Human Phenome Institute, Fudan University, Shanghai, China.
Academy for Engineering and Technology, Fudan University, Shanghai, China.
Ultrasound Med Biol. 2024 Sep;50(9):1459-1471. doi: 10.1016/j.ultrasmedbio.2024.05.027. Epub 2024 Jul 7.
Bone diseases deteriorate the microstructure of bone tissue. Optical-resolution photoacoustic microscopy (OR-PAM) enables high spatial resolution of imaging bone tissues. However, the spatiotemporal trade-off limits the application of OR-PAM. The purpose of this study was to improve the quality of OR-PAM images without sacrificing temporal resolution.
In this study, we proposed the Photoacoustic Dense Attention U-Net (PADA U-Net) model, which was used for reconstructing full-scanning images from under-sampled images. Thereby, this approach breaks the trade-off between imaging speed and spatial resolution.
The proposed method was validated on resolution test targets and bovine cancellous bone samples to demonstrate the capability of PADA U-Net in recovering full-scanning images from under-sampled OR-PAM images. With a down-sampling ratio of [4, 1], compared to bilinear interpolation, the Peak Signal-to-Noise Ratio and Structural Similarity Index Measure values (averaged over the test set of bovine cancellous bone) of the PADA U-Net were improved by 2.325 dB and 0.117, respectively.
The results demonstrate that the PADA U-Net model reconstructed the OR-PAM images well with different levels of sparsity. Our proposed method can further facilitate early diagnosis and treatment of bone diseases using OR-PAM.
骨病会使骨组织的微观结构恶化。光分辨光声显微镜（OR-PAM）能够实现骨组织的高空间分辨率成像。然而，时空权衡限制了 OR-PAM 的应用。本研究旨在在不牺牲时间分辨率的情况下提高 OR-PAM 图像的质量。
在这项研究中，我们提出了 Photoacoustic Dense Attention U-Net（PADA U-Net）模型，该模型用于从欠采样图像重建全扫描图像。这样，该方法打破了成像速度和空间分辨率之间的权衡。
该方法在分辨率测试目标和牛松质骨样本上进行了验证，以证明 PADA U-Net 从欠采样的 OR-PAM 图像中恢复全扫描图像的能力。与双线性插值相比，在 [4,1] 的下采样比下，PADA U-Net 的峰值信噪比和结构相似性指数测量值（在牛松质骨测试集上平均）分别提高了 2.325dB 和 0.117。
结果表明，PADA U-Net 模型可以很好地重建具有不同稀疏度的 OR-PAM 图像。我们提出的方法可以进一步促进使用 OR-PAM 进行早期诊断和治疗骨病。
