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Journal of Biomedical Optics • Open Access

Comparison of magnetic resonance imaging-compatible optical detectors for in-magnet tissue spectroscopy: photodiodes versus silicon photomultipliers

Paper Abstract

Tissue spectroscopy inside the magnetic resonance imaging (MRI) system adds a significant value by measuring fast vascular hemoglobin responses or completing spectroscopic identification of diagnostically relevant molecules. Advances in this type of spectroscopy instrumentation have largely focused on fiber coupling into and out of the MRI; however, nonmagnetic detectors can now be placed inside the scanner with signal amplification performed remotely to the high field environment for optimized light detection. In this study, the two possible detector options, such as silicon photodiodes (PD) and silicon photomultipliers (SiPM), were systematically examined for dynamic range and wavelength performance. Results show that PDs offer 108 (160 dB) dynamic range with sensitivity down to 1 pW, whereas SiPMs have 107 (140 dB) dynamic range and sensitivity down to 10 pW. A second major difference is the spectral sensitivity of the two detectors. Here, wavelengths in the 940 nm range are efficiently captured by PDs (but not SiPMs), likely making them the superior choice for broadband spectroscopy guided by MRI.

Paper Details

Date Published: 9 July 2014
PDF: 3 pages
J. Biomed. Opt. 19(7) 070502 doi: 10.1117/1.JBO.19.7.070502
Published in: Journal of Biomedical Optics Volume 19, Issue 7
Show Author Affiliations
Fadi El-Ghussein, Thayer School of Engineering at Dartmouth (United States)
Shudong Jiang, Thayer School of Engineering at Dartmouth (United States)
Brian W. Pogue, Thayer School of Engineering at Dartmouth (United States)
Keith D. Paulsen, Thayer School of Engineering at Dartmouth (United States)

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