Arthur F Gmitro
- Department Head, Biomedical Engineering
- Professor, Medical Imaging
- Professor, Optical Sciences
- Professor, Biomedical Engineering
- Member of the Graduate Faculty
Dr. Arthur F. Gmitro is a Professor and Department Head of Biomedical Engineering in the College of Engineering at the University of Arizona. He holds joint appointments as a Professor of Medical Imaging and as Professor of Optical Sciences at the University of Arizona. Dr. Gmitro received his Ph.D. in Optical Sciences from the University of Arizona in 1982 under the mentorship of Dr. Harrison H Barrett. He was an Assistant Professor of Diagnostic Radiology at Yale University from 1982 to 1987 and then returned to join the University of Arizona faculty in 1987. Dr. Gmitro has been involved in medical imaging research for over 40 years and published more than 80 papers in the field. He is the recipient of the Rudolph Kingslake award from SPIE and the Francois Erbsmann prize from IPMI (Information Processing in Medical Imaging). Dr. Gmitro is also a Fellow of the American Institute of Medical and Biological Engineering. Dr. Gmitro’s major areas of research are in Biomedical Optical Imaging and in Magnetic Resonance Imaging. He has done fundamental work on development of these technologies and directs an active research program in these areas. Dr. Gmitro has served as the primary mentor for 23 doctoral and 4 post-doc students. Dr. Gmitro is the founding and current Director of the NIH-supported Training Program in Biomedical Imaging and Spectroscopy at the University of Arizona. He has developed and co-teaches five graduate level courses in biomedical imaging (Biomedical Imaging – BME516, Introduction to Image Science – OPTI536, Advanced Medical Imaging – OPTI/BME 638, and Biomedical Optics and Biophotonics – OPTI/BME 630).
- Ph.D. Optical Sciences
- University of Arizona, Tucson, Arizona, United States
- Founder's Day Award Recipient
- University of Arizona, College of Medicine, Fall 2016
Medical Imaging, Optical Imaging - Biomedical and Biological Applications, Magnetic Resonance Imaging, Multimodality Imaging
Image Science, Biomedical Imaging Technology
DissertationOPTI 920 (Fall 2021)
Independent StudyBME 499 (Fall 2021)
Biomedical ImagingBME 416 (Spring 2021)
Master's ReportBME 909 (Spring 2021)
Biomedical ImagingBME 516 (Fall 2020)
DissertationOPTI 920 (Fall 2020)
Biomedical ImagingBME 416 (Spring 2020)
DissertationOPTI 920 (Spring 2020)
Independent StudyBME 499 (Spring 2020)
Intro to Image ScienceOPTI 536 (Spring 2020)
Biomedical ImagingBME 516 (Fall 2019)
Rsrch Meth Biomed EngrBME 597G (Fall 2019)
Directed ResearchBME 492 (Summer I 2019)
DissertationBME 920 (Spring 2019)
Intro to Image ScienceOPTI 536 (Spring 2019)
Biomedical ImagingBME 516 (Fall 2018)
DissertationBME 920 (Fall 2018)
Directed ResearchBME 492 (Summer I 2018)
Master's ReportOPTI 909 (Summer I 2018)
Intro to Image ScienceOPTI 536 (Spring 2018)
Master's ReportOPTI 909 (Spring 2018)
Biomed Optics+BiphotonicBME 630 (Fall 2017)
Biomed Optics+BiphotonicOPTI 630 (Fall 2017)
Biomedical ImagingBME 516 (Fall 2017)
ThesisOPTI 910 (Fall 2017)
Honors Independent StudyOPTI 299H (Spring 2017)
Independent StudyPHYS 599 (Spring 2017)
Biomedical ImagingBME 516 (Fall 2016)
ThesisOPTI 910 (Summer I 2016)
Intro to Image ScienceOPTI 536 (Spring 2016)
ThesisOPTI 910 (Spring 2016)
- Momsen, N. C., Rouse, A. R., & Gmitro, A. F. (2020). Improvement in optical fiber bundle-based imaging using synchronized fiber motion. Applied Optics, 59(22), 6.
- Risi, M. D., Rouse, A. R., Chambers, S. K., Hatch, K. D., Zheng, W., & Gmitro, A. F. (2016). Pilot Clinical Evaluation of a Confocal Microlaparoscope for Ovarian Cancer Detection. International journal of gynecological cancer : official journal of the International Gynecological Cancer Society, 26(2), 248-54.More infoThe aim of this study is to evaluate the performance of a confocal fluorescence microlaparoscope for in vivo detection of ovarian cancer.
- Woolfenden, J. M., Pak, K. Y., Witte, M. H., Gmitro, A. F., Liang, R., Banerjee, B., Patel, C., Rouse, A. R., Furenlid, L. R., Bernas, M., Cai, M., Barber, C., Gray, B. D., & Liu, Z. (2016). Characterization of TCP-1 molecular imaging probes in mouse models with xenografted human colon cancer.. J Control Release, 239, 223-230.
- Leung, H. M., & Gmitro, A. F. (2015). Fluorescence and reflectance spectral imaging system for a murine mammary window chamber model. Biomedical optics express, 6(8), 2887-94.More infoA spectral imaging system was developed to study the development of breast cancer xenografts in a murine mammary window chamber model. The instrument is configured to work with either a laser to excite fluorescence or a broadband light source for diffuse reflectance imaging. Two applications were demonstrated. First, spectral imaging of fluorescence signals was demonstrated with a GFP-breast cancer tumor and fluorescein injection. Second, based on the principles of broadband reflectance spectroscopy, the instrument was used to monitor dynamic changes of tissue absorbance to yield tissue oxygenation maps at different time points during tumor progression.
- Risi, M. D., Makhlouf, H., Rouse, A. R., & Gmitro, A. F. (2015). Analysis of multimode fiber bundles for endoscopic spectral-domain optical coherence tomography. Applied optics, 54(1), 101-13.More infoA theoretical analysis of the use of a fiber bundle in spectral-domain optical coherence tomography (OCT) systems is presented. The fiber bundle enables a flexible endoscopic design and provides fast, parallelized acquisition of the OCT data. However, the multimode characteristic of the fibers in the fiber bundle affects the depth sensitivity of the imaging system. A description of light interference in a multimode fiber is presented along with numerical simulations and experimental studies to illustrate the theoretical analysis.
- Schafer, R., & Gmitro, A. F. (2015). Dynamic oxygenation measurements using a phosphorescent coating within a mammary window chamber mouse model. Biomedical optics express, 6(2), 639-50.More infoPhosphorescent lifetime imaging was employed to measure the spatial and temporal distribution of oxygen partial pressure in tissue under the coverslip of a mammary window chamber breast cancer mouse model. A thin platinum-porphyrin coating, whose phosphorescent lifetime varies monotonically with oxygen partial pressure, was applied to the coverslip surface. Dynamic temporal responses to induced modulations in oxygenation levels were measured using this approach.
- Schafer, R., Leung, H. M., & Gmitro, A. F. (2014). Multi-modality imaging of a murine mammary window chamber for breast cancer research. BioTechniques, 57(1), 45-50.More infoWindow chamber models have been developed and utilized as a means to study the complex microenvironment in which cancers develop, proliferate, and metastasize in small animals. Here we utilize rapid prototyping printer technology to construct a new plastic orthotopic mammary window chamber that is compatible with magnetic resonance imaging, nuclear imaging, and optical imaging. Optical imaging allows for high-resolution cellular and molecular level analysis of tissues; magnetic resonance imaging provides quantitative measures of tumor size, perfusion, diffusion, fat/water content relaxation parameters; and a nuclear imaging technique, called the Beta Imager, supports functional and metabolic imaging. Our demonstration of the multiple imaging capabilities of this model suggests that it can be used as a powerful platform for studying basic cancer biology and developing new cancer therapies.
- Wu, T., Rouse, A. R., Chambers, S. K., Hatch, K. D., & Gmitro, A. F. (2014). Confocal microlaparoscope for imaging the fallopian tube. Journal of biomedical optics, 19(11), 116010.More infoRecent evidence suggests that ovarian cancer can originate in the fallopian tube. Unlike many other cancers, poor access to the ovary and fallopian tubes has limited the ability to study the progression of this deadly disease and to diagnosis it during the early stage when it is most amenable to therapy. A rigid confocal microlaparoscope system designed to image the epithelial surface of the ovary in vivo was previously reported. A new confocal microlaparoscope with an articulating distal tip has been developed to enable in vivo access to human fallopian tubes. The new microlaparoscope is compatible with 5-mm trocars and includes a 2.2-mm-diameter articulating distal tip consisting of a bare fiber bundle and an automated dye delivery system for fluorescence confocal imaging. This small articulating device should enable the confocal microlaparoscope to image early stage ovarian cancer arising inside the fallopian tube. Ex vivo images of animal tissue and human fallopian tube using the new articulating device are presented along with in vivo imaging results using the rigid confocal microlaparoscope system.
- Gmitro, A., Kano, A., Rouse, A. R., & Gmitro, A. F. (2013). Ultrathin single-channel fiberscopes for biomedical imaging. Journal of biomedical optics, 18(1).More infoUltrathin flexible fiberscopes typically have separate illumination and imaging channels and are available in diameters ranging from 0.5 to 2.5 mm. Diameters can potentially be reduced by combining the illumination and imaging paths into a single fiberoptic channel. Single-channel fiberscopes must incorporate a system to minimize Fresnel reflections from air-glass interfaces within the common illumination and detection path. The Fresnel reflection at the proximal surface of the fiber bundle is particularly problematic. This paper describes and compares methods to reduce the background signal from the proximal surface of the fiber bundle. Three techniques are evaluated: (1) antireflective (AR)-coating the proximal face of the fiber, (2) incorporating crossed polarizers into the light path, and (3) a novel technique called numerical aperture sharing, whereby a portion of the image numerical aperture is devoted to illumination and a portion to detection.
- Leung, H. M., Schafer, R., Pagel, M. M., Robey, I. F., & Gmitro, A. F. (2013). Multimodality pH imaging in a mouse dorsal skin fold window chamber model. Progress in Biomedical Optics and Imaging - Proceedings of SPIE, 8574. doi:10.1117/12.2005472More infoAbstract: Upregulate levels of expression and activity of membrane H+ ion pumps in cancer cells drives the extracellular pH (pHe,) to values lower than normal. Furthermore, disregulated pH is indicative of the changes in glycolytic metabolism in tumor cells and has been shown to facilitate extracellular tissue remodeling during metastasis Therefore, measurement of pHe could be a useful cancer biomarker for diagnostic and therapy monitoring evaluation. Multimodality in-vivo imaging of pHe in tumorous tissue in a mouse dorsal skin fold window chamber (DSFWC) model is described. A custom-made plastic window chamber structure was developed that is compatible with both imaging optical and MR imaging modalities and provides a model system for continuous study of the same tissue microenvironment on multiple imaging platforms over a 3-week period. For optical imaging of pH e, SNARF-1 carboxylic acid is injected intravenously into a SCID mouse with an implanted tumor. A ratiometric measurement of the fluorescence signal captured on a confocal microscope reveals the pHe of the tissue visible within the window chamber. This imaging method was used in a preliminary study to evaluate sodium bicarbonate as a potential drug treatment to reverse tissue acidosis. For MR imaging of pHe the chemical exchange saturation transfer (CEST) was used as an alternative way of measuring pHe in a DSFWC model. ULTRAVIST®, a FDA approved x-ray/CT contrast agent has been shown to have a CEST effect that is pH dependent. A ratiometric analysis of water saturation at 5.6 and 4.2 ppm chemical shift provides a means to estimate the local pHe. © 2013 Copyright SPIE.
- Gmitro, A., Lin, Y., Wu, T., & Gmitro, A. F. (2012). Error analysis of ratiometric imaging of extracellular pH in a window chamber model. Journal of biomedical optics, 17(4).More infoRatiometric fluorescence-imaging technique is commonly used to measure extracellular pH in tumors and surrounding tissue within a dorsal skin-fold window chamber. Using a pH-sensitive fluorophore such as carboxy SNARF-1 one can measure pH distributions with high precision. However, it is often observed that the measured pH is lower than expected, with a bias that varies from one image to another. A comprehensive analysis of possible error sources is presented. These error sources include photon noise, estimator bias, instrument errors, temperature, and calibration errors from biological factors.
- Gmitro, A., Lin, Y., & Gmitro, A. F. (2011). Errors in confocal fluorescence ratiometric imaging microscopy due to chromatic aberration. Applied optics, 50(1).More infoConfocal fluorescence ratiometric imaging is an optical technique used to measure a variety of important biological parameters. A small amount of chromatic aberration in the microscope system can introduce a variation in the signal ratio dependent on the fluorophore concentration gradient along the optical axis and lead to bias in the measurement. We present a theoretical model of this effect. Experimental results and simulations clearly demonstrate that this error can be significant and should not be ignored.
- Makhlouf, H., Rouse, A. R., & Gmitro, A. F. (2011). Dual modality fluorescence confocal and spectral-domain optical coherence tomography microendoscope. Biomedical optics express, 2(3), 634-44.More infoOptical biopsy facilitates in vivo disease diagnoses by providing a real-time in situ view of tissue in a clinical setting. Fluorescence confocal microendoscopy and optical coherence tomography (OCT) are two methods that have demonstrated significant potential in this context. These techniques provide complementary viewpoints. The high resolution and contrast associated with confocal systems allow en face visualization of sub-cellular details and cellular organization within a thin layer of biological tissue. OCT provides cross-sectional images showing the tissue micro-architecture to a depth beyond the reach of confocal systems. We present a novel design for a bench-top imaging system that incorporates both confocal and OCT modalities in the same optical train allowing the potential for rapid switching between the two imaging techniques. Preliminary results using simple phantoms show that it is possible to realize both confocal microendoscopy and OCT through a fiber bundle based imaging system.
- Gmitro, A., Lin, Y., & Gmitro, A. F. (2010). Statistical analysis and optimization of frequency-domain fluorescence lifetime imaging microscopy using homodyne lock-in detection. Journal of the Optical Society of America. A, Optics, image science, and vision, 27(5).More infoFluorescence lifetime imaging microscopy is used widely in biological research, but the accuracy and precision of lifetime measurements are limited. Photon noise is an inherent error source that cannot be eliminated. In this paper, we present a general approach to compute the probability density of the estimated lifetime for frequency-domain fluorescence lifetime imaging microscopy using homodyne lock-in detection. The analysis for commonly used excitation methods, including sinusoidal modulation, square-wave modulation, and a periodically pulsed light source, are given and compared to the results of Monte Carlo simulations. The optimum parameters of the excitation waveforms to minimize the variance of the estimated lifetimes are also derived and compared to previously published results.
- Gmitro, A., Tanbakuchi, A. A., Udovich, J. A., Rouse, A. R., Hatch, K. D., & Gmitro, A. F. (2010). In vivo imaging of ovarian tissue using a novel confocal microlaparoscope. American journal of obstetrics and gynecology, 202(1).More infoThe objective of the study was to develop a clinical confocal microlaparoscope for imaging ovary epithelium in vivo with the long-term objective of diagnosing cancer in vivo.
- Li, Z., Graff, C., Gmitro, A. F., Squire, S. W., Bilgin, A., Outwater, E. K., & Altbach, M. I. (2009). Rapid water and lipid imaging with T2 mapping using a radial IDEAL-GRASE technique. Magnetic resonance in medicine, 61(6), 1415-24.More infoThree-point Dixon methods have been investigated as a means to generate water and fat images without the effects of field inhomogeneities. Recently, an iterative algorithm (IDEAL, iterative decomposition of water and fat with echo asymmetry and least squares estimation) was combined with a gradient and spin-echo acquisition strategy (IDEAL-GRASE) to provide a time-efficient method for lipid-water imaging with correction for the effects of field inhomogeneities. The method presented in this work combines IDEAL-GRASE with radial data acquisition. Radial data sampling offers robustness to motion over Cartesian trajectories as well as the possibility of generating high-resolution T(2) maps in addition to the water and fat images. The radial IDEAL-GRASE technique is demonstrated in phantoms and in vivo for various applications including abdominal, pelvic, and cardiac imaging.
- Tanbakuchi, A. A., Rouse, A. R., & Gmitro, A. F. (2009). Monte Carlo characterization of parallelized fluorescence confocal systems imaging in turbid media. Journal of biomedical optics, 14(4).More infoWe characterize and compare the axial and lateral performance of fluorescence confocal systems imaging in turbid media. The aperture configurations studied are a single pinhole, a slit, a Nipkow disk, and a linear array of pinholes. Systems with parallelized apertures are used clinically because they enable high-speed and real-time imaging. Understanding how they perform in highly scattering tissue is important. A Monte Carlo model was developed to characterize parallelized system performance in a scattering media representative of human tissues. The results indicate that a slit aperture has degraded performance, both laterally and axially. In contrast, the analysis reveals that multipinhole apertures such as a Nipkow disk or a linear pinhole array can achieve performance nearly equivalent to a single pinhole aperture. The optimal aperture spacing for the multipinhole apertures was determined for a specific tissue model. In addition to comparing aperture configurations, the effects of tissue nonradiative absorption, scattering anisotropy, and fluorophore concentration on lateral and axial performance of confocal systems were studied.
- Tanbakuchi, A. A., Udovich, J. A., Rouse, A. R., Hatch, K. D., & Gmitro, A. F. (2009). Clinical confocal microlaparoscope for real-time in vivo optical biopsies. Journal of biomedical optics, 14(4).More infoSuccessful treatment of cancer is highly dependent on the stage at which it is diagnosed. Early diagnosis, when the disease is still localized at its origin, results in very high cure rates-even for cancers that typically have poor prognosis. Biopsies are often used for diagnosis of disease. However, because biopsies are destructive, only a limited number can be taken. This leads to reduced sensitivity for detection due to sampling error. A real-time fluorescence confocal microlaparoscope has been developed that provides instant in vivo cellular images, comparable to those provided by histology, through a nondestructive procedure. The device includes an integrated contrast agent delivery mechanism and a computerized depth scan system. The instrument uses a fiber bundle to relay the image plane of a slit-scan confocal microlaparoscope into tissue. It has a 3-mum lateral resolution and a 25-mum axial resolution. Initial in vivo clinical testing using the device to image human ovaries has been done in 21 patients. Results indicate that the device can successfully image organs in vivo without complications. Results with excised tissue demonstrate that the instrument can resolve sufficient cellular detail to visualize the cellular changes associated with the onset of cancer.
- Udovich, J. A., Besselsen, D. G., & Gmitro, A. F. (2009). Assessment of acridine orange and SYTO 16 for in vivo imaging of the peritoneal tissues in mice. Journal of microscopy, 234(2), 124-9.More infoThe effect of peritoneal injection of acridine orange and SYTO 16 in mice was investigated. Images of peritoneal tissues stained with these dyes and obtained through a confocal micro-endoscope are presented. Seventy-five Balb/c mice were split into five groups and given peritoneal injections of dye or saline. The proportions of negative outcomes in each group were compared using confidence intervals and the Fisher's exact statistical test. A statistically significant increase in adverse events due to dye injection was not observed. These data provide an initial investigation into the safety of acridine orange and SYTO 16 for in vivo imaging.
- Chen, L., Gobar, L. S., Knowles, N. G., Liu, Z., Gmitro, A. F., & Barrett, H. H. (2008). Direct imaging of radionuclide-produced electrons and positrons with an ultrathin phosphor. Journal of nuclear medicine : official publication, Society of Nuclear Medicine, 49(7), 1141-5.More infoCurrent electron detectors are either unable to image in vivo or lack sufficient spatial resolution because of electron scattering in thick detector materials. This study was aimed at developing a sensitive high-resolution system capable of detecting electron-emitting isotopes in vivo.
- GMITRO, A., & AZIZ, D. (2008). CONFOCAL MICROSCOPY THROUGH A FIBEROPTIC IMAGING BUNDLE. OPTICS LETTERS, 18(8), 565-567.
- Gmitro, A., Udovich, J. A., Kirkpatrick, N. D., Kano, A., Tanbakuchi, A., Utzinger, U., & Gmitro, A. F. (2008). Spectral background and transmission characteristics of fiber optic imaging bundles. Applied optics, 47(25).More infoThe emission and transmission properties of three commercially produced coherent fiber optic imaging bundles were evaluated. Full fluorescence excitation versus emission data were collected from 250 to 650 nm excitation for high-resolution Sumitomo, Fujikura, and Schott fiber bundles. The results generated show regions of autofluorescence and inelastic Raman scattering in the imaging bundles that represent a wavelength-dependent background signal when these fibers are used for imaging applications. The high-resolution fiber bundles also exhibit significant variation in transmission with the angle of illumination, which affects the overall coupling and transmission efficiency. Knowledge of these properties allows users of high-resolution imaging bundles to optimally design systems that utilize such bundles.
- Makhlouf, H., Gmitro, A. F., Tanbakuchi, A. A., Udovich, J. A., & Rouse, A. R. (2008). Multispectral confocal microendoscope for in vivo and in situ imaging. Journal of biomedical optics, 13(4), 044016.More infoWe describe the design and operation of a multispectral confocal microendoscope. This fiber-based fluorescence imaging system consists of a slit-scan confocal microscope coupled to an imaging catheter that is designed to be minimally invasive and allow for cellular level imaging in vivo. The system can operate in two imaging modes. The grayscale mode of operation provides high resolution real-time in vivo images showing the intensity of fluorescent signal from the specimen. The multispectral mode of operation uses a prism as a dispersive element to collect a full multispectral image of the fluorescence emission. The instrument can switch back and forth nearly instantaneously between the two imaging modes (less than half a second). In the current configuration, the multispectral confocal microendoscope achieves 3-microm lateral resolution and 30-microm axial resolution. The system records light from 500 to 750 nm, and the minimum resolvable wavelength difference varies from 2.9 to 8.3 nm over this spectral range. Grayscale and multispectral imaging results from ex-vivo human tissues and small animal tissues are presented.
- Srivastava, S., Rodríguez, J. J., Rouse, A. R., Brewer, M. A., & Gmitro, A. F. (2008). Computer-aided identification of ovarian cancer in confocal microendoscope images. Journal of biomedical optics, 13(2), 024020 1-13.More infoThe confocal microendoscope is an instrument for imaging the surface of the human ovary. Images taken with this instrument from normal and diseased tissue show significant differences in cellular distribution. A real-time computer-aided system to facilitate the identification of ovarian cancer is introduced. The cellular-level structure present in ex vivo confocal microendoscope images is modeled as texture. Features are extracted based on first-order statistics, spatial gray-level-dependence matrices, and spatial-frequency content. Selection of the features is performed using stepwise discriminant analysis, forward sequential search, a nonparametric method, principal component analysis, and a heuristic technique that combines the results of these other methods. The selected features are used for classification, and the performance of various machine classifiers is compared by analyzing areas under their receiver operating characteristic curves. The machine classifiers studied included linear discriminant analysis, quadratic discriminant analysis, and the k-nearest-neighbor algorithm. The results suggest it is possible to automatically identify pathology based on texture features extracted from confocal microendoscope images and that the machine performance is superior to that of a human observer.
- Taljanovic, M. S., Graham, A. R., Benjamin, J. B., Gmitro, A. F., Krupinski, E. A., Schwartz, S. A., Hunter, T. B., & Resnick, D. L. (2008). Bone marrow edema pattern in advanced hip osteoarthritis: quantitative assessment with magnetic resonance imaging and correlation with clinical examination, radiographic findings, and histopathology. Skeletal radiology, 37(5), 423-31.More infoTo correlate the amount of bone marrow edema (BME) calculated by magnetic resonance imaging(MRI) with clinical findings, histopathology, and radiographic findings, in patients with advanced hip osteoarthritis(OA).
- Gatenby, R. G., Gawlinski, E. T., Gmitro, A. F., Kaylor, B., & Gillies, R. J. (2006). Acid-mediated tumor invasion: a multidisciplinary study. CANCER RESEARCH, 66(10), 5216-5223.
- Rouse, A., Kano, A., Udovich, J., Kroto, S., & Gmitro, A. (2006). Design and demonstration of a miniature catheter for a confocal microendoscope. APPLIED OPTICS, 43(31), 5763-5771.
- Gmitro, A., Altbach, M. I., Bilgin, A., Li, Z., Clarkson, E. W., Trouard, T. P., & Gmitro, A. F. (2005). Processing of radial fast spin-echo data for obtaining T2 estimates from a single k-space data set. Magnetic resonance in medicine : official journal of the Society of Magnetic Resonance in Medicine / Society of Magnetic Resonance in Medicine, 54(3).More infoRadially acquired fast spin-echo data can be processed to obtain T2-weighted images and a T2 map from a single k-space data set. The general approach is to use data at a specific TE (or narrow TE range) in the center of k-space and data at other TE values in the outer part of k-space. With this method high-resolution T2-weighted images and T2 maps are obtained in a time efficient manner. The mixing of TE data, however, introduces errors in the T2-weighted images and T2 maps that affect the accuracy of the T2 estimates. In this work, various k-space data processing methods for reconstructing T2-weighted images and T2 maps from a single radial fast spin-echo k-space data set are analyzed in terms of the accuracy of T2 estimates. The analysis is focused on the effect of image artifacts, object dependency, and noise on the T2 estimates. Results are presented in computer-generated phantoms and in vivo.
- Brewer, M. A., Utzinger, U., Barton, J. K., Hoying, J. B., Kirkpatrick, N. D., Brands, W. R., Davis, J. R., Hunt, K., Stevens, S. J., & Gmitro, A. F. (2004). Imaging of the ovary. Technology in cancer research & treatment, 3(6).More infoEpithelial ovarian cancer has the highest mortality rate among the gynecologic cancers and spreads beyond the ovary in 90% of the women diagnosed with ovarian cancer. Detection before the disease has spread beyond the ovary would significantly improve the survival from ovarian cancer, which is currently only 30% over 5 years, despite extensive efforts to improve the survival. This study describes initial investigation of the use of optical technologies to improve the outcome for this disease by detecting cancers at an earlier and more treatable stage. Women undergoing oophorectomy were recruited for this study. Ovaries were harvested for fluorescence spectroscopy, confocal microscopy, and optical coherence tomography. Fluorescence spectroscopy showed large diagnostic differences between normal and abnormal tissue at 270 and 340 nm excitation. Optical coherence tomography was able to image up to 2mm deep into the ovary with particular patterns of backscattered intensity observed in normal versus abnormal tissue. Fluorescence confocal microscopy was able to visualize sub-cellular structures of the surface epithelium and underlying cell layers. Optical imaging and/or spectroscopy has the potential to improve the diagnostic capability in the ovary, but extended systematic investigations are needed to identify the unique signatures of disease. The combination of optical technologies supported by modern molecular biology may lead to an instrument that can accurately detect early carcinogenesis.
- Fregosi, R., Quan, S., Kaemingk, K., Morgan, W., Goodwin, J., Cabrera, R., & Gmitro, A. (2004). Sleep-disordered breathing, pharyngeal size and soft tissue anatomy in children. JOURNAL OF APPLIED PHYSIOLOGY, 95(5), 2030-2038.
- Gmitro, A., Rouse, A. R., Kano, A., Udovich, J. A., Kroto, S. M., & Gmitro, A. F. (2004). Design and demonstration of a miniature catheter for a confocal microendoscope. Applied optics, 43(31).More infoThe fluorescence confocal microendoscope provides high-resolution, in vivo imaging of cellular pathology during optical biopsy. The confocal microendoscope employs a flexible fiber-optic catheter coupled to a custom-built slit-scan confocal microscope. The catheter consists of a fiber-optic imaging bundle linked to a miniature objective and focus assembly. The 3-mm-diameter catheter may be used on its own or routed though the instrument channel of a commercial endoscope, adding microscopic imaging capability to conventional endoscopy. The design and performance of the miniature objective and focus assembly are discussed. Primary applications of the system include diagnosis of disease in the gastrointestinal tract and female reproductive system.
- Rouse, A., & Gmitro, A. (2004). Multispectral imaging with a confocal microendoscope. OPTICS LETTERS, 25(23), 1708-1710.
- Gmitro, A., Altbach, M. I., Outwater, E. K., Trouard, T. P., Krupinski, E. A., Theilmann, R. J., Stopeck, A. T., Kono, M., & Gmitro, A. F. (2002). Radial fast spin-echo method for T2-weighted imaging and T2 mapping of the liver. Journal of magnetic resonance imaging : JMRI, 16(2).More infoTo evaluate a multishot radial fast-spin echo (RAD-FSE) method developed to improve the quality of abdominal T2-weighted imaging as well as the characterization of focal liver lesions.
- Sabharwal, Y., Rouse, A., Donaldson, L., Hopkins, M., & Gmitro, A. (2002). Slit-scanning confocal microendoscope for high-resolution in vivo imaging. APPLIED OPTICS, 38(34), 7133-7144.
- DECKELBAUM, L., STETZ, M., OBRIEN, K., CUTRUZZOLA, F., GMITRO, A., LAIFER, L., & GINDI, G. (2000). FLUORESCENCE SPECTROSCOPY GUIDANCE OF LASER ABLATION OF ATHEROSCLEROTIC PLAQUE. LASERS IN SURGERY AND MEDICINE, 9(3), 205-214.
- MAJUMDAR, S., ORPHANOUDAKIS, S., GMITRO, A., ODONNELL, M., & GORE, J. (2000). ERRORS IN THE MEASUREMENTS OF T2 USING MULTIPLE-ECHO MRI TECHNIQUES .1. EFFECTS OF RADIOFREQUENCY PULSE IMPERFECTIONS. MAGNETIC RESONANCE IN MEDICINE, 3(3), 397-417.
- Rouse, A. R., & Gmitro, A. F. (2000). Multispectral imaging with a confocal microendoscope. Optics letters, 25(23), 1708-10.More infoThe concept of a multispectral confocal microscope for in vivo imaging is introduced. To demonstrate the concept we modified a slit-scan fluorescence confocal microendoscope incorporating a fiber-optic catheter for in vivo imaging to record multispectral images. The system was designed to examine cellular structures during optical biopsy and to exploit the diagnostic information contained within the spectral domain. Preliminary experiments were carried out in phantoms and cell cultures to demonstrate the potential of the technique.
- Walsh, D. O., Gmitro, A. F., & Marcellin, M. W. (2000). Adaptive reconstruction of phased array MR imagery. MAGNETIC RESONANCE IN MEDICINE, 43(5), 682-690.
- YUE, G., ALEXANDER, A., LAIDLAW, D., GMITRO, A., UNGER, E., & ENOKA, R. (2000). SENSITIVITY OF MUSCLE PROTON SPIN-SPIN RELAXATION-TIME AS AN INDEX OF MUSCLE ACTIVATION. JOURNAL OF APPLIED PHYSIOLOGY, 77(1), 84-92.
- GMITRO, A., & ALEXANDER, A. (1999). USE OF A PROJECTION RECONSTRUCTION METHOD TO DECREASE MOTION SENSITIVITY IN DIFFUSION-WEIGHTED MRI. MAGNETIC RESONANCE IN MEDICINE, 29(6), 835-838.
- Sabharwal, Y. S., Rouse, A. R., Donaldson, L., Hopkins, M. F., & Gmitro, A. F. (1999). Slit-scanning confocal microendoscope for high-resolution in vivo imaging. Applied optics, 38(34), 7133-44.More infoWe discuss the design and construction of a novel imaging system in which a fiber-optic imaging bundle and miniature optical and mechanical components are used to allow confocal fluorescence microscopy in remote locations. The instrumentation has been developed specifically for cellular examination of tissue for optical biopsy. Miniaturization of various components makes the device usable in a clinical setting. The numerical aperture of the beam in the tissue is 0.5, and the field of view is 430 microm. The measured lateral resolution of the system is 3.0 microm. The axial point and the axial planar response functions of the confocal system were measured with a FWHM of 10 and 25 microm, respectively. In vitro and in vivo images obtained with cell cultures, human tissue specimens, and animal models indicate that the performance of the device is adequate for microscopic evaluation of cells.
- Tanbakuchi, A. A., Rouse, A. R., Udovich, J. A., Hatch, K. D., & Gmitro, A. F. (1999). Clinical confocal microlaparoscope for real-time in vivo optical biopsies. JOURNAL OF BIOMEDICAL OPTICS, 14(4).
- OBRIEN, K., GMITRO, A., GINDI, G., STETZ, M., CUTRUZZOLA, F., LAIFER, L., & DECKELBAUM, L. (1996). DEVELOPMENT AND EVALUATION OF SPECTRAL CLASSIFICATION ALGORITHMS FOR FLUORESCENCE GUIDED LASER ANGIOPLASTY. IEEE TRANSACTIONS ON BIOMEDICAL ENGINEERING, 36(4), 424-431.
- Trouard, T., Sabharwal, Y., Altbach, M., & Gmitro, A. (1994). Analysis and comparison of motion-correction techniques in diffusion-weighted imaging. JMRI-JOURNAL OF MAGNETIC RESONANCE IMAGING, 6(6), 925-935.
- MAJUMDAR, S., ORPHANOUDAKIS, S., GMITRO, A., ODONNELL, M., & GORE, J. (1993). ERRORS IN THE MEASUREMENTS OF T2 USING MULTIPLE-ECHO MRI TECHNIQUES .2. EFFECTS OF STATIC-FIELD INHOMOGENEITY. MAGNETIC RESONANCE IN MEDICINE, 3(4), 562-574.
- Van de Walle, R., Barrett, H., Myers, K., Altbach, M., Desplanques, B., Gmitro, A., Cornelis, J., & Lemahieu, . (1993). Reconstruction of MR images from data acquired on a general nonregular grid by pseudoinverse calculation. IEEE TRANSACTIONS ON MEDICAL IMAGING, 19(12), 1160-1167.
- Trouard, T., Theilmann, R., Altbach, M., & Gmitro, A. (1989). High-resolution diffusion imaging with DIFRAD-FSE (diffusion-weighted radial acquisition of data with fast spin-echo) MRI. MAGNETIC RESONANCE IN MEDICINE, 42(1), 11-18.
- GINDI, G. R., & GMITRO, A. F. (1984). OPTICAL-FEATURE EXTRACTION VIA THE RADON-TRANSFORM. OPTICAL ENGINEERING, 23(5), 499-506.
- Gmitro, A. F. (2019, April). Polyscopic Imaging of Window Chamber Mouse Models. OSA Biophotonics Conference. Tucson, AZ: Optical Society of America.
- Woolfenden, J. M., Pak, K. Y., Banerjee, B., Liang, R., Gmitro, A. F., Wan, L., Barber, C., Gray, B., & Liu, Z. (2019, May). Characterization of TCP-1 multimodality imaging probes in targeting colorectal cancer cells. The 23rd International Symposium on Radiopharmaceutical Sciences. Beijing, China: The Society of Radiopharmaceutical Sciences.
- Gmitro, A. F. (2018, 5/15). Biomedical Imaging Systems Based on Optical Fiber Bundles. OSA Bio-Optics: Design and Application. Rice University, Houston TX: Optical Society of America.
- Gmitro, A. F. (2018, Nov 8). Microscopic and Polyscopic Imaging of Living Tissue. Carnegie Mellon University BME Seminar. Carnegie Mellon University, Pittsburgh PA: Carnegie Mellon University.
- Gmitro, A. F. (2018, Oct 13). Multi-Modal Imaging of Vascularization, Oxygenation, and Other Physiological Processes In Window Chamber Mouse Models. Special Workshop on Enabling Technologies. StarPass Resort: Cell Transplant and Regenerative Medicine Society.
- Phung, M., Lee, B. R., Gmitro, A. F., Rouse, A. R., Bell, R., Price, E., Bracamonte, E. R., Bracamonte, E. R., Bell, R., Price, E., Rouse, A. R., Gmitro, A. F., Phung, M., & Lee, B. R. (2018, May). Optical Biopsy using Confocal Microscopy for Differentiation of Renal Cell Carcinoma versus Benign Tissue. American Urological Association National Meeting. San Francisco: American Urological Association.
- Gmitro, A. F. (2015, January). Multi-modality Imaging in a Mammary Window Chamber Mouse Model for Breast Cancer Research. UACC Breast Cancer Retreat. Arizona Inn: University of Arizona Cancer Center.
- Gmitro, A. F. (2015, May). Collaborative Translational Research: Ovarian Cancer and Imaging. UACC Grand Rounds. University of Arizona: University of Arizona Cancer Center.
- Gmitro, A. F., Leung, H., & Schafer, R. (2015, October). Multi-modality Imaging in a Mammary Window Chamber PDX Tumor Mouse Model. Biomedical Engineering Society Annual Meeting. Tampa Bay, FL: BMES.
- Lee, B. R., Gmitro, A. F., Price, E., Bracamonte, E. R., Bell, R., Rouse, A. R., & Phung, M. (2018, May). Optical Biopsy using Confocal Microscopy for Differentiation of Renal Cell Carcinoma versus Benign Tissue. American Urological Association National Meeting. San Francisco: American Urological Association.
- Schafer, R., & Gmitro, A. F. (2015, February). Measuring oxygen tension modulation, induced by a new pre-radiotherapy therapeutic, in a mammary window chamber model. SPIE Photonics West, BIOS. San Francisco, CA: SPIE.