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Keywords:

  • magnetic resonance imaging;
  • compressed sensing;
  • parallel imaging;
  • dynamic imaging;
  • contrast enhanced;
  • sparsity;
  • undersampling

Purpose

Dynamic contrast-enhanced imaging provides unique physiological information, notably the endothelial permeability (Ktrans), and may improve the diagnosis and management of multiple pathologies. Current acquisition methods provide limited spatial-temporal resolution and field-of-view, often preventing characterization of the entire pathology and precluding measurement of the arterial input function. We present a method for highly accelerated dynamic imaging and demonstrate its utility for dynamic contrast-enhanced modeling.

Methods

We propose a novel Poisson ellipsoid sampling scheme and enforce multiple spatial and temporal l1-norm constraints during image reconstruction. Retrospective and prospective analyses were performed to validate the approach.

Results

Retrospectively, no mean bias or diverging trend was observed as the acceleration rate was increased from 3× to 18×; less than 10% error was measured in Ktrans at any individual rates in this range. Prospectively accelerated images at a rate of 36× enabled full brain coverage with 0.94 × 0.94 × 1.9 mm3 spatial and 4.1 s temporal resolutions. Images showed no visible degradation and provided accurate Ktrans values when compared to a clinical population.

Conclusion

Highly accelerated dynamic MRI using compressed sensing and parallel imaging provides accurate permeability modeling and enables full brain, high resolution acquisitions. Magn Reson Med 71:635–644, 2014. © 2013 Wiley Periodicals, Inc.