Magnetic resonance imaging applications to amyotrophic lateral sclerosis beyond the central nervous system

Traditionally, in amyotrophic lateral sclerosis (ALS) and other motor neuron disorders, the diagnostic and research focus in the domain of magnetic resonance imaging (MRI) has been targeted on the brain and spinal cord. Nevertheless, structures outside the central nervous system (CNS) are core structures of the pathological processes and are also assessible by imaging approaches. Advanced imaging of structures like bodyfat and muscles can considerably contribute to the pathophysiological understanding and disease monitoring of ALS. The multiparametric combination of MRI approaches that capture these changes could be very helpful in future studies, especially when machine learning algorithms are used. This review summarizes the current state of the art and the role of imaging beyond the CNS in ALS, examining its diagnostic and monitoring potential and how it might ultimately lead to improved management strategies for patients.