CHAPTER 24: Ultrahigh-Field Whole-Body MRI for Cartilage Imaging: Technical Challenges

In vivo cartilage imaging of the musculoskeletal system using clinical 3 T magnetic resonance imaging (MRI) systems is limited by low spatial resolution, low signal-to-noise ratio, and/or long acquisition times. Ultrahigh-field (≥7 T) whole-body MRI systems have great potential to overcome these limitations and become the new standard for clinical muskuloskeletal imaging of articular cartilage. However, a number of technical challenges must first be addressed, including transmit B₁ field inhomogeneities, radiofrequency heating, errors due to B₀ inhomogeneities, gradients, motion, and extended examination times. In this chapter, we provide an overview of technical solutions to address these challenges and their potential benefit for articular cartilage imaging with particular attention to joints within the torso (hip and shoulder). We also highlight a number of emerging applications for articular and epiphyseal cartilage imaging that may significantly benefit from ultrahigh-field systems and the latest technical developments. Given the rapid development of MRI technology at ultrahigh field strengths and the broad potential of these systems to improve musculoskeletal imaging capabilities of cartilage, ultrahigh-field whole-body MRI is certain to play a significant role in the advancement of our understanding of articular cartilage abnormalities and the investigation of therapeutic interventions.