1064 nm Fiber Probe Raman Imaging for human bladder resectates

Recent advancements in Raman imaging spectroscopy have led to the development of a compact, dispersive 1064 nm fiber probe Raman imaging spectrometer. This new instrument, as discussed in the study titled "Design of a Dispersive 1064 nm Fiber Probe Raman Imaging Spectrometer and Its Application to Human Bladder Resectates" by Muñoz-Bolaños et al., presents a promising alternative to traditional Raman imaging systems using 785 nm excitation lasers. Here’s a detailed look into the key developments and findings from this groundbreaking research.

Improved Fluorescence Suppression and Deeper Tissue Penetration

One of the significant advantages of using a 1064 nm excitation laser is the substantial reduction in fluorescence background. This feature is particularly beneficial for biomedical applications, allowing for deeper tissue penetration and clearer imaging. This improvement is crucial in detecting cancer in human bladder resectates, where accurate and detailed imaging is essential.

Diagram of the 1064 nm excitation laser setup.

Effective Tumor Detection

The study demonstrated the effectiveness of the 1064 nm Raman instrument in differentiating between tumor and non-tumor bladder tissues. Raman images were collected ex vivo from 10 human bladder specimens, both tumor and non-tumor, and compared to images obtained using the 785 nm excitation. Despite a lower spectral resolution, the 1064 nm instrument could identify cancerous tissues similarly to the 785 nm system.

Comparative Raman images of bladder tissues using 1064 nm and 785 nm excitation.

Data Processing with SpectraMap (SpMap)

To manage and analyze the data collected, the researchers used a Python-based open-source toolbox named SpectraMap (SpMap). This tool facilitated K-Means cluster (KMC) analysis and hierarchical cluster analysis (HCA), allowing the identification of Raman signatures associated with control, tumor, necrosis, and lipid-rich tissues. These advanced data processing techniques are crucial for accurate tumor detection and classification.

 SpectraMap (SpMap) 

Potential Applications Beyond Bladder Cancer

The study also explored the application of the 1064 nm Raman spectrometer in analyzing kidney stones, which often present intense fluorescence backgrounds. The new system successfully acquired high-quality spectra from kidney stones that previously could not be analyzed using the 785 nm system. This versatility suggests potential broader applications in urology and other medical fields.

Conclusion

The development of the 1064 nm fiber probe Raman imaging spectrometer marks a significant step forward in medical imaging and cancer detection technology. Its ability to suppress fluorescence background and provide detailed tissue imaging promises to enhance diagnostic accuracy and potentially reduce cancer recurrence rates when used in conjunction with treatments like cryoablation.

This innovative tool not only shows promise for bladder cancer detection but also opens up new possibilities for its application in other medical diagnostics, paving the way for more effective and accurate healthcare solutions.

References

Muñoz-Bolaños, J.D., Shaik, T.A., Miernik, A., Popp, J., & Krafft, C. (2024). Design of a Dispersive 1064 nm Fiber Probe Raman Imaging Spectrometer and Its Application to Human Bladder Resectates. Applied Sciences, 14(4726). https://doi.org/10.3390/app14114726