Comparison of Compressed Sensing Accelerated MR Elastography to Standard Breath-Hold 2D Gradient Recalled Echo MRE for Estimating Liver Stiffness (LS)
J Zhang1*, D Akselrod1, J Tam1, J Gonyea2, S Hipko1, M Bazylewicz1, (1) Department Of Radiology, University Of Vermont Medical Center, (2) University Of Vermont
Presentations
SU-F-207-3 (Sunday, 7/10/2022) 2:00 PM - 3:00 PM [Eastern Time (GMT-4)]
Room 207
Purpose: Magnetic resonance elastograpy(MRE) is widely accepted to assess liver fibrosis. The standard MRE(sMRE) utilizes a 2D gradient echo sequence with four breath-holds (each 14-22s), which is difficult for children and many adults. We investigated the utility of compressed sensing(CS) for MRE(csMRE) to accelerate the MRE acquisition and evaluated the accuracy and confident area for LS quantification.
Methods: Eight patients (age 55±12years; 3 males, BMI 35.7±11.6kg/m²) were referred for LS evaluation and scanned on a 1.5T(Philips). The data was retrospectively analyzed. Institutional review board approved waiver of individual consent.sMRE: FOV=450x(~360)x55mm³, four 2D axial slices with a gap of 5mm, acquired voxel size=1.5x4.7x10mm³, TR/TE/Flip angle=50ms/20ms/20ᴼ, sense factor=2.0; bandwidth=287.4Hz/pixel, breath-hold time=16-22s. Four breath-holds were used to acquire four slices. The MRE amplitude=40-90% and frequency=60Hz. csMRE: A CS factor of 2.8 was used with default denoising level instead of the standard sensing acceleration, yielded a breath-hold of ~10s. All the other MR acquisitions parameters were identical to the sMRE in the same patient. Data analysis: The MRE wave, stiffness, and confidence maps were reconstructed in the scanner. Four ROIs were drawn on the 4 slice to calculate LS and confident area for both sMRE and csMRE. The Bland-Altman analysis and boxplots were used to analyze the LS agreement and area of confident coverage.
Results: A total of 72 LS measurements were analyzed. The Bland-Altman analysis demonstrated agreement between LS(csMRE) and LS(sMRE): -0.21±0.29kPa. The available LS confident area of csMRE increased by 44.9% compared to sMRE: specifically, median increase of 43.2% and 17.5% for normal and elevated LS patients respectively.
Conclusion: CS decreased the breath-hold time by more than 30%. The LS values from csMRE is consistent with the value from sMRE. The larger available LS confident area yielded more diagnosis confidence. A larger cohort of patients is needed to verify these findings.
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