Five-minute knee MRI: An AI-based super resolution reconstruction approach for compressed sensing. A validation study on healthy volunteers

Eur J Radiol. 2024 Jun:175:111418. doi: 10.1016/j.ejrad.2024.111418. Epub 2024 Mar 9.

Abstract

Purpose: To investigate the potential of combining Compressed Sensing (CS) and a newly developed AI-based super resolution reconstruction prototype consisting of a series of convolutional neural networks (CNN) for a complete five-minute 2D knee MRI protocol.

Methods: In this prospective study, 20 volunteers were examined using a 3T-MRI-scanner (Ingenia Elition X, Philips). Similar to clinical practice, the protocol consists of a fat-saturated 2D-proton-density-sequence in coronal, sagittal and transversal orientation as well as a sagittal T1-weighted sequence. The sequences were acquired with two different resolutions (standard and low resolution) and the raw data reconstructed with two different reconstruction algorithms: a conventional Compressed SENSE (CS) and a new CNN-based algorithm for denoising and subsequently to interpolate and therewith increase the sharpness of the image (CS-SuperRes). Subjective image quality was evaluated by two blinded radiologists reviewing 8 criteria on a 5-point Likert scale and signal-to-noise ratio calculated as an objective parameter.

Results: The protocol reconstructed with CS-SuperRes received higher ratings than the time-equivalent CS reconstructions, statistically significant especially for low resolution acquisitions (e.g., overall image impression: 4.3 ± 0.4 vs. 3.4 ± 0.4, p < 0.05). CS-SuperRes reconstructions for the low resolution acquisition were comparable to traditional CS reconstructions with standard resolution for all parameters, achieving a scan time reduction from 11:01 min to 4:46 min (57 %) for the complete protocol (e.g. overall image impression: 4.3 ± 0.4 vs. 4.0 ± 0.5, p < 0.05).

Conclusion: The newly-developed AI-based reconstruction algorithm CS-SuperRes allows to reduce scan time by 57% while maintaining unchanged image quality compared to the conventional CS reconstruction.

Keywords: 2D knee MR imaging; Accelerated MRI; Artificial intelligence; Compressed sensing; Fast MRI; Image sharpness; Knee MRI.

Publication types

  • Validation Study

MeSH terms

  • Adult
  • Algorithms*
  • Data Compression / methods
  • Female
  • Healthy Volunteers*
  • Humans
  • Image Interpretation, Computer-Assisted / methods
  • Knee Joint* / diagnostic imaging
  • Magnetic Resonance Imaging* / methods
  • Male
  • Middle Aged
  • Neural Networks, Computer
  • Prospective Studies
  • Signal-To-Noise Ratio
  • Young Adult