A Decade of Progress: How fNIRS is Transforming Clinical Brain Imaging

NIRS is Transforming Clinical Brain Imaging ©MAJGraphics - stock.adobe.com

In recent years, brain science research has garnered international attention as a frontier in technological innovation, sparking initiatives like the U.S. BRAIN Initiative and the European Brain Research Area project. As nations invest in brain science, there is growing interest in understanding the brain's intricate network of functional anatomical regions. Functional near-infrared spectroscopy (fNIRS) has become a prominent tool in this field, offering noninvasive, real-time imaging of brain activity by measuring blood flow and oxygen levels in the cerebral cortex. This technique has proven particularly valuable in clinical settings, allowing for the study of brain function in patients across various demographics without the need for invasive procedures (1,2).

Exploring fNIRS: A Decade of Innovation and Application
Over the last decade, fNIRS has solidified its position as a key player in brain imaging technologies, with a growing body of research underscoring its clinical significance. A recent bibliometric study, conducted by a team from the Comprehensive Rehabilitation Department at the First Teaching Hospital of Tianjin University of Traditional Chinese Medicine, delves into the evolution of fNIRS research, highlighting its application in detecting and analyzing brain function (1).

Read More: NIR Brain Monitoring

Led by Junfeng Zhang, Tao Yu, Meng Wang, Yuan Zhang, Hong Li, Hao Chen, Yulin Qian, and Long Yan, the study utilized the Web of Science core collection database alongside CiteSpace and VOSviewer software to map out the research publication landscape. The analysis encompassed publications from the past ten years, revealing a steady increase in fNIRS-related research, particularly in clinical contexts (1).

Key Findings: Global Trends and Collaborations
The bibliometric analysis revealed that countries with strong economies, such as the United States and China, are leading the way in fNIRS research. China, in particular, ranked second in the number of publications and fourth in intermediary centrality, reflecting its growing influence in the field. This trend suggests that nations with robust economic resources are more likely to invest in advanced research technologies like fNIRS, fostering international collaborations and driving innovation (1).

Institutions and authors from these leading nations also emerged as key contributors to the field, underscoring the correlation between economic power and research output. The study highlighted the transition from theoretical analyses to clinical research, with an increasing number of experimental studies focusing on the practical applications of fNIRS in understanding the details of brain function (1).

Clinical Applications: From Neurology to Sports Medicine
The versatility of fNIRS has led to its adoption in various clinical disciplines, including neurology, psychiatry, pediatric medicine, and sports science. The technique's ability to noninvasively monitor brain activity during tasks has made it a valuable tool in diagnosing and treating neurological disorders such as depression, anxiety, and stroke. Its application in pediatric medicine, particularly in studying cognitive development and brain function in children, has also been significant (1,2).

In sports medicine, fNIRS has been used to assess brain function in athletes, providing insights into the impact of physical exertion on cognitive processes. The technology's ability to capture real-time data on brain activity during both resting and task-related states has proven crucial in these diverse fields, offering clinicians a deeper understanding of brain function and aiding in the development of targeted treatment plans (1).

The Future of fNIRS: Challenges and Opportunities
While fNIRS has made significant strides, the technology still faces certain limitations. For instance, its current inability to detect subcortical brain functions restricts its application to the superficial cortex. Moreover, interference from factors like hair can affect data quality, highlighting the need for further technological advancements to enhance signal acquisition for routine patient analysis conditions (1).

Despite these challenges, the future of fNIRS looks promising. The integration of fNIRS with other imaging techniques, such as functional magnetic resonance imaging (fMRI) and electroencephalography (EEG), could pave the way for more comprehensive brain imaging solutions. Additionally, the development of portable and hyperscan fNIRS equipment is expected to expand the technology's applicability in naturalistic settings, enabling more accurate and widespread use in clinical research (1,2).

Conclusion:
The past decade has seen remarkable progress in the application of fNIRS in clinical settings, with the technology proving to be an extremely valuable tool in brain imaging. The bibliometric study by Zhang and colleagues not only highlights the current state of fNIRS research but also points to a future where this noninvasive technique could play a central role in diagnosing and treating a wide range of brain disorders. As the technology continues to advance, its potential to revolutionize clinical practice and enhance our understanding of brain function remains immense (1,2).

References

(1) Zhang, J.; Yu, T.; Wang, M.; Zhang, Y.; Li, H.; Chen, H.; Qian, Y.; Yan, L. Clinical applications of functional near-infrared spectroscopy in the past decade: a bibliometric study. Appl. Spectrosc. Rev. 2024, 59 (7), 908–934. DOI: 10.1080/05704928.2023.2268416

(2) Phillips, Z.; Canoy, R. J.; Paik, S. H.; Lee, S. H.; Kim, B. M. Functional near-infrared spectroscopy as a personalized digital healthcare tool for brain monitoring. J Clin Neurol. 2023 19 (2), 115–124. DOI: 10.3988/jcn.2022.0406