Whole-body PET-CT, simultaneous whole-body PET-MRI, and multimodal molecular imaging system are the recent milestone developments in nuclear medicine and molecular imaging. These high-end molecular imaging scanners with probes or tracers provide a potential to significantly improve the accuracy in localization and quantification of biological processes at cellular and molecular levels in humans and other living systems. There are many challenges in image processing and mathematical and statistical modeling to extract physiological and biochemical information from these multimodal dynamic image data. Tremendous efforts have been made recently in experimental design, probe development, data acquisition, quantification, and exploring its applications in medicine and biology. This special issue focuses on the recent advances in quantitative nuclear medicine and molecular imaging.

Potential topics include but are not limited to the following:

• Quantitative molecular imaging in tracer and drug development, delivery, and evaluation
• Experiment design for data acquisition in multimodal imaging
• Evaluation of PET-CT and PET-MRI image reconstruction algorithms with time-of-flight and point-spread-function
• Dynamic SPECT-CT, PET-CT, and PET-MRI
• Radioligand-receptor imaging from brain to whole body
• Kinetic modeling and parametric imaging
• Quantitative metrics in nuclear medicine and molecular imaging
• Radiomics in multimodal multiparametric imaging
• Correlation study between genotype and quantitative molecular imaging-based phenotype