Anatomically Faithful Artifact Suppression in SENSE Accelerated Brain MRI
Authors: Changjing Chai, Bin Huang, Libo Xu, Jian Zhou, Boyang Pan, Kristen W Yeom, Qiyong Gong, Nan-Jie Gong
Organizations: Shanghai Key Laboratory of Magnetic Resonance, School of Physics, East China Normal University, Shanghai 200041, China · Institute of Magnetic Resonance and Molecular Imaging in Medicine, East China Normal University, Shanghai 200062, China · Department of Radiology, Affiliated Hospital of Guizhou Medical University, Guiyang, China · Department of Radiology and Huaxi MR Research Center (HMRRC), Institution of Radiology and Medical Imaging, West China Hospital, Sichuan University, Chengdu, China · Research Unit of Psychoradiology, Chinese Academy of Medical Sciences, Chengdu, China · RadioDynamic Medical, Shanghai 200031, China · Department of Radiology, Lucile Packard Children’s Hospital, Stanford, California 94304, USA · Department of Radiology, West China Xiamen Hospital of Sichuan University, Xiamen, China
Background: Four-fold accelerated sensitivity encoding (SENSE4) can shorten brain MRI acquisition time but may amplify noise and result in residual aliasing artifacts after conventional reconstruction. Purpose: To evaluate whether an image-domain refinement framework can improve the quality of SENSE4 brain MRI while preserving anatomical information for quantitative measurements. Methods: In this prospective paired study, 80 participants underwent fully sampled and four-fold accelerated SENSE T1-weighted MRI. We developed an Anatomy-aware Residual Attention Network (ART-Net) to refine accelerated reconstructions through generalized self-attention and correlation-based residual artifact regularization. Participant-level splitting yielded training, validation, and independent test cohort (45/5/30 participants). The independent test cohort underwent quantitative, segmentation-based, and blinded radiologist assessments of image quality and anatomical preservation. Results: ART-Net demonstrated highly competitive reconstruction performance, achieving the highest peak signal-to-noise ratio (31.03 +/- 2.88 dB) and structural similarity index (0.963 +/- 0.022) among evaluated methods. It also demonstrated improved anatomical fidelity, with numerically highest Dice coefficients for medial temporal structures relevant to atrophy assessment (0.8824 +/- 0.0827) and whole-brain regions (0.8857 +/- 0.0885). Moreover, ART-Net improved gradient fidelity, regional contrast preservation, and radiologist-rated structural quality. Conclusion: ART-Net improved agreement between SENSE4 and fully sampled T1-weighted images in a single-center, held-out test cohort while maintaining segmentation-derived anatomical measurements. These findings suggest that ART-Net may support accelerated brain MRI by improving image fidelity and enabling reliable downstream anatomical analysis.
Figures & tables
Figure 1: Architecture of the proposed Anatomy-aware Residual Attention Network (ART-Net) with COBRAI regularization. (a) Overall encoder–decoder architecture of the ART-Net backbone; (b) Detailed structure of the GSB-enhanced Residual Block (GSB-ResBlock), where the Generalized Self-Attention Block (GSB) is embedded within the residual pathway; (c) Internal configuration of the GSB module consisting of parallel spatial-attention and channel-attention branches.
Algorithm
PSNR (dB)
SSIM
LPIPS
FID
SENSE4
29.89±2.53 ***
0.953±0.022 ***
0.0245±0.0070 ***
7.90±2.91 ***
ART-Net w/o COBRAI
30.72±2.69 ***
0.960±0.021 ***
0.0183±0.0080 ***
2.91±0.92 ***
CBAM-ART
30.68±2.81 ***
0.961±0.022 ***
0.0163±0.0080
2.20±0.95
ART-Net
31.03±2.88
0.963±0.022
0.0161±0.0082
2.38±1.10
Table 1: Participant-level quantitative results of the ablation study in the independent test cohort ( n=30 ). Values are mean ± SD. * P<0.05 , ** P<0.01 , *** P<0.001 vs ART-Net; absence of an asterisk denotes ns.
Figure 2: Visual comparison of ablation study results for accelerated SENSE4 reconstruction. Representative axial and sagittal images from the independent test cohort are shown for SENSE4, ART-Net without Correlation-Based Residual Artifact Inhibition (COBRAI), ART-Net, and the fully sampled reference (AF0). Red boxes indicate regions of tissue boundaries and regional contrast, and blue boxes indicate residual artifact-prone regions in the cerebellum.
Figure 3: Visual comparison of cerebellar structure preservation across different reconstruction methods. Representative sagittal slices from the independent test cohort are shown for SENSE4, CBAM-ART, ART-Net, and fully sampled reference images (AF0).
Algorithm
PSNR (dB)
SSIM
LPIPS
FID
DAGAN
30.31±2.56 ***
0.958±0.021 ***
0.0187±0.0071 ***
2.87±0.93 ***
DAGAN_generator
30.68±2.70 ***
0.960±0.021 ***
0.0174±0.0078 ***
2.65±1.02 ***
SwinGAN
30.41±2.68 ***
0.960±0.021 ***
0.0181±0.0080 ***
2.76±1.18 ***
ART-Net
31.03±2.88
0.963±0.022
0.0161±0.0082
2.38±1.10
Table 2: Participant-level quantitative comparison of image-domain post-processing methods in the independent test cohort ( n=30 ). Values are mean ± SD. * P<0.05 , ** P<0.01 , *** P<0.001 vs ART-Net; absence of an asterisk denotes ns.
Figure 4: Qualitative comparison of reconstruction results from different algorithms. Fully sampled AF0 images serve as the reference standard. Red arrows indicate typical aliasing and noise artifacts, while blue rectangles show magnified cerebellar regions for detailed texture comparison. Representative images from the independent test cohort are shown.
Figure 5: Representative axial and sagittal brain MRI slices showing reconstruction performance of SENSE4, ART-Net, and fully sampled AF0 reference. Red arrows highlight aliasing artifacts and blurring in SENSE4 images. Representative images from the independent test cohort are shown.
Figure 6: Qualitative comparison of SENSE4 reconstruction methods with corresponding absolute error maps. For each method, the reconstructed image is shown above its absolute error map ( ∣Error∣=∣y^−yAF0∣ ). Slice-level PSNR (dB) and SSIM are annotated above each reconstruction. The color bar indicates error magnitude ( 0 – 0.175 ). A representative case from the independent test cohort is shown.
Algorithm
Basal Ganglia
Central Nuclei
Medial Temporal
Whole-Brain
SwinGAN
0.8507±0.0888 ***
0.9306±0.0593 ***
0.8666±0.0806 ***
0.8652±0.0865 ***
CBAM-ART
0.8775±0.0869
0.9414±0.0594 ***
0.8819±0.0812
0.8832±0.0871 **
DAGAN
0.8621±0.0847 ***
0.9367±0.0583 ***
0.8597±0.0786 ***
0.8607±0.0844 ***
DAGAN_generator
0.8753±0.0882
0.9440±0.0603 *
0.8721±0.0812 ***
0.8758±0.0862 ***
ART-Net w/o COBRAI
0.8624±0.0872 ***
0.9412±0.0596 ***
0.8770±0.0810 ***
0.8653±0.0837 ***
ART-Net
0.8758±0.0889
0.9455±0.0601
0.8824±0.0827
0.8857±0.0885
Table 3: Participant-level anatomical consistency measured by Dice coefficients between reconstructed and AF0-derived segmentation masks in the independent test cohort ( n=30 ). * P<0.05 , ** P<0.01 , *** P<0.001 versus ART-Net; absence of an asterisk indicates ns. Boldface: highest; underline: second-highest.
Method
GWM Boundary
Basal Ganglia
Cerebellum & Brainstem
Overall
AF0
4.62±0.87
4.33±0.73
4.63±0.69
4.53±0.77
SENSE4
2.35±0.55
1.78±0.58
1.95±0.57
2.03±0.61
DAGAN_generator
3.02±0.57
2.55±0.65
2.43±0.56
2.67±0.64
ART-Net w/o COBRAI
3.43±0.74
2.92±0.70
3.00±0.74
3.12±0.76
CBAM-ART
3.27±0.69
2.78±0.69
2.82±0.62
2.96±0.70
DAGAN
2.45±0.67
2.05±0.75
2.12±0.58
2.21±0.69
Table 4: Radiologist evaluation scores of reconstruction quality across seven methods. Two reader scores were averaged for each participant; values are participant-level mean ± SD ( n=30 ). Overall = mean of three domain ratings. Bold: highest; underline: second-highest.
Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, Massachusetts, United States · Harvard Medical School, Boston, Massachusetts, United States · Department of Radiology, Massachusetts General Hospital, Charlestown, Massachusetts, United States
Department of Radiology & Biomedical Imaging, Yale School of Medicine, New Haven, CT 06510 USA · Department of Biomedical Engineering, Rensselaer Polytechnic Institute, Troy, NY 12180 USA