The core problem the researchers set out to solve is deceptively simple to state. Wound healing in diabetes is a complex, slow and frequently derailed biological process, often complicated by infection and poor blood supply. Clinical assessment currently relies on visual examination and surface measurement, methods the authors describe as strongly subjective and incapable of evaluating what lies beneath the wound bed. A wound may look dry and closed while the microvascular network beneath it remains dysfunctional and fragile, a mismatch that contributes to the high rate of ulcer recurrence. What is needed, the team argued, is a way to quantify the repair process itself: how blood flows through the skin, how new vessels sprout and mature, and how the internal architecture of the wound remodels over time.

No single imaging modality can capture all of that at once, which is precisely why the researchers combined three. The first is laser speckle contrast imaging, or LSCI, a technique that shines coherent laser light across the wound surface and reads the interference patterns, or speckles, produced by moving red blood cells. Because the blurring of the speckle pattern is directly related to the speed of blood flow, LSCI can generate real-time, full-field maps of cutaneous blood perfusion without any contrast agent, any contact and any ionizing radiation. It is essentially a live weather map of circulation at the wound surface, refreshed many times per second.

The second technique reaches deeper into the near-infrared spectrum. Second near-infrared region imaging, known as NIR-II, operates at wavelengths roughly between 1,000 and 1,700 nanometers, where tissue scatters far less light than in the visible range. The result is dramatically improved penetration depth and spatial resolution, allowing the team to trace the spatial and temporal evolution of vascular networks as they regrew across the healing wounds. Whereas LSCI reports on how fast blood moves, NIR-II delineates the plumbing itself, the architecture of the vessels carrying that blood, resolved in three dimensions over days and weeks.

The third modality, optical coherence tomography angiography, or OCTA, borrows the depth-resolving power of OCT and applies it to moving blood cells. By detecting flow-induced changes in repeated cross-sectional scans, OCTA reconstructs high-resolution maps of microvessels without injecting any dye, while simultaneously characterizing the internal microarchitecture of the wound. Together the three techniques span a striking range of scales: LSCI for dynamic whole-surface perfusion, NIR-II for vascular network structure over time, and OCTA for depth-resolved microvascular and tissue detail. The researchers describe the resulting dataset as a uniquely comprehensive record of the microvascular repair process, one that no individual modality could deliver on its own.

To put the platform to the test, the team carried out longitudinal imaging of full-thickness skin wounds in both normal mice and db/db mice, a widely used model of type 2 diabetes in which wounds heal slowly and incompletely, mirroring the clinical situation. All animal work was conducted between August 2024 and March 2025 under protocols approved by the Ethics Committee of the Second Hospital of Shanxi Medical University, in accordance with National Institutes of Health guidelines, with anesthesia, analgesia and standard-compliant postoperative care to minimize suffering. The multimodal setup allowed the same wounds to be tracked continuously through the entire healing trajectory, a demanding experimental design that required synchronizing three optical systems around a single wound site over many sessions.

The results demonstrated that each modality pulled its weight, and that their combination produced information neither could supply alone. LSCI captured real-time dynamic changes in cutaneous blood perfusion, revealing how flow returned, fluctuated and redistributed across the wound surface as healing advanced. NIR-II imaging traced the growth and remodeling of vascular networks in space and time, documenting the emergence of new vessel structures that later consolidated. OCTA, meanwhile, peered inside the wound to characterize microarchitecture and microvascular patterns at high resolution, exposing differences between normally healing wounds and the impaired regeneration seen in the diabetic animals. The platform thereby enabled both qualitative and quantitative assessment of wound repair capacity, with the authors describing the resolution and completeness of the data as unprecedented.

Beyond simply watching wounds close, the study had a therapeutic ambition. The team used the platform to quantitatively evaluate zinc-ion-based treatment strategies aimed at promoting the reconstruction of microcirculation in diabetic wounds. Zinc has long interested wound researchers for its roles in enzymatic function, immune defense and angiogenesis, but demonstrating that a pro-angiogenic therapy is actually rebuilding functional vessels, rather than merely shrinking a wound, requires exactly the kind of vascular-level measurement the new platform provides. By combining perfusion data from LSCI, structural vascular data from NIR-II and depth-resolved microvascular data from OCTA, the researchers could assess treatment effects across multiple physiological dimensions simultaneously, rather than inferring efficacy from wound area alone.

The implications for clinical practice could be significant. Diabetic wound care currently suffers from a measurement gap: decisions about debridement, dressings, revascularization procedures and amputation are guided largely by surface appearance, photographs and manual measurements, supplemented in some centers by transcutaneous oxygen testing or Doppler ultrasound. Laser Doppler flowmetry, an older optical perfusion technique, measures flow only at single points, while indocyanine green angiography requires an injected dye and offers limited depth information. The platform presented by the Shanxi team addresses these shortcomings by fusing agent-free, contact-free measurements of flow, vessel architecture and tissue structure into a single longitudinal record. The authors argue that the approach demonstrates promising feasibility for assessing novel pro-angiogenic treatments and may eventually help guide clinical wound management, although translation from mice to patients will require further validation, including work on appropriate imaging windows for human tissue and the workflow demands of busy clinics.

The study also fits into a broader movement in biomedical optics toward multimodal, quantitative imaging of disease processes. Techniques such as polarization-sensitive OCT, magnetic resonance angiography and advanced fluorescence imaging each contribute pieces of the wound-healing picture, but their integration into a practical bedside workflow remains an open challenge. What the Shanxi team has shown is that three optical methods with overlapping but distinct strengths can be orchestrated to produce a coherent, quantifiable narrative of tissue repair, from the first surge of perfusion at the wound margin to the maturation of a new capillary network beneath a closing epithelium. If that narrative can eventually be read in a human clinic as reliably as it now can in a mouse model, the humble ruler may finally give way to a far more revealing instrument, one that sees not just whether a wound is closing but whether the vessels underneath it are truly built to last.

Subject of Research: Multimodal noninvasive optical imaging of microvascular repair in diabetic wound healing

Article Title: Noninvasive assessment of the repair process in diabetic wound healing using multimodal imaging techniques

Article References: Li, Y., Zhang, H., Ren, Y., Wang, H., Cao, G., Fan, K., Lu, C., Zhang, Y., Han, J., & Dong, H. (2026). Noninvasive assessment of the repair process in diabetic wound healing using multimodal imaging techniques. BMC Medical Imaging. https://doi.org/10.1186/s12880-026-02811-4

Image Credits: AI Generated

DOI: 10.1186/s12880-026-02811-4

Keywords: diabetic wound healing, laser speckle contrast imaging, NIR-II imaging, OCTA, angiogenesis, blood perfusion, microcirculation, noninvasive imaging, db/db mice, wound assessment, biomedical optics, zinc therapy