Alexandra S Gersing1, Jannis Bodden2, Jan Neumann3, Maximillian N Diefenbach4, Sophia Kronthaler5, Daniela Pfeiffer6, Carolin Knebel7, Thomas Baum8, Benedikt J Schwaiger9, Andreas Hock10, Ernst J Rummeny11, Klaus Woertler12, Dimitrios C Karampinos13. 1. Department of Radiology, Technical University of Munich, Ismaninger Strasse 22, 81675, Munich, Germany; Department of Radiology and Biomedical Imaging, University of California, 185 Berry Street, Suite 350, San Francisco, CA, 94107, USA. Electronic address: alexandra.gersing@tum.de. 2. Department of Radiology, Technical University of Munich, Ismaninger Strasse 22, 81675, Munich, Germany. Electronic address: jannis.bodden@tum.de. 3. Department of Radiology, Technical University of Munich, Ismaninger Strasse 22, 81675, Munich, Germany. Electronic address: jan.neumann@tum.de. 4. Department of Radiology, Technical University of Munich, Ismaninger Strasse 22, 81675, Munich, Germany. Electronic address: maximilian.diefenbach@tum.de. 5. Department of Radiology, Technical University of Munich, Ismaninger Strasse 22, 81675, Munich, Germany. Electronic address: sophia.kronthaler@tum.de. 6. Department of Radiology, Technical University of Munich, Ismaninger Strasse 22, 81675, Munich, Germany. Electronic address: daniela.pfeiffer@tum.de. 7. Department of Orthopaedic Surgery, Klinikum rechts der Isar, Technical University of Munich, Munich, Germany. Electronic address: carolin.knebel@tum.de. 8. Department of Neuroradiology, Technical University of Munich, Ismaninger Strasse 22, 81675 Munich, Germany. Electronic address: thomas.baum@tum.de. 9. Department of Radiology, Technical University of Munich, Ismaninger Strasse 22, 81675, Munich, Germany. Electronic address: benedikt.schwaiger@tum.de. 10. Philips MR Clinical Science, Zurich, Switzerland. Electronic address: andreas.hock@philips.com. 11. Department of Radiology, Technical University of Munich, Ismaninger Strasse 22, 81675, Munich, Germany. Electronic address: ernst.rummeny@tum.de. 12. Department of Radiology, Technical University of Munich, Ismaninger Strasse 22, 81675, Munich, Germany. Electronic address: klaus.woertler@tum.de. 13. Department of Radiology, Technical University of Munich, Ismaninger Strasse 22, 81675, Munich, Germany. Electronic address: dimitrios.karampinos@tum.de.
Abstract
INTRODUCTION: To assess the feasibility and diagnostic value of compressed sensing for accelerating two-dimensional turbo spin echo imaging of the ankle. MATERIALS AND METHODS: Ankles of 20 volunteers were scanned (mean age 30.2 ± 7.3 years, 13 men) at 3 T MRI. Coronal and sagittal intermediate-weighted (IM) sequences with fat saturation as well as axial T2- and coronal T1-weighted sequences were acquired using parallel imaging based on sensitivity encoding (SENSE) only as well as with a combination of compressed sensing (CS) and SENSE. Compressed sensing is a technique that acquires less data through k-space random undersampling and enables a reduction in total acquisition time by 20%. All images were reviewed by two radiologists, image quality was graded using a 5-point Likert scale and signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) of different anatomical structures of the ankle were assessed and compared between sequences with SENSE only and with the combination of CS and SENSE using Wilcoxon signed-rank tests and Cohen's kappa. RESULTS: There was a substantial to perfect agreement for the rating between the images acquired with SENSE only and with the combination of CS and SENSE when assessing cartilage, subchondral bone and ligaments (κ = 0.75 - 0.89). SNR was slightly higher for the combination of CS and SENSE sequences compared to the sequences acquired with SENSE only, yet this finding was not significant (P = 0.18-0.62). Moreover, CNR of cartilage/fluid, subchondral bone/cartilage, ligaments/fluid and ligaments/fat did not show significant differences between the sequences acquired with SENSE only and the combination of CS and SENSE (P > 0.05). The interreader agreement was substantial to excellent for both techniques (κ=0.75 - 0.89). CONCLUSIONS: Compressed sensing reduced the acquisition time of conventional MR imaging of the ankle by 20% without decreasing diagnostic image quality, SNR and CNR.
INTRODUCTION: To assess the feasibility and diagnostic value of compressed sensing for accelerating two-dimensional turbo spin echo imaging of the ankle. MATERIALS AND METHODS: Ankles of 20 volunteers were scanned (mean age 30.2 ± 7.3 years, 13 men) at 3 T MRI. Coronal and sagittal intermediate-weighted (IM) sequences with fat saturation as well as axial T2- and coronal T1-weighted sequences were acquired using parallel imaging based on sensitivity encoding (SENSE) only as well as with a combination of compressed sensing (CS) and SENSE. Compressed sensing is a technique that acquires less data through k-space random undersampling and enables a reduction in total acquisition time by 20%. All images were reviewed by two radiologists, image quality was graded using a 5-point Likert scale and signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) of different anatomical structures of the ankle were assessed and compared between sequences with SENSE only and with the combination of CS and SENSE using Wilcoxon signed-rank tests and Cohen's kappa. RESULTS: There was a substantial to perfect agreement for the rating between the images acquired with SENSE only and with the combination of CS and SENSE when assessing cartilage, subchondral bone and ligaments (κ = 0.75 - 0.89). SNR was slightly higher for the combination of CS and SENSE sequences compared to the sequences acquired with SENSE only, yet this finding was not significant (P = 0.18-0.62). Moreover, CNR of cartilage/fluid, subchondral bone/cartilage, ligaments/fluid and ligaments/fat did not show significant differences between the sequences acquired with SENSE only and the combination of CS and SENSE (P > 0.05). The interreader agreement was substantial to excellent for both techniques (κ=0.75 - 0.89). CONCLUSIONS: Compressed sensing reduced the acquisition time of conventional MR imaging of the ankle by 20% without decreasing diagnostic image quality, SNR and CNR.
Authors: Victoria Y Yu; Kristen Zakian; Neelam Tyagi; Minsi Zhang; Paul B Romesser; Alex Dresner; Laura Cerviño; Ricardo Otazo Journal: Adv Radiat Oncol Date: 2021-09-09