Numerical Investigation of the Mechanisms of Ultrasound-Modulated Bioluminescence Tomography

Abstract

(2015) Numerical investigation of the mechanisms of ultrasound-modulated bioluminescence tomography. IEEE Transactions on Biomedical Engineering, 62 (9). pp. 2135 -2143 Access from the University of Nottingham repository: http://eprints.nottingham.ac.uk/46414/1/Qimei_Bioluminescence_Paper_v12%20final %20submitted.pdf Copyright and reuse:The Nottingham ePrints service makes this work by researchers of the University of Nottingham available open access under the following conditions. This article is made available under the University of Nottingham End User licence and may be reused according to the conditions of the licence. For more details see: http://eprints.nottingham.ac.uk/end_user_agreement.pdf A note on versions:The version presented here may differ from the published version or from the version of record. If you wish to cite this item you are advised to consult the publisher's version. Please see the repository url above for details on accessing the published version and note that access may require a subscription.

Ultrasound-mediation of self-illuminating reporters improves imaging resolution in optically scattering media

“…4 Influence of varying UST pressure on light source inside the phantom increases (a) Acousto-optic (AC) signals and intensity of light source (DC) and; (b) Modulation depth and SNR of the received AC and DC signals. illustrates how an increase in pressure causes an increase in both the AC and DC signals whereas using the mechanisms described previously [ 21 ] relating to US modulation, only an increase in AC signal would be anticipated. The plot of SNR of AC and DC in Fig.…”

“…Using our system ( Fig. 1 ) parameters, the surface radiance (L DC ) of the turbid medium is calculated using the relationship [ 21 ]: where h is Plank’s constant (6.634 × 10 −34 J s), ν = c/λ is the light frequency, c is the speed of light (3 × 10 8 m s −1 ), λ is the light wavelength, Ω is the collection solid angle, E Ano and S PMT is the anode radiance sensitivity and effective area of the PMT respectively.…”

“…The use of CW US is likely to produce an increased DC CL signal due to either an increase in temperature [ 29 , 30 ] or an increase in the chemical reaction rate due to agitation of the sample [ 31 ]. The AC US signal will also increase due to these effects and due to the previously described US modulation methods [ 21 ]. Therefore, a second set of experiments is carried out to investigate and decouple these effects using a tissue phantom with the same properties as described in section 2.2.…”

“…The feasibility of translating this to in vivo imaging was later investigated in a numerical study using NIRFAST [ 20 ], an open source software tool that simulates the propagation of light in biological tissue based on finite element method (FEM). The mechanisms of ultrasound modulated bioluminescence tomography (USMBLT) [ 21 ] were investigated by modifying NIRFAST to incorporate the effects of US induced variations on the optical properties (scattering coefficient, absorption coefficient, and refractive index) of tissue and fluence rate from bioluminescence concentration located in a tissue sample. The simulation results showed US induced changes in BL concentration to produce a hundred times stronger modulation as compared to changes in the optical properties of the scattering medium.…”

“…In view of the encouraging aforementioned USMBLT [ 21 ] simulation results, we have characterized the USMBLT system experimentally to investigate if the detection system is capable of imaging incoherent luminescent reporters with improved spatial resolution, and sufficient SNR. Preliminary results were presented in a recent conference paper [ 22 ].…”