Multimodal comparisons of QSM and PET in neurodegeneration and aging

Quantitative susceptibility mapping (QSM) has been used to study susceptibility changes that may occur based on tissue composition and mineral deposition. Iron is a primary contributor to changes in magnetic susceptibility and of particular interest in applications of QSM to neurodegeneration and aging. Iron can contribute to neu-rodegeneration through inflammatory processes and via interaction with aggregation of disease-related proteins. To better understand the local susceptibility changes observed on QSM, its signal has been studied in association with other imaging metrics such as positron emission tomography (PET). The associations of QSM and PET may provide insight into the pathophysiology of disease processes, such as the role of iron in aging and neurodegen-eration, and help to determine the diagnostic utility of QSM as an indirect indicator of disease processes typically evaluated with PET. In this review we discuss the proposed mechanisms and summarize prior studies of the as-sociations of QSM and amyloid PET, tau PET, TSPO PET, FDG-PET, 15O-PET, and F-DOPA PET in evaluation of neurologic diseases with a focus on aging and neurodegeneration.

Automated summary

Quantitative susceptibility mapping (QSM) is used to study susceptibility changes based on tissue composition and mineral deposition. Iron plays a significant role in magnetic susceptibility changes, especially in neurodegeneration and aging. The association of QSM with other imaging metrics such as positron emission tomography (PET) can provide insights into the pathophysiology of diseases and determine the diagnostic utility of QSM as an indicator of disease processes typically evaluated with PET.