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1.
J Surg Case Rep ; 2023(11): rjad628, 2023 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-38026739

RESUMEN

Among intraabdominal lymphangiomas, colonic lymphangiomas are rare. These cystic tumors are generally asymptomatic and incidentally found but may present with bleeding or obstructive symptoms. Intussusception by such tumors is scarcely reported, with only nine previously reported cases listed in Pubmed. We report a case of a 41-year-old female Asian patient who presented with acute abdomen and was diagnosed with colonic intussusception caused by lymphangioma. She received emergent right hemicolectomy, recovered well without complications, and was discharged on the 5th postoperative day.

2.
IEEE Trans Med Robot Bionics ; 5(2): 335-342, 2023 May.
Artículo en Inglés | MEDLINE | ID: mdl-37312886

RESUMEN

MR-guided focal cryoablation of prostate cancer has often been selected as a minimally-invasive treatment option. Placing multiple cryo-needles accurately to form an ablation volume that adequately covers the target volume is crucial for better oncological/functional outcomes. This paper presents an MRI-compatible system combining a motorized tilting grid template with insertion depth sensing capabilities, enabling the physician to precisely place the cryo-needles into the desired location. In vivo animal study in a swine model (3 animals) was performed to test the device performance including targeting accuracy and the procedure workflow. The study showed that the insertion depth feedback improved the 3D targeting accuracy when compared to the conventional insertion technique (7.4 mm vs. 11.2 mm, p=0.04). All three cases achieved full iceball coverage without repositioning the cryo-needles. The results demonstrate the advantages of the motorized tilting mechanism and real-time insertion depth feedback, as well as the feasibility of the proposed workflow for MRI-guided focal cryoablation of prostate cancer.

3.
Transl Biophotonics ; 4(3)2022 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-36176918

RESUMEN

Noninvasive assessment of skin lesions, especially of basal cell carcinoma (BCC), has benefited more recently from the use of optical imaging techniques such as optical coherence tomography (OCT) and reflectance confocal microscopy (RCM). While RCM provides submicron scale resolution and thus enables identification of skin morphological changes of the skin, with the downside of limited penetration depth, OCT imaging of the same lesion brings the benefit of better resolving its depth of invasion. OCT and RCM can be used either individually or combined within the same instrument for the noninvasive diagnosis of nonmelanoma skin cancers (NMSCs). Their combined use has shown to provide certain benefits such as better characterization of the lesion's margins, both in depth and laterally, as well as improved sensitivity and specificity, as previously demonstrated by our team. In this paper we report a new "fiber-based" implementation of the second-generation RCM-OCT hand-held probe. The fiber-based implementation of both imaging modalities enabled the construction of a smaller footprint/lower weight hand-held probe. Its preliminary evaluation on the skin of healthy volunteers is reported here, demonstrating improved capabilities for resolving sub-cellular structures and image skin morphology with micron-scale resolution to a higher depth than in the previous implementation, while also enabling the construction of angiography maps showing vascular remodeling.

4.
Eur Surg Res ; 63(3): 123-131, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-34864732

RESUMEN

PURPOSE: This study investigated the antiadhesive effects of Mediclore®, rosuvastatin, and a combination of Mediclore and rosuvastatin in a rat adhesion model. METHODS: The adhesion models (a total of 58 adult male rats) were divided into 4 groups. The control group (group C) received no special materials except for a saline. The experimental groups were treated with 5 mL of Mediclore (group M), rosuvastatin (group R), or rosuvastatin and Mediclore (group RM), and these materials were intraperitoneally placed under the incision. At postoperative day 14, the rats underwent re-laparotomy and adhesiolysis. Three investigators blinded to group assignment scored the extent of adhesion formation, the numbers of remote adhesions, and the extent of acute/chronic inflammation, fibrosis, edema, and congestion on resected specimens via histologic examination. RESULTS: The macroscopic adhesion score in group RM (7.27 ± 3.51) was significantly lower than those in groups C (13.36 ± 2.24) and R (11.71 ± 1.98); group M (9.13 ± 4.09) had a significantly lower adhesion score than group C. The number of remote adhesions was significantly lower in groups R and RM than in group C. The acute inflammation score, chronic inflammation score, and fibrosis score in group RM; the acute inflammation score in group R; and the fibrosis score in group M were significantly lower than those in group C. CONCLUSION: The intraperitoneal application of Mediclore and a combination of Mediclore and rosuvastatin effectively reduced postoperative adhesions.


Asunto(s)
Inhibidores de Hidroximetilglutaril-CoA Reductasas , Animales , Modelos Animales de Enfermedad , Fibrosis , Inhibidores de Hidroximetilglutaril-CoA Reductasas/farmacología , Inflamación/tratamiento farmacológico , Inflamación/patología , Inflamación/prevención & control , Masculino , Complicaciones Posoperatorias/prevención & control , Ratas , Rosuvastatina Cálcica/farmacología , Adherencias Tisulares/prevención & control
5.
Environ Pollut ; 289: 117311, 2021 Nov 15.
Artículo en Inglés | MEDLINE | ID: mdl-34015691

RESUMEN

Studies in the literature concern the toxicity of nanoparticles either in a Petri dish or in agar media-based tests. Therefore, for environmental relevance, individual and binary mixtures of metal oxide nanoparticles (M-NPs) cadmium oxide (CdO-NP) and copper oxide (CuO-NP) were tested in this study for their effect on Vigna radiata in soil with and without the addition of sawdust. Seed germination was 67% in 100 mg CuO-NP in soil without sawdust. Seeds failed to germinate in 100 mg CdO +100 mg CuO-NPs in soil without the addition of sawdust and germination was 83% at the same concentration in soil with sawdust. In sawdust added to soil, when compared with control (soil without M-NPs), the maximum reduction in shoot (82%) and root (80%) length and wet (61%) and dry (54%) weight of plant was recorded in CdO-NP treated soil. Similarly, compared with control (soil without sawdust and M-NPs), the percent reduction in shoot (61%) and root (70%) length and wet (44%) and dry (48%) weight was highest in CdO-NP treated soil not supplemented with sawdust. In a binary mixture test (CdO-NP + CuO-NP), the addition of sawdust promoted the above plant growth parameters compared with individual CdO-NP and CuO-NP tests. Cadmium (511 mg kg-1 for individual and 303 mg kg-1 for binary mixture tests) and Cu (953 mg kg-1 for individual and 2954 mg kg-1 for binary mixture tests) accumulation was higher in plants grown in soil without sawdust. The beneficial effect of sawdust addition was observed in seed germination, plant growth, and metal accumulation. With or without sawdust, the binary mixture of CdO and CuO was antagonistic. These results indicate that sawdust can prevent M-NP-induced toxicity and reduce metal accumulation in plant tissues.


Asunto(s)
Nanopartículas del Metal , Nanopartículas , Vigna , Cadmio/toxicidad , Cobre/toxicidad , Nanopartículas del Metal/toxicidad , Óxidos , Semillas
6.
Med Phys ; 48(5): 2553-2565, 2021 May.
Artículo en Inglés | MEDLINE | ID: mdl-33651407

RESUMEN

PURPOSE: Magnetic resonance imaging (MRI)-guided transperineal prostate biopsy has been practiced since the early 2000s. The technique often suffers from targeting error due to deviation of the needle as a result of physical interaction between the needle and inhomogeneous tissues. Existing needle guide devices, such as a grid template, do not allow choosing an alternative insertion path to mitigate the deviation because of their limited degree-of-freedom (DoF). This study evaluates how an angulated needle insertion path can reduce needle deviation and improve needle placement accuracy. METHODS: We extended a robotic needle-guidance device (Smart Template) for in-bore MRI-guided transperineal prostate biopsy. The new Smart Template has a 4-DoF needle-guiding mechanism allowing a translational range of motion of 65 and 58 mm along the vertical and horizontal axis, and a needle rotational motion around the vertical and horizontal axis ± 30 ∘ and a vertical rotational range of - 30 ∘ , + 10 ∘ , respectively. We defined a path planning strategy, which chooses between straight and angulated insertion paths depending on the anatomical structures on the potential insertion path. We performed (a) a set of experiments to evaluate the device positioning accuracy outside the MR-bore, and (b) an in vivo experiment to evaluate the improvement of targeting accuracy combining straight and angulated insertions in animal models (swine, n = 3 ). RESULTS: We analyzed 46 in vivo insertions using either straight or angulated insertions paths. The experiment showed that the proposed strategy of selecting straight or angulated insertions based on the subject's anatomy outperformed the conventional approach of just straight insertions in terms of targeting accuracy (2.4 mm [1.3-3.7] vs 3.9 mm [2.4-5.0] {Median IQR } ); p = 0.041 after the bias correction). CONCLUSION: The in vivo experiment successfully demonstrated that an angulated needle insertion path could improve needle placement accuracy with a path planning strategy that takes account of the subject-specific anatomical structures.


Asunto(s)
Neoplasias de la Próstata , Robótica , Animales , Humanos , Biopsia Guiada por Imagen , Imagen por Resonancia Magnética , Masculino , Agujas , Próstata/diagnóstico por imagen , Neoplasias de la Próstata/diagnóstico por imagen , Porcinos
7.
PLoS One ; 16(2): e0245334, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33571221

RESUMEN

Providing surgical margin information during breast cancer surgery is crucial for the success of the procedure. The margin is defined as the distance from the tumor to the cut surface of the resection specimen. The consensus among surgeons and radiation oncologists is that there should be no tumor left within 1 to maximum 2 mm from the surface of the surgical specimen. If a positive margin remains, there is substantial risk for tumor recurrence, which may also result in potentially reduced cosmesis and eventual need for mastectomy. In this paper we report a novel multimodal optical imaging instrument based on combined high-resolution confocal microscopy-optical coherence tomography imaging for assessing the presence of potential positive margins on surgical specimens. Since rapid specimen analysis is critical during surgery, this instrument also includes a fluorescence imaging channel to enable rapid identification of the areas of the specimen that have potential positive margins. This is possible by specimen incubation with a cancer specific agent prior to imaging. In this study we used a quenched contrast agent, which is activated by cancer specific enzymes, such as urokinase plasminogen activators (uPA). Using this agent or a similar one, one may limit the use of high-resolution optical imaging to only fluorescence-highlighted areas for visualizing tissue morphology at the sub-cellular scale and confirming or ruling out cancer presence. Preliminary evaluation of this technology was performed on 20 surgical specimens and testing of the optical imaging findings was performed against histopathology. The combination of the three imaging modes allowed for high correlation between optical image analysis and histological ground-truth. The initial results are encouraging, showing instrument capability to assess margins on clinical specimens with a positive predictive value of 1.0 and a negative predictive value of 0.83.


Asunto(s)
Neoplasias de la Mama , Procesamiento de Imagen Asistido por Computador/métodos , Márgenes de Escisión , Microscopía Confocal , Imagen Óptica , Mama/diagnóstico por imagen , Mama/patología , Neoplasias de la Mama/diagnóstico por imagen , Neoplasias de la Mama/cirugía , Estudios de Factibilidad , Femenino , Humanos , Microscopía Confocal/instrumentación , Microscopía Confocal/métodos , Imagen Óptica/instrumentación , Imagen Óptica/métodos
8.
Surg Laparosc Endosc Percutan Tech ; 29(6): 543-547, 2019 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-31568256

RESUMEN

Laparoscopic appendectomy (LA) is perceived as a procedure requiring a short hospital stay; however, some patients require prolonged hospitalization because of postoperative ileus and pain; therefore, we introduced clipless LA, using only an ultrasonic energy device only for coagulation. A total of 1013 patients (clipless LA; n=290 and conventional LA; n=723) who underwent LA at our hospital between January 2015 and February 2018 were analyzed. The mean operative time was shorter (P<0.001), and postoperative pain score at 24 hours was lower (P<0.001) for clipless than for conventional LA. There were no significant differences in postoperative complications, except with regard to early postoperative ileus (clipless LA; 18.1% vs. conventional LA; 31.6%, P=0.025), and the operative method had significantly influenced early postoperative ileus (relative risk, 0.505; 95% confidence interval, 0.257-0.994; P=0.048). Clipless LA is comparable to conventional LA with regard to operative safety but results in significantly less pain and postoperative ileus.


Asunto(s)
Apendicectomía/métodos , Apendicitis/cirugía , Ileus/prevención & control , Laparoscopía/métodos , Dolor Postoperatorio/prevención & control , Técnicas de Sutura , Adulto , Femenino , Estudios de Seguimiento , Humanos , Ileus/epidemiología , Incidencia , Tiempo de Internación/tendencias , Masculino , Dolor Postoperatorio/epidemiología , República de Corea/epidemiología , Estudios Retrospectivos , Factores de Riesgo , Factores de Tiempo , Resultado del Tratamiento
9.
Biomed Opt Express ; 9(2): 694-704, 2018 Feb 01.
Artículo en Inglés | MEDLINE | ID: mdl-29552405

RESUMEN

We report the development and the pre-clinical testing of a new technology based on optical coherence tomography (OCT) for investigating tissue composition at the tip of the core biopsy needle. While ultrasound, computed tomography, and magnetic resonance imaging are routinely used to guide needle placement within a tumor, they still do not provide the resolution needed to investigate tissue cellularity (ratio between viable tumor and benign stroma) at the needle tip prior to taking a biopsy core. High resolution OCT imaging, however, can be used to investigate tissue morphology at the micron scale, and thus to determine if the biopsy core would likely have the expected composition. Therefore, we implemented this capability within a custom-made biopsy gun and evaluated its capability for a correct estimation of tumor tissue cellularity. A pilot study on a rabbit model of soft tissue cancer has shown the capability of this technique to provide correct evaluation of tumor tissue cellularity in over 85% of the cases. These initial results indicate the potential benefit of the OCT-based approach for improving the success of the core biopsy procedures.

10.
J Biomed Opt ; 22(7): 76006, 2017 07 01.
Artículo en Inglés | MEDLINE | ID: mdl-28697233

RESUMEN

We present a hand-held implementation and preliminary evaluation of a combined optical coherence tomography (OCT) and reflectance confocal microscopy (RCM) probe for detecting and delineating the margins of basal cell carcinomas (BCCs) in human skin

Asunto(s)
Carcinoma Basocelular/diagnóstico por imagen , Microscopía Confocal , Tomografía de Coherencia Óptica , Estudios Transversales , Humanos , Proyectos Piloto
11.
Biomed Opt Express ; 7(5): 2000-15, 2016 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-27231638

RESUMEN

It is known that the progression of oral cancer is accompanied by changes in both tissue biochemistry and morphology. A multimodal imaging approach combining functional and structural imaging modalities could therefore provide a more comprehensive prognosis of oral cancer. This idea forms the central theme of the current study, wherein this premise is examined in the context of a multimodal imaging system that combines fluorescence lifetime imaging (FLIM) and optical coherence tomography (OCT). Towards this end, in the first part of the present study, the diagnostic advantage obtained by using both fluorescence intensity and lifetime information is assessed. In the second part of the study, the diagnostic potential of FLIM-derived biochemical features is compared with that of OCT-derived morphological features. For an objective assessment, several quantitative biochemical and morphological features from FLIM and OCT data, respectively, were obtained using signal and image processing techniques. These features were subsequently used in a statistical classification framework to quantify the diagnostic potential of different features. The classification accuracy for combined FLIM and OCT features was estimated to be 87.4%, which was statistically higher than accuracy based on only FLIM (83.2%) or OCT (81.0%) features. Moreover, the complimentary information provided by FLIM and OCT features, resulted in highest sensitivity and specificity for the combined FLIM and OCT features for discriminating benign (88.2% sens., 92.0% spec.), pre-cancerous (81.5% sens., 96.0% spec.), and cancerous (90.1% sens., 92.0% spec.) classes.

12.
J Biomed Opt ; 19(8): 086022, 2014 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-25162909

RESUMEN

Most studies evaluating the potential of optical coherence tomography (OCT) for the diagnosis of oral cancer are based on visual assessment of OCT B-scans by trained experts. Human interpretation of the large pool of data acquired by modern high-speed OCT systems, however, can be cumbersome and extremely time consuming. Development of image analysis methods for automated and quantitative OCT image analysis could therefore facilitate the evaluation of such a large volume of data. We report automated algorithms for quantifying structural features that are associated with the malignant transformation of the oral epithelium based on image processing of OCT data. The features extracted from the OCT images were used to design a statistical classification model to perform the automated tissue diagnosis. The sensitivity and specificity of distinguishing malignant lesions from benign lesions were found to be 90.2% and 76.3%, respectively. The results of the study demonstrate the feasibility of using quantitative image analysis algorithms for extracting morphological features from OCT images to perform the automated diagnosis of oral malignancies in a hamster cheek pouch model.


Asunto(s)
Algoritmos , Inteligencia Artificial , Interpretación de Imagen Asistida por Computador/métodos , Mucosa Bucal/patología , Neoplasias de la Boca/patología , Reconocimiento de Normas Patrones Automatizadas/métodos , Tomografía de Coherencia Óptica/métodos , Animales , Mejilla , Cricetinae , Aumento de la Imagen/métodos , Mesocricetus , Reproducibilidad de los Resultados , Sensibilidad y Especificidad
13.
Artículo en Inglés | MEDLINE | ID: mdl-21096785

RESUMEN

Early detection of cancer is key to reducing morbidity and mortality. Morphological and chemical biomarkers presage the transition from normal to cancerous tissue. We have developed a noninvasive imaging system incorporating optical coherence tomography and fluorescence lifetime imaging to acquire both sets of biomarkers. Here we report early favorable results from an animal study designed to measure the capacity of this approach for early diagnosis of oral cancer.


Asunto(s)
Neoplasias de la Boca/diagnóstico , Neoplasias de la Boca/patología , Neoplasias Glandulares y Epiteliales/diagnóstico , Neoplasias Glandulares y Epiteliales/patología , Algoritmos , Animales , Simulación por Computador , Cricetinae , Dermoscopía/métodos , Diagnóstico por Imagen/métodos , Modelos Animales de Enfermedad , Humanos , Mesocricetus , Modelos Estadísticos , Óptica y Fotónica/métodos , Programas Informáticos , Tomografía de Coherencia Óptica/métodos
14.
Opt Lett ; 35(15): 2558-60, 2010 Aug 01.
Artículo en Inglés | MEDLINE | ID: mdl-20680057

RESUMEN

Fluorescence lifetime imaging microscopy (FLIM) offers a noninvasive approach for characterizing the biochemical composition of biological tissue. In recent years, there has been an increasing interest in the application of multispectral FLIM for medical diagnosis. Central to the clinical translation of FLIM technology is the development of robust, fast, and cost-effective FLIM instrumentation suitable for in vivo tissue imaging. Unfortunately, the predominant multispectral FLIM approaches suffer from limitations that impede the development of high-speed instruments for in vivo applications. We present a cost-effective scanning multispectral FLIM implementation capable of achieving pixel rates on the order of tens of kilohertz, which will facilitate the evaluation of FLIM for in vivo applications.


Asunto(s)
Procesamiento de Imagen Asistido por Computador/métodos , Microscopía Fluorescente/métodos , Animales , Cricetinae , Diagnóstico por Imagen/métodos , Modelos Animales de Enfermedad , Diseño de Equipo , Humanos , Rayos Láser , Neoplasias de la Boca/patología , Procesamiento de Señales Asistido por Computador
15.
IEEE Trans Biomed Eng ; 57(10): 2596-9, 2010 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-20656649

RESUMEN

Early detection of cancer is key to reducing morbidity and mortality. Morphological and chemical biomarkers presage the transition from normal to cancerous tissue. We have developed a noninvasive imaging system incorporating optical coherence tomography (OCT) and fluorescence lifetime imaging microscopy (FLIM) into a single optical system for the first time, in order to acquire both sets of biomarkers. OCT can provide morphological images of tissue with high resolution, while FLIM can provide biochemical tissue maps. Coregistered OCT volumes and FLIM images have been acquired simultaneously in an in vivo hamster cheek pouch model of oral cancer. The OCT images indicate morphological biomarkers for cancer including thickening of the epithelial layer and loss of the layered structure. The FLIM images indicate chemical biomarkers including increased nicotinamide adenine dinucleotide and reduced collagen emission. While both sets of biomarkers can differentiate normal and cancerous tissue, we believe their combination will enable the discrimination of benign lesions possessing some of the indicated biomarkers, e.g., scarring or inflammation.


Asunto(s)
Procesamiento de Imagen Asistido por Computador/métodos , Microscopía Fluorescente/métodos , Mucosa Bucal/patología , Neoplasias de la Boca/patología , Tomografía de Coherencia Óptica/métodos , Animales , Estudios de Casos y Controles , Cricetinae , Epitelio/patología
16.
J Biomed Opt ; 15(2): 026023, 2010.
Artículo en Inglés | MEDLINE | ID: mdl-20459268

RESUMEN

Skin cancer is the most common form of human cancer. Its early diagnosis and timely treatment is of paramount importance for dermatology and surgical oncology. In this study, we evaluate the use of reflectance and fluorescence confocal microscopy for detecting skin cancers in an in-vivo trial with B16F10 melanoma and SCCVII squamous cell carcinoma in mice. For the experiments, the mice are anesthetized, then the tumors are infiltrated with aqueous solution of methylene blue and imaged. Reflectance images are acquired at 658 nm. Fluorescence is excited at 658 nm and registered in the range between 690 and 710 nm. After imaging, the mice are sacrificed. The tumors are excised and processed for hematoxylin and eosin histopathology, which is compared to the optical images. The results of the study indicate that in-vivo reflectance images provide valuable information on vascularization of the tumor, whereas the fluorescence images mimic the structural features seen in histopathology. Simultaneous dye-enhanced reflectance and fluorescence confocal microscopy shows promise for the detection, demarcation, and noninvasive monitoring of skin cancer development.


Asunto(s)
Modelos Animales de Enfermedad , Microscopía Confocal/instrumentación , Microscopía Fluorescente/instrumentación , Neoplasias Cutáneas/patología , Animales , Línea Celular Tumoral , Diseño de Equipo , Análisis de Falla de Equipo , Masculino , Ratones , Ratones Endogámicos C57BL , Reproducibilidad de los Resultados , Sensibilidad y Especificidad
17.
Arch Otolaryngol Head Neck Surg ; 136(2): 126-33, 2010 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-20157056

RESUMEN

OBJECTIVE: To investigate the benefit of using time-resolved, laser-induced fluorescence spectroscopy for diagnosing malignant and premalignant lesions of the oral cavity. DESIGN: The carcinogen 7,12-dimethylbenz[a]anthracene (DMBA) was applied to 1 cheek pouch of 19 hamsters. The contralateral pouch and the cheek pouches of 3 hamsters without DMBA exposure served as controls. SETTING: University of California, Davis. PARTICIPANTS: Twenty-two golden/Syrian hamsters. INTERVENTION: A nitrogen pulse laser was used to induce tissue autofluorescence between the wavelengths of 360 and 650 nm. MAIN OUTCOME MEASURES: Spectral intensities and time-domain measurements were obtained and compared with the histopathologic findings at each corresponding site. RESULTS: Spectral intensities and lifetime values at 3 spectral bands (SBs; SB1 = 380 +/- 10 nm; SB2 = 460 +/- 10 nm, and SB3 = 635 +/- 10 nm) allowed for discrimination among healthy epithelium, dysplasia, carcinoma in situ, and invasive carcinoma. The lifetime values at SB2 were the most important when distinguishing the lesions using only time-resolved parameters. An algorithm combining spectral fluorescence parameters derived from both spectral and time-domain parameters (peak intensities, average fluorescence lifetimes, and the Laguerre coefficient [zero-order]) for healthy epithelium, dysplasia, carcinoma in situ, and invasive carcinoma provided the best diagnostic discrimination, with 100%, 100%, 69.2%, and 76.5% sensitivity and 100%, 92.2%, 97.1%, and 96.2% specificity, respectively. CONCLUSIONS: The addition of time-resolved fluorescence-derived parameters significantly improves the capability of fluorescence spectroscopy-based diagnostics in the hamster buccal pouch. This technique provides a potential noninvasive diagnostic instrument for head and neck cancer.


Asunto(s)
Carcinoma de Células Escamosas/diagnóstico , Neoplasias de la Boca/diagnóstico , Lesiones Precancerosas/diagnóstico , Espectrometría de Fluorescencia , Algoritmos , Animales , Carcinoma de Células Escamosas/inducido químicamente , Mejilla/patología , Cricetinae , Modelos Animales de Enfermedad , Masculino , Mesocricetus , Neoplasias de la Boca/inducido químicamente , Lesiones Precancerosas/inducido químicamente
18.
Biomed Opt Express ; 1(1): 186-200, 2010 Jul 16.
Artículo en Inglés | MEDLINE | ID: mdl-21258457

RESUMEN

Most pathological conditions elicit changes in the tissue optical response that may be interrogated by one or more optical imaging modalities. Any single modality typically only furnishes an incomplete picture of the tissue optical response, hence an approach that integrates complementary optical imaging modalities is needed for a more comprehensive non-destructive and minimally-invasive tissue characterization. We have developed a dual-modality system, incorporating optical coherence tomography (OCT) and fluorescence lifetime imaging microscopy (FLIM), that is capable of simultaneously characterizing the 3-D tissue morphology and its biochemical composition. The Fourier domain OCT subsystem, at an 830 nm center wavelength, provided high-resolution morphological volumetric tissue images with an axial and lateral resolution of 7.3 and 13.4 µm, respectively. The multispectral FLIM subsystem, based on a direct pulse-recording approach (upon 355 nm laser excitation), provided two-dimensional superficial maps of the tissue autofluorescence intensity and lifetime at three customizable emission bands with 100 µm lateral resolution. Both subsystems share the same excitation/illumination optical path and are simultaneously raster scanned on the sample to generate coregistered OCT volumes and FLIM images. The developed OCT/FLIM system was capable of a maximum A-line rate of 59 KHz for OCT and a pixel rate of up to 30 KHz for FLIM. The dual-modality system was validated with standard fluorophore solutions and subsequently applied to the characterization of two biological tissue types: postmortem human coronary atherosclerotic plaques, and in vivo normal and cancerous hamster cheek pouch epithelial tissue.

19.
Proc IEEE Ultrason Symp ; : 570-573, 2008.
Artículo en Inglés | MEDLINE | ID: mdl-21894259

RESUMEN

We report the development and validate a multi-modal tissue diagnostic technology, which combines three complementary techniques into one system including ultrasound backscatter microscopy (UBM), photoacoustic imaging (PAI), and time-resolved laser-induced fluorescence spectroscopy (TR-LIFS). UBM enables the reconstruction of the tissue microanatomy. PAI maps the optical absorption heterogeneity of the tissue associated with structure information and has the potential to provide functional imaging of the tissue. Examination of the UBM and PAI images allows for localization of regions of interest for TR-LIFS evaluation of the tissue composition. The hybrid probe consists of a single element ring transducer with concentric fiber optics for multi-modal data acquisition. Validation and characterization of the multi-modal system and ultrasonic, photoacoustic, and spectroscopic data coregistration were conducted in a physical phantom with properties of ultrasound scattering, optical absorption, and fluorescence. The UBM system with the 41 MHz ring transducer can reach the axial and lateral resolution of 30 and 65 µm, respectively. The PAI system with 532 nm excitation light from a Nd:YAG laser shows great contrast for the distribution of optical absorbers. The TR-LIFS system records the fluorescence decay with the time resolution of ~300 ps and a high sensitivity of nM concentration range. Biological phantom constructed with different types of tissues (tendon and fat) was used to demonstrate the complementary information provided by the three modalities. Fluorescence spectra and lifetimes were compared to differentiate chemical composition of tissues at the regions of interest determined by the coregistered high resolution UBM and PAI image. Current results demonstrate that the fusion of these techniques enables sequentially detection of functional, morphological, and compositional features of biological tissue, suggesting potential applications in diagnosis of tumors and atherosclerotic plaques.

20.
Arch Facial Plast Surg ; 9(4): 281-4, 2007.
Artículo en Inglés | MEDLINE | ID: mdl-17638764

RESUMEN

OBJECTIVE: To compare the tensile strength of nylon, polypropylene, and fast-absorbing gut sutures treated with either 3% hydrogen peroxide or water for a period of 5 days to emulate a wound care regimen. METHODS: An In-Spec 2200 bench-top tester was used to find the maximum load that a particular suture could sustain prior to breaking. RESULTS: Analysis of the data showed a statistically significant decrease in tensile strength of fast-absorbing gut sutures treated with hydrogen peroxide compared with fast-absorbing gut suture control samples and fast-absorbing gut sutures treated with only water. CONCLUSION: Though no in vivo studies were performed, a logical extension of these results would be that premature degradation of fast-absorbing gut sutures secondary to use of hydrogen peroxide might lead to widened and/or hypertrophic scars.


Asunto(s)
Antiinfecciosos Locales/farmacología , Peróxido de Hidrógeno/farmacología , Infección de la Herida Quirúrgica/prevención & control , Suturas , Resistencia a la Tracción/efectos de los fármacos , Antiinfecciosos Locales/administración & dosificación , Humanos , Peróxido de Hidrógeno/administración & dosificación
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