Whole-heart cine MRI in a single breath-hold - A compressed sensing accelerated 3D acquisition technique for assessment of cardiac function

Abstract

Purpose: The aim of this study was to perform functional MR imaging of the whole heart in a single breath-hold using an undersampled 3D trajectory for data acquisition in combination with compressed sensing for image reconstruction. Materials and Methods: Measurements were performed using an SSFP sequence on a 3T whole-body system equipped with a 32-channel body array coil. A 3D radial stack-of-stars sampling scheme was utilized enabling efficient undersampling of the k-space and thereby accelerating data acquisition. Compressed sensing was applied for the reconstruction of the missing data. A validation study was performed based on a fully sampled dataset acquired by standard Cartesian cine imaging of 2D slices on a healthy volunteer. The results were investigated with regard to systematic errors and resolution losses possibly introduced by the developed reconstruction. Subsequently, the proposed technique was applied for in-vivo functional cardiac imaging of the whole heart in a single breath-hold of 27s. The developed technique was tested on three healthy volunteers to examine its reproducibility. Results: By means of the results of the simulation (temporal resolution: 47ms, spatial resolution: 1.4×1.4×8mm, 3D image matrix: 208×208×10), an overall acceleration factor of 10 has been found where the compressed sensing reconstructed image series shows only very low systematic errors and a slight in-plane resolution loss of 15%. The results of the in-vivo study (temporal resolution: 40.5ms, spatial resolution: 2.1×2.1×8mm, 3D image matrix: 224×224×12) performed with an acceleration factor of 10.7 confirm the overall good image quality of the presented technique for undersampled acquisitions. Conclusion: The combination of 3D radial data acquisition and model-based compressed sensing reconstruction allows high acceleration factors enabling cardiac functional imaging of the whole heart within only one breath-hold. The image quality in the simulated dataset and the in-vivo measurement highlights the great potential of the presented technique for an efficient assessment of cardiac functional parameters. © 2013 Georg Thieme Verlag KG Stuttgart New York.