Parallel and sparse MR imaging: methods and instruments—Part 1

Xiaoliang Zhang, Jim X. Ji


Magnetic resonance imaging (MRI), capable of providing information on morphology, metabolism and function of living systems non-invasively, has become one of the most important imaging modalities in today’s clinical diagnosis and basic biomedical research. However, comparing with other medical imaging methods, such as computed tomography (CT), ultrasound (US), and even the more conventional X-ray radiography, the imaging speed of MRI is low. The slow imaging speed of MRI has significantly limited its capability in some in vivo imaging applications. Beating heart, respiratory motion, pulsating cerebrospinal fluid, and involuntary motion could drastically degrade image quality by motion artifacts, particularly in high resolution imaging. This slow imaging acquisition also impacts negatively on the emerging hyperpolarized C-13 MRI where enhanced MR signal intensity rapidly decays (within ~60 seconds for pyruvate). It is critical to have an efficient fast imaging strategy to collect the augmented signals so that the high sensitivity advantages of hyperpolarized C-13 MR can be maximally realized.