1
|
Multi-time-point analysis: A time course analysis with functional near-infrared spectroscopy. Behav Res Methods 2020; 52:1700-1713. [PMID: 32026386 DOI: 10.3758/s13428-019-01344-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
In the data analysis of functional near-infrared spectroscopy (fNIRS), linear model frameworks, in particular mass univariate analysis, are often used when researchers consider examining the difference between conditions at each sampled time point. However, some statistical issues, such as assumptions of linearity, autocorrelation and multiple comparison problems, influence statistical inferences when mass univariate analysis is used on fNIRS time course data. In order to address these issues, the present study proposes a novel perspective, multi-time-point analysis (MTPA), to discriminate signal differences between conditions by combining temporal information from multiple time points in fNIRS. In addition, MTPA adopts the random forest algorithm from the statistical learning domain, followed by a series of cross-validation procedures, providing reasonable power for detecting significant time points and ensuring generalizability. Using a real fNIRS data set, the proposed MTPA outperformed mass univariate analysis in detecting more time points, showing significant differences between experimental conditions. Finally, MTPA was also able to make comparisons between different areas, leading to a novel viewpoint of fNIRS time course analysis and providing additional theoretical implications for future fNIRS studies. The data set and all source code are available for researchers to replicate the analyses and to adapt the program for their own needs in future fNIRS studies.
Collapse
|
2
|
Valence processing of first impressions in the dorsomedial prefrontal cortex: a near-infrared spectroscopy study. Neuroreport 2018; 27:574-9. [PMID: 27035730 DOI: 10.1097/wnr.0000000000000571] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Previous studies have suggested that the dorsomedial prefrontal cortex (dmPFC) plays a central role in processing first impressions; however, little is known about how dmPFC processes different valences of first impressions. Moreover, it is still unclear as to whether the dmPFC shows lateralization or only induces different levels of activation when processing positive and negative impressions. To address these questions in the present study, the brain activities for the impression judgments expressed by participants were measured with near-infrared spectroscopy. For each real facial picture, participants were asked to evaluate their first impressions on a scale from 'bad' to 'good' using a keyboard. The results showed that although the right dmPFC has a higher sensitivity in processing impressions, both the hemispheres of dmPFC showed a significant trend where the activation of positive impressions was higher than the negative ones. Accordingly, it is proposed that the dmPFC acts as a single mechanism responsible for delineating the processing of first impressions rather than two lateralized systems. Therefore, a 'positivity dominance hypothesis' is also proposed, which states that dmPFC in both hemispheres have a higher sensitivity and priority for positive impressions than negative ones. The present study provides valuable findings with respect to the role of the dmPFC in the processes of first impression formation.
Collapse
|
3
|
Daly SM, Leahy MJ. 'Go with the flow ': a review of methods and advancements in blood flow imaging. JOURNAL OF BIOPHOTONICS 2013; 6:217-55. [PMID: 22711377 DOI: 10.1002/jbio.201200071] [Citation(s) in RCA: 67] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/23/2012] [Revised: 05/22/2012] [Accepted: 05/23/2012] [Indexed: 05/25/2023]
Abstract
Physics has delivered extraordinary developments in almost every facet of modern life. From the humble thermometer and stethoscope to X-Ray, CT, MRI, ultrasound, PET and radiotherapy, our health has been transformed by these advances yielding both morphological and functional metrics. Recently high resolution label-free imaging of the microcirculation at clinically relevant depths has become available in the research domain. In this paper, we present a comprehensive review on current imaging techniques, state-of-the-art advancements and applications, and general perspectives on the prospects for these modalities in the clinical realm.
Collapse
Affiliation(s)
- Susan M Daly
- Biophotonics Research Facility, Department of Physics & Energy, University of Limerick, Ireland.
| | | |
Collapse
|
4
|
Poellinger A. Near-infrared imaging of breast cancer using optical contrast agents. JOURNAL OF BIOPHOTONICS 2012; 5:815-26. [PMID: 23132668 DOI: 10.1002/jbio.201200123] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
Breast cancer is the most common malignancy in women worldwide and the second leading cause of cancer death. On the basis of three studies performed by our group, this article reviews the current status of optical breast imaging using extrinsic contrast agents. To date, only two contrast agents have been applied in human studies, indocyanine green (ICG) and omocianine. Both contrast media were used for absorption and fluorescence imaging. Generally speaking, malignant breast lesions exhibited higher absorption contrast as well as higher fluorescence contrast compared to benign lesions or non-diseased breast tissue. Some groups consider early enhancement characteristics helpful for differentiation between malignant and benign lesions. Late fluorescence ICG imaging - capitalizing on the extravasation of the dye through the wall of tumorous vessels - seems to be a promising technique to distinguish malignant from benign breast lesions.
Collapse
Affiliation(s)
- Alexander Poellinger
- Charité, Universitätsmedizin Berlin, Department of Radiology, Charité Campus Virchow Klinikum, Berlin, Germany.
| |
Collapse
|
5
|
Choe R, Durduran T. Diffuse Optical Monitoring of the Neoadjuvant Breast Cancer Therapy. IEEE JOURNAL OF SELECTED TOPICS IN QUANTUM ELECTRONICS : A PUBLICATION OF THE IEEE LASERS AND ELECTRO-OPTICS SOCIETY 2012; 18:1367-1386. [PMID: 23243386 PMCID: PMC3521564 DOI: 10.1109/jstqe.2011.2177963] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/19/2023]
Abstract
Recent advances in the use of diffuse optical techniques for monitoring the hemodynamic, metabolic and physiological signatures of the neoadjuvant breast cancer therapy effectiveness is critically reviewed. An extensive discussion of the state-of-theart diffuse optical mammography is presented alongside a discussion of the current approaches to breast cancer therapies. Overall, the diffuse optics field is growing rapidly with a great deal of promise to fill an important niche in the current approaches to monitor, predict and personalize neoadjuvant breast cancer therapies.
Collapse
Affiliation(s)
- Regine Choe
- Department of Biomedical Engineering, University of Rochester, Rochester, NY, USA;
| | - Turgut Durduran
- ICFO- Institut de Ciències Fotòniques, Mediterranean Technology Park, 08860, Barcelona, Spain;
| |
Collapse
|
6
|
Ferrari M, Quaresima V. A brief review on the history of human functional near-infrared spectroscopy (fNIRS) development and fields of application. Neuroimage 2012; 63:921-35. [PMID: 22510258 DOI: 10.1016/j.neuroimage.2012.03.049] [Citation(s) in RCA: 1066] [Impact Index Per Article: 88.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2011] [Revised: 02/21/2012] [Accepted: 03/16/2012] [Indexed: 12/14/2022] Open
Abstract
This review is aimed at celebrating the upcoming 20th anniversary of the birth of human functional near-infrared spectroscopy (fNIRS). After the discovery in 1992 that the functional activation of the human cerebral cortex (due to oxygenation and hemodynamic changes) can be explored by NIRS, human functional brain mapping research has gained a new dimension. fNIRS or optical topography, or near-infrared imaging or diffuse optical imaging is used mainly to detect simultaneous changes in optical properties of the human cortex from multiple measurement sites and displays the results in the form of a map or image over a specific area. In order to place current fNIRS research in its proper context, this paper presents a brief historical overview of the events that have shaped the present status of fNIRS. In particular, technological progresses of fNIRS are highlighted (i.e., from single-site to multi-site functional cortical measurements (images)), introduction of the commercial multi-channel systems, recent commercial wireless instrumentation and more advanced prototypes.
Collapse
Affiliation(s)
- Marco Ferrari
- Department of Health Sciences, University of L'Aquila, L'Aquila, Italy.
| | | |
Collapse
|
7
|
Bembich S, Lanzara C, Clarici A, Demarini S, Tepper BJ, Gasparini P, Grasso DL. Individual differences in prefrontal cortex activity during perception of bitter taste using fNIRS methodology. Chem Senses 2010; 35:801-12. [PMID: 20801896 DOI: 10.1093/chemse/bjq080] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Although bitter taste has a crucial role in nutrition by preventing the ingestion of toxic foods, there are few studies on bitter taste neuroimaging. To identify cortical areas involved in bitter taste perception and to determine if individual differences in taste sensitivity to 6-n-propylthiouracil (PROP) are represented in the brain by different cortical activation patterns, we examined 48 healthy volunteers using functional near-infrared spectroscopy. Participants rated the perceived intensity of filter paper disks impregnated with PROP and NaCl during the imaging procedure and were then classified as PROP tasters and nontasters. We monitored cortical activity in both the anterior and posterior regions of the dorsolateral prefrontal cortex (DLPFC) and in the ventrolateral prefrontal cortex (VLPFC). No activity was detected in the anterior DLPFC in any of the participants. However, during the administration of PROP, significant cortical activation was detected in the more posterior regions of the left DLPFC and in the left and right VLPFC but only in PROP tasters. PROP nontasters showed no cortical activity in these areas. These data suggest that the prefrontal cortex is involved in the conscious perception of the bitter taste of PROP and that the pattern of activity is consistent with individual differences in the ability to taste this compound. Thus, the PROP phenotype is associated with fundamental differences in cortical taste processing.
Collapse
Affiliation(s)
- Stefano Bembich
- Department of Reproductive and Developmental Sciences, and Public Medicine Sciences, University of Trieste, via dell'Istria 65/1, 34137 Trieste, Italy
| | | | | | | | | | | | | |
Collapse
|
8
|
Chen HC, Vaid J, Boas DA, Bortfeld H. Examining the phonological neighborhood density effect using near infrared spectroscopy. Hum Brain Mapp 2010; 32:1363-70. [PMID: 20690126 DOI: 10.1002/hbm.21115] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2009] [Accepted: 05/22/2010] [Indexed: 11/08/2022] Open
Abstract
Phonological density refers to the number of words that can be generated by replacing a phoneme in a target word with another phoneme in the same position. Although the precise nature of the phonological neighborhood density effect is not firmly established, many behavioral psycholinguistic studies have shown that visual recognition of individual words is influenced by the number and type of neighbors the words have. This study explored neurobehavioral correlates of phonological neighborhood density in skilled readers of English using near infrared spectroscopy. On the basis of a lexical decision task, our findings showed that words with many phonological neighbors (e.g., FRUIT) were recognized more slowly than words with few phonological neighbors (e.g., PROOF), and that words with many neighbors elicited significantly greater changes in blood oxygenation in the left than in the right hemisphere of the brain, specifically in the areas BA 22/39/40. In previous studies these brain areas have been implicated in fine-grained phonological processing in readers of English. The present findings provide the first demonstration that areas BA 22/39/40 are also sensitive to phonological density effects.
Collapse
Affiliation(s)
- Hsin-Chin Chen
- Department of Psychology, National Chung Cheng University, Chia-Yi, Taiwan.
| | | | | | | |
Collapse
|
9
|
Durduran T, Choe R, Baker WB, Yodh AG. Diffuse Optics for Tissue Monitoring and Tomography. REPORTS ON PROGRESS IN PHYSICS. PHYSICAL SOCIETY (GREAT BRITAIN) 2010; 73:076701. [PMID: 26120204 PMCID: PMC4482362 DOI: 10.1088/0034-4885/73/7/076701] [Citation(s) in RCA: 555] [Impact Index Per Article: 39.6] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
This review describes the diffusion model for light transport in tissues and the medical applications of diffuse light. Diffuse optics is particularly useful for measurement of tissue hemodynamics, wherein quantitative assessment of oxy- and deoxy-hemoglobin concentrations and blood flow are desired. The theoretical basis for near-infrared or diffuse optical spectroscopy (NIRS or DOS, respectively) is developed, and the basic elements of diffuse optical tomography (DOT) are outlined. We also discuss diffuse correlation spectroscopy (DCS), a technique whereby temporal correlation functions of diffusing light are transported through tissue and are used to measure blood flow. Essential instrumentation is described, and representative brain and breast functional imaging and monitoring results illustrate the workings of these new tissue diagnostics.
Collapse
Affiliation(s)
- T Durduran
- ICFO- Institut de Ciències Fotòniques, Mediterranean Technology Park, 08860 Castelldefels (Barcelona), Spain
| | - R Choe
- Department of Physics and Astronomy, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - W B Baker
- Department of Physics and Astronomy, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - A G Yodh
- Department of Physics and Astronomy, University of Pennsylvania, Philadelphia, PA 19104, USA
| |
Collapse
|
10
|
Gibson A, Dehghani H. Diffuse optical imaging. PHILOSOPHICAL TRANSACTIONS. SERIES A, MATHEMATICAL, PHYSICAL, AND ENGINEERING SCIENCES 2009; 367:3055-72. [PMID: 19581255 DOI: 10.1098/rsta.2009.0080] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Diffuse optical imaging is a medical imaging technique that is beginning to move from the laboratory to the hospital. It is a natural extension of near-infrared spectroscopy (NIRS), which is now used in certain niche applications clinically and particularly for physiological and psychological research. Optical imaging uses sophisticated image reconstruction techniques to generate images from multiple NIRS measurements. The two main clinical applications--functional brain imaging and imaging for breast cancer--are reviewed in some detail, followed by a discussion of other issues such as imaging small animals and multimodality imaging. We aim to review the state of the art of optical imaging.
Collapse
Affiliation(s)
- Adam Gibson
- Department of Medical Physics and Bioengineering, University College London, London WC1E 6BT, UK.
| | | |
Collapse
|
11
|
Chen HC, Vaid J, Bortfeld H, Boas DA. Optical imaging of phonological processing in two distinct orthographies. Exp Brain Res 2007; 184:427-33. [PMID: 17999056 DOI: 10.1007/s00221-007-1200-0] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2007] [Accepted: 10/20/2007] [Indexed: 12/01/2022]
Abstract
Recent fMRI studies comparing the processing of alphabetic versus logographic scripts provide evidence for shared and orthography-specific regions of neural activity. The present study used near-infrared spectroscopy to compare (within and across brain regions) the time course of neural activation for these two distinct orthographies. Native readers of English and of Chinese were tested on a homophone judgment task. Differences across groups were obtained in the time course of hemodynamic change for the left middle frontal, left superior temporal, and left supramarginal gyri. Results thus support previous findings using fMRI and suggest that different neural mappings arise depending on whether an individual has learned to process written language using an alphabetic or logographic script.
Collapse
Affiliation(s)
- Hsin-Chin Chen
- Department of Psychology, National Chung Cheng University, 168 University Rd, Ming-Hsiung Chia-Yi, Taiwan.
| | | | | | | |
Collapse
|
12
|
Leff DR, Warren OJ, Enfield LC, Gibson A, Athanasiou T, Patten DK, Hebden J, Yang GZ, Darzi A. Diffuse optical imaging of the healthy and diseased breast: A systematic review. Breast Cancer Res Treat 2007; 108:9-22. [PMID: 17468951 DOI: 10.1007/s10549-007-9582-z] [Citation(s) in RCA: 189] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2006] [Accepted: 03/26/2007] [Indexed: 11/28/2022]
Abstract
Screening X-ray mammography is limited by false positives and negatives leading to unnecessary physical and psychological morbidity. Diffuse Optical Imaging using harmless near infra red light, provides lesion detection based on functional abnormalities and represents a novel diagnostic arm that could complement traditional mammography. Reviews of optical breast imaging have not been systematic, are focused mainly on technological developments, and have become superseded by rapid technological advancement. The aim of this study is to review clinically orientated studies involving approximately 2,000 women in whom optical mammography has been used to evaluate the healthy or diseased breast. The results suggest that approximately 85% of breast lesions are detectable on optical mammography. Spectroscopic resolution of tissue haemoglobin composition and oxygen saturation may improve the detectability of breast diseases. Results suggest that breast lesions contain approximately twice the haemoglobin concentration of background tissue. Current evidence suggests that it is not possible to distinguish benign from malignant disease using optical imaging techniques in isolation. Methods to improve the performance of Diffuse Optical Imaging, such as better spectral coverage with additional wavelengths, improved modelling of light transport in tissues and the use of extrinsic dyes may augment lesion detection and characterisation. Future research should involve large clinical trials to determine the overall sensitivity and specificity of optical imaging techniques as well as to establish patient satisfaction and economic viability.
Collapse
Affiliation(s)
- Daniel Richard Leff
- Department of Biosurgery and Surgical Technology, Imperial College London, St Mary's Hospital, London, UK.
| | | | | | | | | | | | | | | | | |
Collapse
|
13
|
Lisy MR, Schüler E, Lehmann F, Czerney P, Kaiser WA, Hilger I. Diagnosis of peritonitis using near-infrared optical imaging of in vivo labeled monocytes-macrophages. JOURNAL OF BIOMEDICAL OPTICS 2006; 11:064014. [PMID: 17212537 DOI: 10.1117/1.2409310] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
Peritonitis is an inflammatory process characterized by massive monocytes-macrophages infiltration. Since early diagnosis is important for a successful therapeutic outcome, the feasibility for a selective labeling and imaging of macrophages for highly sensitive optical imaging was assessed. After in vitro incubation of mouse macrophages J774A.1 with the far-red/near-infrared fluorochrome DY-676, distinct fluorescence intensities (1026+/-142 a.u.) were detected as compared to controls (552+/-54 a.u.) using a whole-body small animal near-infrared fluorescence (NIRF) imaging system. Macrophage labeling was confirmed by confocal laser scanning microscopy (CLSM) and fluorescence-activated cell sorting, (FACS). The fluorochrome was also found to be predominantly distributed within compartments in the cytoplasm. Additionally, peritonitis was induced in mice by intraperitoneal injection of zymosanA. After intravenous injection of fluorochrome (55 nmol/kg) and using whole-body fluorescence imaging, higher fluorescence intensities (869+/-151 a.u.) were detected in the peritoneal area of diseased mice as compared to controls (188+/-41 a.u.). Furthermore, cells isolated from peritoneal lavage revealed the presence of labeled monocytes-macrophages. The results indicate that in vivo diagnosis of peritonitis by near-infrared optical imaging of labeled monocytes-macrophages is feasible. Possibly, early stages of other inflammatory diseases could also be detected by the proposed diagnostic method in the long term.
Collapse
Affiliation(s)
- Marcus-René Lisy
- Friedrich Schiller University Jena, Institute of Diagnostic and Interventional Radiology, FZL Erlanger Allee 101, D-07747 Jena, Germany.
| | | | | | | | | | | |
Collapse
|
14
|
Abstract
We review the current state-of-the-art of diffuse optical imaging, which is an emerging technique for functional imaging of biological tissue. It involves generating images using measurements of visible or near-infrared light scattered across large (greater than several centimetres) thicknesses of tissue. We discuss recent advances in experimental methods and instrumentation, and examine new theoretical techniques applied to modelling and image reconstruction. We review recent work on in vivo applications including imaging the breast and brain, and examine future challenges.
Collapse
Affiliation(s)
- A P Gibson
- Department of Medical Physics and Bioengineering, University College London, UK
| | | | | |
Collapse
|
15
|
Yates T, Hebden JC, Gibson A, Everdell N, Arridge SR, Douek M. Optical tomography of the breast using a multi-channel time-resolved imager. Phys Med Biol 2005; 50:2503-17. [PMID: 15901951 DOI: 10.1088/0031-9155/50/11/005] [Citation(s) in RCA: 79] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
A time-resolved optical tomography system has been used to generate cross-sectional images of the human breast. Images are reconstructed using an iterative, nonlinear algorithm and measurements of mean photon flight time relative to those acquired on a homogeneous reference phantom. Thirty-eight studies have been performed on three healthy volunteers and 21 patients with a variety of breast lesions including cancer. We have successfully detected 17 out of 19 lesions, and shown that optical images of the healthy breast of the same volunteer display a heterogeneity which is repeatable over a period of months. However, results also indicate that the lack of accurate quantitation of optical parameters and limited morphological information limits the ability to characterize different types of lesions and distinguish benign from malignant tissues. Drawbacks of our current methodology and plans for overcoming them are discussed.
Collapse
Affiliation(s)
- Tara Yates
- Department of Medical Physics and Bioengineering, University College London, Gower Street, London WC1E 6BT, UK
| | | | | | | | | | | |
Collapse
|
16
|
Hebden JC, Yates TD, Gibson A, Everdell N, Arridge SR, Chicken DW, Douek M, Keshtgar MRS. Monitoring recovery after laser surgery of the breast with optical tomography: a case study. APPLIED OPTICS 2005; 44:1898-1904. [PMID: 15813526 DOI: 10.1364/ao.44.001898] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Results are presented of a study to monitor the changes in the optical properties of breast tissue over a 12-month period after interstitial laser photocoagulation treatment of a fibroadenoma. The study involved generating cross-sectional images of the breast with a multichannel time-resolved imaging system and a nonlinear image reconstruction algorithm. Images of the internal absorbing and scattering properties revealed the expected initial inflammatory response, followed by the development of low-scattering cysts consistent with corresponding ultrasound examinations. Although results indicate that purely qualitative images can potentially provide clinically valuable data, means of enhancing diagnostic information by overcoming present limitations of the approach are discussed.
Collapse
Affiliation(s)
- Jeremy C Hebden
- Department of Medical Physics and Bioengineering, University College London, Gower Street, London WC1E 6BT, United Kingdom.
| | | | | | | | | | | | | | | |
Collapse
|
17
|
Horovitz SG, Gore JC. Simultaneous event-related potential and near-infrared spectroscopic studies of semantic processing. Hum Brain Mapp 2004; 22:110-5. [PMID: 15108298 PMCID: PMC6872128 DOI: 10.1002/hbm.20018] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
Near-infrared optical topography (NIROT) signals and event-related potentials (ERPs) were measured simultaneously during a semantic processing task to evaluate the ability of these techniques to detect hemodynamic and electrophysiologic responses generated by semantic anomalies and to compare these results to earlier independent functional magnetic resonance imaging (fMRI) and ERP measurements. Candidate brain regions were first identified from activations detected by NIROT during a simple block-design task (in this case reading sentences vs. passive viewing), and defined regions (corresponding to Broca's and Wernicke's areas) were used for guiding the localization of optodes and electrodes for recording during tasks involving semantic anomalies. In five of six subjects, ERP measurements showed the characteristic N400 wave, whereas event-related NIROT showed results that agreed with previous fMRI studies. There were transient hemodynamic signals recorded in specific optodes that corresponded to activation in Broca's area, but slightly anterior to the region activated during the simple reading task, and in Wernicke's area, but slightly inferior to that for the simple reading task. A between-subject correlation of the ERP and NIRS data was also employed to identify areas of activation. The highest correlations were obtained in Broca's area, centered more anterior than for the reading task and in Wernicke's area, slightly inferior to that for the reading task. This study confirms that event-related studies are feasible using NIROT and produce results similar to those obtained with fMRI. Even though the spatial resolution is lower in NIROT than in fMRI, small differences in the locations of activation centers could be detected with NIROT. This, together with the feasibility of simultaneous ERP recording, makes NIROT attractive as a new approach to studying language function in healthy subjects as well as in those with functional abnormalities.
Collapse
Affiliation(s)
- Silvina G Horovitz
- Engineering and Applied Science, Yale University, New Haven, Connecticut, USA.
| | | |
Collapse
|
18
|
Jones GB, Xie L, El-Shafey A, Crasto CF, Bubley GJ, D'Amico AV. Image contrast agents activated by prostate specific antigen (PSA). Bioorg Med Chem Lett 2004; 14:3081-4. [PMID: 15149649 DOI: 10.1016/j.bmcl.2004.04.041] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2004] [Accepted: 04/10/2004] [Indexed: 11/22/2022]
Abstract
A family of image contrast agent conjugates designed to undergo enzymatic activation has been synthesized. The agents underwent activation both with enzymatically active prostate specific antigen and alpha-chymotrypsin, releasing free fluorophore via cleavage of a three-component system.
Collapse
Affiliation(s)
- Graham B Jones
- Department of Chemistry and Chemical Biology, Northeastern University, Boston, MA 02115, USA.
| | | | | | | | | | | |
Collapse
|
19
|
Meek J. Basic principles of optical imaging and application to the study of infant development. Dev Sci 2002. [DOI: 10.1111/1467-7687.00376] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
|
20
|
Kennan RP, Kim D, Maki A, Koizumi H, Constable RT. Non-invasive assessment of language lateralization by transcranial near infrared optical topography and functional MRI. Hum Brain Mapp 2002; 16:183-9. [PMID: 12112772 PMCID: PMC6871823 DOI: 10.1002/hbm.10039] [Citation(s) in RCA: 83] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2001] [Accepted: 02/20/2002] [Indexed: 11/10/2022] Open
Abstract
Near infrared optical topography (OT) is the simultaneous acquisition of hemoglobin absorption from an array of optical fibers on the scalp to construct maps of cortical activity. We demonstrate that OT can be used to determine lateralization of prefrontal areas to a language task that has been validated by functional MRI (fMRI). Studies were performed on six subjects using a visually presented language task. Laterality was quantified by the relative number of activated pixels in each hemisphere for fMRI, and the total hemoglobin responses in each hemisphere for OT. All subjects showed varying degrees of left hemisphere language dominance and the mean laterality indices for subjects who underwent both OT and fMRI were in good agreement. These studies demonstrate that OT gives predictions of hemispheric dominance that are consistent with fMRI. Due to the ease of use and portable nature of OT, it is anticipated that optical topography will be valuable tool for neurological examinations of cognitive function.
Collapse
Affiliation(s)
- Richard P Kennan
- Department of Diagnostic Radiology, Yale University School of Medicine, New Haven, Connecticut, USA.
| | | | | | | | | |
Collapse
|
21
|
Kennan RP, Horovitz SG, Maki A, Yamashita Y, Koizumi H, Gore JC. Simultaneous recording of event-related auditory oddball response using transcranial near infrared optical topography and surface EEG. Neuroimage 2002; 16:587-92. [PMID: 12169245 DOI: 10.1006/nimg.2002.1060] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Near infrared optical topography (OT) is the measurement of hemoglobin absorption simultaneously from an array of optical fibers on the scalp to construct maps of cortical activity. We demonstrate that OT can be used to simultaneously detect and characterize the hemodynamic responses associated with an "oddball" auditory stimulus and that corresponding electrical event related potentials can be acquired simultaneously using conventional scalp recordings. In addition to the measured electrical response, the hemodynamic localization is consistent with fMRI studies, which show significant activation in the temporal and parietal cortical regions. The event-related response of total hemoglobin showed relatively slow peak latencies (5.8 +/- 0.3 s), which were also consistent with fMRI. The current study shows the regions of peak hemodynamic activity that are in closest proximity to areas of peak electrical activity. This is the first demonstration of simultaneous ERP electrical recording and non-invasive optical mapping in human subjects, which promises to be an important tool in the characterization of both normal and abnormal brain function.
Collapse
Affiliation(s)
- Richard P Kennan
- Department of Medicine, Albert Einstein College of Medicine, USA
| | | | | | | | | | | |
Collapse
|
22
|
Kennan RP, Behar KL. Continuous-wave near-infrared spectroscopy using pathlength-independent hypoxia normalization. JOURNAL OF BIOMEDICAL OPTICS 2002; 7:228-235. [PMID: 11966308 DOI: 10.1117/1.1463048] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/26/2001] [Revised: 10/23/2001] [Accepted: 12/07/2001] [Indexed: 05/23/2023]
Abstract
A general physiological model for the hemodynamic response during altered blood flow, oxygenation, and metabolism is presented. Calculations of oxy-, deoxy-, and total hemoglobin changes during stimulation are given. It is shown that by using a global hyperoxic or mild hypoxic challenge it is possible to normalize the activation response in terms of the fractional changes in the cerebral blood volume, tissue oxygenation index, and oxygen extraction ratio, which are independent of the optical pathlength. Using a dual wavelength spectrometer, the method is validated by measuring pathlength-independent hemodynamic responses during mild hypercarbia in a rat model. Phantom experiments showed that the changes in optical pathlength were small as the hemoglobin concentration was varied over a wide range. The determination of quantitative parameters facilitates the use of continuous-wave transcranial methods by providing a means by which to characterize activation response across subjects.
Collapse
Affiliation(s)
- Richard P Kennan
- Yale University School of Medicine, Department of Diagnostic Radiology, New Haven, Connecticut 06511, USA.
| | | |
Collapse
|
23
|
Hebden JC, Veenstra H, Dehghani H, Hillman EM, Schweiger M, Arridge SR, Delpy DT. Three-dimensional time-resolved optical tomography of a conical breast phantom. APPLIED OPTICS 2001; 40:3278-87. [PMID: 11958270 DOI: 10.1364/ao.40.003278] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
A 32-channel time-resolved imaging device for medical optical tomography has been employed to evaluate a scheme for imaging the human female breast. The fully automated instrument and the reconstruction procedure have been tested on a conical phantom with tissue-equivalent optical properties. The imaging protocol has been designed to obviate compression of the breast and the need for coupling fluids. Images are generated from experimental data with an iterative reconstruction algorithm that employs a three-dimensional (3D) finite-element diffusion-based forward model. Embedded regions with twice the background optical properties are revealed in separate 3D absorption and scattering images of the phantom. The implications for 3D time-resolved optical tomography of the breast are discussed.
Collapse
Affiliation(s)
- J C Hebden
- Department of Medical Physics and Bioengineering, University College London, UK.
| | | | | | | | | | | | | |
Collapse
|
24
|
Bugaj JE, Achilefu S, Dorshow RB, Rajagopalan R. Novel fluorescent contrast agents for optical imaging of in vivo tumors based on a receptor-targeted dye-peptide conjugate platform. JOURNAL OF BIOMEDICAL OPTICS 2001; 6:122-133. [PMID: 11375721 DOI: 10.1117/1.1352748] [Citation(s) in RCA: 94] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/01/2000] [Revised: 12/13/2000] [Accepted: 12/13/2000] [Indexed: 05/23/2023]
Abstract
We have designed, synthesized, and evaluated the efficacy of novel dye-peptide conjugates that are receptor specific. Contrary to the traditional approach of conjugating dyes to large proteins and antibodies, we used small peptide-dye conjugates that target over-expressed receptors on tumors. Despite the fact that the peptide and the dye probe have similar molecular mass, our results demonstrate that the affinity of the peptide for its receptor and the dye fluorescence properties are both retained. The use of small peptides has several advantages over large biomolecules, including ease of synthesis of a variety of compounds for potential combinatorial screening of new targets, reproducibility of high purity compounds, diffusiveness to solid tumors, and the ability to incorporate a variety of functional groups that modify the pharmacokinetics of the peptide-dye conjugates. The efficacy of these new fluorescent optical contrast agents was evaluated in vivo in well-characterized rat tumor lines expressing somatostatin (sst(2)) and bombesin receptors. A simple continuous wave optical imaging system was employed. The resulting optical images clearly show that successful specific tumor targeting was achieved. Thus, we have demonstrated that small peptide-dye conjugates are effective as contrast agents for optical imaging of tumors.
Collapse
Affiliation(s)
- J E Bugaj
- Mallinckrodt Inc., P.O. Box 5840, St. Louis, Missouri 63134-0840, USA
| | | | | | | |
Collapse
|
25
|
Ebert B, Sukowski U, Grosenick D, Wabnitz H, Moesta KT, Licha K, Becker A, Semmler W, Schlag PM, Rinneberg H. Near-infrared fluorescent dyes for enhanced contrast in optical mammography: phantom experiments. JOURNAL OF BIOMEDICAL OPTICS 2001; 6:134-140. [PMID: 11375722 DOI: 10.1117/1.1350561] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/01/2000] [Revised: 01/03/2001] [Accepted: 01/03/2001] [Indexed: 05/23/2023]
Abstract
Optical mammography with near-infrared (NIR) light using time-domain, frequency-domain, or continuous-wave techniques is a novel imaging modality to locate human breast tumors. By investigating excised specimens of normal and diseased mamma tissue we were able to demonstrate that differences in their scattering properties are a poor predictive parameter for normal and diseased mamma tissue. This paper describes the application of a NIR dye to improve the differentiation between breast tumors and normal tissue in a rat model. The NIR dye furnished a high tumor-to-tissue contrast ratio (6:1) in fluorescence images. Furthermore, this dye was used to develop liquid scattering phantoms with absorbing and fluorescent inhomogeneities. Using frequency-domain and time-domain instrumentation these inhomogeneities were localized at sufficient contrast by their increased absorption and fluorescence. Contrast between inhomogeneities and surrounding medium could be improved by combining fluorescence and transmittance images.
Collapse
Affiliation(s)
- B Ebert
- Physikalisch-Technische Bundesanstalt, Abbestrasse 2-12, D-10587 Berlin, Germany.
| | | | | | | | | | | | | | | | | | | |
Collapse
|
26
|
Ito Y, Kennan RP, Watanabe E, Koizumi H. Assessment of heating effects in skin during continuous wave near infrared spectroscopy. JOURNAL OF BIOMEDICAL OPTICS 2000; 5:383-90. [PMID: 11092426 DOI: 10.1117/1.1287730] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/02/1999] [Revised: 04/04/2000] [Accepted: 06/07/2000] [Indexed: 05/20/2023]
Abstract
Near infrared spectroscopy is an increasingly important tool for the investigation of human brain function, however, to date there have been few systematic evaluations of accompanying thermal effects due to absorption. We have measured the spatial distribution of temperature changes during near infrared irradiation (789 nm) as a function of laser power, in both excised tissue (chicken meat and skin) and in the forearm of an awake human volunteer. Light was applied using a 1 mm optical fiber which is characteristic of the topographic system. The temperature of excised chicken tissue increased linearly with power level as 0.097 and 0.042 degrees C/mW at depths of 0 and 1 mm, respectively. Human forearm studies yielded temperature changes of 0.101, 0.038, and 0.030 degrees C/mW at depths of 0.5, 1.0, and 1.5 mm, respectively. Due to direct irradiation of the thermocouple all measurements represent the maximum temperature increase from the laser. In all cases the estimated heating effects from continuous wave optical topography systems were small and well below levels which would endanger tissue cells. The close similarity between ex vivo and in vivo measurements suggests negligible contributions from blood flow in the skin which was further supported by measurements during cuff ischemia. Heating effects decreased sharply with both depth and lateral position; thus, for optode spacings greater than a few millimeters, fibers can be treated independently. Finite element analysis confirms that the experimental results are consistent with a simple heat conduction model.
Collapse
Affiliation(s)
- Y Ito
- Hitachi Central Research Laboratory, Kokubunji-shi, Tokyo, Japan
| | | | | | | |
Collapse
|
27
|
Achilefu S, Dorshow RB, Bugaj JE, Rajagopalan R. Novel receptor-targeted fluorescent contrast agents for in vivo tumor imaging. Invest Radiol 2000; 35:479-85. [PMID: 10946975 DOI: 10.1097/00004424-200008000-00004] [Citation(s) in RCA: 259] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
RATIONALE AND OBJECTIVES To evaluate the efficacy of a novel tumor receptor-specific small-peptide-near-infrared dye conjugate for tumor detection by optical imaging. METHODS A novel, near-infrared dye-peptide conjugate was synthesized and evaluated for tumor-targeting efficacy in a well-characterized rat tumor model (CA20948) known to express receptors for the chosen peptide. A simple continuous-wave optical imaging system, consisting of a near-infrared laser diode, a cooled CCD camera, and an interference filter, was used in this study. RESULTS Tumor retention of two non-tumor-specific dyes, indocyanine green and its derivatized analogue, bis-propanoic acid cyanine dye (cypate), was negligible. In contrast, the receptor-specific peptide-cypate conjugate (cytate) was retained in the CA20948 tumor, with an excellent tumor-tonormal-tissue ratio in the six rats examined. CONCLUSIONS Optical detection of tumors with a receptor-targeted fluorescent contrast agent has been demonstrated. This result represents a new direction in cancer diagnosis and patient management.
Collapse
Affiliation(s)
- S Achilefu
- Discovery Research, Mallinckrodt Inc., St. Louis, Missouri 63042, USA.
| | | | | | | |
Collapse
|
28
|
Mahmood U, Tung CH, Bogdanov A, Weissleder R. Near-infrared optical imaging of protease activity for tumor detection. Radiology 1999; 213:866-70. [PMID: 10580968 DOI: 10.1148/radiology.213.3.r99dc14866] [Citation(s) in RCA: 212] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
PURPOSE To build and test an optical imaging system that is sensitive to near-infrared fluorescent molecular probes activated by specific enzymes in tumor tissues in mice. MATERIALS AND METHODS The imaging system consisted of a source that delivered 610-650-nm excitation light within a lighttight chamber, a 700-nm longpass filter for selecting near-infrared fluorescence emission photons from tissues, and a charge-coupled device (CCD) for recording images. The molecular probe was a biocompatible autoquenched near-infrared fluorescent compound that was activated by tumor-associated proteases for cathepsins B and H. Imaging experiments were performed 0-72 hours after intravenous injection of the probe in nude mice that bore human breast carcinoma (BT-20). RESULTS The imaging system had a maximal spatial resolution of 60 microns, with a field of view of 14 cm2. The detection threshold of the nonquenched near-infrared fluorescent dye was subpicomolar in the imaging phantom experiments. In tissue, 250 pmol of fluorochrome was easily detected during the 10-second image acquisition. After intravenous injection of the probe into the tumor-bearing animals, tumors as small as 1 mm became detectable because of tumor-associated enzymatic activation of the quenched compound. CONCLUSION Tumor proteases can be used as molecular targets, allowing visualization of millimeter-sized tumors. The development of this technology, probe design, and optical imaging systems hold promise for molecular imaging, cancer detection, and evaluation of treatment.
Collapse
Affiliation(s)
- U Mahmood
- Department of Radiology, Massachusetts General Hospital, Boston 02125, USA
| | | | | | | |
Collapse
|
29
|
Weissleder R, Tung CH, Mahmood U, Bogdanov A. In vivo imaging of tumors with protease-activated near-infrared fluorescent probes. Nat Biotechnol 1999; 17:375-8. [PMID: 10207887 DOI: 10.1038/7933] [Citation(s) in RCA: 1107] [Impact Index Per Article: 44.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
We have developed a method to image tumor-associated lysosomal protease activity in a xenograft mouse model in vivo using autoquenched near-infrared fluorescence (NIRF) probes. NIRF probes were bound to a long circulating graft copolymer consisting of poly-L-lysine and methoxypolyethylene glycol succinate. Following intravenous injection, the NIRF probe carrier accumulated in solid tumors due to its long circulation time and leakage through tumor neovasculature. Intratumoral NIRF signal was generated by lysosomal proteases in tumor cells that cleave the macromolecule, thereby releasing previously quenched fluorochrome. In vivo imaging showed a 12-fold increase in NIRF signal, allowing the detection of tumors with submillimeter-sized diameters. This strategy can be used to detect such early stage tumors in vivo and to probe for specific enzyme activity.
Collapse
Affiliation(s)
- R Weissleder
- Center of Molecular Imaging Research, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA.
| | | | | | | |
Collapse
|