Cerenkov luminescence imaging utilizes visible photons emitted from radiopharmaceuticals to achieve in vivo optical molecular-derived signals. Since Cerenkov radiation is weak, non-optimum for tissue penetration and continuous regardless of biological interactions, it is challenging to detect this signal with a diagnostic dose. Therefore, it is challenging to achieve useful activated optical imaging for the acquisition of direct molecular information. Here we introduce a novel imaging strategy, which converts γ and Cerenkov radiation from radioisotopes into fluorescence through europium oxide nanoparticles. After a series of imaging studies, we demonstrate that this approach provides strong optical signals with high signal-to-background ratios, an ideal tissue penetration spectrum and activatable imaging ability. In comparison with present imaging techniques, it detects tumour lesions with low radioactive tracer uptake or small tumour lesions more effectively. We believe it will facilitate the development of nuclear and optical molecular imaging for new, highly sensitive imaging applications.

Multimodality imaging of positron emission tomography/computed tomography (PET/CT) provides both metabolic information and the anatomic structure, which is significantly superior to either PET or CT alone and has greatly improved its clinical applications. Because of the higher soft-tissue contrast of magnetic resonance imaging (MRI) and no extra ionizing radiation, PET/MRI imaging is the hottest topic currently. PET/MRI is swiftly making its way into clinical practice. However, it has many technical difficulties to overcome, such as photomultiplier tubes, which cannot work properly in a magnetic field, and the inability to provide density information on the object for attenuation correction. This paper introduces the technique process of PET/MRI and summarizes its clinical applications, including imaging in oncology, neurology, and cardiology.

Cerenkov luminescence tomography (CLT) is a promising tool that enables three-dimensional noninvasive in vivo detection of radiopharmaceuticals. Conventionally, multispectral information and diffusion theory were introduced to achieve whole-body tomographic reconstruction. However, the diffusion theory inevitably causes systematic error in blue bands of the electromagnetic spectrum due to high-tissue absorption, and CL has a blue-weighted broad spectrum. Therefore, it is challenging to improve the accuracy of CLT. The performance of the n -order simplified spherical harmonics approximation (SPn) in different spectra is evaluated, and a multispectral hybrid CLT based on the combination of different SPn models is proposed to handle the Cerenkov photon transport problem in complex media. The in vivo xenograft experiment shows that this approach can effectively improve the quality and accuracy of the reconstructed light source. We believe that the new reconstruction method will advance the development of CLT for more in vivo imaging applications