Content area
Full Text
Annals of Biomedical Engineering, Vol. 39, No. 6, June 2011 ( 2011) pp. 17281735 DOI: 10.1007/s10439-011-0261-1
Whole-Body Cerenkov Luminescence Tomography with the Finite Element SP3 Method
JIANGHONG ZHONG, JIE TIAN, XIN YANG, and CHENGHU QIN
Medical Image Processing Group, Institute of Automation, Chinese Academy of Sciences, 95 Zhongguancun East Road, Haidian Dist., Beijing 100190, Peoples Republic of China
(Received 8 November 2010; accepted 24 January 2011; published online 8 February 2011)
Associate Editor Jing Bai oversaw the review of this article.
AbstractGeneration of an accurate Cerenkov luminescence imaging model is a current issue of nuclear tomography with optical techniques. The article takes a pro-active approach toward whole-body Cerenkov luminescence tomography. The nite element framework employs the equation of radiative transfer via the third-order simplied spherical harmonics approximation to model Cerenkov photon propagation in a small animal. After this forward model is performed on a digital mouse with optical property heterogeneity and compared with the Monte Carlo method, we investigated the whole body reconstruction algorithm along a regularization path via coordinate descent. The endpoint of the follow-up study is the in vivo application, which provides three-dimensional biodistribution of the radiotracer uptake in the mouse from measured partial boundary currents. The combination of the forward and inverse model with elastic-net penalties is not only validated by numerical simulation, but it also effectively demonstrates in vivo imaging in small animals. Our exact reconstruction method enables optical molecular imaging to best utilize Cerenkov radiation emission from the decay of medical isotopes in tissues.
KeywordsCerenkov, Mathematical model, Light propagation in tissues, Tomography, Molecular imaging.
INTRODUCTION
Whole-body Cerenkov tomographic imaging provides a new molecular imaging strategy to image radionuclides in vivo in a cost-effective and timely manner.13 Radiotracers are generally imaged with nuclear imaging modalities such as positron emission tomography (PET) and single photon emission computed tomography (SPECT). An optical imaging modality has been recently discovered to be able to
image medical isotopes such as 18F, 131I, and 225Ac
in vivo in small animals utilizing VavilovCerenkov radiation (VCR).811,1618 VCR is generated during the initial decay process before the annihilation event and emits a continuum of ultraviolet and visible light. More than a low-cost PET or SPECT alternative, utilization of Cerenkov luminescence and tomographic techniques breaks the limitation of pure optical approaches...