization of therapy response and the stability of complex nanoparticles
under certain biological conditions. Future research must focus on rectifying the current flaws in
multimodal and multifunctional imaging probes by introducing new biocompatible polymers. Finally,
multimodal and multifunctional techniques may enhance clinical theranostics in the near future.