Musculoskeletal magnetic resonance imaging revisited – Does tesla of magnetic resonance imaging machines matter?

Abstract

The field of modern medical science has been revolutionized by magnetic resonance imaging (MRI) which is the preferred modality for the investigation of a whole spectrum of musculoskeletal (MSK) conditions. MRI is a careful interplay between the temporal, spatial, and contrast resolution which forms the foundation for its improved diagnostic performance and value. There are a lot of aspects that improve the image quality and diagnostic performance, however, a higher magnet strength of 3-Tesla has the biggest impact within the current diagnostic range. However various advancements in the hardware and software parameters such as multichannel multi-phased array coils, advanced gradient systems and better post processing techniques have significantly improved image quality at 1.5T scanners as well. All the leading manufacturers offer MRI systems with a higher field strength of 3T which are increasingly being used in recent clinical settings. Scanning at 3T has the advantage of a better signal-to-noise ratio which translates into better spatial and temporal resolution with the added advantage of faster acquisition. Challenges of 3T scanning include higher magnetic susceptibility, chemical shift, and higher radiofrequency energy deposition. This is particularly important in the presence of orthopedic implants because of the two-fold increase in susceptibility artifacts resulting in significant periprosthetic signal loss, signal displacements with voids and pileups, and failed spectral fat suppression. Various modifications are needed to minimize the artifacts at 3T scanners to better utilize the improved spatial and contrast resolution achieved as a result of scanning at a higher field strength. This review discusses the technical features of scanning at 1.5 and 3T scanners along with their clinical implications and diagnostic usefulness in MSK imaging.