Potential of PET-MRI for imaging of non-oncologic musculoskeletal disease

Abstract

Early detection of musculoskeletal disease leads to improved therapies and patient outcomes, and would benefit greatly from imaging at the cellular and molecular level. As it becomes clear that assessment of multiple tissues and functional processes are often necessary to study the complex pathogenesis of musculoskeletal disorders, the role of multi-modality molecular imaging becomes increasingly important.New positron emission tomography-magnetic resonance imaging (PET-MRI) systems offer to combine high-resolution MRI with simultaneous molecular information from PET to study the multifaceted processes involved in numerous musculoskeletal disorders. In this article, we aim to outline the potential clinical utility of hybrid PET-MRI to these non-oncologic musculoskeletal diseases. We summarize current applications of PET molecular imaging in osteoarthritis (OA), rheumatoid arthritis (RA), metabolic bone diseases and neuropathic peripheral pain. Advanced MRI approaches that reveal biochemical and functional information offer complementary assessment in soft tissues. Additionally, we discuss technical considerations for hybrid PET-MR imaging including MR attenuation correction, workflow, radiation dose, and quantification.

Applications of PET‐MRI in musculoskeletal disease

“…18 F‐NaF is used in the detection and evaluation of skeletal metastasis, particularly in tumors with low FDG affinity such as thyroid and renal cell cancers . Furthermore, 18 F‐NaF provides an excellent opportunity to study bone turnover and repair in nononcologic musculoskeletal disorders such as metabolic bone diseases, arthritic diseases, and fracture healing …”

“…23,26 Furthermore, 18 F-NaF provides an excellent opportunity to study bone turnover and repair in nononcologic musculoskeletal disorders such as metabolic bone diseases, arthritic diseases, and fracture healing. 23,27 While PET imaging is unmatched for molecular imaging, it needs the assistance of higher-resolution, anatomic information to localize these physiologic processes. It is most often combined with CT imaging, which is able to provide not only high resolution anatomic detail but also attenuation correction information for acquired PET data.…”

Quantitative imaging of bone–cartilage interactions in ACL-injured patients with PET–MRI

“…Simultaneous PET/MRI systems provide a unique tool to simultaneously image multiple markers of early OA and to study spatiotemporal relationships between degenerative changes in bone and cartilage 11–13 . This study aims to investigate subchondral bone 18 F-NaF uptake in ACL-reconstructed knees as well as the spatial relationship between bone 18 F-NaF uptake and adjacent cartilage T 2 relaxation times.…”

Translation of morphological and functional musculoskeletal imaging

“…al., 89 whereby repetitive joint loading causes an initial increase in bone remodeling, that is associated with increased vascular invasion of the deep layers of cartilage, which allows access to the cartilage by chondrolytic enzymes unopposed by inhibitors of the degradative proteinases, that cause a breakdown of the extra-cellular matrix, loss of Simultaneous PET-MRI was also recently used to study cartilage and bone interactions. [91][92][93][94][95] Savic et. al.…”