Task Group ♯118 of the AAPM was established to describe the basis of parallel magnetic resonance imaging (pMRI) and its applications to the Medical Physics community. This presentation reviews the aspects of parallel imaging methods that have led to this technology becoming important clinically. The signature enhancement attributable to pMRI is faster MR image acquisition which leads to decreased motion artifact, reduced breath‐hold time, shorter durations of exams or more series acquired per exam. Increased flexibility is also achieved since parallel imaging has distinct advantages for limiting specific absorption rate (SAR) at higher magnetic field strengths. There are currently two general approaches to pMRI; one based on image‐space reconstruction and the other on k‐space based methods. Details of the design of RF coils, or the entire RF systems, for improving imaging performance in pMRI will be surveyed. Additional benefits may be derived from the use of pMRI in balanced gradient echo imaging, fast spin echo imaging, dynamic MRI, BOLD contrast MRI and diffusion MRI. In addition, the image quality trade‐offs in pMRI will be considered with particular focus on the different ways that signal and noise are handled in pMRI image reconstruction. Finally advanced results, which will likely lead to continuing improvements in pMRI technology, will be discussed. In summary, this presentation will provide practical guidance and assistance for the practicing medical physicist so that pMRI may be more readily applied and understood within the clinical environment. By the end of this presentation the attendee should: 1. understand the basic concept of parallel imaging and how it can be used to reduce the acquisition time of MR images. 2. recognize in which clinical protocols the use of parallel imaging methods is most advantageous and what benefits are bestowed on each. 3. be aware of the image quality trade‐offs involved in implementing pMRI and 4. understand the new image artifacts inherent with this approach.
ASJC Scopus subject areas
- Radiology Nuclear Medicine and imaging