Molecular imaging—The first visual themed issue published in the British Journal of Pharmacology

Abstract

With this British Journal of Pharmacology ‘Molecular imaging visual themed issue’, we have provided an up-to-date account of a select group of molecular imaging techniques that we believe have and will enable interrogation of the pharmacology of novel compounds and ultimately to the development of new therapeutic agents. Molecular imaging is the visualization and quantification of molecules within living patients. Revealing information on biomarkers and cellular and molecular pathways can improve disease diagnosis and therapeutic intervention. In addition, these advanced techniques also offer opportunities to identify novel pharmacological targets, thus facilitating both drug discovery and treatment stratification. The optimum molecular imaging modality ideally should possess high sensitivity and resolution, an acceptable safety profile, and be capable of non-invasive quantitative multiplex imaging. Currently, there are no clinical imaging modalities routinely used in the clinic for molecular imaging; therefore, new approaches are required to meet this goal. The focus of this British Journal of Pharmacology visual-themed issue is on cardiovascular medicine and cancer. This themed issue is not meant to provide an exhaustive list of molecular imaging modalities for our topic areas, rather it is deliberately focused on a few select approaches to test a completely new ‘visual’ layout for the British Journal of Pharmacology. Each of the four invited reviews has been designed and presented in a format with a predominance of visual material over text. Seeing is believing as they say, and so we have attempted to select the most helpful representative images and videos for each topic covered, to guide the readers through the respective merits and limitations of established and emerging imaging modalities, whilst also highlighting their potential theranostics applications. Video podcasts and figures, available in PowerPoint format, complement each published article. The themed issue starts with an article by MacRitchie et al. (2021). The authors provide an overview of molecular imaging of cardiovascular inflammation. Immuno-inflammatory responses play key roles in the development and clinical manifestation of several cardiovascular diseases (CVD) (Libby et al., 2018; Rodriguez-Iturbe et al., 2017; Schloss et al., 2020). However, routinely used medical imaging modalities are restricted to anatomical or functional imaging and are unable to reveal the cellular and molecular inflammatory pathways at the level of resolution required for a more timely and precise diagnosis and pharmacological treatment (MacRitchie et al., 2020). In this visual review, the authors discuss strengths and weaknesses of molecular imaging modalities in CVD, spanning from those already being used in the clinic such as magnetic resonance imaging (MRI) and positron emission tomography (PET), to novel technologies emerging at the pre-clinical stage. In CVD, not only does inflammation cause thrombosis but the opposite is also true, that thrombosis can trigger inflammation (Stark & Massberg, 2021). As such, faster and more reliable imaging modalities for the diagnosis of thrombosis are needed. In this visual issue, Wang et al. (2021) discuss the state-of-the-art in molecular imaging of arterial and venous thrombosis, highlighting recent improvements in the identification of biomarkers for thromboembolic diseases; the development of optimized contrast agents with improved signal to noise ratio and recent developments in scanner technologies with higher sensitivity and resolution. The review covers modalities used for the clinical imaging of thrombosis, including PET, MRI, X-ray computed tomography (CT), and ultrasound imaging, to preclinical fluorescence and bioluminescent imaging modalities. A clear demonstration of the potential to translate molecular imaging into clinical practice is presented in the review of Kotanidis and Antoniades (2021), providing a virtual guide to perivascular fat imaging using CT. The authors discuss their recent elegant work (Antonopoulos et al., 2017; Oikonomou et al., 2018; Oikonomou et al., 2019), demonstrating non-invasive phenotyping of perivascular adipose tissue (PVAT) using CT as a promising marker for early detection of vascular inflammation in atherosclerosis. In particular, they highlight the use of the Perivascular Fat Attenuation Index (FAIPVAT) for cardiovascular risk stratification and the diagnostic and prognostic value of macroscopic adipose tissue radiomics. Along similar lines, the use of artificial intelligence (AI), a set of advanced computational algorithms that can accurately perform predictions for decision support, is thoroughly covered in the fourth Abbreviations: AI, artificial intelligence; CT, X-ray computed tomography; CVD, cardiovascular disease; FAIPVAT, perivascular Fat Attenuation Index; MRI, magnetic resonance imaging; PET, positron emission tomography; PVAT, perivascular adipose tissue. LINKED ARTICLES: This article is part of a themed issue on Molecular imaging visual themed issue. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v178.21/issuetoc DOI: 10.1111/bph.15632