Pérez-Bueno Fernando, Li Hongwei B, Rosen Matthew S, Nasr Shahin, Caballero-Gaudes César, Iglesias Juan E
Basque Center on Cognition, Brain, and Language (BCBL), Spain.
Athinoula A. Martinos Center for Biomedical Imaging, Harvard Medical School, USA.
Proc IEEE Int Symp Biomed Imaging. 2025 Apr;2025. doi: 10.1109/isbi60581.2025.10980709. Epub 2025 May 12.
While functional Magnetic Resonance Imaging (fMRI) offers valuable insights into cognitive processes, its inherent spatial limitations pose challenges for detailed analysis of the fine-grained functional architecture of the brain. More specifically, MRI scanner and sequence specifications impose a trade-off between temporal resolution, spatial resolution, signal-to-noise ratio, and scan time. Deep Learning (DL) Super-Resolution (SR) methods have emerged as a promising solution to enhance fMRI resolution, generating high-resolution (HR) images from low-resolution (LR) images typically acquired with lower scanning times. However, most existing SR approaches depend on supervised DL techniques, which require training ground truth (GT) HR data, which is often difficult to acquire and simultaneously sets a bound for how far SR can go. In this paper, we introduce a novel self-supervised DL SR model that combines a DL network with an analytical approach and Total Variation (TV) regularization. Our method eliminates the need for external GT images, achieving competitive performance compared to supervised DL techniques and preserving the functional maps.
虽然功能磁共振成像(fMRI)为认知过程提供了有价值的见解,但其固有的空间局限性给大脑精细功能结构的详细分析带来了挑战。更具体地说,MRI扫描仪和序列规格在时间分辨率、空间分辨率、信噪比和扫描时间之间进行权衡。深度学习(DL)超分辨率(SR)方法已成为提高fMRI分辨率的一种有前途的解决方案,可从通常以较短扫描时间获取的低分辨率(LR)图像生成高分辨率(HR)图像。然而,大多数现有的SR方法依赖于监督式DL技术,这需要训练真实的高分辨率(GT)数据,而这些数据往往难以获取,同时也限制了SR的提升幅度。在本文中,我们引入了一种新颖的自监督DL SR模型,该模型将DL网络与一种解析方法和全变差(TV)正则化相结合。我们的方法无需外部的GT图像,与监督式DL技术相比具有竞争力的性能,同时保留了功能图谱。