Imaging of Muscle

Welcome to this issue of Seminars in Musculoskeletal Radiology dedicated to muscle. Muscle universally covers our skeleton, and rarely do we perform a study that does not include muscle within the image. I've created a comprehensive overview of this important body organ by engaging numerous experts from around the world, all of whom have published and spoken on this subject. I would like to thank them all for their efforts. Each article has been illustrated beautifully and referenced comprehensively. When attempting something of this scope, inevitably there is some overlap and repetition. However, in the interests of continuity, I've allowed the authors a lot of latitude and let their contributions speak for themselves.

Radiologists should not forget basic science, and so Dan Exeter and I begin by reviewing functional anatomy and pathophysiology before exploring variations in normal muscle anatomy. I recommend the article by Martinoli and colleagues on muscle variants of the upper and lower limb because much of their information is new and has not been published before. Thereafter, we recall that both ultrasound and magnetic resonance imaging (MRI) provide exquisite detail with respect to localization and characterization of strain that occurs to the muscle-tendon-bone unit as it fails around the body. Hopper et al look at the upper limb and body. Linklater and colleagues review the most common muscle injury, the hamstring muscle. They explore the literature with respect to efforts to accelerate and mitigate the effects of muscle healing and the role of imaging-guided interventions. Then Counsel and Breidahl review injury to the calf musculature.

It is important that radiologists understand the temporal changes that occur with healing following injury. This subject is explored by Blankenbaker and Tuite. Slavotinek relates his experience of how imaging can be used in a prognostic fashion and guide athletes as they return to play. Of course complications can occur as part of the healing process. Tyler and Saifuddin's article discusses the imaging of myositis ossificans.

We appreciate that muscle is part of a neuromuscular unit. Inflammatory states are considered by Bashir and O'Donnell. Galloway reviews various nerve entrapments and denervation states, followed by a discussion of compartment syndromes (McDonald and Bearcroft). Furthermore, no comprehensive review would be complete without looking at muscle tumors and strategies to guide their recognition and diagnosis. Davies and colleagues present this in a very logical, practical, and professional manner.

Finally, we take a glimpse into the future of MRI in articles by Noseworthy et al (tensor diffusion and BOLD imaging) and Chang and colleagues (7 T and 11 T) as they consider advanced techniques for muscle imaging.

I hope you enjoy reading this issue of seminars, which I believe should serve as a valuable resource in all radiology departments.