1
|
Nouizi F, Algarawi M, Erkol H, Gulsen G. Gold nanoparticle-mediated photothermal therapy guidance with multi-wavelength photomagnetic imaging. Photodiagnosis Photodyn Ther 2024; 45:103956. [PMID: 38159834 DOI: 10.1016/j.pdpdt.2023.103956] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2023] [Revised: 12/11/2023] [Accepted: 12/27/2023] [Indexed: 01/03/2024]
Abstract
Difficulty in heating tumors with high spatial selectivity while protecting surrounding healthy tissues from thermal harm is a challenge for cancer photothermal treatment (PTT). To mitigate this problem, PTT mediated by photothermal agents (PTAs) has been established as a potential therapeutic technique to boost selectivity and reduce damage to surrounding healthy tissues. Various gold nanoparticles (AuNP) have been effectively utilized as PTAs, mainly using strategies to target cancerous tissue and increase selective thermal damage. Meanwhile, imaging can be used in tandem to monitor the AuNP distribution and guide the PTT. Mainly, the parameters impacting the induced temperature can be determined using simulation tools before treatment for effective PTT. However, accurate simulations can only be performed if the amount of AuNPs accumulated in the tumor is known. This study introduces Photo-Magnetic Imaging (PMI), which can appropriately recover the AuNP concentration to guide the PTT. Using multi-wavelength measurements, PMI can provide AuNP concentration based on their distinct absorption spectra. Tissue-simulating phantom studies are conducted to demonstrate the potential of PMI in recovering AuNP concentration for PTT planning. The recovered AuNP concentration is used to model the temperature increase accurately in a small inclusion representing tumor using a multiphysics solver that takes into account the light propagation and heat diffusion in turbid media.
Collapse
Affiliation(s)
- Farouk Nouizi
- Department of Radiological Sciences, University of California Irvine, USA
| | - Maha Algarawi
- Department of Physics, Imam Mohammad Ibn Saud Islamic University (IMSIU), Saudi Arabia
| | - Hakan Erkol
- Department of Physics, Bogazici University, Turkey
| | - Gultekin Gulsen
- Department of Radiological Sciences, University of California Irvine, USA.
| |
Collapse
|
2
|
Nouizi F, Erkol H, Nikkhah D, Kwong TC, Gulsen G. Development of a preclinical CCD-based temperature modulated fluorescence tomography platform. BIOMEDICAL OPTICS EXPRESS 2022; 13:5740-5752. [PMID: 36733748 PMCID: PMC9872903 DOI: 10.1364/boe.470723] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/18/2022] [Revised: 09/25/2022] [Accepted: 09/26/2022] [Indexed: 05/11/2023]
Abstract
In preclinical research, fluorescence molecular tomography (FMT) is the most sensitive imaging modality to interrogate whole-body and provide 3D distribution of fluorescent contract agents. Despite its superior sensitivity, its mediocre spatial-resolution has been the main barrier to its clinical translation. This limitation is mainly due to the high scattering of optical photons in biological tissue together with the limited boundary measurements that lead to an undetermined and ill-posed inverse problem. To overcome the limitations of FMT, we previously introduced a novel method termed, Temperature Modulated Fluorescence Tomography (TMFT). TMFT utilizes thermos-sensitive fluorescent agents (ThermoDots) as a key component and localizes them with high-intensity focused ultrasound (HIFU). Scanning the focused HIFU beam having a diameter Ø = 1.3 mm across the tissue while monitoring the variation in the measured fluorescence signals reveals the position of the ThermoDots with high spatial accuracy. We have formerly built a prototype TMFT system that uses optical fibers for detection. In this paper, we present an upgraded version using a CCD camera-based detection that enables non-contact imaging. In this version, the animal under investigation is placed on an ultrasound transparent membrane, which eliminates the need for its immersion in optical matching fluids that were required by the fiber-based system. This CCD-based system will pave the way for convenient and wide-spread use of TMFT in preclinical research. Its performance validation on phantom studies demonstrates that high spatial-resolution (∼1.3 mm) and quantitative accuracy in recovered fluorophore concentration (<3% error) can be achieved.
Collapse
Affiliation(s)
- Farouk Nouizi
- Tu and Yuen Center for Functional Onco-Imaging, Department of Radiological Sciences, University of California Irvine, CA 92697, USA
- Chao Family Comprehensive Cancer Center, University of California Irvine, CA 92697, USA
| | - Hakan Erkol
- Department of Physics, Bogazici University, Bebek, 34342, Istanbul, Turkey
| | - Deniz Nikkhah
- Tu and Yuen Center for Functional Onco-Imaging, Department of Radiological Sciences, University of California Irvine, CA 92697, USA
| | - Tiffany C. Kwong
- Tu and Yuen Center for Functional Onco-Imaging, Department of Radiological Sciences, University of California Irvine, CA 92697, USA
| | - Gultekin Gulsen
- Tu and Yuen Center for Functional Onco-Imaging, Department of Radiological Sciences, University of California Irvine, CA 92697, USA
- Chao Family Comprehensive Cancer Center, University of California Irvine, CA 92697, USA
| |
Collapse
|
3
|
Lo PA, Su SP, Chiang HK. Small-animal 360-deg fluorescence diffuse optical tomography using structural prior information from ultrasound imaging. JOURNAL OF BIOMEDICAL OPTICS 2020; 25:1-11. [PMID: 32129028 PMCID: PMC7052526 DOI: 10.1117/1.jbo.25.3.036001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/11/2019] [Accepted: 01/23/2020] [Indexed: 06/10/2023]
Abstract
We demonstrate dual modality of free-space fluorescence diffuse optical tomography (FDOT) and handheld ultrasound (US) imaging to reveal both functional and structural information in small animals. FDOT is a noninvasive method for examining the fluorophore inside an object from the light distribution of the surface. In FDOT, a 660-nm continuous wave diode laser was used as an excitation source and an electron-multiplying charge-coupled device (EMCCD) was used for fluorescence data acquisition. Both the laser and EMCCD were mounted on a 360-deg rotation gantry for the transmission optical data collection. The structural information is obtained from a 6- to 17-MHz handheld US linear transducer by single-side access and conducts in the reconstruction as soft priors. The rotation ranges from 0 deg to 360 deg; different rotation degrees, object positions, and parameters were determined for comparison. Both phantom and tissue phantom results demonstrate that fluorophore distribution can be recovered accurately and quantitatively using this imaging system. Finally, an animal study confirms that the system can extract a dual-modality image, validating its feasibility for further in vivo experiments. In all experiments, the error and standard deviation decrease as the rotation degree is increased and the error was reduced to 10% when the rotation degree was increased over 135 deg.
Collapse
Affiliation(s)
- Pei-An Lo
- National Yang-Ming University, Institute of Biomedical Engineering, Taipei, Taiwan
| | - Shih-Po Su
- National Yang-Ming University, Institute of Biomedical Engineering, Taipei, Taiwan
| | - Huihua Kenny Chiang
- National Yang-Ming University, Institute of Biomedical Engineering, Taipei, Taiwan
| |
Collapse
|
4
|
KWONG TIFFANYC, NOUIZI FAROUK, CHO JAEDU, LIN YUTING, SAMPATHKUMARAN UMA, GULSEN GULTEKIN. Feasibility study of high spatial resolution multimodality fluorescence tomography in ex vivo biological tissue. APPLIED OPTICS 2017; 56:7886-7891. [PMID: 29047774 PMCID: PMC6855592 DOI: 10.1364/ao.56.007886] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/26/2017] [Accepted: 08/31/2017] [Indexed: 05/25/2023]
Abstract
Previously, we demonstrated that temperature-modulated fluorescence tomography (TM-FT) could provide fluorescence images with high quantitative accuracy and the spatial resolution of focused ultrasound. TM-FT is based on scanning the focused ultrasound across the medium to activate temperature-reversible fluorescent nanoprobes (ThermoDots). This technique can resolve small fluorescent targets located several centimeters deep in turbid media with millimeter resolution. Our past studies with this multimodality technique used agar phantoms, which could not represent the true heterogeneous nature of the acoustic and optical properties of biological tissue. In this work, we report the results of the first TM-FT study performed on ex vivo chicken breast tissue. In order to improve the spatial resolution of this technique, diffuse optical tomography is also used to better estimate the optical property maps of the tissue, which is utilized as functional a priori for the TM-FT reconstruction algorithm. These ex vivo results show that TM-FT can accurately recover the concentration and position of a 1.5 mm×5 mm inclusion filled with ThermoDots. Since the inclusion is embedded 2 cm deep in the chicken breast sample, these results demonstrate the great potential of TM-FT for future in vivo small animal imaging.
Collapse
Affiliation(s)
- TIFFANY C. KWONG
- Tu and Yuen Center for Functional Onco-Imaging, Department of Radiological Sciences, University of California, Irvine, California 92697, USA
| | - FAROUK NOUIZI
- Tu and Yuen Center for Functional Onco-Imaging, Department of Radiological Sciences, University of California, Irvine, California 92697, USA
| | - JAEDU CHO
- Tu and Yuen Center for Functional Onco-Imaging, Department of Radiological Sciences, University of California, Irvine, California 92697, USA
| | - YUTING LIN
- Tu and Yuen Center for Functional Onco-Imaging, Department of Radiological Sciences, University of California, Irvine, California 92697, USA
- Department of Radiation Oncology, Duke University, Durham, North Carolina 27708, USA
| | | | - GULTEKIN GULSEN
- Tu and Yuen Center for Functional Onco-Imaging, Department of Radiological Sciences, University of California, Irvine, California 92697, USA
| |
Collapse
|
5
|
Wan W, Wang Y, Qi J, Liu L, Ma W, Li J, Zhang L, Zhou Z, Zhao H, Gao F. Region-based diffuse optical tomography with registered atlas: in vivo acquisition of mouse optical properties. BIOMEDICAL OPTICS EXPRESS 2016; 7:5066-5080. [PMID: 28018725 PMCID: PMC5175552 DOI: 10.1364/boe.7.005066] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/01/2016] [Revised: 10/20/2016] [Accepted: 11/09/2016] [Indexed: 05/14/2023]
Abstract
The reconstruction quality in the model-based optical tomography modalities can greatly benefit from a priori information of accurate tissue optical properties, which are difficult to be obtained in vivo with a conventional diffuse optical tomography (DOT) system alone. One of the solutions is to apply a priori anatomical structures obtained with anatomical imaging systems such as X-ray computed tomography (XCT) to constrain the reconstruction process of DOT. However, since X-ray offers low soft-tissue contrast, segmentation of abdominal organs from sole XCT images can be problematic. In order to overcome the challenges, the current study proposes a novel method of recovering a priori organ-oriented tissue optical properties, where anatomical structures of an in vivo mouse are approximately obtained by registering a standard anatomical atlas, i.e., the Digimouse, to the target XCT volume with the non-rigid image registration, and, in turn, employed to guide DOT for extracting the optical properties of inner organs. Simulative investigations have validated the methodological availability of such atlas-registration-based DOT strategy in revealing both a priori anatomical structures and optical properties. Further experiments have demonstrated the feasibility of the proposed method for acquiring the organ-oriented tissue optical properties of in vivo mice, making it as an efficient way of the reconstruction enhancement.
Collapse
Affiliation(s)
- Wenbo Wan
- College of Precision Instrument and Optoelectronics Engineering, Tianjin University, Tianjin 300072, China
| | - Yihan Wang
- College of Precision Instrument and Optoelectronics Engineering, Tianjin University, Tianjin 300072, China
| | - Jin Qi
- College of Precision Instrument and Optoelectronics Engineering, Tianjin University, Tianjin 300072, China
- Cancer Institute and Hospital, Tianjin Medical University, Tianjin 300060, China
| | - Lingling Liu
- College of Precision Instrument and Optoelectronics Engineering, Tianjin University, Tianjin 300072, China
| | - Wenjuan Ma
- Cancer Institute and Hospital, Tianjin Medical University, Tianjin 300060, China
| | - Jiao Li
- College of Precision Instrument and Optoelectronics Engineering, Tianjin University, Tianjin 300072, China
- Tianjin Key Laboratory of Biomedical Detecting Techniques and Instruments, Tianjin 300072, China
| | - Limin Zhang
- College of Precision Instrument and Optoelectronics Engineering, Tianjin University, Tianjin 300072, China
- Tianjin Key Laboratory of Biomedical Detecting Techniques and Instruments, Tianjin 300072, China
| | - Zhongxing Zhou
- College of Precision Instrument and Optoelectronics Engineering, Tianjin University, Tianjin 300072, China
- Tianjin Key Laboratory of Biomedical Detecting Techniques and Instruments, Tianjin 300072, China
| | - Huijuan Zhao
- College of Precision Instrument and Optoelectronics Engineering, Tianjin University, Tianjin 300072, China
- Tianjin Key Laboratory of Biomedical Detecting Techniques and Instruments, Tianjin 300072, China
| | - Feng Gao
- College of Precision Instrument and Optoelectronics Engineering, Tianjin University, Tianjin 300072, China
- Tianjin Key Laboratory of Biomedical Detecting Techniques and Instruments, Tianjin 300072, China
| |
Collapse
|
6
|
Lian L, Deng Y, Xie W, Xu G, Yang X, Zhang Z, Luo Q. High-dynamic-range fluorescence molecular tomography for imaging of fluorescent targets with large concentration differences. OPTICS EXPRESS 2016; 24:19920-33. [PMID: 27557267 DOI: 10.1364/oe.24.019920] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
When CCD-based free-space fluorescence molecular tomography (FMT) is used for imaging of fluorescent targets with a large concentration difference, the limited dynamic range of the CCD diminishes the localization and quantitative accuracy of FMT. To overcome this, we present a high-dynamic-range FMT (HDR-FMT) method. Under the multiple-exposure scheme, HDR fluorescence projection images are constructed using the recovered CCD response curve. Image reconstruction is implemented using iterative reweighted L1 regularization which can reduce artifacts by using fewer HDR fluorescence projection images. Phantom and in vivo animal studies indicate that localization of fluorescent targets with a large concentration difference is effectively improved with HDR-FMT and with good quantitative accuracy.
Collapse
|
7
|
Zhang X, Zhang J, Luo J. Reconstruction of in vivo fluorophore concentration variation with structural priors and smooth penalty. APPLIED OPTICS 2016; 55:2732-2740. [PMID: 27139679 DOI: 10.1364/ao.55.002732] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Reconstruction of fluorophore concentration variation in fluorescence molecular tomography is expected to reveal the metabolic processes of fluorescent biomarkers in vivo. However, the complicated and strong noise within in vivo data inhibits its applications for in vivo cases. A smooth penalty method is presented in this work to suppress the noise. The method is based on a recursive reconstruction scheme which reconstructs the fluorophore concentration variation rates (FCVRs) of two neighboring frames at the same time within an inner iteration. In addition, the performance of the Laplacian-type regularization incorporating structural priors is investigated. Results of simulations suggest that the smooth penalty method almost has no influence on the reconstructed FCVRs when the target curve is smooth, and results of in vivo experiments on mice indicate that the method is capable of suppressing the noise and achieving smooth time courses of fluorescent yield. Results of both the simulations and in vivo experiments demonstrate that the Laplacian-type regularization can improve the image quality.
Collapse
|
8
|
Lin Y, Nouizi F, Kwong TC, Gulsen G. Simulation-based evaluation of the resolution and quantitative accuracy of temperature-modulated fluorescence tomography. APPLIED OPTICS 2015; 54:7612-21. [PMID: 26368884 PMCID: PMC4896397 DOI: 10.1364/ao.54.007612] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
Conventional fluorescence tomography (FT) can recover the distribution of fluorescent agents within a highly scattering medium. However, poor spatial resolution remains its foremost limitation. Previously, we introduced a new fluorescence imaging technique termed "temperature-modulated fluorescence tomography" (TM-FT), which provides high-resolution images of fluorophore distribution. TM-FT is a multimodality technique that combines fluorescence imaging with focused ultrasound to locate thermo-sensitive fluorescence probes using a priori spatial information to drastically improve the resolution of conventional FT. In this paper, we present an extensive simulation study to evaluate the performance of the TM-FT technique on complex phantoms with multiple fluorescent targets of various sizes located at different depths. In addition, the performance of the TM-FT is tested in the presence of background fluorescence. The results obtained using our new method are systematically compared with those obtained with the conventional FT. Overall, TM-FT provides higher resolution and superior quantitative accuracy, making it an ideal candidate for in vivo preclinical and clinical imaging. For example, a 4 mm diameter inclusion positioned in the middle of a synthetic slab geometry phantom (D:40 mm×W:100 mm) is recovered as an elongated object in the conventional FT (x=4.5 mm; y=10.4 mm), while TM-FT recovers it successfully in both directions (x=3.8 mm; y=4.6 mm). As a result, the quantitative accuracy of the TM-FT is superior because it recovers the concentration of the agent with a 22% error, which is in contrast with the 83% error of the conventional FT.
Collapse
Affiliation(s)
- Yuting Lin
- Tu and Yuen Center for Functional Onco Imaging, Department of Radiological Sciences, University of California, Irvine, California 92697, USA
- Department of Radiation Oncology, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts 02114, USA
| | - Farouk Nouizi
- Tu and Yuen Center for Functional Onco Imaging, Department of Radiological Sciences, University of California, Irvine, California 92697, USA
| | - Tiffany C. Kwong
- Tu and Yuen Center for Functional Onco Imaging, Department of Radiological Sciences, University of California, Irvine, California 92697, USA
| | - Gultekin Gulsen
- Tu and Yuen Center for Functional Onco Imaging, Department of Radiological Sciences, University of California, Irvine, California 92697, USA
- Department of Biomedical Engineering, University of California, Irvine, California 92697, USA
| |
Collapse
|
9
|
Individual variability analysis of fluorescence parameters measured in skin with different levels of nutritive blood flow. Med Eng Phys 2015; 37:574-83. [DOI: 10.1016/j.medengphy.2015.03.011] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2014] [Revised: 01/14/2015] [Accepted: 03/27/2015] [Indexed: 01/27/2023]
|
10
|
Zhang X, Liu F, Zuo S, Shi J, Zhang G, Bai J, Luo J. Reconstruction of fluorophore concentration variation in dynamic fluorescence molecular tomography. IEEE Trans Biomed Eng 2014; 62:138-44. [PMID: 25073161 DOI: 10.1109/tbme.2014.2342293] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Dynamic fluorescence molecular tomography (DFMT) is a potential approach for drug delivery, tumor detection, diagnosis, and staging. The purpose of DFMT is to quantify the changes of fluorescent agents in the bodies, which offer important information about the underlying physiological processes. However, the conventional method requires that the fluorophore concentrations to be reconstructed are stationary during the data collection period. As thus, it cannot offer the dynamic information of fluorophore concentration variation within the data collection period. In this paper, a method is proposed to reconstruct the fluorophore concentration variation instead of the fluorophore concentration through a linear approximation. The fluorophore concentration variation rate is introduced by the linear approximation as a new unknown term to be reconstructed and is used to obtain the time courses of fluorophore concentration. Simulation and phantom studies are performed to validate the proposed method. The results show that the method is able to reconstruct the fluorophore concentration variation rates and the time courses of fluorophore concentration with relative errors less than 0.0218.
Collapse
|
11
|
Mohajerani P, Hipp A, Willner M, Marschner M, Trajkovic-Arsic M, Ma X, Burton NC, Klemm U, Radrich K, Ermolayev V, Tzoumas S, Siveke JT, Bech M, Pfeiffer F, Ntziachristos V. FMT-PCCT: hybrid fluorescence molecular tomography-x-ray phase-contrast CT imaging of mouse models. IEEE TRANSACTIONS ON MEDICAL IMAGING 2014; 33:1434-46. [PMID: 24686244 DOI: 10.1109/tmi.2014.2313405] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
The implementation of hybrid fluorescence molecular tomography (FMT) and X-ray computed tomography (CT) has been shown to be a necessary development, not only for combining anatomical with functional and molecular contrast, but also for generating optical images of high accuracy. FMT affords highly sensitive 3-D imaging of fluorescence bio-distribution, but in stand-alone form it offers images of low resolution. It was shown that FMT accuracy significantly improves by considering anatomical priors from CT. Conversely, CT generally suffers from low soft tissue contrast. Therefore utilization of CT data as prior information in FMT inversion is challenging when different internal organs are not clearly differentiated. Instead, we combined herein FMT with emerging X-ray phase-contrast CT (PCCT). PCCT relies on phase shift differences in tissue to achieve soft tissue contrast superior to conventional CT. We demonstrate for the first time FMT-PCCT imaging of different animal models, where FMT and PCCT scans were performed in vivo and ex vivo, respectively. The results show that FMT-PCCT expands the potential of FMT in imaging lesions with otherwise low or no CT contrast, while retaining the cost benefits of CT and simplicity of hybrid device realizations. The results point to the most accurate FMT performance to date.
Collapse
|
12
|
Li B, Berti R, Abran M, Lesage F. Ultrasound guided fluorescence molecular tomography with improved quantification by an attenuation compensated Born-normalization and in vivo preclinical study of cancer. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2014; 85:053703. [PMID: 24880378 DOI: 10.1063/1.4875256] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Ultrasound imaging, having the advantages of low-cost and non-invasiveness over MRI and X-ray CT, was reported by several studies as an adequate complement to fluorescence molecular tomography with the perspective of improving localization and quantification of fluorescent molecular targets in vivo. Based on the previous work, an improved dual-modality Fluorescence-Ultrasound imaging system was developed and then validated in imaging study with preclinical tumor model. Ultrasound imaging and a profilometer were used to obtain the anatomical prior information and 3D surface, separately, to precisely extract the tissue boundary on both sides of sample in order to achieve improved fluorescence reconstruction. Furthermore, a pattern-based fluorescence reconstruction on the detection side was incorporated to enable dimensional reduction of the dataset while keeping the useful information for reconstruction. Due to its putative role in the current imaging geometry and the chosen reconstruction technique, we developed an attenuation compensated Born-normalization method to reduce the attenuation effects and cancel off experimental factors when collecting quantitative fluorescence datasets over large area. Results of both simulation and phantom study demonstrated that fluorescent targets could be recovered accurately and quantitatively using this reconstruction mechanism. Finally, in vivo experiment confirms that the imaging system associated with the proposed image reconstruction approach was able to extract both functional and anatomical information, thereby improving quantification and localization of molecular targets.
Collapse
Affiliation(s)
- Baoqiang Li
- Institute of Biomedical Engineering, École Polytechnique de Montréal, Montreal, Quebec H3C 3A7, Canada
| | - Romain Berti
- Institute of Biomedical Engineering, École Polytechnique de Montréal, Montreal, Quebec H3C 3A7, Canada
| | - Maxime Abran
- Institute of Biomedical Engineering, École Polytechnique de Montréal, Montreal, Quebec H3C 3A7, Canada
| | - Frédéric Lesage
- Institute of Biomedical Engineering, École Polytechnique de Montréal, Montreal, Quebec H3C 3A7, Canada
| |
Collapse
|
13
|
Luk AT, Ha S, Nouizi F, Thayer D, Lin Y, Gulsen G. A True Multi-modality Approach for High Resolution Optical Imaging: Photo-Magnetic Imaging. PROCEEDINGS OF SPIE--THE INTERNATIONAL SOCIETY FOR OPTICAL ENGINEERING 2014; 8937. [PMID: 25767691 DOI: 10.1117/12.2040870] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
Multi-modality imaging leverages the competitive advantage of different imaging systems to improve the overall resolution and quantitative accuracy. Our new technique, Photo-Magnetic Imaging (PMI) is one of these true multi-modality imaging approaches, which can provide quantitative optical absorption map at MRI spatial resolution. PMI uses laser light to illuminate tissue and elevate its temperature while utilizing MR thermometry to measure the laser-induced temperature variation with high spatial resolution. The high-resolution temperature maps are later converted to tissue absorption maps by a finite element based inverse solver that is based on modeling of photon migration and heat diffusion in tissue. Previously, we have demonstrated the feasibility of PMI with phantom studies. Recently, we have managed to reduce the laser power under ANSI limit for maximum skin exposure therefore, we have well positioned PMI for in vivo imaging. Currently we are expanding our system by adding multi-wavelength imaging capability. This will allow us not only to resolve spatial distribution of tissue chromophores but also exogenous contrast agents. Although we test PMIs feasibility with animal studies, our future goal is to use PMI for breast cancer imaging due to its high translational potential.
Collapse
Affiliation(s)
- Alex T Luk
- Tu and Yuen Center for Functional Onco-Imaging and Department of Radiological Sciences, University of California Irvine, Irvine, CA, United States
| | - Seunghoon Ha
- Tu and Yuen Center for Functional Onco-Imaging and Department of Radiological Sciences, University of California Irvine, Irvine, CA, United States
| | - Farouk Nouizi
- Tu and Yuen Center for Functional Onco-Imaging and Department of Radiological Sciences, University of California Irvine, Irvine, CA, United States
| | - David Thayer
- Tu and Yuen Center for Functional Onco-Imaging and Department of Radiological Sciences, University of California Irvine, Irvine, CA, United States
| | - Yuting Lin
- Tu and Yuen Center for Functional Onco-Imaging and Department of Radiological Sciences, University of California Irvine, Irvine, CA, United States
| | - Gultekin Gulsen
- Tu and Yuen Center for Functional Onco-Imaging and Department of Radiological Sciences, University of California Irvine, Irvine, CA, United States ; Department of Biomedical Engineering, University of California Irvine, California 92697
| |
Collapse
|
14
|
Ye J, Chi C, Xue Z, Wu P, An Y, Xu H, Zhang S, Tian J. Fast and robust reconstruction for fluorescence molecular tomography via a sparsity adaptive subspace pursuit method. BIOMEDICAL OPTICS EXPRESS 2014; 5:387-406. [PMID: 24575335 PMCID: PMC3920871 DOI: 10.1364/boe.5.000387] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/25/2013] [Revised: 12/25/2013] [Accepted: 12/27/2013] [Indexed: 05/07/2023]
Abstract
Fluorescence molecular tomography (FMT), as a promising imaging modality, can three-dimensionally locate the specific tumor position in small animals. However, it remains challenging for effective and robust reconstruction of fluorescent probe distribution in animals. In this paper, we present a novel method based on sparsity adaptive subspace pursuit (SASP) for FMT reconstruction. Some innovative strategies including subspace projection, the bottom-up sparsity adaptive approach, and backtracking technique are associated with the SASP method, which guarantees the accuracy, efficiency, and robustness for FMT reconstruction. Three numerical experiments based on a mouse-mimicking heterogeneous phantom have been performed to validate the feasibility of the SASP method. The results show that the proposed SASP method can achieve satisfactory source localization with a bias less than 1mm; the efficiency of the method is much faster than mainstream reconstruction methods; and this approach is robust even under quite ill-posed condition. Furthermore, we have applied this method to an in vivo mouse model, and the results demonstrate the feasibility of the practical FMT application with the SASP method.
Collapse
Affiliation(s)
- Jinzuo Ye
- Key Laboratory of Molecular Imaging of Chinese Academy of Sciences, Institute of Automation, Chinese Academy of Sciences, Beijing 100190, China
| | - Chongwei Chi
- Key Laboratory of Molecular Imaging of Chinese Academy of Sciences, Institute of Automation, Chinese Academy of Sciences, Beijing 100190, China
| | - Zhenwen Xue
- Chengdu Institute of Huawei Technologies Co. Ltd., Chengdu, Sichuan 611731, China
| | - Ping Wu
- Key Laboratory of Molecular Imaging of Chinese Academy of Sciences, Institute of Automation, Chinese Academy of Sciences, Beijing 100190, China
| | - Yu An
- Beijing Jiaotong University, School of Computer and Information Technology, Department of Biomedical Engineering, Beijing 100044, China
| | - Han Xu
- Beijing Jiaotong University, School of Computer and Information Technology, Department of Biomedical Engineering, Beijing 100044, China
| | - Shuang Zhang
- Northeastern University, Sino-Dutch Biomedical and Information Engineering School, Shenyang, Liaoning 110819, China
| | - Jie Tian
- Key Laboratory of Molecular Imaging of Chinese Academy of Sciences, Institute of Automation, Chinese Academy of Sciences, Beijing 100190, China
| |
Collapse
|
15
|
Lin Y, Gao H, Thayer D, Luk AL, Gulsen G. Photo-magnetic imaging: resolving optical contrast at MRI resolution. Phys Med Biol 2013; 58:3551-62. [PMID: 23640084 DOI: 10.1088/0031-9155/58/11/3551] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
In this paper, we establish the mathematical framework of a novel imaging technique, namely photo-magnetic imaging (PMI). PMI uses a laser to illuminate biological tissues and measure the induced temperature variations using magnetic resonance imaging (MRI). PMI overcomes the limitation of conventional optical imaging and allows imaging of the optical contrast at MRI spatial resolution. The image reconstruction for PMI, using a finite-element-based algorithm with an iterative approach, is presented in this paper. The quantitative accuracy of PMI is investigated for various inclusion sizes, depths and absorption values. Then, a comparison between conventional diffuse optical tomography (DOT) and PMI is carried out to illustrate the superior performance of PMI. An example is presented showing that two 2 mm diameter inclusions embedded 4.5 mm deep and located side by side in a 25 mm diameter circular geometry medium are recovered as a single 6 mm diameter object with DOT. However, these two objects are not only effectively resolved with PMI, but their true concentrations are also recovered successfully.
Collapse
Affiliation(s)
- Yuting Lin
- Tu and Yuen Center for Functional Onco-Imaging, Department of Radiological Sciences, University of California, Irvine, CA, USA.
| | | | | | | | | |
Collapse
|
16
|
Piao D, Zhang A, Xu G. Photon diffusion in a homogeneous medium bounded externally or internally by an infinitely long circular cylindrical applicator. V. Steady-state fluorescence. JOURNAL OF THE OPTICAL SOCIETY OF AMERICA. A, OPTICS, IMAGE SCIENCE, AND VISION 2013; 30:791-805. [PMID: 23595341 DOI: 10.1364/josaa.30.000791] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
As Part V in our series, this paper examines steady-state fluorescence photon diffusion in a homogenous medium that contains a homogenous distribution of fluorophores, and is enclosed by a "concave" circular cylindrical applicator or is enclosing a "convex" circular cylindrical applicator, both geometries being infinite in the longitudinal dimension. The aim is to predict by analytics and examine with the finite-element method the changing characteristics of the fluorescence-wavelength photon-fluence rate and the ratio (sometimes called the Born ratio) of it versus the excitation-wavelength photon-fluence rate, with respect to the source-detector distance. The analysis is performed for a source and a detector located on the medium-applicator interface and aligned either azimuthally or longitudinally in both concave and convex geometries. When compared to its steady-state counterparts on a semi-infinite medium-applicator interface with the same line-of-sight source-detector distance, the fluorescence-wavelength photon-fluence rate reduces faster along the longitudinal direction and slower along the azimuthal direction in the concave geometry, and conversely in the convex geometry. However, the Born ratio increases slower in both azimuthal and longitudinal directions in the concave geometry and faster in both directions in the convex geometry, respectively, when compared to that in the semi-infinite geometry.
Collapse
Affiliation(s)
- Daqing Piao
- School of Electrical and Computer Engineering, Oklahoma State University, Stillwater, Oklahoma 74078, USA.
| | | | | |
Collapse
|
17
|
Zhang G, Cao X, Zhang B, Liu F, Luo J, Bai J. MAP estimation with structural priors for fluorescence molecular tomography. Phys Med Biol 2012; 58:351-72. [PMID: 23257468 DOI: 10.1088/0031-9155/58/2/351] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Fluorescence molecular tomography (FMT) is an attractive imaging tool for quantitatively and three-dimensionally resolving fluorophore distributions in small animals, but it suffers from low spatial resolution due to its inherent ill-posed nature. Structural priors obtained from a secondary modality system such as x-ray computed tomography or magnetic resonance imaging can help to improve FMT reconstruction results. However, challenge remains in how to fully take advantage of the structural priors while effectively avoid undesirable influence caused by an immoderate usage. In this paper, we propose a new method to resolve the FMT inverse problem based on maximum a posteriori (MAP) estimation with structural priors (MAP-SP) in a Bayesian framework. Instead of imposing the structural priors directly on the reconstruction results, the MAP-SP method utilizes them to constrain the unknown hyperparameters of the prior information model which is essential for the Bayesian framework. Then, a low dimensional inverse problem and an alternating optimization scheme are used to automatically calculate the unknown hyperparameters, which make the FMT reconstruction process self-adaptive. Simulation and phantom results show that the proposed MAP-SP method can effectively make use of the structural priors and leads to improvements in reconstruction quality as compared with traditional regularization methods.
Collapse
Affiliation(s)
- Guanglei Zhang
- Department of Biomedical Engineering, School of Medicine, Tsinghua University, Beijing 100084, People's Republic of China
| | | | | | | | | | | |
Collapse
|
18
|
Lin Y, Ghijsen M, Nalcioglu O, Gulsen G. In vivo validation of quantitative frequency domain fluorescence tomography. JOURNAL OF BIOMEDICAL OPTICS 2012; 17:126021. [PMID: 23323291 PMCID: PMC3525318 DOI: 10.1117/1.jbo.17.12.126021] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
We have developed a hybrid frequency domain fluorescence tomography and magnetic resonance imaging system (MRI) for small animal imaging. The main purpose of this system is to obtain quantitatively accurate fluorescence concentration and lifetime images using a multi-modality approach. In vivo experiments are undertaken to evaluate the system. We compare the recovered fluorescence parameters with and without MRI structural a priori information. In addition, we compare two optical background heterogeneity correction methods: Born normalization and utilizing diffuse optical tomography (DOT) functional a priori information. The results show that the concentration and lifetime of a 4.2-mm diameter indocyanine green inclusion located 15 mm deep inside a rat can be recovered with less than a 5% error when functional a priori information from DOT and structural a priori information from MRI are utilized.
Collapse
Affiliation(s)
- Yuting Lin
- University of California, Tu and Yuen Center for Functional Onco-Imaging, Department of Radiological Sciences, 164 Irvine Hall, Irvine, California 92697
| | - Michael Ghijsen
- University of California, Tu and Yuen Center for Functional Onco-Imaging, Department of Radiological Sciences, 164 Irvine Hall, Irvine, California 92697
| | - Orhan Nalcioglu
- University of California, Tu and Yuen Center for Functional Onco-Imaging, Department of Radiological Sciences, 164 Irvine Hall, Irvine, California 92697
| | - Gultekin Gulsen
- University of California, Tu and Yuen Center for Functional Onco-Imaging, Department of Radiological Sciences, 164 Irvine Hall, Irvine, California 92697
- Address all correspondence to: Gultekin Gulsen, University of California, Tu and Yuen Center for Functional Onco-Imaging, 164 Irvine Hall, Irvine, California 92697. Tel: 949 824 6557; Fax: 949 824 3481; E-mail:
| |
Collapse
|
19
|
Darne CD, Lu Y, Tan IC, Zhu B, Rasmussen JC, Smith AM, Yan S, Sevick-Muraca EM. A compact frequency-domain photon migration system for integration into commercial hybrid small animal imaging scanners for fluorescence tomography. Phys Med Biol 2012; 57:8135-52. [PMID: 23171509 DOI: 10.1088/0031-9155/57/24/8135] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
The work presented herein describes the system design and performance evaluation of a miniaturized near-infrared fluorescence (NIRF) frequency-domain photon migration (FDPM) system with non-contact excitation and homodyne detection capability for small animal fluorescence tomography. The FDPM system was developed specifically for incorporation into a Siemens micro positron emission tomography/computed tomography (microPET/CT) commercial scanner for hybrid small animal imaging, but could be adapted to other systems. Operating at 100 MHz, the system noise was minimized and the associated amplitude and phase errors were characterized to be ±0.7% and ±0.3°, respectively. To demonstrate the tomographic ability, a commercial mouse-shaped phantom with 50 µM IRDye800CW and ⁶⁸Ga containing inclusion was used to associate PET and NIRF tomography. Three-dimensional mesh generation and anatomical referencing was accomplished through CT. A third-order simplified spherical harmonics approximation (SP₃) algorithm, for efficient prediction of light propagation in small animals, was tailored to incorporate the FDPM approach. Finally, the PET-NIRF target co-localization accuracy was analyzed in vivo with a dual-labeled imaging agent targeting orthotopic growth of human prostate cancer. The obtained results validate the integration of time-dependent fluorescence tomography system within a commercial microPET/CT scanner for multimodality small animal imaging.
Collapse
Affiliation(s)
- Chinmay D Darne
- Center for Molecular Imaging, The Brown Foundation Institute of Molecular Medicine, University of Texas Health Science Center at Houston, 1825 Pressler Street, Houston, TX 77030, USA
| | | | | | | | | | | | | | | |
Collapse
|
20
|
Yi H, Chen D, Qu X, Peng K, Chen X, Zhou Y, Tian J, Liang J. Multilevel, hybrid regularization method for reconstruction of fluorescent molecular tomography. APPLIED OPTICS 2012; 51:975-86. [PMID: 22410902 DOI: 10.1364/ao.51.000975] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/01/2011] [Accepted: 11/19/2011] [Indexed: 05/20/2023]
Abstract
In this paper, a multilevel, hybrid regularization method is presented for fluorescent molecular tomography (FMT) based on the hp-finite element method (hp-FEM) with a continuous wave. The hybrid regularization method combines sparsity regularization and Landweber iterative regularization to improve the stability of the solution of the ill-posed inverse problem. In the first coarse mesh level, considering the fact that the fluorescent probes are sparsely distributed in the entire reconstruction region in most FMT applications, the sparse regularization method is employed to take full advantage of this sparsity. In the subsequent refined mesh levels, since the reconstruction region is reduced and the initial value of the unknown parameters is provided from the previous mesh, these mesh levels seem to be different from the first level. As a result, the Landweber iterative regularization method is applied for reconstruction. Simulation experiments on a 3D digital mouse atlas and physical experiments on a phantom are conducted to evaluate the performance of our method. The reconstructed results show the potential and feasibility of the proposed approach.
Collapse
Affiliation(s)
- Huangjian Yi
- Life Sciences Research Center, School of Life Sciences and Technology, Xidian University, Xi'an, Shaanxi 710071, China
| | | | | | | | | | | | | | | |
Collapse
|
21
|
Abascal JFPJ, Aguirre J, Chamorro-Servent J, Schweiger M, Arridge S, Ripoll J, Vaquero JJ, Desco M. Influence of absorption and scattering on the quantification of fluorescence diffuse optical tomography using normalized data. JOURNAL OF BIOMEDICAL OPTICS 2012; 17:036013. [PMID: 22502571 DOI: 10.1117/1.jbo.17.3.036013] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Reconstruction algorithms for imaging fluorescence in near infrared ranges usually normalize fluorescence light with respect to excitation light. Using this approach, we investigated the influence of absorption and scattering heterogeneities on quantification accuracy when assuming a homogeneous model and explored possible reconstruction improvements by using a heterogeneous model. To do so, we created several computer-simulated phantoms: a homogeneous slab phantom (P1), slab phantoms including a region with a two- to six-fold increase in scattering (P2) and in absorption (P3), and an atlas-based mouse phantom that modeled different liver and lung scattering (P4). For P1, reconstruction with the wrong optical properties yielded quantification errors that increased almost linearly with the scattering coefficient while they were mostly negligible regarding the absorption coefficient. This observation agreed with the theoretical results. Taking the quantification of a homogeneous phantom as a reference, relative quantification errors obtained when wrongly assuming homogeneous media were in the range +41 to +94% (P2), 0.1 to -7% (P3), and -39 to +44% (P4). Using a heterogeneous model, the overall error ranged from -7 to 7%. In conclusion, this work demonstrates that assuming homogeneous media leads to noticeable quantification errors that can be improved by adopting heterogeneous models.
Collapse
|
22
|
Li B, Abran M, Matteau-Pelletier C, Rouleau L, Lam T, Sharma R, Rhéaume E, Kakkar A, Tardif JC, Lesage F. Low-cost three-dimensional imaging system combining fluorescence and ultrasound. JOURNAL OF BIOMEDICAL OPTICS 2011; 16:126010. [PMID: 22191927 DOI: 10.1117/1.3662455] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
In this paper, we present a dual-modality imaging system combining three-dimensional (3D) continuous-wave transillumination fluorescence tomography with 3D ultrasound (US) imaging. We validated the system with two phantoms, one containing fluorescent inclusions (Cy5.5) at different depths, and another varying-thickness semicylindrical phantom. Using raster scanning, the combined fluorescence/US system was used to collect the boundary fluorescent emission in the X-Y plane, as well as recovered the 3D surface and position of the inclusions from US signals. US images were segmented to provide soft priors for the fluorescence image reconstruction. Phantom results demonstrated that with priors derived from the US images, the fluorescent reconstruction quality was significantly improved. As further evaluation, we show pilot in vivo results using an Apo-E mouse to assess the feasibility and performance of this system in animal studies. Limitations and potential to be used in artherosclerosis studies are then discussed.
Collapse
Affiliation(s)
- Baoqiang Li
- École Polytechnique de Montréal, Institute of Biomedical Engineering, Montreal, H3C 3A7, Canada
| | | | | | | | | | | | | | | | | | | |
Collapse
|
23
|
Ardeshirpour Y, Chernomordik V, Capala J, Hassan M, Zielinsky R, Griffiths G, Achilefu S, Smith P, Gandjbakhckhe A. Using in-vivo fluorescence imaging in personalized cancer diagnostics and therapy, an image and treat paradigm. Technol Cancer Res Treat 2011; 10:549-60. [PMID: 22066595 PMCID: PMC3718028 DOI: 10.1177/153303461101000605] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
The major goal in developing drugs targeting specific tumor receptors, such as Monoclonal AntiBodies (MAB), is to make a drug compound that targets selectively the cancer-causing biomarkers, inhibits their functionality, and/or delivers the toxin specifically to the malignant cells. Recent advances in MABs show that their efficacy depends strongly on characterization of tumor biomarkers. Therefore, one of the main tasks in cancer diagnostics and treatment is to develop non-invasive in-vivo imaging techniques for detection of cancer biomarkers and monitoring their down regulation during the treatment. Such methods can potentially result in a new imaging and treatment paradigm for cancer therapy. In this article we have reviewed fluorescence imaging approaches, including those developed in our group, to detect and monitor Human Epidermal Growth Factor 2 (HER2) receptors before and during therapy. Transition of these techniques from the bench to bedside is the ultimate goal of our project. Similar approaches can be used potentially for characterization of other cancer related cell biomarkers.
Collapse
Affiliation(s)
- Yasaman Ardeshirpour
- NIH/National Institute of Child Health and Human Development, Building 9, 9 Memorial Dr., Bethesda, MD, 20892
| | - Victor Chernomordik
- NIH/National Institute of Child Health and Human Development, Building 9, 9 Memorial Dr., Bethesda, MD, 20892
| | - Jacek Capala
- NIH/National Cancer Institute, Building 10-Magnuson Clinical Center, 10 Center Dr, Bethesda, MD, 20892
| | - Moinuddin Hassan
- NIH/National Institute of Child Health and Human Development, Building 9, 9 Memorial Dr., Bethesda, MD, 20892
| | - Rafal Zielinsky
- NIH/National Cancer Institute, Building 10-Magnuson Clinical Center, 10 Center Dr, Bethesda, MD, 20892
| | - Gary Griffiths
- NIH/Imaging Probe Development Center, Building 9800, Medical Center Dr., Rockville, MD, 20850
| | - Samuel Achilefu
- Optical Radiology Lab, Department of Radiology, Washington University, 4525 Scott Avenue, St. Louis, MO 63110
| | - Paul Smith
- NIH/National Institute of Biomedical Imaging and Bioengineering, Building 13, 3N18A 13 South Dr, Bethesda, MD, 20892
| | - Amir Gandjbakhckhe
- NIH/National Institute of Child Health and Human Development, Building 9, 9 Memorial Dr., Bethesda, MD, 20892
| |
Collapse
|
24
|
Fu J, Yang X, Wang K, Luo Q, Gong H. A generic, geometric cocalibration method for a combined system of fluorescence molecular tomography and microcomputed tomography with arbitrarily shaped objects. Med Phys 2011; 38:6561-70. [DOI: 10.1118/1.3658727] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
|
25
|
Zhang B, Cao X, Liu F, Liu X, Wang X, Bai J. Early-photon fluorescence tomography of a heterogeneous mouse model with the telegraph equation. APPLIED OPTICS 2011; 50:5397-5407. [PMID: 22016206 DOI: 10.1364/ao.50.005397] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
In this study, we investigate the performance of early-photon fluorescence tomography based on a heterogeneous mouse model. The telegraph equation is used to accurately describe the propagation of light in tissues at short times. The optimal time gate for early photons is determined by singular value analysis at first. Then, fluorescent targets located in different organs of the mouse model are investigated. The simulation results demonstrate that the reconstructed tomographic images based on early photons yield improvement in spatial resolution and quantification than the quasi-CW measurements. Meanwhile, compared with the homogeneous model, the use of the heterogeneous model can improve the accuracy of fluorescence distribution and quantification in early-photon fluorescence tomography.
Collapse
Affiliation(s)
- Bin Zhang
- Department of Biomedical Engineering, Tsinghua University, Beijing, China
| | | | | | | | | | | |
Collapse
|
26
|
Zhang X, Badea C, Hood G, Wetzel A, Qi Y, Stiles J, Johnson GA. High-resolution reconstruction of fluorescent inclusions in mouse thorax using anatomically guided sampling and parallel Monte Carlo computing. BIOMEDICAL OPTICS EXPRESS 2011; 2:2449-60. [PMID: 21991539 PMCID: PMC3184855 DOI: 10.1364/boe.2.002449] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/23/2011] [Revised: 07/25/2011] [Accepted: 07/28/2011] [Indexed: 05/03/2023]
Abstract
We present a method for high-resolution reconstruction of fluorescent images of the mouse thorax. It features an anatomically guided sampling method to retrospectively eliminate problematic data and a parallel Monte Carlo software package to compute the Jacobian matrix for the inverse problem. The proposed method was capable of resolving microliter-sized femtomole amount of quantum dot inclusions closely located in the middle of the mouse thorax. The reconstruction was verified against co-registered micro-CT data. Using the proposed method, the new system achieved significantly higher resolution and sensitivity compared to our previous system consisting of the same hardware. This method can be applied to any system utilizing similar imaging principles to improve imaging performance.
Collapse
Affiliation(s)
- Xiaofeng Zhang
- Center for In Vivo Microscopy, Department of Radiology, Duke University Medical Center, Durham, NC 27710, USA
| | - Cristian Badea
- Center for In Vivo Microscopy, Department of Radiology, Duke University Medical Center, Durham, NC 27710, USA
| | - Greg Hood
- National Resource for Biomedical Supercomputing, Pittsburgh Supercomputing Center, Carnegie Mellon University, Pittsburgh, PA 15213, USA
| | - Arthur Wetzel
- National Resource for Biomedical Supercomputing, Pittsburgh Supercomputing Center, Carnegie Mellon University, Pittsburgh, PA 15213, USA
| | - Yi Qi
- Center for In Vivo Microscopy, Department of Radiology, Duke University Medical Center, Durham, NC 27710, USA
| | - Joel Stiles
- National Resource for Biomedical Supercomputing, Pittsburgh Supercomputing Center, Carnegie Mellon University, Pittsburgh, PA 15213, USA
| | - G. Allan Johnson
- Center for In Vivo Microscopy, Department of Radiology, Duke University Medical Center, Durham, NC 27710, USA
| |
Collapse
|
27
|
Lin Y, Ghijsen MT, Gao H, Liu N, Nalcioglu O, Gulsen G. A photo-multiplier tube-based hybrid MRI and frequency domain fluorescence tomography system for small animal imaging. Phys Med Biol 2011; 56:4731-47. [PMID: 21753235 PMCID: PMC3961472 DOI: 10.1088/0031-9155/56/15/007] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Fluorescence tomography (FT) is a promising molecular imaging technique that can spatially resolve both fluorophore concentration and lifetime parameters. However, recovered fluorophore parameters highly depend on the size and depth of the object due to the ill-posedness of the FT inverse problem. Structural a priori information from another high spatial resolution imaging modality has been demonstrated to significantly improve FT reconstruction accuracy. In this study, we have constructed a combined magnetic resonance imaging (MRI) and FT system for small animal imaging. A photo-multiplier tube is used as the detector to acquire frequency domain FT measurements. This is the first MR-compatible time-resolved FT system that can reconstruct both fluorescence concentration and lifetime maps simultaneously. The performance of the hybrid system is evaluated with phantom studies. Two different fluorophores, indocyanine green and 3-3' diethylthiatricarbocyanine iodide, which have similar excitation and emission spectra but different lifetimes, are utilized. The fluorescence concentration and lifetime maps are both reconstructed with and without the structural a priori information obtained from MRI for comparison. We show that the hybrid system can accurately recover both fluorescence intensity and lifetime within 10% error for two 4.2 mm-diameter cylindrical objects embedded in a 38 mm-diameter cylindrical phantom when MRI structural a priori information is utilized.
Collapse
Affiliation(s)
- Y Lin
- Tu and Yuen Center for Functional Onco Imaging, University of California, Irvine, CA, 92697, USA
| | - M T Ghijsen
- Tu and Yuen Center for Functional Onco Imaging, University of California, Irvine, CA, 92697, USA
| | - H Gao
- Department of Mathematics, University of California, Los Angeles, CA 90095, USA
| | - N Liu
- Tu and Yuen Center for Functional Onco Imaging, University of California, Irvine, CA, 92697, USA
| | - O Nalcioglu
- Tu and Yuen Center for Functional Onco Imaging, University of California, Irvine, CA, 92697, USA
- Department of Cogno-Mechatronics Engineering, Pusan National University, Pusan, Korea
| | - G Gulsen
- Tu and Yuen Center for Functional Onco Imaging, University of California, Irvine, CA, 92697, USA
| |
Collapse
|
28
|
Aksel EB, Turkoglu AN, Ercan AE, Akin A. Localization of an absorber in a turbid semi-infinite medium by spatially resolved continuous-wave diffuse reflectance measurements. JOURNAL OF BIOMEDICAL OPTICS 2011; 16:086010. [PMID: 21895322 DOI: 10.1117/1.3615238] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
A method to locate an absorber embedded in a semi-infinite turbid medium by spatially-resolved continuous-wave (SRCW) diffuse reflectance measurements is introduced. The depth of the absorber is assessed by single wavelength SRCW diffuse reflectance measurements by two detectors in a radial row. The ratio of perturbations introduced by the defect at two detectors is used to be matched with the ratio-versus-depth curve, which are generated by approximate formulas of continuous wave diffuse reflectance. The error due to approximation and the error in depth assessment are studied for different cases revealing favorable source-detector placements with respect to planar position of the defect. The effect of lateral displacement of the source with respect to defect is studied. A strategy to overcome errors introduced by erroneous prediction of background medium optical properties is suggested. Theoretical results indicate that the depth of the absorber can be obtained with 0.1 mm precision independent of its absorption coefficient and its size for the values chosen in the study. The approach is tested experimentally and it is observed that theoretical results fit with experimental data.
Collapse
|
29
|
Optimal analysis method for dynamic contrast-enhanced diffuse optical tomography. Int J Biomed Imaging 2011; 2011:426503. [PMID: 21811492 PMCID: PMC3147123 DOI: 10.1155/2011/426503] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2011] [Accepted: 05/11/2011] [Indexed: 01/16/2023] Open
Abstract
Diffuse Optical Tomography (DOT) is an optical imaging modality that has various clinical applications. However, the spatial resolution and quantitative accuracy of DOT is poor due to strong photon scatting in biological tissue. Structural a priori information from another high spatial resolution imaging modality such as Magnetic Resonance Imaging (MRI) has been demonstrated to significantly improve DOT accuracy. In addition, a contrast agent can be used to obtain differential absorption images of the lesion by using dynamic contrast enhanced DOT (DCE-DOT). This produces a relative absorption map that consists of subtracting a reconstructed baseline image from reconstructed images in which optical contrast is included. In this study, we investigated and compared different reconstruction methods and analysis approaches for regular endogenous DOT and DCE-DOT with and without MR anatomical a priori information for arbitrarily-shaped objects. Our phantom and animal studies have shown that superior image quality and higher accuracy can be achieved using DCE-DOT together with MR structural a priori information. Hence, implementation of a combined MRI-DOT system to image ICG enhancement can potentially be a promising tool for breast cancer imaging.
Collapse
|
30
|
Fluorescence molecular tomography: principles and potential for pharmaceutical research. Pharmaceutics 2011; 3:229-74. [PMID: 24310495 PMCID: PMC3864234 DOI: 10.3390/pharmaceutics3020229] [Citation(s) in RCA: 92] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2011] [Revised: 04/07/2011] [Accepted: 04/15/2011] [Indexed: 11/17/2022] Open
Abstract
Fluorescence microscopic imaging is widely used in biomedical research to study molecular and cellular processes in cell culture or tissue samples. This is motivated by the high inherent sensitivity of fluorescence techniques, the spatial resolution that compares favorably with cellular dimensions, the stability of the fluorescent labels used and the sophisticated labeling strategies that have been developed for selectively labeling target molecules. More recently, two and three-dimensional optical imaging methods have also been applied to monitor biological processes in intact biological organisms such as animals or even humans. These whole body optical imaging approaches have to cope with the fact that biological tissue is a highly scattering and absorbing medium. As a consequence, light propagation in tissue is well described by a diffusion approximation and accurate reconstruction of spatial information is demanding. While in vivo optical imaging is a highly sensitive method, the signal is strongly surface weighted, i.e., the signal detected from the same light source will become weaker the deeper it is embedded in tissue, and strongly depends on the optical properties of the surrounding tissue. Derivation of quantitative information, therefore, requires tomographic techniques such as fluorescence molecular tomography (FMT), which maps the three-dimensional distribution of a fluorescent probe or protein concentration. The combination of FMT with a structural imaging method such as X-ray computed tomography (CT) or Magnetic Resonance Imaging (MRI) will allow mapping molecular information on a high definition anatomical reference and enable the use of prior information on tissue's optical properties to enhance both resolution and sensitivity. Today many of the fluorescent assays originally developed for studies in cellular systems have been successfully translated for experimental studies in animals. The opportunity of monitoring molecular processes non-invasively in the intact organism is highly attractive from a diagnostic point of view but even more so for the drug developer, who can use the techniques for proof-of-mechanism and proof-of-efficacy studies. This review shall elucidate the current status and potential of fluorescence tomography including recent advances in multimodality imaging approaches for preclinical and clinical drug development.
Collapse
|
31
|
Ardeshirpour Y, Biswal N, Aguirre A, Zhu Q. Artifact reduction method in ultrasound-guided diffuse optical tomography using exogenous contrast agents. JOURNAL OF BIOMEDICAL OPTICS 2011; 16:046015. [PMID: 21529084 PMCID: PMC3094466 DOI: 10.1117/1.3569088] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/16/2010] [Revised: 01/29/2011] [Accepted: 02/22/2011] [Indexed: 05/18/2023]
Abstract
In diffuse optical tomography (DOT), a typical perturbation approach requires two sets of measurements obtained at the lesion breast (lesion or target site) and a contra-lateral location of the normal breast (reference site) for image reconstruction. For patients who have a small amount of breast tissue, the chest-wall underneath the breast tissue at both sites affects the imaging results. In this group of patients, the perturbation, which is the difference between measurements obtained at the lesion and reference sites, may include the information of background mismatch which can generate artifacts or affect the reconstructed quantitative absorption coefficient of the lesion. Also, for patients who have a single breast due to prior surgery, the contra-lateral reference is not available. To improve the DOT performance or overcome its limitation, we introduced a new method based on an exogenous contrast agent and demonstrate its performance using animal models. Co-registered ultrasound was used to guide the lesion localization. The results have shown that artifacts caused by background mismatch can be reduced significantly by using this new method.
Collapse
Affiliation(s)
- Yasaman Ardeshirpour
- Electrical and Computer Engineering Department, University of Connecticut, Storrs, Connecticut 06269, USA
| | | | | | | |
Collapse
|
32
|
Liu X, Liu F, Bai J. A linear correction for principal component analysis of dynamic fluorescence diffuse optical tomography images. IEEE Trans Biomed Eng 2011; 58:1602-11. [PMID: 21245001 DOI: 10.1109/tbme.2011.2106501] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The analysis of dynamic fluorescence diffuse optical tomography (D-FDOT) is important both for drug delivery research and for medical diagnosis and treatment. The low spatial resolution and complex kinetics, however, limit the ability of FDOT in resolving drug distributions within small animals. Principal component analysis (PCA) provides the capability of detecting and visualizing functional structures with different kinetic patterns from D-FDOT images. A particular challenge in using PCA is to reduce the level of noise in D-FDOT images. This is particularly relevant in drug study, where the time-varying fluorophore concentration (drug concentration) will result in the reconstructed images containing more noise and, therefore, affect the performance of PCA. In this paper, a new linear corrected method is proposed for modeling these time-varying fluorescence measurements before performing PCA. To evaluate the performance of the new method in resolving drug biodistribution, the metabolic processes of indocyanine green within mouse is dynamically simulated and used as the input data of PCA. Simulation results suggest that the principal component (PC) images generated using the new method improve SNR and discrimination capability, compared to the PC images generated using the uncorrected D-FDOT images.
Collapse
Affiliation(s)
- Xin Liu
- Department of Biomedical Engineering, School of Medicine, Tsinghua University, Beijing, China
| | | | | |
Collapse
|
33
|
Liu K, Lu Y, Tian J, Qin C, Yang X, Zhu S, Yang X, Gao Q, Han D. Evaluation of the simplified spherical harmonics approximation in bioluminescence tomography through heterogeneous mouse models. OPTICS EXPRESS 2010; 18:20988-1002. [PMID: 20940994 DOI: 10.1364/oe.18.020988] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
In vivo bioluminescence imaging (BLI) has played a more and more important role in biomedical research of small animals. Bioluminescence tomography (BLT) further translates the BLI optical information into three-dimensional bioluminescent source distribution, which could greatly facilitate applications in related studies. Although the diffusion approximation (DA) is one of the most widely-used forward models, higher-order approximations are still needed for in vivo small animal imaging. In this work, as a relatively accurate and higher-order approximation theory, the performance of the simplified spherical harmonics approximation (SPN) in BLT is evaluated detailedly in heterogeneous small animals. In the numerical validations, the SPN based results demonstrate better imaging quality compared with diffusion approximation heterogeneously under various source locations over wide optical domain. Although the evaluation for the effects of the optical property mismatch indicates the sensitivity of SPN is similar with DA model in the source localization, it may offer improved performance with much less artifacts. In what follows, heterogeneous experimental BLT reconstructions using in vivo mouse further evaluate the capability of the higher-order method for practical biomedical applications.
Collapse
Affiliation(s)
- Kai Liu
- Medical Image Processing Group, Institute of Automation, Chinese Academy of Sciences, Beijing 100190, China
| | | | | | | | | | | | | | | | | |
Collapse
|
34
|
Guo X, Liu X, Wang X, Tian F, Liu F, Zhang B, Hu G, Bai J. A combined fluorescence and microcomputed tomography system for small animal imaging. IEEE Trans Biomed Eng 2010; 57:2876-83. [PMID: 20833597 DOI: 10.1109/tbme.2010.2073468] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Fluorescence molecular tomography (FMT) plays an important role in studying physiological and pathological processes of small animals in vivo at molecular level. However, this technique suffers from relatively low spatial resolution. To complement the problem, there has been a strong demand for providing functional and morphological analysis at the same time. In this paper, we proposed a hybrid full-angle free-space FMT and X-ray micro-cone-beam computed tomography (CT) (micro-CBCT) prototype system, providing both functional and anatomical images. During the whole acquisition, the two subsystems acquire projection images (fluorescence and CT) synchronously to keep consistent body position without moving the animals. The acquired datasets are intrinsically coregistered in the corresponding coordinate and identified geometry. Tomographic fluorescence and CT images are reconstructed using normalized Born-based spatial regularization and Feldkamp-Davis-Kress methods, respectively. The experimental results of both phantom and in vivo mouse preliminarily validate the accuracy and performance of the integrated system.
Collapse
Affiliation(s)
- Xiaolian Guo
- Department of Biomedical Engineering, School of Medicine, Tsinghua University, Beijing, China.
| | | | | | | | | | | | | | | |
Collapse
|
35
|
Li M, Zhang Y, Bai J. In Vivo Diffuse Optical Tomography and Fluorescence Molecular Tomography. JOURNAL OF HEALTHCARE ENGINEERING 2010. [DOI: 10.1260/2040-2295.1.3.477] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
|
36
|
Davis SC, Samkoe KS, O'Hara JA, Gibbs-Strauss SL, Paulsen KD, Pogue BW. Comparing implementations of magnetic-resonance-guided fluorescence molecular tomography for diagnostic classification of brain tumors. JOURNAL OF BIOMEDICAL OPTICS 2010; 15:051602. [PMID: 21054076 PMCID: PMC2951993 DOI: 10.1117/1.3483902] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/14/2010] [Revised: 05/10/2010] [Accepted: 05/17/2010] [Indexed: 05/25/2023]
Abstract
Fluorescence molecular tomography (FMT) systems coupled to conventional imaging modalities such as magnetic resonance imaging (MRI) and computed tomography provide unique opportunities to combine data sets and improve image quality and content. Yet, the ideal approach to combine these complementary data is still not obvious. This preclinical study compares several methods for incorporating MRI spatial prior information into FMT imaging algorithms in the context of in vivo tissue diagnosis. Populations of mice inoculated with brain tumors that expressed either high or low levels of epidermal growth factor receptor (EGFR) were imaged using an EGF-bound near-infrared dye and a spectrometer-based MRI-FMT scanner. All data were spectrally unmixed to extract the dye fluorescence from the tissue autofluorescence. Methods to combine the two data sets were compared using student's t-tests and receiver operating characteristic analysis. Bulk fluorescence measurements that made up the optical imaging data set were also considered in the comparison. While most techniques were able to distinguish EGFR(+) tumors from EGFR(-) tumors and control animals, with area-under-the-curve values=1, only a handful were able to distinguish EGFR(-) tumors from controls. Bulk fluorescence spectroscopy techniques performed as well as most imaging techniques, suggesting that complex imaging algorithms may be unnecessary to diagnose EGFR status in these tissue volumes.
Collapse
Affiliation(s)
- Scott C Davis
- Dartmouth College, Thayer School of Engineering, HB 8000, Hanover, New Hampshire 03755, USA.
| | | | | | | | | | | |
Collapse
|
37
|
Gorpas D, Yova D, Politopoulos K. A priori fluorophore distribution estimation in fluorescence imaging through application of a segmentation process and a data fitting technique. Comput Med Imaging Graph 2010; 34:435-45. [DOI: 10.1016/j.compmedimag.2009.12.010] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2009] [Revised: 11/25/2009] [Accepted: 12/09/2009] [Indexed: 11/27/2022]
|
38
|
Ge J, Erickson SJ, Godavarty A. Multi-projection fluorescence optical tomography using a handheld-probe-based optical imager: phantom studies. APPLIED OPTICS 2010; 49:4343-4354. [PMID: 20697435 PMCID: PMC2975621 DOI: 10.1364/ao.49.004343] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
A handheld-probe-based optical imager has recently been developed toward three-dimensional tomography. In this study, the improvement of target depth recovery was demonstrated using a multi-projection technique on large slab phantoms using 0.45 cc fluorescing target(s) (with 1:0 contrast ratio) of 1.5 to 2.5 cm deep. Tomographic results using single- and multi- (here dual) projection measurements (with and without a priori information of target location) were compared. In all experimental cases, the use of multi-projection measurements along with a priori information recovered target depth and location closer to their true values, demonstrating its applicability for clinical translation.
Collapse
|
39
|
|
40
|
Lin Y, Barber WC, Iwanczyk JS, Roeck WW, Nalcioglu O, Gulsen G. Quantitative fluorescence tomography using a trimodality system: in vivo validation. JOURNAL OF BIOMEDICAL OPTICS 2010; 15:040503. [PMID: 20799770 PMCID: PMC2937044 DOI: 10.1117/1.3467495] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/23/2010] [Revised: 06/23/2010] [Accepted: 06/25/2010] [Indexed: 05/25/2023]
Abstract
A fully integrated trimodality fluorescence, diffuse optical, and x-ray computed tomography (FT/DOT/XCT) system for small animal imaging is reported in this work. The main purpose of this system is to obtain quantitatively accurate fluorescence concentration images using a multimodality approach. XCT offers anatomical information, while DOT provides the necessary background optical property map to improve FT image accuracy. The quantitative accuracy of this trimodality system is demonstrated in vivo. In particular, we show that a 2-mm-diam fluorescence inclusion located 8 mm deep in a nude mouse can only be localized when functional a priori information from DOT is available. However, the error in the recovered fluorophore concentration is nearly 87%. On the other hand, the fluorophore concentration can be accurately recovered within 2% error when both DOT functional and XCT structural a priori information are utilized together to guide and constrain the FT reconstruction algorithm.
Collapse
|
41
|
Freyer M, Ale A, Schulz RB, Zientkowska M, Ntziachristos V, Englmeier KH. Fast automatic segmentation of anatomical structures in x-ray computed tomography images to improve fluorescence molecular tomography reconstruction. JOURNAL OF BIOMEDICAL OPTICS 2010; 15:036006. [PMID: 20615008 DOI: 10.1117/1.3431101] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
The recent development of hybrid imaging scanners that integrate fluorescence molecular tomography (FMT) and x-ray computed tomography (XCT) allows the utilization of x-ray information as image priors for improving optical tomography reconstruction. To fully capitalize on this capacity, we consider a framework for the automatic and fast detection of different anatomic structures in murine XCT images. To accurately differentiate between different structures such as bone, lung, and heart, a combination of image processing steps including thresholding, seed growing, and signal detection are found to offer optimal segmentation performance. The algorithm and its utilization in an inverse FMT scheme that uses priors is demonstrated on mouse images.
Collapse
Affiliation(s)
- Marcus Freyer
- Technical University Munich, Biological Imaging, Munich, Germany.
| | | | | | | | | | | |
Collapse
|
42
|
Yang X, Gong H, Quan G, Deng Y, Luo Q. Combined system of fluorescence diffuse optical tomography and microcomputed tomography for small animal imaging. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2010; 81:054304. [PMID: 20515159 DOI: 10.1063/1.3422252] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
We developed a dual-modality system that combines fluorescence diffuse optical tomography (fDOT) and flat panel detector-based microcomputed tomography (micro-CT) to simultaneously reveal molecular and structural information in small animals. In fDOT, a 748 nm diode laser was used as an excitation source, while a cooled charge coupled device camera was adopted to collect transmission fluorescence. In micro-CT, a flat panel detector based on amorphous silicon, with active area of 13 x 13 cm(2), and a microfocus x-ray tube were used. The fDOT system was mounted orthogonally to the micro-CT and the projection images were acquired without rotation of the sample, which is different from the method used for micro-CT alone. Both the finite element method and the algebraic reconstruction technique were used to reconstruct images from the fDOT. Phantom data showed that the resolution of the fDOT system was about 3 mm at an imaging depth of 7 mm. Quantitative error was no more than 5% and imaging sensitivity for 1,1(')-dioctadecyl-3,3,3('),3(')-etramethylindotricarbocyanine iodide bis-oleate (DiR-BOA) was estimated to be higher than 100 nM at a depth of 7 mm. Calculations of the phantom's center of mass showed that the location accuracy of fDOT was about 0.7 mm. We applied a Feldkamp algorithm to reconstruct the micro-CT image. By measuring the presampled modulation transfer function with a 30 microm tungsten thread, we estimated that the micro-CT has a resolution of 5 mm(-1) when the field of view was 6.5 cm. Our results indicate the uniformity of the transaxial micro-CT image and the contrast-to-noise ratio was measured as 1.95 for a radiation dose of 1 cGy. A non-image-based method was employed for merging images from the two imaging modalities. A nude mouse with DiR-BOA, imaged ex vivo, was used to validate the feasibility of the dual-modality system.
Collapse
Affiliation(s)
- Xiaoquan Yang
- Britton Chance Center for Biomedical Photonics, Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan 430074, People's Republic of China
| | | | | | | | | |
Collapse
|
43
|
Barber WC, Lin Y, Nalcioglu O, Iwanczyk JS, Hartsough NE, Gulsen G. Combined fluorescence and X-Ray tomography for quantitative in vivo detection of fluorophore. Technol Cancer Res Treat 2010; 9:45-52. [PMID: 20082529 DOI: 10.1177/153303461000900105] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Initial results from a novel dual modality preclinical imager which combines non-contact fluorescence tomography (FT) and x-ray computed tomography (CT) for preclinical functional and anatomical in vivo imaging are presented. The anatomical data from CT provides a priori information to the FT reconstruction to create overlaid functional and anatomical images with accurate localization and quantification of fluorophore distribution. Phantoms with inclusions containing Indocyanine-Green (ICG), and with heterogeneous backgrounds including iodine in compartments at different concentrations for CT contrast, have been imaged with the dual modality FT/CT system. Anatomical information from attenuation maps and optical morphological information from absorption and scattering maps are used as a priori information in the FT reconstruction. Although ICG inclusions can be located without the a priori information, the recovered ICG concentration shows 75% error. When the a priori information is utilized, the ICG concentration can be recovered with only 15% error. Developing the ability to accurately quantify fluorophore concentration in anatomical regions of interest may provide a powerful tool for in vivo small animal imaging.
Collapse
Affiliation(s)
- W C Barber
- DxRay Inc., 19355 Business Center Dr. Suite 10, Northridge, CA 91324, USA.
| | | | | | | | | | | |
Collapse
|
44
|
Lin Y, Barber WC, Iwanczyk JS, Roeck W, Nalcioglu O, Gulsen G. Quantitative fluorescence tomography using a combined tri-modality FT/DOT/XCT system. OPTICS EXPRESS 2010; 18:7835-50. [PMID: 20588625 PMCID: PMC2898749 DOI: 10.1364/oe.18.007835] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/18/2009] [Revised: 03/02/2010] [Accepted: 03/10/2010] [Indexed: 05/20/2023]
Abstract
In this work, a first-of-its-kind fully integrated tri-modality system that combines fluorescence, diffuse optical and x-ray tomography (FT/DOT/XCT) into the same setting is presented. The purpose of this system is to perform quantitative fluorescence tomography using multi-modality imaging approach. XCT anatomical information is used as structural priori while optical background heterogeneity information obtained by DOT measurements is used as functional priori. The performance of the hybrid system is evaluated using multi-modality phantoms. In particular, we show that a 2.4 mm diameter fluorescence inclusion located in a heterogeneous medium can be localized accurately with the functional a priori information, although the fluorophore concentration is recovered with 70% error. On the other hand, the fluorophore concentration can be accurately recovered within 8% error only when both DOT optical background functional and XCT structural a priori information are utilized to guide and constrain the FT reconstruction algorithm.
Collapse
Affiliation(s)
- Yuting Lin
- Tu and Yuen Center for Functional Onco-Imaging, University of California, Irvine, CA 92697
USA
| | | | | | - Werner Roeck
- Tu and Yuen Center for Functional Onco-Imaging, University of California, Irvine, CA 92697
USA
| | - Orhan Nalcioglu
- Tu and Yuen Center for Functional Onco-Imaging, University of California, Irvine, CA 92697
USA
| | - Gultekin Gulsen
- Tu and Yuen Center for Functional Onco-Imaging, University of California, Irvine, CA 92697
USA
| |
Collapse
|
45
|
Schulz RB, Ale A, Sarantopoulos A, Freyer M, Soehngen E, Zientkowska M, Ntziachristos V. Hybrid system for simultaneous fluorescence and x-ray computed tomography. IEEE TRANSACTIONS ON MEDICAL IMAGING 2010; 29:465-73. [PMID: 19906585 DOI: 10.1109/tmi.2009.2035310] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
A hybrid imaging system for simultaneous fluorescence tomography and X-ray computed tomography (XCT) of small animals has been developed and presented. The system capitalizes on the imaging power of a 360 ( degrees )-projection free-space fluorescence tomography system, implemented within a microcomputed tomography scanner. Image acquisition is based on techniques that automatically adjust a series of imaging parameters to offer a high dynamic range dataset. Image segmentation further allows the incorporation of structural priors in the optical reconstruction problem to improve the imaging performance. The functional system characteristics are showcased, and images from a brain imaging study are shown, which are reconstructed using XCT-derived priors into the optical forward problem.
Collapse
Affiliation(s)
- Ralf B Schulz
- Chair for Biological Imaging, Technical University Munich, 80333 Munich, Germany.
| | | | | | | | | | | | | |
Collapse
|
46
|
Biswal NC, Gamelin JK, Yuan B, Backer MV, Backer JM, Zhu Q. Fluorescence imaging of vascular endothelial growth factor in tumors for mice embedded in a turbid medium. JOURNAL OF BIOMEDICAL OPTICS 2010; 15:016012. [PMID: 20210458 PMCID: PMC2839800 DOI: 10.1117/1.3306704] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/22/2009] [Revised: 11/23/2009] [Accepted: 11/24/2009] [Indexed: 05/27/2023]
Abstract
We demonstrate the feasibility of fluorescence imaging of deeply seated tumors using mice injected with an angiogenesis tracer, a vascular endothelial growth factor conjugated with the infrared dye cyanine 7 (VEGF/Cy7). Our optical-only imaging reconstruction method separately estimates the target depth, and then applies this information to reconstruct functional information such as fluorophore concentration. Fluorescence targets with concentrations as low as sub-25 nM are well reconstructed at depths up to 2 cm in both homogeneous and heterogeneous media with this technique.
Collapse
Affiliation(s)
- Nrusingh C Biswal
- University of Connecticut, Department of Electrical and Computer Engineering, Storrs, Connecticut 06269, USA
| | | | | | | | | | | |
Collapse
|
47
|
Leblond F, Davis SC, Valdés PA, Pogue BW. Pre-clinical whole-body fluorescence imaging: Review of instruments, methods and applications. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY B-BIOLOGY 2009; 98:77-94. [PMID: 20031443 DOI: 10.1016/j.jphotobiol.2009.11.007] [Citation(s) in RCA: 362] [Impact Index Per Article: 24.1] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Received: 07/22/2009] [Revised: 11/16/2009] [Accepted: 11/20/2009] [Indexed: 01/07/2023]
Abstract
Fluorescence sampling of cellular function is widely used in all aspects of biology, allowing the visualization of cellular and sub-cellular biological processes with spatial resolutions in the range from nanometers up to centimeters. Imaging of fluorescence in vivo has become the most commonly used radiological tool in all pre-clinical work. In the last decade, full-body pre-clinical imaging systems have emerged with a wide range of utilities and niche application areas. The range of fluorescent probes that can be excited in the visible to near-infrared part of the electromagnetic spectrum continues to expand, with the most value for in vivo use being beyond the 630 nm wavelength, because the absorption of light sharply decreases. Whole-body in vivo fluorescence imaging has not yet reached a state of maturity that allows its routine use in the scope of large-scale pre-clinical studies. This is in part due to an incomplete understanding of what the actual fundamental capabilities and limitations of this imaging modality are. However, progress is continuously being made in research laboratories pushing the limits of the approach to consistently improve its performance in terms of spatial resolution, sensitivity and quantification. This paper reviews this imaging technology with a particular emphasis on its potential uses and limitations, the required instrumentation, and the possible imaging geometries and applications. A detailed account of the main commercially available systems is provided as well as some perspective relating to the future of the technology development. Although the vast majority of applications of in vivo small animal imaging are based on epi-illumination planar imaging, the future success of the method relies heavily on the design of novel imaging systems based on state-of-the-art optical technology used in conjunction with high spatial resolution structural modalities such as MRI, CT or ultrasound.
Collapse
Affiliation(s)
- Frederic Leblond
- Thayer School of Engineering, Dartmouth College, Hanover, NH 03755, USA.
| | | | | | | |
Collapse
|
48
|
Zhang X, Badea C. Effects of sampling strategy on image quality in noncontact panoramic fluorescence diffuse optical tomography for small animal imaging. OPTICS EXPRESS 2009; 17:5125-38. [PMID: 19333276 PMCID: PMC2664524 DOI: 10.1364/oe.17.005125] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Fluorescence diffuse optical tomography is an emerging technology for molecular imaging with recent technological advances in biomarkers and photonics. The introduction of noncontact imaging methods enables very large-scale data acquisition that is orders of magnitude larger than that from earlier systems. In this study, the effects of sampling strategy on image quality were investigated using an imaging phantom mimicking small animals and further analyzed using singular value analysis (SVA). The sampling strategy was represented in terms of a number of key acquisition parameters, namely the numbers of sources, detectors, and imaging angles. A number of metrics were defined to quantitatively evaluate image quality. The effects of acquisition parameters on image quality were subsequently studied by varying each of the parameters within a reasonable range while maintaining the other parameters constant, a method analogue to partial derivative in mathematical analysis. It was found that image quality improves at a much slower rate if the acquisition parameters are above certain critical values (approximately 5 sources, approximately 15 detectors, and approximately 20 angles for our system). These critical values remain virtually the same even if other acquisition parameters are doubled. It was also found that increasing different acquisition parameters improves image quality with different efficiencies in terms of the number of measurements: for a system characterized by a smaller threshold in SVA (less than 10(-5) in our study), the number of sources is the most efficient, followed by the number of detectors and subsequently the number of imaging angles. However, for systems characterized by a larger threshold, the numbers of sources and angles are equally more efficient than the number of detectors.
Collapse
Affiliation(s)
- Xiaofeng Zhang
- Department of Radiology, Center for In Vivo Microscopy, Duke University Medical Center, Durham, NC 27710, USA.
| | | |
Collapse
|
49
|
Lin Y, Yan H, Nalcioglu O, Gulsen G. Quantitative fluorescence tomography with functional and structural a priori information. APPLIED OPTICS 2009; 48:1328-36. [PMID: 19252634 PMCID: PMC2737514 DOI: 10.1364/ao.48.001328] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
We demonstrate the necessity of functional and structural a priori information for quantitative fluorescence tomography (FT) with phantom studies. Here the functional a priori information is defined as the optical properties of the heterogeneous background that can be measured by a diffuse optical tomography (DOT) system. A CCD-based noncontact hybrid FT/DOT system that could take measurements at multiple views was built. Multimodality phantoms with multiple compartments were constructed and used in the experiments to mimic a heterogeneous optical background. A 3.6 mm diameter object deeply embedded in a heterogeneous optical background could be localized without any a priori information, but the recovered fluorophore concentration only reached one tenth of the true concentration. On the other hand, the true fluorophore concentration could be recovered when both functional and structural a priori information is utilized to guide and constrain the FT reconstruction algorithm.
Collapse
|
50
|
Zhang X, Badea C, Jacob M, Johnson GA. Development of a noncontact 3-D fluorescence tomography system for small animal in vivo imaging. PROCEEDINGS OF SPIE--THE INTERNATIONAL SOCIETY FOR OPTICAL ENGINEERING 2009; 7191:nihpa106691. [PMID: 19587837 DOI: 10.1117/12.808199] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
Fluorescence imaging is an important tool for tracking molecular-targeting probes in preclinical studies. It offers high sensitivity, but nonetheless low spatial resolution compared to other leading imaging methods such CT and MRI. We demonstrate our methodological development in small animal in vivo whole-body imaging using fluorescence tomography. We have implemented a noncontact fluid-free fluorescence diffuse optical tomography system that uses a raster-scanned continuous-wave diode laser as the light source and an intensified CCD camera as the photodetector. The specimen is positioned on a motorized rotation stage. Laser scanning, data acquisition, and stage rotation are controlled via LabVIEW applications. The forward problem in the heterogeneous medium is based on a normalized Born method, and the sensitivity function is determined using a Monte Carlo method. The inverse problem (image reconstruction) is performed using a regularized iterative algorithm, in which the cost function is defined as a weighted sum of the L-2 norms of the solution image, the residual error, and the image gradient. The relative weights are adjusted by two independent regularization parameters. Our initial tests of this imaging system were performed with an imaging phantom that consists of a translucent plastic cylinder filled with tissue-simulating liquid and two thin-wall glass tubes containing indocyanine green. The reconstruction is compared to the output of a finite element method-based software package NIRFAST and has produced promising results.
Collapse
Affiliation(s)
- Xiaofeng Zhang
- Dept. of Radiology, Duke University Medical Center, Box 3302, Durham, NC, 27710
| | | | | | | |
Collapse
|