Low-dimensional-structure self-learning and thresholding: regularization beyond compressed sensing for MRI reconstruction.

Journal Article (Journal Article)

An improved image reconstruction method from undersampled k-space data, low-dimensional-structure self-learning and thresholding (LOST), which utilizes the structure from the underlying image is presented. A low-resolution image from the fully sampled k-space center is reconstructed to learn image patches of similar anatomical characteristics. These patches are arranged into "similarity clusters," which are subsequently processed for dealiasing and artifact removal, using underlying low-dimensional properties. The efficacy of the proposed method in scan time reduction was assessed in a pilot coronary MRI study. Initially, in a retrospective study on 10 healthy adult subjects, we evaluated retrospective undersampling and reconstruction using LOST, wavelet-based l(1)-norm minimization, and total variation compressed sensing. Quantitative measures of vessel sharpness and mean square error, and qualitative image scores were used to compare reconstruction for rates of 2, 3, and 4. Subsequently, in a prospective study, coronary MRI data were acquired using these rates, and LOST-reconstructed images were compared with an accelerated data acquisition using uniform undersampling and sensitivity encoding reconstruction. Subjective image quality and sharpness data indicate that LOST outperforms the alternative techniques for all rates. The prospective LOST yields images with superior quality compared with sensitivity encoding or l(1)-minimization compressed sensing. The proposed LOST technique greatly improves image reconstruction for accelerated coronary MRI acquisitions.

Full Text

Duke Authors

Cited Authors

  • Akçakaya, M; Basha, TA; Goddu, B; Goepfert, LA; Kissinger, KV; Tarokh, V; Manning, WJ; Nezafat, R

Published Date

  • September 2011

Published In

Volume / Issue

  • 66 / 3

Start / End Page

  • 756 - 767

PubMed ID

  • 21465542

Pubmed Central ID

  • PMC4212512

Electronic International Standard Serial Number (EISSN)

  • 1522-2594

International Standard Serial Number (ISSN)

  • 0740-3194

Digital Object Identifier (DOI)

  • 10.1002/mrm.22841


  • eng