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Phan T, Rowland R, Ponticorvo A, Le BC, Sharif SA, Kennedy GT, Wilson RH, Durkin AJ. Quantifying the confounding effect of pigmentation on measured skin tissue optical properties: a comparison of colorimetry with spatial frequency domain imaging. J Biomed Opt 2022; 27:JBO-210337GR. [PMID: 35324096 PMCID: PMC8942554 DOI: 10.1117/1.jbo.27.3.036002] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/27/2021] [Accepted: 02/16/2022] [Indexed: 05/20/2023]
Abstract
SIGNIFICANCE Spatial frequency domain imaging (SFDI) is a wide-field diffuse optical imaging technique for separately quantifying tissue reduced scattering (μs ' ) and absorption (μa) coefficients at multiple wavelengths, providing wide potential utility for clinical applications such as burn wound characterization and cancer detection. However, measured μs ' and μa can be confounded by absorption from melanin in patients with highly pigmented skin. This issue arises because epidermal melanin is highly absorbing for visible wavelengths and standard homogeneous light-tissue interaction models do not properly account for this complexity. Tristimulus colorimetry (which quantifies pigmentation using the L * "lightness" parameter) can provide a point of comparison between μa, μs ' , and skin pigmentation. AIM We systematically compare SFDI and colorimetry parameters to quantify confounding effects of pigmentation on measured skin μs ' and μa. We assess the correlation between SFDI and colorimetry parameters as a function of wavelength. APPROACH μs ' and μa from the palm and ventral forearm were measured for 15 healthy subjects with a wide range of skin pigmentation levels (Fitzpatrick types I to VI) using a Reflect RS® (Modulim, Inc., Irvine, California) SFDI instrument (eight wavelengths, 471 to 851 nm). L * was measured using a Chroma Meter CR-400 (Konica Minolta Sensing, Inc., Tokyo). Linear correlation coefficients were calculated between L * and μs ' and between L * and μa at all wavelengths. RESULTS For the ventral forearm, strong linear correlations between measured L * and μs ' values were observed at shorter wavelengths (R > 0.92 at ≤659 nm), where absorption from melanin confounded the measured μs ' . These correlations were weaker for the palm (R < 0.59 at ≤659 nm), which has less melanin than the forearm. Similar relationships were observed between L * and μa. CONCLUSIONS We quantified the effects of epidermal melanin on skin μs ' and μa measured with SFDI. This information may help characterize and correct pigmentation-related inaccuracies in SFDI skin measurements.
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Affiliation(s)
- Thinh Phan
- University of California, Irvine, Beckman Laser Institute and Medical Clinic, Irvine, California, United States
| | - Rebecca Rowland
- University of California, Irvine, Beckman Laser Institute and Medical Clinic, Irvine, California, United States
| | - Adrien Ponticorvo
- University of California, Irvine, Beckman Laser Institute and Medical Clinic, Irvine, California, United States
| | - Binh Cong Le
- University of California, Irvine, Beckman Laser Institute and Medical Clinic, Irvine, California, United States
| | - Seyed A. Sharif
- University of California, Irvine, Beckman Laser Institute and Medical Clinic, Irvine, California, United States
| | - Gordon T. Kennedy
- University of California, Irvine, Beckman Laser Institute and Medical Clinic, Irvine, California, United States
| | - Robert H. Wilson
- University of California, Irvine, Beckman Laser Institute and Medical Clinic, Irvine, California, United States
- University of California, Irvine, Department of Medicine, Irvine, California, United States
- University of California, Irvine, Health Policy Research Institute, Irvine, California, United States
- Address all correspondence to Anthony J. Durkin, ; Robert H. Wilson,
| | - Anthony J. Durkin
- University of California, Irvine, Beckman Laser Institute and Medical Clinic, Irvine, California, United States
- University of California, Irvine, Department of Biomedical Engineering, Irvine, California, United States
- Address all correspondence to Anthony J. Durkin, ; Robert H. Wilson,
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Sayadi LR, Rowland R, Naides A, Tomlinson L, Ponticorvo A, Durkin AJ, Widgerow AD. A Quantitative Assessment of Wound Healing With Oxygenated Micro/Nanobubbles in a Preclinical Burn Model. Ann Plast Surg 2021; 87:421-426. [PMID: 34559711 PMCID: PMC8555472 DOI: 10.1097/sap.0000000000003017] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
BACKGROUND Burns are devastating injuries, carry significant morbidity, and require long-term treatment or multiple reconstructive procedures. Wound healing and secondary insults caused by burn wound conversion are amendable to therapeutic intervention, where ischemia has been cited as one of the major factors (Dermatol Surg. 2008;34:1159-1169). Halting injury progression in the zone of stasis is crucial as conversion creates increased burn surface area and depth, leading to local and systemic consequences (J Burns Wounds. 2006;5:e2). Oxygen-carrying micro/nanobubbles, MNB(O2), offer a novel technology that can be used to effectively deliver oxygen to burn wounds and potentially counteract burn wound ischemia. METHODS Topical irrigation with MNB(O2) of full-thickness burn wounds on a rodent model (n = 3) was compared against saline-treated controls (n = 3). Tissue structure (reduced scattering coefficient, μs'), oxyhemoglobin concentration (cHbO2), and tissue perfusion were quantified over the course of 28 days through spatial frequency domain imaging and laser speckle imaging. Histological samples taken at the end of the experiment were examined for evidence of wound healing. RESULTS Findings in this preliminary study showed hastened healing with significant differences in spatial frequency domain imaging-measured μs' during wound healing (days 11-28) in MNB(O2) group. The healing "tipping point" seemed to occur at days 9 to 11 with increased collagen organization and increased cHbO2 occurring around that period confirming the gross healing improvements observed. In addition, histological evidence indicated that only the MNB(O2) burns had reached the remodeling phase by the end of 28-day study period. CONCLUSIONS These preliminary findings propose the potential of MNB(O2) as a topical method for improving burn wound healing.
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Affiliation(s)
- Lohrasb R. Sayadi
- Center for Tissue Engineering, Department of Plastic Surgery, University of California, Irvine, 200 S. Manchester Ave., Suite 650, Orange, CA 92868
| | - Rebecca Rowland
- Beckman Laser Institute and Medical Clinic, University of California, Irvine, 1002 Health Sciences Road East, Irvine, CA 92617
| | - Alexandra Naides
- Center for Tissue Engineering, Department of Plastic Surgery, University of California, Irvine, 200 S. Manchester Ave., Suite 650, Orange, CA 92868
| | - Luke Tomlinson
- Center for Tissue Engineering, Department of Plastic Surgery, University of California, Irvine, 200 S. Manchester Ave., Suite 650, Orange, CA 92868
| | - Adrien Ponticorvo
- Beckman Laser Institute and Medical Clinic, University of California, Irvine, 1002 Health Sciences Road East, Irvine, CA 92617
| | - Anthony J. Durkin
- Beckman Laser Institute and Medical Clinic, University of California, Irvine, 1002 Health Sciences Road East, Irvine, CA 92617
- Department of Biomedical Engineering, University of California, Irvine, 3120 Natural Sciences II, Irvine, CA 92697
| | - Alan D. Widgerow
- Center for Tissue Engineering, Department of Plastic Surgery, University of California, Irvine, 200 S. Manchester Ave., Suite 650, Orange, CA 92868
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Kennedy GT, Kagawa K, Rowland R, Ponticorvo A, Tanida J, Durkin AJ. Spatial frequency domain imager based on a compact multiaperture camera: testing and feasibility for noninvasive burn severity assessment. J Biomed Opt 2021; 26:JBO-210116-APPEALR. [PMID: 34387050 PMCID: PMC8358666 DOI: 10.1117/1.jbo.26.8.086001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/24/2021] [Accepted: 07/26/2021] [Indexed: 05/20/2023]
Abstract
SIGNIFICANCE Spatial frequency domain imaging (SFDI) is a wide-field imaging technique that provides quantitative maps of tissue optical properties. We describe a compact SFDI imager that employs a multispectral compound-eye camera. This design enables simultaneous image acquisition at multiple wavelengths. Such a device has potential for application for quantitative evaluation of superficial tissues by nonspecialists in low-resource settings. AIM The aim of this work was to develop a compact SFDI imager for widefield imaging of in-vivo tissue optical properties and verify its ability to measure optical properties of tissue-simulating phantoms and in a preclinical model of burn wounds. APPROACH This compound-eye imager was constructed using a CMOS sensor subdivided into multiple regions, each having a bandpass filter and objective lens. The ability of the instrument to image optical properties was compared with (1) a commercial SFDI imager and (2) a laboratory-based system. Initial validation of ability to accurately characterize optical properties was performed using a tissue-simulating optical phantom. It was then applied to an established murine model of thermal contact burn severity. In-vivo measurements of the optical properties of rat skin were performed before and after the application of burns. Histology was used to verify burn severity. RESULTS Measurements of the tissue-simulating phantom optical properties made using the compound-eye imager agree with measurements made using the two comparison SFDI devices. For the murine burn model, the burns showed a decrease in the reduced scattering coefficient at all measurement wavelengths compared with preburn measurements at the same locations. This is consistent with previously reported changes in scattering that occur in full-thickness burns. CONCLUSION We demonstrate the potential for SFDI to be translated into compact form factor using a compound-eye camera that is capable of obtaining multiple wavelengths channels simultaneously.
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Affiliation(s)
- Gordon T Kennedy
- University of California, Irvine, Beckman Laser Institute and Medical Clinic, Irvine, California, United States
| | - Keiichiro Kagawa
- Shizuoka University, Research Institute of Electronics, Shizuoka, Japan
| | - Rebecca Rowland
- University of California, Irvine, Beckman Laser Institute and Medical Clinic, Irvine, California, United States
| | - Adrien Ponticorvo
- University of California, Irvine, Beckman Laser Institute and Medical Clinic, Irvine, California, United States
| | - Jun Tanida
- Osaka University, Graduate School of Information Science and Technology, Osaka, Japan
| | - Anthony J Durkin
- University of California, Irvine, Beckman Laser Institute and Medical Clinic, Irvine, California, United States
- University of California, Irvine, Department of Biomedical Engineering, Irvine, California, United States
- Address all correspondence to Anthony Durkin,
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Phan T, Rowland R, Ponticorvo A, Le BC, Wilson RH, Sharif SA, Kennedy GT, Bernal N, Durkin AJ. Characterizing reduced scattering coefficient of normal human skin across different anatomic locations and Fitzpatrick skin types using spatial frequency domain imaging. J Biomed Opt 2021; 26:JBO-200290R. [PMID: 33569936 PMCID: PMC7874851 DOI: 10.1117/1.jbo.26.2.026001] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/02/2020] [Accepted: 12/23/2020] [Indexed: 05/20/2023]
Abstract
SIGNIFICANCE Spatial frequency domain imaging (SFDI), a noncontact wide-field imaging technique using patterned illumination with multiple wavelengths, has been used to quantitatively measure structural and functional parameters of in vivo tissue. Using SFDI in a porcine model, we previously found that scattering changes in skin could potentially be used to noninvasively assess burn severity and monitor wound healing. Translating these findings to human subjects necessitates a better understanding of the variation in "baseline" human skin scattering properties across skin types and anatomical locations. AIM Using SFDI, we aim to characterize the variation in the reduced scattering coefficient (μs') for skin across a range of pigmentation and anatomic sites (including common burn locations) for normal human subjects. These measurements are expected to characterize baseline human skin properties to inform our use of SFDI for clinical burn severity and wound healing assessments. APPROACH SFDI was used to measure μs' in the visible- and near-infrared regime (471 to 851 nm) in 15 subjects at 10 anatomical locations. Subjects varied in age, gender, and Fitzpatrick skin type. RESULTS For all anatomical locations, the coefficient of variation in measured μs' decreased with increasing wavelength. High intersubject variation in μs' at visible wavelengths coincided with large values of the melanin extinction coefficient at those wavelengths. At 851 nm, where intersubject variation in μs' was smallest for all anatomical locations and absorption from melanin is minimal, significant intrasubject differences in μs' were observed at the different anatomical locations. CONCLUSIONS Our study is the first report of wide-field mapping of human skin scattering properties across multiple skin types and anatomical locations using SFDI. Measured μs' values varied notably between skin types at wavelengths where absorption from melanin was prominent. Additionally, μs' varied considerably across different anatomical locations at 851 nm, where the confounding effects from melanin absorption are minimized.
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Affiliation(s)
- Thinh Phan
- University of California, Irvine, Beckman Laser Institute and Medical Clinic, Irvine, California, United States
- University of California, Irvine, Department of Biomedical Engineering, Irvine, California, United States
| | - Rebecca Rowland
- University of California, Irvine, Beckman Laser Institute and Medical Clinic, Irvine, California, United States
| | - Adrien Ponticorvo
- University of California, Irvine, Beckman Laser Institute and Medical Clinic, Irvine, California, United States
| | - Binh C. Le
- University of California, Irvine, Beckman Laser Institute and Medical Clinic, Irvine, California, United States
| | - Robert H. Wilson
- University of California, Irvine, Beckman Laser Institute and Medical Clinic, Irvine, California, United States
| | - Seyed A. Sharif
- University of California, Irvine, Beckman Laser Institute and Medical Clinic, Irvine, California, United States
| | - Gordon T. Kennedy
- University of California, Irvine, Beckman Laser Institute and Medical Clinic, Irvine, California, United States
| | - Nicole Bernal
- University of California, Irvine, UC Irvine Regional Burn Center, Department of Surgery, Orange, California, United States
| | - Anthony J. Durkin
- University of California, Irvine, Beckman Laser Institute and Medical Clinic, Irvine, California, United States
- University of California, Irvine, Department of Biomedical Engineering, Irvine, California, United States
- Address all correspondence to Anthony J. Durkin,
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Ponticorvo A, Rowland R, Baldado M, Kennedy GT, Hosking AM, Burmeister DM, Christy RJ, Bernal NP, Durkin AJ. Spatial Frequency Domain Imaging (SFDI) of clinical burns: A case report. Burns Open 2020; 4:67-71. [PMID: 32832745 PMCID: PMC7442210 DOI: 10.1016/j.burnso.2020.02.004] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
While visual assessment by a clinician is the standard of care for burn severity evaluations, new technologies at various stages of development are attempting to add objectivity to this practice by quantifying burn severity. Assessment accuracy generally improves after the burn injury has progressed, but early assessments that correctly identify superficial partial and deep partial burns have the potential to lead to more prompt treatments and shorter recovery times. To date, Spatial Frequency Domain Imaging (SFDI) has only been used in animal models of burns, but has shown the potential to categorize burns accurately at earlier time points. Here we examine the potential for SFDI to assess burn severity in clinical patients. We also utilize Laser Speckle Imaging (LSI), an FDA cleared non-invasive imaging technology that typically measures blood perfusion in order to evaluate burns in clinical patients. We present a case series of two patients, both with partial thickness burns of varying severity. Partial thickness burns are often difficult for clinicians to categorize based on visual appearance alone. SFDI and LSI were both performed on each patient at approximately 24 and 72 h after their respective burn incidents. Each technique was able to render spatially resolved information that enabled improved assessment accuracy for each burn. This represents the first publication of SFDI applied to clinical burn patients after being successfully utilized in animal models, and highlights the potential for SFDI as a feasible tool for the timely categorization of burn severity.
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Affiliation(s)
- Adrien Ponticorvo
- Beckman Laser Institute and Medical Clinic, University of
California, Irvine, 1002 Health Sciences Road East, Irvine, CA 92617, United
States
| | - Rebecca Rowland
- Beckman Laser Institute and Medical Clinic, University of
California, Irvine, 1002 Health Sciences Road East, Irvine, CA 92617, United
States
| | - Melissa Baldado
- Beckman Laser Institute and Medical Clinic, University of
California, Irvine, 1002 Health Sciences Road East, Irvine, CA 92617, United
States
| | - Gordon T. Kennedy
- Beckman Laser Institute and Medical Clinic, University of
California, Irvine, 1002 Health Sciences Road East, Irvine, CA 92617, United
States
| | - Anna-Marie Hosking
- UC Irvine Medical Center, Department of Surgery, 333 City
Boulevard West, Suite 705, Orange, CA 92868, United States
| | - David M. Burmeister
- United States Army Institute of Surgical Research, 3650
Chambers Pass, Fort Sam Houston, TX, 78234, United States
| | - Robert J. Christy
- United States Army Institute of Surgical Research, 3650
Chambers Pass, Fort Sam Houston, TX, 78234, United States
| | - Nicole P. Bernal
- UC Irvine Medical Center, Department of Surgery, 333 City
Boulevard West, Suite 705, Orange, CA 92868, United States
| | - Anthony J. Durkin
- Beckman Laser Institute and Medical Clinic, University of
California, Irvine, 1002 Health Sciences Road East, Irvine, CA 92617, United
States
- Department of Biomedical Engineering, University of
California, Irvine, 3120 Natural Sciences II, Irvine, CA 92697, United States
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Rowland R, Ponticorvo A, Jarrin Lopez A, Li S, Li X, Ichii H, Durkin AJ. Monitoring kidney optical properties during cold storage preservation with spatial frequency domain imaging. J Biomed Opt 2019; 24:1-7. [PMID: 31777223 PMCID: PMC6882458 DOI: 10.1117/1.jbo.24.11.116003] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/26/2019] [Accepted: 11/11/2019] [Indexed: 05/18/2023]
Abstract
Transplantation of kidneys results in delayed graft function in as many as 40% of cases. During the organ transplantation process, donor kidneys undergo a period of cold ischemic time (CIT), where the organ is preserved with a cold storage solution to maintain tissue viability. Some complications observed after grafting may be due to damage sustained to the kidney during CIT. However, the effects due to this damage are not apparent until well after transplant surgery has concluded. To this end, we have used spatial frequency domain imaging (SFDI) to measure spatially resolved optical properties of porcine kidneys over the course of 80-h CIT. During this time, we observed an increase in both reduced scattering (μ s& ' ) and absorption (μa) coefficients. The measured scattering b parameter increased until 24 h of CIT, then returned toward baseline during the remaining duration of the imaging sequence. These results show that the optical properties of kidney tissue change with increasing CIT and suggest that continued investigation into the application of SFDI to kidneys under CIT may lead to the development of a noninvasive method for assessing graft viability.
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Affiliation(s)
- Rebecca Rowland
- University of California, Irvine, Beckman Laser Institute and Medical Clinic, Irvine, California, United States
| | - Adrien Ponticorvo
- University of California, Irvine, Beckman Laser Institute and Medical Clinic, Irvine, California, United States
| | - Alberto Jarrin Lopez
- University of California, Irvine, Department of Surgery, UC Irvine Division of Transplantation, Orange, California, United States
| | - Shiri Li
- University of California, Irvine, Department of Surgery, UC Irvine Division of Transplantation, Orange, California, United States
| | - Xiaodong Li
- UC Irvine Health Douglas Hospital, Department of Pathology, Orange, California, United States
| | - Hirohito Ichii
- University of California, Irvine, Department of Surgery, UC Irvine Division of Transplantation, Orange, California, United States
| | - Anthony J. Durkin
- University of California, Irvine, Beckman Laser Institute and Medical Clinic, Irvine, California, United States
- University of California, Irvine, Department of Biomedical Engineering, Irvine, California, United States
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Kennedy GT, Stone R, Kowalczewski AC, Rowland R, Chen JH, Baldado ML, Ponticorvo A, Bernal N, Christy RJ, Durkin AJ. Spatial frequency domain imaging: a quantitative, noninvasive tool for in vivo monitoring of burn wound and skin graft healing. J Biomed Opt 2019; 24:1-9. [PMID: 31313538 PMCID: PMC6630099 DOI: 10.1117/1.jbo.24.7.071615] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/12/2018] [Accepted: 06/27/2019] [Indexed: 05/12/2023]
Abstract
There is a need for noninvasive, quantitative methods to characterize wound healing in the context of longitudinal investigations related to regenerative medicine. Such tools have the potential to inform the assessment of wound status and healing progression and aid the development of new treatments. We employed spatial frequency domain imaging (SFDI) to characterize the changes in optical properties of tissue during wound healing progression in a porcine model of split-thickness skin grafts and also in a model of burn wound healing with no graft intervention. Changes in the reduced scattering coefficient measured using SFDI correlated with structural changes reported by histology of biopsies taken concurrently. SFDI was able to measure spatial inhomogeneity in the wounds and predicted heterogeneous healing. In addition, we were able to visualize differences in healing rate, depending on whether a wound was debrided and grafted, versus not debrided and left to heal without intervention apart from topical burn wound care. Changes in the concentration of oxy- and deoxyhemoglobin were also quantified, giving insight into hemodynamic changes during healing.
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Affiliation(s)
- Gordon T. Kennedy
- University of California, Beckman Laser Institute and Medical Clinic, Irvine, California, United States
| | - Randolph Stone
- Combat Trauma and Burn Injury Research, United States Army Institute of Surgical Research, JBSA Fort Sam Houston, Texas, United States
| | - Andrew C. Kowalczewski
- Combat Trauma and Burn Injury Research, United States Army Institute of Surgical Research, JBSA Fort Sam Houston, Texas, United States
| | - Rebecca Rowland
- University of California, Beckman Laser Institute and Medical Clinic, Irvine, California, United States
| | - Jeffrey H. Chen
- University of California, Beckman Laser Institute and Medical Clinic, Irvine, California, United States
| | - Melissa L. Baldado
- University of California, Beckman Laser Institute and Medical Clinic, Irvine, California, United States
| | - Adrien Ponticorvo
- University of California, Beckman Laser Institute and Medical Clinic, Irvine, California, United States
| | - Nicole Bernal
- UC Irvine Regional Burn Center, Department of Surgery, Orange, California, United States
| | - Robert J. Christy
- Combat Trauma and Burn Injury Research, United States Army Institute of Surgical Research, JBSA Fort Sam Houston, Texas, United States
| | - Anthony J. Durkin
- University of California, Beckman Laser Institute and Medical Clinic, Irvine, California, United States
- University of California, Department of Biomedical Engineering, Irvine, California, United States
- Address all correspondence to Anthony J. Durkin, E-mail:
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8
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Rowland R, Ponticorvo A, Baldado M, Kennedy GT, Burmeister DM, Christy RJ, Bernal NP, Durkin AJ. Burn wound classification model using spatial frequency-domain imaging and machine learning. J Biomed Opt 2019; 24:1-9. [PMID: 31134769 PMCID: PMC6536007 DOI: 10.1117/1.jbo.24.5.056007] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/17/2018] [Accepted: 05/02/2019] [Indexed: 05/13/2023]
Abstract
Accurate assessment of burn severity is critical for wound care and the course of treatment. Delays in classification translate to delays in burn management, increasing the risk of scarring and infection. To this end, numerous imaging techniques have been used to examine tissue properties to infer burn severity. Spatial frequency-domain imaging (SFDI) has also been used to characterize burns based on the relationships between histologic observations and changes in tissue properties. Recently, machine learning has been used to classify burns by combining optical features from multispectral or hyperspectral imaging. Rather than employ models of light propagation to deduce tissue optical properties, we investigated the feasibility of using SFDI reflectance data at multiple spatial frequencies, with a support vector machine (SVM) classifier, to predict severity in a porcine model of graded burns. Calibrated reflectance images were collected using SFDI at eight wavelengths (471 to 851 nm) and five spatial frequencies (0 to 0.2 mm - 1). Three models were built from subsets of this initial dataset. The first subset included data taken at all wavelengths with the planar (0 mm - 1) spatial frequency, the second comprised data at all wavelengths and spatial frequencies, and the third used all collected data at values relative to unburned tissue. These data subsets were used to train and test cubic SVM models, and compared against burn status 28 days after injury. Model accuracy was established through leave-one-out cross-validation testing. The model based on images obtained at all wavelengths and spatial frequencies predicted burn severity at 24 h with 92.5% accuracy. The model composed of all values relative to unburned skin was 94.4% accurate. By comparison, the model that employed only planar illumination was 88.8% accurate. This investigation suggests that the combination of SFDI with machine learning has potential for accurately predicting burn severity.
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Affiliation(s)
- Rebecca Rowland
- University of California, Irvine, Beckman Laser Institute and Medical Clinic, Irvine, California, United States
| | - Adrien Ponticorvo
- University of California, Irvine, Beckman Laser Institute and Medical Clinic, Irvine, California, United States
| | - Melissa Baldado
- University of California, Irvine, Beckman Laser Institute and Medical Clinic, Irvine, California, United States
| | - Gordon T. Kennedy
- University of California, Irvine, Beckman Laser Institute and Medical Clinic, Irvine, California, United States
| | - David M. Burmeister
- United States Army Institute of Surgical Research, San Antonio, Texas, United States
| | - Robert J. Christy
- United States Army Institute of Surgical Research, San Antonio, Texas, United States
| | - Nicole P. Bernal
- UC Irvine Regional Burn Center, Department of Surgery, Orange, California, United States
| | - Anthony J. Durkin
- University of California, Irvine, Beckman Laser Institute and Medical Clinic, Irvine, California, United States
- University of California, Irvine, Department of Biomedical Engineering, Irvine, California, United States
- Address all correspondence to Anthony J. Durkin, E-mail:
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Rowland R, Ponticorvo A, Burmeister D, Christy R, Bernal N, Durkin A. 359 Burn Wound Severity Prediction in a Porcine Model using Spatial Frequency Domain Imaging & Machine Learning. J Burn Care Res 2019. [DOI: 10.1093/jbcr/irz013.269] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Affiliation(s)
- R Rowland
- Beckman Laser Institute, Irvine, CA; United States Army Institute of Surgical Research, San Antonio, TX; UC Irvine Regional Burn Center, Department of Surgery, Orange, CA
| | - A Ponticorvo
- Beckman Laser Institute, Irvine, CA; United States Army Institute of Surgical Research, San Antonio, TX; UC Irvine Regional Burn Center, Department of Surgery, Orange, CA
| | - D Burmeister
- Beckman Laser Institute, Irvine, CA; United States Army Institute of Surgical Research, San Antonio, TX; UC Irvine Regional Burn Center, Department of Surgery, Orange, CA
| | - R Christy
- Beckman Laser Institute, Irvine, CA; United States Army Institute of Surgical Research, San Antonio, TX; UC Irvine Regional Burn Center, Department of Surgery, Orange, CA
| | - N Bernal
- Beckman Laser Institute, Irvine, CA; United States Army Institute of Surgical Research, San Antonio, TX; UC Irvine Regional Burn Center, Department of Surgery, Orange, CA
| | - A Durkin
- Beckman Laser Institute, Irvine, CA; United States Army Institute of Surgical Research, San Antonio, TX; UC Irvine Regional Burn Center, Department of Surgery, Orange, CA
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Saager RB, Rowland RA, Baldado ML, Kennedy GT, Bernal NP, Ponticorvo A, Christy RJ, Durkin AJ. Impact of hemoglobin breakdown products in the spectral analysis of burn wounds using spatial frequency domain spectroscopy. J Biomed Opt 2019; 24:1-4. [PMID: 30724041 PMCID: PMC6398280 DOI: 10.1117/1.jbo.24.2.020501] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/17/2018] [Accepted: 01/15/2019] [Indexed: 05/23/2023]
Abstract
Burn wounds and wound healing invoke several biological processes that may complicate the interpretation of spectral imaging data. Through analysis of spatial frequency domain spectroscopy data (450 to 1000 nm) obtained from longitudinal investigations using a graded porcine burn wound healing model, we have identified features in the absorption spectrum that appear to suggest the presence of hemoglobin breakdown products, e.g., methemoglobin. Our results show that the calculated concentrations of methemoglobin directly correlate with burn severity, 24 h after the injury. In addition, tissue parameters such as oxygenation (StO2) and water fraction may be underestimated by 20% and 78%, respectively, if methemoglobin is not included in the spectral analysis.
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Affiliation(s)
- Rolf B Saager
- University of California Irvine, Beckman Laser Institute and Medical Clinic, Irvine, California, United States
| | - Rebecca A Rowland
- University of California Irvine, Beckman Laser Institute and Medical Clinic, Irvine, California, United States
| | - Melissa L Baldado
- University of California Irvine, Beckman Laser Institute and Medical Clinic, Irvine, California, United States
| | - Gordon T Kennedy
- University of California Irvine, Beckman Laser Institute and Medical Clinic, Irvine, California, United States
| | - Nicole P Bernal
- UC Irvine Regional Burn Center, Department of Surgery, Orange, California, United States
| | - Adrien Ponticorvo
- University of California Irvine, Beckman Laser Institute and Medical Clinic, Irvine, California, United States
| | - Robert J Christy
- United States Army Institute of Surgical Research, Burn and Soft Tissue Injury, San Antonio, Texas, United States
| | - Anthony J Durkin
- University of California Irvine, Beckman Laser Institute and Medical Clinic, Irvine, California, United States
- University of California Irvine, Department of Biomedical Engineering, Irvine, California, United States
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11
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Ponticorvo A, Rowland R, Baldado M, Burmeister DM, Christy RJ, Bernal NP, Durkin AJ. Evaluating clinical observation versus Spatial Frequency Domain Imaging (SFDI), Laser Speckle Imaging (LSI) and thermal imaging for the assessment of burn depth. Burns 2018; 45:450-460. [PMID: 30327232 DOI: 10.1016/j.burns.2018.09.026] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2018] [Revised: 08/31/2018] [Accepted: 09/13/2018] [Indexed: 01/14/2023]
Abstract
While clinical examination is needed for burn severity diagnosis, several emerging technologies aim to quantify this process for added objectivity. Accurate assessments become easier after burn progression, but earlier assessments of partial thickness burn depth could lead to earlier excision and grafting and subsequent improved healing times, reduced rates of scarring/infection, and shorter hospital stays. Spatial Frequency Domain Imaging (SFDI), Laser Speckle Imaging (LSI) and thermal imaging are three non-invasive imaging modalities that have some diagnostic ability for noninvasive assessment of burn severity, but have not been compared in a controlled experiment. Here we tested the ability of these imaging techniques to assess the severity of histologically confirmed graded burns in a swine model. Controlled, graded burn wounds, 3cm in diameter were created on the dorsum of Yorkshire pigs (n=3, 45-55kg) using a custom-made burn tool that ensures consistent pressure has been employed by various burn research groups. For each pig, a total of 16 burn wounds were created on the dorsal side. Biopsies were taken for histological analysis to verify the severity of the burn. Clinical analysis, SFDI, LSI and thermal imaging were performed at 24 and 72h after burn to assess the accuracy of each imaging technique. In terms of diagnostic accuracy, using histology as a reference, SFDI (85%) and clinical analysis (83%) performed significantly better that LSI (75%) and thermography (73%) 24h after the burn. There was no statistically significant improvement from 24 to 72h across the different imaging modalities. These data indicate that these imaging modalities, and specifically SFDI, can be added to the burn clinicians' toolbox to aid in early assessment of burn severity.
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Affiliation(s)
- Adrien Ponticorvo
- Beckman Laser Institute and Medical Clinic, University of California, 1002 Health Sciences Road East, Irvine, CA 92617, United States
| | - Rebecca Rowland
- Beckman Laser Institute and Medical Clinic, University of California, 1002 Health Sciences Road East, Irvine, CA 92617, United States
| | - Melissa Baldado
- Beckman Laser Institute and Medical Clinic, University of California, 1002 Health Sciences Road East, Irvine, CA 92617, United States
| | - David M Burmeister
- United States Army Institute of Surgical Research, 3650 Chambers Pass, Fort Sam Houston, TX, 78234, United States
| | - Robert J Christy
- United States Army Institute of Surgical Research, 3650 Chambers Pass, Fort Sam Houston, TX, 78234, United States
| | - Nicole P Bernal
- UC Irvine Regional Burn Center, Department of Surgery, 333 City Boulevard West, Suite 705, Orange, CA 92868, United States
| | - Anthony J Durkin
- Beckman Laser Institute and Medical Clinic, University of California, 1002 Health Sciences Road East, Irvine, CA 92617, United States; Department of Biomedical Engineering, University of California, 3120 Natural Sciences II, Irvine, CA 92697, United States.
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12
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Saidian M, Lakey JRT, Ponticorvo A, Rowland R, Baldado M, Williams J, Pronda M, Alexander M, Flores A, Shiri L, Zhang S, Choi B, Kohen R, Tromberg BJ, Durkin AJ. Characterisation of impaired wound healing in a preclinical model of induced diabetes using wide-field imaging and conventional immunohistochemistry assays. Int Wound J 2018; 16:144-152. [PMID: 30273979 DOI: 10.1111/iwj.13005] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2018] [Revised: 09/06/2018] [Accepted: 09/07/2018] [Indexed: 12/17/2022] Open
Abstract
Major complications of diabetes lead to inflammation and oxidative stress, delayed wound healing, and persistent ulcers. The high morbidity, mortality rate, and associated costs of management suggest a need for non-invasive methods that will enable the early detection of at-risk tissue. We have compared the wound-healing process that occurs in streptozotocin (STZ)-treated diabetic rats with non-diabetic controls using contrast changes in colour photography (ie, Weber Contrast) and the non-invasive optical method Spatial Frequency Domain Imaging (SFDI). This technology can be used to quantify the structural and metabolic properties of in-vivo tissue by measuring oxyhaemoglobin concentration (HbO2 ), deoxyhaemoglobin concentration (Hb), and oxygen saturation (StO2 ) within the visible boundaries of each wound. We also evaluated the changes in inducible nitric oxide synthase (iNOS) in the dermis using immunohistochemistry. Contrast changes in colour photographs showed that diabetic rats healed at a slower rate in comparison with non-diabetic control, with the most significant change occurring at 7 days after the punch biopsy. We observed lower HbO2 , StO2 , and elevated Hb concentrations in the diabetic wounds. The iNOS level was higher in the dermis of the diabetic rats compared with the non-diabetic rats. Our results showed that, in diabetes, there is higher level of iNOS that can lead to an observed reduction in HbO2 levels. iNOS is linked to increased inflammation, leading to prolonged wound healing. Our results suggest that SFDI has potential as a non-invasive assessment of markers of wound-healing impairment.
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Affiliation(s)
- Mayer Saidian
- The Institute for Drug Research, School of Pharmacy, The Hebrew University of Jerusalem, Jerusalem, Israel.,Beckman Laser Institute and Medical Clinic, University of California Irvine, Irvine, California
| | - Jonathan R T Lakey
- Department of Surgery, University of California Irvine, Orange, California
| | - Adrien Ponticorvo
- Beckman Laser Institute and Medical Clinic, University of California Irvine, Irvine, California
| | - Rebecca Rowland
- Beckman Laser Institute and Medical Clinic, University of California Irvine, Irvine, California
| | - Melissa Baldado
- Beckman Laser Institute and Medical Clinic, University of California Irvine, Irvine, California
| | - Joshua Williams
- Beckman Laser Institute and Medical Clinic, University of California Irvine, Irvine, California
| | - Maaikee Pronda
- Beckman Laser Institute and Medical Clinic, University of California Irvine, Irvine, California
| | - Michael Alexander
- Department of Surgery, University of California Irvine, Orange, California
| | - Antonio Flores
- Department of Surgery, University of California Irvine, Orange, California
| | - Li Shiri
- Department of Surgery, University of California Irvine, Orange, California
| | - Stellar Zhang
- Department of Surgery, University of California Irvine, Orange, California
| | - Bernard Choi
- Beckman Laser Institute and Medical Clinic, University of California Irvine, Irvine, California.,Department of Biomedical Engineering, University of California Irvine, Irvine, California.,Edwards Life Sciences Center for Advanced Cardiovascular Technology, University of California Irvine, Irvine, California
| | - Roni Kohen
- The Institute for Drug Research, School of Pharmacy, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Bruce J Tromberg
- Beckman Laser Institute and Medical Clinic, University of California Irvine, Irvine, California.,Department of Biomedical Engineering, University of California Irvine, Irvine, California
| | - Anthony J Durkin
- Beckman Laser Institute and Medical Clinic, University of California Irvine, Irvine, California.,Department of Biomedical Engineering, University of California Irvine, Irvine, California
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13
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Lertsakdadet B, Yang BY, Dunn CE, Ponticorvo A, Crouzet C, Bernal N, Durkin AJ, Choi B. Correcting for motion artifact in handheld laser speckle images. J Biomed Opt 2018; 23:1-7. [PMID: 29546735 PMCID: PMC5852319 DOI: 10.1117/1.jbo.23.3.036006] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/17/2017] [Accepted: 02/21/2018] [Indexed: 05/03/2023]
Abstract
Laser speckle imaging (LSI) is a wide-field optical technique that enables superficial blood flow quantification. LSI is normally performed in a mounted configuration to decrease the likelihood of motion artifact. However, mounted LSI systems are cumbersome and difficult to transport quickly in a clinical setting for which portability is essential in providing bedside patient care. To address this issue, we created a handheld LSI device using scientific grade components. To account for motion artifact of the LSI device used in a handheld setup, we incorporated a fiducial marker (FM) into our imaging protocol and determined the difference between highest and lowest speckle contrast values for the FM within each data set (Kbest and Kworst). The difference between Kbest and Kworst in mounted and handheld setups was 8% and 52%, respectively, thereby reinforcing the need for motion artifact quantification. When using a threshold FM speckle contrast value (KFM) to identify a subset of images with an acceptable level of motion artifact, mounted and handheld LSI measurements of speckle contrast of a flow region (KFLOW) in in vitro flow phantom experiments differed by 8%. Without the use of the FM, mounted and handheld KFLOW values differed by 20%. To further validate our handheld LSI device, we compared mounted and handheld data from an in vivo porcine burn model of superficial and full thickness burns. The speckle contrast within the burn region (KBURN) of the mounted and handheld LSI data differed by <4 % when accounting for motion artifact using the FM, which is less than the speckle contrast difference between superficial and full thickness burns. Collectively, our results suggest the potential of handheld LSI with an FM as a suitable alternative to mounted LSI, especially in challenging clinical settings with space limitations such as the intensive care unit.
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Affiliation(s)
- Ben Lertsakdadet
- Beckman Laser Institute and Medical Clinic, Irvine, California, United States
- University of California, Department of Biomedical Engineering, Irvine, California, United States
- University of California, Irvine, California, United States
| | - Bruce Y. Yang
- Beckman Laser Institute and Medical Clinic, Irvine, California, United States
- University of California, Irvine, California, United States
| | - Cody E. Dunn
- Beckman Laser Institute and Medical Clinic, Irvine, California, United States
- University of California, Department of Biomedical Engineering, Irvine, California, United States
- University of California, Irvine, California, United States
| | - Adrien Ponticorvo
- Beckman Laser Institute and Medical Clinic, Irvine, California, United States
- University of California, Irvine, California, United States
| | - Christian Crouzet
- Beckman Laser Institute and Medical Clinic, Irvine, California, United States
- University of California, Department of Biomedical Engineering, Irvine, California, United States
- University of California, Irvine, California, United States
| | - Nicole Bernal
- University of California, Irvine, California, United States
- University of California, Department of Surgery, Irvine, California, United States
| | - Anthony J. Durkin
- Beckman Laser Institute and Medical Clinic, Irvine, California, United States
- University of California, Department of Biomedical Engineering, Irvine, California, United States
- University of California, Irvine, California, United States
| | - Bernard Choi
- Beckman Laser Institute and Medical Clinic, Irvine, California, United States
- University of California, Department of Biomedical Engineering, Irvine, California, United States
- University of California, Irvine, California, United States
- Address all correspondence to: Bernard Choi, E-mail:
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14
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Kennedy GT, Lentsch GR, Trieu B, Ponticorvo A, Saager RB, Durkin AJ. Solid tissue simulating phantoms having absorption at 970 nm for diffuse optics. J Biomed Opt 2017; 22:76013. [PMID: 28727869 PMCID: PMC5518810 DOI: 10.1117/1.jbo.22.7.076013] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/09/2017] [Accepted: 06/26/2017] [Indexed: 05/14/2023]
Abstract
Tissue simulating phantoms can provide a valuable platform for quantitative evaluation of the performance of diffuse optical devices. While solid phantoms have been developed for applications related to characterizing exogenous fluorescence and intrinsic chromophores such as hemoglobin and melanin, we report the development of a poly(dimethylsiloxane) (PDMS) tissue phantom that mimics the spectral characteristics of tissue water. We have developed these phantoms to mimic different water fractions in tissue, with the purpose of testing new devices within the context of clinical applications such as burn wound triage. Compared to liquid phantoms, cured PDMS phantoms are easier to transport and use and have a longer usable life than gelatin-based phantoms. As silicone is hydrophobic, 9606 dye was used to mimic the optical absorption feature of water in the vicinity of 970 nm. Scattering properties are determined by adding titanium dioxide, which yields a wavelength-dependent scattering coefficient similar to that observed in tissue in the near-infrared. Phantom properties were characterized and validated using the techniques of inverse adding-doubling and spatial frequency domain imaging. Results presented here demonstrate that we can fabricate solid phantoms that can be used to simulate different water fractions
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Affiliation(s)
- Gordon T. Kennedy
- University of California, Beckman Laser Institute and Medical Clinic, Irvine, California, United States
| | - Griffin R. Lentsch
- University of California, Beckman Laser Institute and Medical Clinic, Irvine, California, United States
| | - Brandon Trieu
- University of California, Beckman Laser Institute and Medical Clinic, Irvine, California, United States
| | - Adrien Ponticorvo
- University of California, Beckman Laser Institute and Medical Clinic, Irvine, California, United States
| | - Rolf B. Saager
- University of California, Beckman Laser Institute and Medical Clinic, Irvine, California, United States
| | - Anthony J. Durkin
- University of California, Beckman Laser Institute and Medical Clinic, Irvine, California, United States
- University of California, Department of Biomedical Engineering, Irvine, California, United States
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15
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Ponticorvo A, Burmeister DM, Rowland R, Baldado M, Kennedy GT, Saager R, Bernal N, Choi B, Durkin AJ. Quantitative long-term measurements of burns in a rat model using Spatial Frequency Domain Imaging (SFDI) and Laser Speckle Imaging (LSI). Lasers Surg Med 2017; 49:293-304. [PMID: 28220508 DOI: 10.1002/lsm.22647] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/25/2017] [Indexed: 01/05/2023]
Abstract
BACKGROUND AND OJECTIVES The current standard for diagnosis of burn severity and subsequent wound healing is through clinical examination, which is highly subjective. Several new technologies are shifting focus to burn care in an attempt to help quantify not only burn depth but also the progress of healing. While accurate early assessment of partial thickness burns is critical for dictating the course of treatment, the ability to quantitatively monitor wound status over time is critical for understanding treatment efficacy. SFDI and LSI are both non-invasive imaging modalities that have been shown to have great diagnostic value for burn severity, but have yet to be tested over the course of wound healing. METHODS In this study, a hairless rat model (n = 6, 300-450 g) was used with a four pronged comb to create four identical partial thickness burns (superficial n = 3 and deep n = 3) that were used to monitor wound healing over a 28 days period. Weekly biopsies were taken for histological analysis to verify wound progression. Both SFDI and LSI were performed weekly to track the evolution of hemodynamic (blood flow and oxygen saturation) and structural (reduced scattering coefficient) properties for the burns. RESULTS LSI showed significant changes in blood flow from baseline to 220% in superficial and 165% in deep burns by day 7. In superficial burns, blood flow returned to baseline levels by day 28, but not for deep burns where blood flow remained elevated. Smaller increases in blood flow were also observed in the surrounding tissue over the same time period. Oxygen saturation values measured with SFDI showed a progressive increase from baseline values of 66-74% in superficial burns and 72% in deep burns by day 28. Additionally, SFDI showed significant decreases in the reduced scattering coefficient shortly after the burns were created. The scattering coefficient progressively decreased in the wound area, but returned towards baseline conditions at the end of the 28 days period. Scattering changes in the surrounding tissue remained constant despite the presence of hemodynamic changes. CONCLUSIONS Here, we show that LSI and SFDI are capable of monitoring changes in hemodynamic and scattering properties in burn wounds over a 28 days period. These results highlight the potential insights that can be gained by using non-invasive imaging technologies to study wound healing. Further development of these technologies could be revolutionary for wound monitoring and studying the efficacy of different treatments. Lasers Surg. Med. 49:293-304, 2017. © 2017 Wiley Periodicals, Inc.
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Affiliation(s)
- Adrien Ponticorvo
- Beckman Laser Institute Medical Clinic, University of California, Irvine, 1002 Health Sciences Road East, Irvine, California 92617
| | - David M Burmeister
- United States Army Institute of Surgical Research, 36950 Chambers Pass, Fort Sam Houston, Texas 78234
| | - Rebecca Rowland
- Beckman Laser Institute Medical Clinic, University of California, Irvine, 1002 Health Sciences Road East, Irvine, California 92617
| | - Melissa Baldado
- Beckman Laser Institute Medical Clinic, University of California, Irvine, 1002 Health Sciences Road East, Irvine, California 92617
| | - Gordon T Kennedy
- Beckman Laser Institute Medical Clinic, University of California, Irvine, 1002 Health Sciences Road East, Irvine, California 92617
| | - Rolf Saager
- Beckman Laser Institute Medical Clinic, University of California, Irvine, 1002 Health Sciences Road East, Irvine, California 92617
| | - Nicole Bernal
- Department of Surgery, UC Irvine Regional Burn Center, 333 City Boulevard West, Suite 705, Orange, California 92868
| | - Bernard Choi
- Beckman Laser Institute Medical Clinic, University of California, Irvine, 1002 Health Sciences Road East, Irvine, California 92617.,Department of Biomedical Engineering, University of California, Irvine, 3120 Natural Sciences II, Irvine, California 92697
| | - Anthony J Durkin
- Beckman Laser Institute Medical Clinic, University of California, Irvine, 1002 Health Sciences Road East, Irvine, California 92617
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16
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Lin AJ, Ponticorvo A, Durkin AJ, Venugopalan V, Choi B, Tromberg BJ. Differential pathlength factor informs evoked stimulus response in a mouse model of Alzheimer's disease. Neurophotonics 2015; 2:045001. [PMID: 26835482 PMCID: PMC4718154 DOI: 10.1117/1.nph.2.4.045001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/27/2015] [Accepted: 09/15/2015] [Indexed: 05/03/2023]
Abstract
Baseline optical properties are typically assumed in calculating the differential pathlength factor (DPF) of mouse brains, a value used in the modified Beer-Lambert law to characterize an evoked stimulus response. We used spatial frequency domain imaging to measure in vivo baseline optical properties in 20-month-old control ([Formula: see text]) and triple transgenic APP/PS1/tau (3xTg-AD) ([Formula: see text]) mouse brains. Average [Formula: see text] for control and 3xTg-AD mice was [Formula: see text] and [Formula: see text], respectively, at 460 nm; and [Formula: see text] and [Formula: see text], respectively, at 530 nm. Average [Formula: see text] for control and 3xTg-AD mice was [Formula: see text] and [Formula: see text], respectively, at 460 nm; and [Formula: see text] and [Formula: see text], respectively, at 530 nm. The calculated DPF for control and 3xTg-AD mice was [Formula: see text] and [Formula: see text] OD mm, respectively, at 460 nm; and [Formula: see text] and [Formula: see text] OD mm, respectively, at 530 nm. In hindpaw stimulation experiments, the hemodynamic increase in brain tissue concentration of oxyhemoglobin was threefold larger and two times longer in the control mice compared to 3xTg-AD mice. Furthermore, the washout of deoxyhemoglobin from increased brain perfusion was seven times larger in controls compared to 3xTg-AD mice ([Formula: see text]).
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Affiliation(s)
- Alexander J. Lin
- University of California, Irvine, Beckman Laser Institute and Medical Clinic, 1002 Health Sciences Road, Irvine, California 92612, United States
- University of California, Irvine, Department of Biomedical Engineering, 3120 Natural Sciences II, Irvine, California 92697-2715, United States
| | - Adrien Ponticorvo
- University of California, Irvine, Beckman Laser Institute and Medical Clinic, 1002 Health Sciences Road, Irvine, California 92612, United States
| | - Anthony J. Durkin
- University of California, Irvine, Beckman Laser Institute and Medical Clinic, 1002 Health Sciences Road, Irvine, California 92612, United States
| | - Vasan Venugopalan
- University of California, Irvine, Beckman Laser Institute and Medical Clinic, 1002 Health Sciences Road, Irvine, California 92612, United States
- University of California, Irvine, Department of Chemical Engineering and Materials Science, 916 Engineering Tower, Irvine, California 92697-2575, United States
| | - Bernard Choi
- University of California, Irvine, Beckman Laser Institute and Medical Clinic, 1002 Health Sciences Road, Irvine, California 92612, United States
- University of California, Irvine, Department of Biomedical Engineering, 3120 Natural Sciences II, Irvine, California 92697-2715, United States
- University of California, Irvine, Edwards Lifesciences Center for Advanced Cardiovascular Technology, 2400 Engineering Hall, Irvine, California 92697-2730, United States
| | - Bruce J. Tromberg
- University of California, Irvine, Beckman Laser Institute and Medical Clinic, 1002 Health Sciences Road, Irvine, California 92612, United States
- University of California, Irvine, Department of Biomedical Engineering, 3120 Natural Sciences II, Irvine, California 92697-2715, United States
- Address all correspondence to: Bruce J. Tromberg, E-mail:
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17
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Burmeister DM, Ponticorvo A, Yang B, Becerra SC, Choi B, Durkin AJ, Christy RJ. Utility of spatial frequency domain imaging (SFDI) and laser speckle imaging (LSI) to non-invasively diagnose burn depth in a porcine model. Burns 2015; 41:1242-52. [PMID: 26138371 DOI: 10.1016/j.burns.2015.03.001] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2014] [Revised: 02/26/2015] [Accepted: 03/02/2015] [Indexed: 01/26/2023]
Abstract
Surgical intervention of second degree burns is often delayed because of the difficulty in visual diagnosis, which increases the risk of scarring and infection. Non-invasive metrics have shown promise in accurately assessing burn depth. Here, we examine the use of spatial frequency domain imaging (SFDI) and laser speckle imaging (LSI) for predicting burn depth. Contact burn wounds of increasing severity were created on the dorsum of a Yorkshire pig, and wounds were imaged with SFDI/LSI starting immediately after-burn and then daily for the next 4 days. In addition, on each day the burn wounds were biopsied for histological analysis of burn depth, defined by collagen coagulation, apoptosis, and adnexal/vascular necrosis. Histological results show that collagen coagulation progressed from day 0 to day 1, and then stabilized. Results of burn wound imaging using non-invasive techniques were able to produce metrics that correlate to different predictors of burn depth. Collagen coagulation and apoptosis correlated with SFDI scattering coefficient parameter [Formula: see text] and adnexal/vascular necrosis on the day of burn correlated with blood flow determined by LSI. Therefore, incorporation of SFDI scattering coefficient and blood flow determined by LSI may provide an algorithm for accurate assessment of the severity of burn wounds in real time.
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Affiliation(s)
- David M Burmeister
- United States Army Institute of Surgical Research, 3698 Chambers Pass, JBSA Fort Sam Houston, TX 78234, USA
| | - Adrien Ponticorvo
- Beckman Laser Institute and Medical Clinic, University of California Irvine, 1002 Health Sciences Road East, Irvine, CA 92617, USA
| | - Bruce Yang
- Beckman Laser Institute and Medical Clinic, University of California Irvine, 1002 Health Sciences Road East, Irvine, CA 92617, USA
| | - Sandra C Becerra
- United States Army Institute of Surgical Research, 3698 Chambers Pass, JBSA Fort Sam Houston, TX 78234, USA
| | - Bernard Choi
- Beckman Laser Institute and Medical Clinic, University of California Irvine, 1002 Health Sciences Road East, Irvine, CA 92617, USA; Biomedical Engineering Department, University of California Irvine, 3120 Natural Sciences II, Irvine, CA 92697, USA
| | - Anthony J Durkin
- Biomedical Engineering Department, University of California Irvine, 3120 Natural Sciences II, Irvine, CA 92697, USA
| | - Robert J Christy
- United States Army Institute of Surgical Research, 3698 Chambers Pass, JBSA Fort Sam Houston, TX 78234, USA.
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18
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Ponticorvo A, Taydas E, Mazhar A, Ellstrom CL, Rimler J, Scholz T, Tong J, Evans GRD, Cuccia DJ, Durkin AJ. Evaluating visual perception for assessing reconstructed flap health. J Surg Res 2015; 197:210-7. [PMID: 25935469 DOI: 10.1016/j.jss.2015.03.099] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2014] [Revised: 02/20/2015] [Accepted: 03/31/2015] [Indexed: 11/28/2022]
Abstract
BACKGROUND Detecting failing tissue flaps before they are clinically apparent has the potential to improve postoperative flap management and salvage rates. This study demonstrates a model to quantitatively compare clinical appearance, as recorded via digital camera, with spatial frequency domain imaging (SFDI), a noninvasive imaging technique using patterned illumination to generate images of total hemoglobin and tissue oxygen saturation (stO2). METHODS Using a swine pedicle model in which blood flow was carefully controlled with occlusion cuffs and monitored with ultrasound probes, throughput was reduced by 25%, 50%, 75%, and 100% of baseline values in either the artery or the vein of each of the flaps. The color changes recorded by a digital camera were quantified to predict which occlusion levels were visible to the human eye. SFDI was also used to quantify the changes in physiological parameters including total hemoglobin and oxygen saturation associated with each occlusion. RESULTS There were no statistically significant changes in color above the noticeable perception levels associated with human vision during any of the occlusion levels. However, there were statistically significant changes in total hemoglobin and stO2 levels detected at the 50%, 75%, and 100% occlusion levels for arterial and venous occlusions. CONCLUSIONS As demonstrated by the color imaging data, visual flap changes are difficult to detect until significant occlusion has occurred. SFDI is capable of detecting changes in total hemoglobin and stO2 as a result of partial occlusions before they are perceivable, thereby potentially improving response times and salvage rates.
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Affiliation(s)
- Adrien Ponticorvo
- Beckman Laser Institute and Medical Clinic, University of California Irvine, Irvine, California
| | - Eren Taydas
- Beckman Laser Institute and Medical Clinic, University of California Irvine, Irvine, California
| | - Amaan Mazhar
- Modulated Imaging Inc., Beckman Laser Institute Photonic Incubator, Irvine, California
| | - Christopher L Ellstrom
- Department of Plastic Surgery, University of California Irvine Medical Center, Orange, California
| | - Jonathan Rimler
- Department of Plastic Surgery, University of California Irvine Medical Center, Orange, California
| | - Thomas Scholz
- Department of Plastic Surgery, University of California Irvine Medical Center, Orange, California
| | - June Tong
- Beckman Laser Institute and Medical Clinic, University of California Irvine, Irvine, California
| | - Gregory R D Evans
- Department of Plastic Surgery, University of California Irvine Medical Center, Orange, California
| | - David J Cuccia
- Modulated Imaging Inc., Beckman Laser Institute Photonic Incubator, Irvine, California
| | - Anthony J Durkin
- Beckman Laser Institute and Medical Clinic, University of California Irvine, Irvine, California.
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19
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Crouzet C, Nguyen JQ, Ponticorvo A, Bernal NP, Durkin AJ, Choi B. Acute discrimination between superficial-partial and deep-partial thickness burns in a preclinical model with laser speckle imaging. Burns 2015; 41:1058-63. [PMID: 25814299 DOI: 10.1016/j.burns.2014.11.018] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2014] [Revised: 10/24/2014] [Accepted: 11/25/2014] [Indexed: 11/26/2022]
Abstract
A critical need exists for a robust method that enables early discrimination between superficial-partial and deep-partial thickness burn wounds. In this study, we report on the use of laser speckle imaging (LSI), a simple, non-invasive, optical imaging modality, to measure acute blood flow dynamics in a preclinical burn model. We used a heated brass comb to induce burns of varying severity to nine rats and collected raw speckle reflectance images over the course of three hours after burn. We induced a total of 12 superficial-partial and 18 deep-partial thickness burn wounds. At 3h after burn we observed a 28% and 44% decrease in measured blood flow for superficial-partial and deep-partial thickness burns, respectively, and that these reductions were significantly different (p=0.00007). This preliminary data suggests the potential role of LSI in the clinical management of burn wounds.
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Affiliation(s)
- Christian Crouzet
- Beckman Laser Institute and Medical Clinic, University of California, Irvine, CA 92612, United States; Department of Biomedical Engineering, University of California, Irvine, CA 92697, United States
| | - John Quan Nguyen
- Beckman Laser Institute and Medical Clinic, University of California, Irvine, CA 92612, United States
| | - Adrien Ponticorvo
- Beckman Laser Institute and Medical Clinic, University of California, Irvine, CA 92612, United States
| | - Nicole P Bernal
- Department of Surgery, University of California, Irvine, CA 92868, United States
| | - Anthony J Durkin
- Beckman Laser Institute and Medical Clinic, University of California, Irvine, CA 92612, United States; Department of Surgery, University of California, Irvine, CA 92868, United States
| | - Bernard Choi
- Beckman Laser Institute and Medical Clinic, University of California, Irvine, CA 92612, United States; Department of Biomedical Engineering, University of California, Irvine, CA 92697, United States; Department of Surgery, University of California, Irvine, CA 92868, United States; Edwards Lifesciences Center for Advanced Cardiovascular Technology, University of California, Irvine, CA 92697, United States.
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20
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Ponticorvo A, Burmeister DM, Yang B, Choi B, Christy RJ, Durkin AJ. Quantitative assessment of graded burn wounds in a porcine model using spatial frequency domain imaging (SFDI) and laser speckle imaging (LSI). Biomed Opt Express 2014; 5:3467-81. [PMID: 25360365 PMCID: PMC4206317 DOI: 10.1364/boe.5.003467] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/24/2014] [Accepted: 08/28/2014] [Indexed: 05/02/2023]
Abstract
Accurate and timely assessment of burn wound severity is a critical component of wound management and has implications related to course of treatment. While most superficial burns and full thickness burns are easily diagnosed through visual inspection, burns that fall between these extremes are challenging to classify based on clinical appearance. Because of this, appropriate burn management may be delayed, increasing the risk of scarring and infection. Here we present an investigation that employs spatial frequency domain imaging (SFDI) and laser speckle imaging (LSI) as non-invasive technologies to characterize in-vivo burn severity. We used SFDI and LSI to investigate controlled burn wounds of graded severity in a Yorkshire pig model. Burn wounds were imaged starting at one hour after the initial injury and daily at approximately 24, 48 and 72 hours post burn. Biopsies were taken on each day in order to correlate the imaging data to the extent of burn damage as indicated via histological analysis. Changes in reduced scattering coefficient and blood flow could be used to categorize burn severity as soon as one hour after the burn injury. The results of this study suggest that SFDI and LSI information have the potential to provide useful metrics for quantifying the extent and severity of burn injuries.
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Affiliation(s)
- Adrien Ponticorvo
- Beckman Laser Institute and Medical Clinic, University of California, Irvine, 1002 Health Sciences Road East, Irvine, CA 92617, USA
- co-first authors
| | - David M. Burmeister
- United States Army Institute of Surgical Research, 3698 Chambers Pass, Fort Sam Houston, TX, 78234, USA
- co-first authors
| | - Bruce Yang
- Beckman Laser Institute and Medical Clinic, University of California, Irvine, 1002 Health Sciences Road East, Irvine, CA 92617, USA
| | - Bernard Choi
- Beckman Laser Institute and Medical Clinic, University of California, Irvine, 1002 Health Sciences Road East, Irvine, CA 92617, USA
- Department of Biomedical Engineering, University of California, Irvine, 3120 Natural Sciences II, Irvine, CA 92697, USA
| | - Robert J. Christy
- United States Army Institute of Surgical Research, 3698 Chambers Pass, Fort Sam Houston, TX, 78234, USA
| | - Anthony J. Durkin
- Beckman Laser Institute and Medical Clinic, University of California, Irvine, 1002 Health Sciences Road East, Irvine, CA 92617, USA
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21
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Nadeau KP, Ponticorvo A, Lee HJ, Lu D, Durkin AJ, Tromberg BJ. Quantitative assessment of renal arterial occlusion in a porcine model using spatial frequency domain imaging. Opt Lett 2013; 38:3566-9. [PMID: 24104815 PMCID: PMC3959861 DOI: 10.1364/ol.38.003566] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
We present the results of a feasibility study with spatial frequency domain imaging (SFDI) to produce quantitative measurements of optical property and chromophore concentration maps of three porcine kidneys utilizing a renal occlusion model at the near-infrared wavelengths of 658, 730, and 850 nm. Using SFDI, we examined the dynamics of absolute oxygen saturation (StO2). The mean StO2 for the kidneys varied from approximately 60% before occlusion, to 20% during occlusion, to 55% after reperfusion. We also present, for the first time to the best of our knowledge, reduced scattering coefficient (μ(s)') maps of the kidney during occlusion. We observed a substantial decrease in the wavelength dependence of scattering (i.e., scattering power) in the three kidneys, with a mean decrease of 18%±2.6%, which is indicative of an increase in scatterer size, and is likely due to tissue changes such as edema that follow from occlusion and inflammation.
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Affiliation(s)
- K. P. Nadeau
- Laser Microbeam and Medical Program (LAMMP), Beckman Laser Institute, 1002 Health Sciences Road, Irvine, California 92612, USA
| | - A. Ponticorvo
- Laser Microbeam and Medical Program (LAMMP), Beckman Laser Institute, 1002 Health Sciences Road, Irvine, California 92612, USA
| | - H. J. Lee
- Department of Urology, University of California, Irvine, 333 The City Boulevard West, Suite 2100, Orange, California 92868, USA
| | - D. Lu
- Department of Pathology, University of California, Irvine, D440 Medical Sciences I, Irvine, California 92697, USA
| | - A. J. Durkin
- Laser Microbeam and Medical Program (LAMMP), Beckman Laser Institute, 1002 Health Sciences Road, Irvine, California 92612, USA
| | - B. J. Tromberg
- Laser Microbeam and Medical Program (LAMMP), Beckman Laser Institute, 1002 Health Sciences Road, Irvine, California 92612, USA
- Corresponding author:
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22
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Lin AJ, Ponticorvo A, Konecky SD, Cui H, Rice TB, Choi B, Durkin AJ, Tromberg BJ. Visible spatial frequency domain imaging with a digital light microprojector. J Biomed Opt 2013; 18:096007. [PMID: 24005154 PMCID: PMC3762936 DOI: 10.1117/1.jbo.18.9.096007] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/09/2013] [Revised: 07/16/2013] [Accepted: 07/31/2013] [Indexed: 05/18/2023]
Abstract
There is a need for cost effective, quantitative tissue spectroscopy and imaging systems in clinical diagnostics and pre-clinical biomedical research. A platform that utilizes a commercially available light-emitting diode (LED) based projector, cameras, and scaled Monte Carlo model for calculating tissue optical properties is presented. These components are put together to perform spatial frequency domain imaging (SFDI), a model-based reflectance technique that measures and maps absorption coefficients (μa) and reduced scattering coefficients (μs') in thick tissue such as skin or brain. We validate the performance of the flexible LED and modulation element (FLaME) system at 460, 530, and 632 nm across a range of physiologically relevant μa values (0.07 to 1.5 mm-1) in tissue-simulating intralipid phantoms, showing an overall accuracy within 11% of spectrophotometer values for μa and 3% for μs'. Comparison of oxy- and total hemoglobin fits between the FLaME system and a spectrophotometer (450 to 1000 nm) is differed by 3%. Finally, we acquire optical property maps of a mouse brain in vivo with and without an overlying saline well. These results demonstrate the potential of FLaME to perform tissue optical property mapping in visible spectral regions and highlight how the optical clearing effect of saline is correlated to a decrease in μs' of the skull.
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Affiliation(s)
- Alexander J. Lin
- University of California, Beckman Laser Institute and Medical Clinic, Department of Surgery, Irvine, California
- University of California, Department of Biomedical Engineering, Irvine, California
| | - Adrien Ponticorvo
- University of California, Beckman Laser Institute and Medical Clinic, Department of Surgery, Irvine, California
| | - Soren D. Konecky
- University of California, Beckman Laser Institute and Medical Clinic, Department of Surgery, Irvine, California
| | - Haotian Cui
- University of California, Beckman Laser Institute and Medical Clinic, Department of Surgery, Irvine, California
- University of California, Department of Biomedical Engineering, Irvine, California
| | - Tyler B. Rice
- University of California, Beckman Laser Institute and Medical Clinic, Department of Surgery, Irvine, California
| | - Bernard Choi
- University of California, Beckman Laser Institute and Medical Clinic, Department of Surgery, Irvine, California
- University of California, Department of Biomedical Engineering, Irvine, California
- University of California, Edwards Lifesciences Center for Advanced Cardiovascular Technology, Irvine, California
| | - Anthony J. Durkin
- University of California, Beckman Laser Institute and Medical Clinic, Department of Surgery, Irvine, California
| | - Bruce J. Tromberg
- University of California, Beckman Laser Institute and Medical Clinic, Department of Surgery, Irvine, California
- University of California, Department of Biomedical Engineering, Irvine, California
- Address all correspondence to: Bruce J. Tromberg, Beckman Laser Institute, 1002 Health Sciences Road, Irvine, California 92612. Tel: +949-824-8705; Fax: +949-824-8413; E-mail:
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23
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Ponticorvo A, Cardenas D, Dunn AK, Ts’o D, Duong TQ. Laser speckle contrast imaging of blood flow in rat retinas using an endoscope. J Biomed Opt 2013; 18:090501. [PMID: 24064947 PMCID: PMC3782556 DOI: 10.1117/1.jbo.18.9.090501] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/16/2013] [Accepted: 09/04/2013] [Indexed: 05/02/2023]
Abstract
Laser speckle contrast imaging (LSCI) offers a cost-effective means to image blood flow in vivo. However, it is not commonly used to image rodent retinas because of the challenges associated with imaging through the curved cornea and delivering light through the highly scattering lens. A solution to overcome these problems by using LSCI in conjunction with an endoscope to obtain high spatiotemporal blood flow images is described. Its utility is demonstrated by imaging blood flow changes in rat retinas using hyperoxic, hypercapnic, and visual (flicker) stimulations. Hypercapnia increases blood flow, hyperoxia decreases blood flow, and visual stimulation increases blood flow in the retina relative to basal conditions. The time-to-peak of the LSCI response to visual stimulation is also measured. This approach may prove useful to investigate dysregulation in blood flow-evoked responses in retinal diseases and to evaluate treatment strategies in rodents.
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Affiliation(s)
- Adrien Ponticorvo
- University of Texas Health Science Center, Research Imaging Institute, San Antonio, Texas 78229
| | - Damon Cardenas
- University of Texas Health Science Center, Research Imaging Institute, San Antonio, Texas 78229
| | - Andrew K. Dunn
- University of Texas at Austin, Department of Biomedical Engineering, Austin, Texas 78712
| | - Daniel Ts’o
- SUNY Upstate Medical University, Departments of Neurosurgery and Neuroscience, Syracuse, New York 13210
| | - Timothy Q. Duong
- University of Texas Health Science Center, Research Imaging Institute, San Antonio, Texas 78229
- South Texas Veterans Health Care System, Department of Veterans Affairs, San Antonio, Texas 78229
- Address all correspondence to: Timothy Q. Duong, University of Texas Health Science Center, Research Imaging Institute, San Antonio, Texas 78229. Tel: 210 567 8100; Fax: 210 567 8152; E-mail:
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Nguyen JQ, Crouzet C, Mai T, Riola K, Uchitel D, Liaw LH, Bernal N, Ponticorvo A, Choi B, Durkin AJ. Spatial frequency domain imaging of burn wounds in a preclinical model of graded burn severity. J Biomed Opt 2013; 18:66010. [PMID: 23764696 PMCID: PMC3680730 DOI: 10.1117/1.jbo.18.6.066010] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Abstract
Frequent monitoring of early-stage burns is necessary for deciding optimal treatment and management. Both superficial and full thickness burns are relatively easy to diagnose based on clinical observation. In between these two extremes are superficial-partial thickness and deep-partial thickness burns. These burns, while visually similar, differ dramatically in terms of clinical treatment and are known to progress in severity over time. The objective of this study was to determine the potential of spatial frequency domain imaging (SFDI) for noninvasively mapping quantitative changes in chromophore and optical properties that may be an indicative of burn wound severity. A controlled protocol of graded burn severity was developed and applied to 17 rats. SFDI data was acquired at multiple near-infrared wavelengths over a course of 3 h. Burn severity was verified using hematoxylin and eosin histology. From this study, we found that changes in water concentration (edema), deoxygenated hemoglobin concentration, and optical scattering (tissue denaturation) to be statistically significant at differentiating superficial partial-thickness burns from deep-partial thickness burns.
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Affiliation(s)
- John Quan Nguyen
- Beckman Laser Institute and Medical Clinic, 1002 Health Sciences Road, Irvine, California 92617-3010
| | - Christian Crouzet
- Beckman Laser Institute and Medical Clinic, 1002 Health Sciences Road, Irvine, California 92617-3010
| | - Tuan Mai
- Beckman Laser Institute and Medical Clinic, 1002 Health Sciences Road, Irvine, California 92617-3010
| | - Kathleen Riola
- Beckman Laser Institute and Medical Clinic, 1002 Health Sciences Road, Irvine, California 92617-3010
| | - Daniel Uchitel
- Beckman Laser Institute and Medical Clinic, 1002 Health Sciences Road, Irvine, California 92617-3010
| | - Lih-Huei Liaw
- Beckman Laser Institute and Medical Clinic, 1002 Health Sciences Road, Irvine, California 92617-3010
| | - Nicole Bernal
- UC Irvine Regional Burn Center, Department of Surgery, 333 City Boulevard West, Suite 705, Orange, California 92868
| | - Adrien Ponticorvo
- Beckman Laser Institute and Medical Clinic, 1002 Health Sciences Road, Irvine, California 92617-3010
| | - Bernard Choi
- Beckman Laser Institute and Medical Clinic, 1002 Health Sciences Road, Irvine, California 92617-3010
| | - Anthony J. Durkin
- Beckman Laser Institute and Medical Clinic, 1002 Health Sciences Road, Irvine, California 92617-3010
- Address all correspondence to: Anthony J. Durkin, Beckman Laser Institute and Medical Clinic, 1002 Health Sciences Road, Irvine, California 92617-3010. Tel: (949)824-3284; E-mail:
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25
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Ponticorvo A, Taydas E, Mazhar A, Scholz T, Kim HS, Rimler J, Evans GRD, Cuccia DJ, Durkin AJ. Quantitative assessment of partial vascular occlusions in a swine pedicle flap model using spatial frequency domain imaging. Biomed Opt Express 2013; 4:298-306. [PMID: 23412357 PMCID: PMC3567716 DOI: 10.1364/boe.4.000298] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/08/2012] [Revised: 12/21/2012] [Accepted: 01/04/2013] [Indexed: 05/03/2023]
Abstract
The use of tissue transfer flaps has become a common and effective technique for reconstructing or replacing damaged tissue. While the overall failure rate associated with these procedures is relatively low (5-10%), the failure rate of tissue flaps that require additional surgery is significantly higher (40-60%). The reason for this is largely due to the absence of a technique for objectively assessing tissue health after surgery. Here we have investigated spatial frequency domain imaging (SFDI) as a potential tool to do this. By projecting wide-field patterned illumination at multiple wavelengths onto a tissue surface, SFDI is able to quantify absolute concentrations of oxygenated and deoxygenated hemoglobin over a large field of view. We have assessed the sensitivity of SFDI in a swine pedicle flap model by using a controlled vascular occlusion system that reduced blood flow by 25%, 50%, 75%, or 100% of the baseline values in either the vein or artery. SFDI was able to detect significant changes for oxygenated hemoglobin, deoxygenated hemoglobin, or tissue oxygen saturation in partial arterial occlusions of at least 50% and partial venous occlusions of at least 25%. This shows SFDI is sensitive enough to quantify changes in the tissue hemoglobin state during partial occlusions and thus has the potential to be a powerful tool for the early prediction of tissue flap failure.
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Affiliation(s)
- Adrien Ponticorvo
- Beckman Laser Institute and Medical Clinic, University of California
Irvine, 1002 Health Sciences Road East, Irvine, CA 92617, USA
| | - Eren Taydas
- Beckman Laser Institute and Medical Clinic, University of California
Irvine, 1002 Health Sciences Road East, Irvine, CA 92617, USA
| | - Amaan Mazhar
- Modulated Imaging Inc., Beckman Laser Institute Photonic Incubator,
1002 Health Sciences Rd. East, Irvine, CA 92617, USA
| | - Thomas Scholz
- Department of Plastic Surgery, University of California Irvine
Medical Center, 200 S. Manchester Ave., Suite 650, Orange, CA 92868, USA
| | - Hak-Su Kim
- Department of Plastic Surgery, University of California Irvine
Medical Center, 200 S. Manchester Ave., Suite 650, Orange, CA 92868, USA
| | - Jonathan Rimler
- Department of Plastic Surgery, University of California Irvine
Medical Center, 200 S. Manchester Ave., Suite 650, Orange, CA 92868, USA
| | - Gregory R. D. Evans
- Department of Plastic Surgery, University of California Irvine
Medical Center, 200 S. Manchester Ave., Suite 650, Orange, CA 92868, USA
| | - David J. Cuccia
- Modulated Imaging Inc., Beckman Laser Institute Photonic Incubator,
1002 Health Sciences Rd. East, Irvine, CA 92617, USA
| | - Anthony J. Durkin
- Beckman Laser Institute and Medical Clinic, University of California
Irvine, 1002 Health Sciences Road East, Irvine, CA 92617, USA
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26
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Davis MA, Shams Kazmi SM, Ponticorvo A, Dunn AK. Depth dependence of vascular fluorescence imaging. Biomed Opt Express 2011; 2:3349-62. [PMID: 22162824 PMCID: PMC3233253 DOI: 10.1364/boe.2.003349] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/23/2011] [Revised: 11/01/2011] [Accepted: 11/15/2011] [Indexed: 05/19/2023]
Abstract
In vivo surface imaging of fluorescently labeled vasculature has become a widely used tool for functional brain imaging studies. Techniques such as phosphorescence quenching for oxygen tension measurements and indocyanine green fluorescence for vessel perfusion monitoring rely on surface measurements of vascular fluorescence. However, the depth dependence of the measured fluorescence signals has not been modeled in great detail. In this paper, we investigate the depth dependence of the measured signals using a three-dimensional Monte Carlo model combined with high resolution vascular anatomy. We found that a bulk-vascularization assumption to modeling the depth dependence of the signal does not provide an accurate picture of penetration depth of the collected fluorescence signal in most cases. Instead the physical distribution of microvasculature, the degree of absorption difference between extravascular and intravascular space, and the overall difference in absorption at the excitation and emission wavelengths must be taken into account to determine the depth penetration of the fluorescence signal. Additionally, we found that using targeted illumination can provide for superior surface vessel sensitivity over wide-field illumination, with small area detection offering an even greater amount of sensitivity to surface vasculature. Depth sensitivity can be enhanced by either increasing the detector area or increasing the illumination area. Finally, we see that excitation wavelength and vessel size can affect intra-vessel sampling distribution, as well as the amount of signal that originates from inside the vessel under targeted illumination conditions.
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Affiliation(s)
- Mitchell A. Davis
- Department of Electrical and Computer Engineering, The University of Texas at Austin, Austin, Texas 78712,
USA
| | - S. M. Shams Kazmi
- Department of Biomedical Engineering, The University of Texas at Austin, Austin, TX 78712,
USA
| | - Adrien Ponticorvo
- Department of Biomedical Engineering, The University of Texas at Austin, Austin, TX 78712,
USA
| | - Andrew K. Dunn
- Department of Biomedical Engineering, The University of Texas at Austin, Austin, TX 78712,
USA
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27
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Abstract
Laser Speckle Contrast Imaging (LSCI) is a simple yet powerful technique that is used for full-field imaging of blood flow. The technique analyzes fluctuations in a dynamic speckle pattern to detect the movement of particles similar to how laser Doppler analyzes frequency shifts to determine particle speed. Because it can be used to monitor the movement of red blood cells, LSCI has become a popular tool for measuring blood flow in tissues such as the retina, skin, and brain. It has become especially useful in neuroscience where blood flow changes during physiological events like functional activation, stroke, and spreading depolarization can be quantified. LSCI is also attractive because it provides excellent spatial and temporal resolution while using inexpensive instrumentation that can easily be combined with other imaging modalities. Here we show how to build a LSCI setup and demonstrate its ability to monitor blood flow changes in the brain during an animal experiment.
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Affiliation(s)
- Adrien Ponticorvo
- Biomedical Engineering Department, University of Texas at Austin, USA
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28
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Abstract
In this study we present a novel imaging method that combines high resolution cerebral blood flow imaging with a highly flexible map of absolute pO(2). In vivo measurements of pO(2) in animals using phosphorescence quenching is a well established method, and is preferable over electrical probes which are inherently invasive and are limited to single point measurements. However, spatially resolved pO(2) measurements using phosphorescence lifetime quenching typically require expensive cameras to obtain images of pO(2) and often suffer from poor signal to noise. Our approach enables us to retain the high temporal resolution and sensitivity of single point detection of phosphorescence by using a digital micromirror device (DMD) to selectively illuminate arbitrarily shaped regions of tissue. In addition, by simultaneously using Laser Speckle Contrast Imaging (LSCI) to measure relative blood flow, we can better examine the relationship between blood flow and absolute pO(2). We successfully used this instrument to study changes that occur during ischemic conditions in the brain with enough spatial resolution to clearly distinguish different regions. This novel instrument will provide researchers with an inexpensive and improved technique to examine multiple hemodynamic parameters simultaneously in the brain as well as other tissues.
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Affiliation(s)
- Adrien Ponticorvo
- Department of Biomedical Engineering, University of Texas at Austin, 1 University Station C0800, Austin, Texas 78712, USA
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29
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Abstract
Though laser speckle contrast imaging enables the measurement of scattering particle dynamics with high temporal resolution, the subsequent processing has previously been much slower. In prior studies, generating a laser speckle contrast image required about 1 s to process a raw image potentially collected in 10 ms or less. In this paper, novel algorithms are described which are demonstrated to convert 291 raw images per second to laser speckle contrast images and as many as 410 laser speckle contrast images per second to relative correlation time images. As long as image processing occurs during image acquisition, these algorithms render processing time irrelevant in most circumstances and enable real-time imaging of blood flow dynamics.
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Affiliation(s)
- W James Tom
- Department of Biomedical Engineering, The University of Texas at Austin, Austin, TX 78712, USA.
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30
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Abstract
An instrument is demonstrated that is capable of three-dimensional (3D) vasculature imaging and pO(2) quantification with high spatial resolution. The instrument combines two-photon (2P) microscopy with phosphorescence quenching to measure pO(2). The instrument was demonstrated by performing depth-resolved microvascular pO(2) measurements of rat cortical vessels down to 120 microm below the surface. 2P excitation of porphyrin was confirmed, and measured pO(2) values were consistent with previously published data for normoxic and hyperoxic conditions. The ability to perform 3D pO(2) measurements using optical techniques will allow researchers to overcome existing limitations imposed by polarographic electrodes, magnetic resonance techniques, and surface-only pO(2) measurement techniques.
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Affiliation(s)
- Arnold D Estrada
- Biomedical Engineering Department, University of Texas at Austin, 1 University Station, C0800, Austin, TX 78712-0238, USA.
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