@article{MRA, author = {Christopher Palestro and Charito Love and Kuldeep Bhargava}, title = { Molecular Imaging of Inflammation and Infection: A Glimpse of the Past and a Look at the Future}, journal = {Medical Research Archives}, volume = {12}, number = {12}, year = {2024}, keywords = {}, abstract = {Despite significant advances in our understanding of microorganisms and an increased availability of antimicrobial therapy, infection remains a major cause of morbidity and mortality. The diagnosis is not always clearcut and imaging studies often are used for confirmation and localization. For nearly sixty years, molecular imaging has played a significant role in the diagnosis of infection. Bone scintigraphy, for musculoskeletal infections, and gallium-67 (67Ga) scintigraphy were the first molecular imaging agents used for diagnosing and localizing infection. There are significant drawbacks to both tests. Bone scintigraphy, though sensitive, lacks specificity, and its role is limited to that of a screening test. Poor imaging characteristics, together with lack of specificity, the 48-72 hour interval between administration and imaging, and limited availability, are significant disadvantages to 67Ga. Presently 67Ga is used primarily for differentiating acute tubular necrosis from interstitial nephritis and as an alternative to fluorine-18 fluorodeoxyglucose (18F-FDG) for some indications, i.e. sarcoid, spondylodiscitis, and fever of unknown origin, when this agent is not available. The development of a technique to radiolabel leukocytes in vitro and image their accumulation in infection was a watershed event in molecular imaging of infection. In-vitro labeled autologous leukocyte imaging replaced 67Ga as the molecular imaging test of choice for most infections in immunocompetent individuals and, nearly forty years after its approval in the United States, remains a valuable diagnostic test. Although developed for tumor imaging, 18F-FDG also accumulates in infection and inflammation. Over the past twenty-five years 18F-FDG has established itself as a valuable imaging agent for musculoskeletal and cardiovascular infections and as the molecular imaging agent of choice for fever of unknown origin, sarcoid, tuberculosis and spondylodiscitis and has shown promise for monitoring treatment response. Despite their utility, the uptake of these agents depends on the host response to infection, not infection itself. These agents are not infection specific, and investigators have, for many years, sought to develop infection specific agents. Initial attempts such as radiolabeled antibiotics and vitamins met with limited success. More recent investigations with radiolabeled nucleoside analogs, peptides, sugars, and amino acids, are encouraging and hold great promise for the future.}, issn = {2375-1924}, doi = {10.18103/mra.v12i12.6117}, url = {https://esmed.org/MRA/mra/article/view/6117} }