摘要： Nanohybrids with well-defined optical properties and integrated functionalities are considered to be the most advanced next-generation blend of therapeutics and diagnostics: a simultaneous “theranostics”. Targeted delivery, real-time monitoring of administration, distribution, biotransformation, and elimination from the body are some of the beneficial attributes which have enabled it to get wide attention and acceptability. A spectrum of new-generation hybrid nanosystems for future biomedical applications has been fabricated, and has a variety of applications towards in vivo optical imaging, ultrasound (US) imaging, computed tomography (CT) of X-rays, magnetic resonance imaging (MRI), and positron emission tomography (PET). Multifunctional nanoparticles containing multiple contrast agents not only allow multimodal imaging but also improve the resolution of each of these imaging modalities. This chapter provides one of the most comprehensive detailed reports on the development of nanohybrids for cancer imaging to date.