Journal Article

Deep learning–based acceleration of Compressed Sense MR imaging of the ankle

Harrasser, Norbert, Weiss, Kilian, Foreman, Sarah C., Gersing, Alexandra S., Han, Jessie, Makowski, Marcus R., Peeters, Johannes M., Karampinos, Dimitrios C., Woertler, Klaus, Neumann, Jan

2022

Overview

Objectives To evaluate a compressed sensing artificial intelligence framework (CSAI) to accelerate MRI acquisition of the ankle. Methods Thirty patients were scanned at 3T. Axial T2-w, coronal T1-w, and coronal/sagittal intermediate-w scans with fat saturation were acquired using compressed sensing only (12:44 min, CS), CSAI with an acceleration factor of 4.6–5.3 (6:45 min, CSAI2x), and CSAI with an acceleration factor of 6.9–7.7 (4:46 min, CSAI3x). Moreover, a high-resolution axial T2-w scan was obtained using CSAI with a similar scan duration compared to CS. Depiction and presence of abnormalities were graded. Signal-to-noise and contrast-to-noise were calculated. Wilcoxon signed-rank test and Cohen’s kappa were used to compare CSAI with CS sequences. Results The correlation was perfect between CS and CSAI2x ( κ = 1.0) and excellent for CS and CSAI3x ( κ = 0.86–1.0). No significant differences were found for the depiction of structures between CS and CSAI2x and the same abnormalities were detected in both protocols. For CSAI3x the depiction was graded lower ( p ≤ 0.001), though most abnormalities were also detected. For CSAI2x contrast-to-noise fluid/muscle was higher compared to CS ( p ≤ 0.05), while no differences were found for other tissues. Signal-to-noise and contrast-to-noise were higher for CSAI3x compared to CS ( p ≤ 0.05). The high - resolution axial T2-w sequence specifically improved the depiction of tendons and the tibial nerve ( p ≤ 0.005). Conclusions Acquisition times can be reduced by 47% using CSAI compared to CS without decreasing diagnostic image quality. Reducing acquisition times by 63% is feasible but should be reserved for specific patients. The depiction of specific structures is improved using a high-resolution axial T2-w CSAI scan. Key Points • Prospective study showed that CSAI enables reduction in acquisition times by 47% without decreasing diagnostic image quality. • Reducing acquisition times by 63% still produces images with an acceptable diagnostic accuracy but should be reserved for specific patients. • CSAI may be implemented to scan at a higher resolution compared to standard CS images without increasing acquisition times.

• Publisher: Springer Berlin Heidelberg,Springer Nature B.V
• Subject: Abnormalities / Acceleration / Ankle / Ankle - diagnostic imaging / Artificial Intelligence / Deep Learning / Diagnostic Radiology / Diagnostic systems / High resolution / Humans / Image acquisition / Image quality / Imaging / Imaging, Three-Dimensional - methods / Internal Medicine / Interventional Radiology / Magnetic resonance imaging / Magnetic Resonance Imaging - methods / Medical imaging / Medicine / Medicine & Public Health / Microscopes / Muscles / Musculoskeletal / Neuroradiology / Prospective Studies / Radiology / Rank tests / Signal-To-Noise Ratio / Tendons / Tibial nerve / Ultrasound