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Updated: Apr 6, 2026

Ultrasound Localization Microscopy for Super-Resolution Mapping of the Rodent Brain Microvasculature
Published on: November 14, 2025
Ultrasound Localization Microscopy Learned from power doppler by uncertainty frequency density estimation and
Qinghua Lin1, Xuan Ren1, Boqian Zhou1
1College of Biomedical Engineering, Fudan University, Shanghai, 200433, China.
Abstract:
Ultrasound Localization Microscopy (ULM) achieves micron-level vascular visualization beyond the resolution of conventional ultrasound imaging by tracking microbubble positions. However, ULM relies on high-frame-count ultrasound images, which leads to long acquisition times, poor real-time performance, and high post-processing costs. Therefore, we propose a Power Doppler (PD) to ULM image super-resolution method named PDSR. Specifically, to address the issues of content distortion and training instability in PD image super-resolution, we propose a Patch Consistency Regularization (PCR), which enhances the representation capability of unpaired image translation models through cross-region patch-wise information interaction. Then, we propose a Semantic Consistency Awareness (SCA) to constrain the semantic alignment between PD and ULM images in high-weight regions sampled under discriminator guidance, reducing the generator's tendency to translate false structures from PD images. Finally, we propose an uncertainty frequency Density Variation Constraint (DVC), which enhances vessel realism by constraining the translation of high-information-density regions in PD images to corresponding regions in ULM images. Extensive experiments and ablation studies demonstrate that the proposed method achieves state-of-the-art performance in PD-to-ULM image translation, attaining an SSIM of 78.45% and a PSNR of 15.03 dB, while requiring only 13.1 ms per image for reconstruction. Given its unpaired training strategy and high-fidelity imaging results in preclinical rat studies, PDSR offers potential for enabling contrast-free ULM imaging. Code is available at: https://github.com/LQH89757/PDSR.
Insights
We developed a Power Doppler to Ultrasound Localization Microscopy (PD-ULM) super-resolution method (PDSR) to improve vascular imaging speed and quality. PDSR enhances image resolution and realism, enabling faster, contrast-free ULM imaging.
Area of Science:
- Medical Imaging
- Biomedical Engineering
- Image Processing
Background:
- Ultrasound Localization Microscopy (ULM) offers micron-level vascular visualization by tracking microbubbles.
- Conventional ULM requires high-frame-count images, leading to long acquisition times and high costs.
- Existing methods struggle with content distortion and training instability in Power Doppler (PD) to ULM image translation.
Purpose of the Study:
- To develop a novel super-resolution method (PDSR) for transforming Power Doppler (PD) images into high-resolution Ultrasound Localization Microscopy (ULM) images.
- To address limitations of existing PD-to-ULM translation methods, focusing on content distortion and training instability.
- To enable faster and potentially contrast-free ULM imaging.
Main Methods:
- Proposed PDSR method utilizing unpaired image translation.
- Introduced Patch Consistency Regularization (PCR) for enhanced representation capability via cross-region patch interaction.
- Implemented Semantic Consistency Awareness (SCA) to align PD and ULM image semantics, reducing false structure translation.
- Developed Density Variation Constraint (DVC) to improve vessel realism by mapping high-information-density regions.
Main Results:
- Achieved state-of-the-art performance in PD-to-ULM image translation.
- Attained high image quality metrics: 78.45% SSIM and 15.03 dB PSNR.
- Demonstrated rapid reconstruction time of 13.1 ms per image.
- Validated high-fidelity imaging in preclinical rat studies.
Conclusions:
- PDSR significantly improves PD-to-ULM image translation, offering superior resolution and realism.
- The method's unpaired training strategy and speed make it suitable for real-time applications.
- PDSR holds promise for advancing contrast-free ULM imaging in preclinical research.

