Molecular Imaging in Genomic Medicine

Molecular imaging is the result of advances in the fields of molecular biology and imaging technology and has become an increasingly important tool in the discovery and understanding of a wide range of pathophysiologic processes, ranging from genetic disorders to malignant conditions. The advancement in molecular pathology techniques has enabled us to study the complex genotype of disease entities and how it impacts their behaviour and natural history. Image-guided genomic medicine utilises methodologies to integrate genomic and radiologic data to develop insights into the genotype–phenotype relationship, which in turn can guide medical decision-making and treatment planning. Key Concepts Molecular imaging comprises the visualisation, characterisation and measurement of biological processes at the molecular and cellular levels, which can synergise with genomic medicine to enhance our understanding of disease processes. Reporter gene imaging entails encoding proteins that can be rapidly and sensitively assayed as surrogate markers when fused with regulatory regions of the gene of interest as a means of indirectly monitoring molecular basis of diseases. Optical imaging is based on the principle of detecting light in living organisms that reflect molecular processes; types include bioluminescence and fluorescence imaging. ImmunoPET is based on combining the PET with monoclonal antibodies raised against a tumoural antigen. Functional MRI uses the MRI technology to provide a means of measuring brain activity by detecting changes associated with blood flow as a phenotype that can be correlated with genotypic data. Radiomics/imaging genomics leverage machine learning technology to process large data sets acquired through imaging and genomic biomarker extraction and provide valuable insights into pathophysiology and personalised disease management. Gene therapeutics is another area where molecular imaging can be valuable in therapy monitoring and response assessment. Keywords: molecular; imaging; genomic; reporter; gene; PET; MRI; optical