Instrumentation and method for measuring NIR light absorbed in tissue during MR imaging in medical NIRS measurements

Teemu S. Myllylä; Hannu S. S. Sorvoja; Juha Nikkinen; Osmo Tervonen; Vesa Kiviniemi; Risto A. Myllylä

doi:10.1117/12.889677

16 June 2011 Instrumentation and method for measuring NIR light absorbed in tissue during MR imaging in medical NIRS measurements

Teemu S. Myllylä, Hannu S. S. Sorvoja, Juha Nikkinen, Osmo Tervonen, Vesa Kiviniemi, Risto A. Myllylä

Author Affiliations +

Proceedings Volume 8090, Novel Biophotonic Techniques and Applications; 80900Y (2011) https://doi.org/10.1117/12.889677
Event: European Conferences on Biomedical Optics, 2011, Munich, Germany

Abstract

Our goal is to provide a cost-effective method for examining human tissue, particularly the brain, by the simultaneous use of functional magnetic resonance imaging (fMRI) and near-infrared spectroscopy (NIRS). Due to its compatibility requirements, MRI poses a demanding challenge for NIRS measurements. This paper focuses particularly on presenting the instrumentation and a method for the non-invasive measurement of NIR light absorbed in human tissue during MR imaging. One practical method to avoid disturbances in MR imaging involves using long fibre bundles to enable conducting the measurements at some distance from the MRI scanner. This setup serves in fact a dual purpose, since also the NIRS device will be less disturbed by the MRI scanner. However, measurements based on long fibre bundles suffer from light attenuation. Furthermore, because one of our primary goals was to make the measuring method as cost-effective as possible, we used high-power light emitting diodes instead of more expensive lasers. The use of LEDs, however, limits the maximum output power which can be extracted to illuminate the tissue. To meet these requirements, we improved methods of emitting light sufficiently deep into tissue. We also show how to measure NIR light of a very small power level that scatters from the tissue in the MRI environment, which is characterized by strong electromagnetic interference. In this paper, we present the implemented instrumentation and measuring method and report on test measurements conducted during MRI scanning. These measurements were performed in MRI operating rooms housing 1.5 Tesla-strength closed MRI scanners (manufactured by GE) in the Dept. of Diagnostic Radiology at the Oulu University Hospital.

Citation Download Citation

Teemu S. Myllylä, Hannu S. S. Sorvoja, Juha Nikkinen, Osmo Tervonen, Vesa Kiviniemi, and Risto A. Myllylä "Instrumentation and method for measuring NIR light absorbed in tissue during MR imaging in medical NIRS measurements", Proc. SPIE 8090, Novel Biophotonic Techniques and Applications, 80900Y (16 June 2011); https://doi.org/10.1117/12.889677

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available