WorldWideScience

Sample records for tomography guided fluorescence

  1. Enhancing early bladder cancer detection with fluorescence-guided endoscopic optical coherence tomography

    Science.gov (United States)

    Pan, Y. T.; Xie, T. Q.; Du, C. W.; Bastacky, S.; Meyers, S.; Zeidel, M. L.

    2003-12-01

    We report an experimental study of the possibility of enhancing early bladder cancer diagnosis with fluorescence-image-guided endoscopic optical coherence tomography (OCT). After the intravesical instillation of a 10% solution of 5-aminolevulinic acid, simultaneous fluorescence imaging (excitation of 380-420 nm, emission of 620-700 nm) and OCT are performed on rat bladders to identify the photochemical and morphological changes associated with uroepithelial tumorigenesis. The preliminary results of our ex vivo study reveal that both fluorescence and OCT can identify early uroepithelial cancers, and OCT can detect precancerous lesions (e.g., hyperplasia) that fluorescence may miss. This suggests that a cystoscope combining 5-aminolevulinic acid fluorescence and OCT imaging has the potential to enhance the efficiency and sensitivity of early bladder cancer diagnosis.

  2. A study of MRI-guided diffuse fluorescence molecular tomography for monitoring PDT effects in pancreas cancer

    Science.gov (United States)

    Samkoe, Kimberley S.; Davis, Scott C.; Srinivasan, Subhadra; O'Hara, Julia A.; Hasan, Tayyaba; Pogue, Brian W.

    2009-06-01

    Over the last several decades little progress has been made in the therapy and treatment monitoring of pancreas adenocarcinoma, a devastating and aggressive form of cancer that has a 5-year patient survival rate of 3%. Currently, investigations for the use of interstitial Verteporfin photodynamic therapy (PDT) are being undertaken in both orthotopic xenograft mouse models and in human clinical trials. In the mouse models, magnetic resonance (MR) imaging has been used as a measure of surrogate response to Verteporfin PDT; however, MR imaging alone lacks the molecular information required to assess the metabolic function and growth rates of the tumor immediately after treatment. We propose the implementation of MR-guided fluorescence tomography in conjunction with a fluorescently labeled (IR-Dye 800 CW, LI-COR) epidermal growth factor (EGF) as a molecular measure of surrogate response. To demonstrate the effectiveness of MR-guided diffuse fluorescence tomography for molecular imaging, we have used the AsPC-1 (+EGFR) human pancreatic adenocarcinoma in an orthotopic mouse model. EGF IRDye 800CW was injected 48 hours prior to imaging. MR image sequences were collected simultaneously with the fluorescence data using a MR-coupled diffuse optical tomography system. Image reconstruction was performed multiple times with varying abdominal organ segmentation in order to obtain a optimal tomographic image. It is shown that diffuse fluorescence tomography of the orthotopic pancreas model is feasible, with consideration of confounding fluorescence signals from the multiple organs and tissues surrounding the pancreas. MR-guided diffuse fluorescence tomography will be used to monitor EGF response after photodynamic therapy. Additionally, it provide the opportunity to individualize subsequent therapies based on response to PDT as well as to evaluate the success of combination therapies, such as PDT with chemotherapy, antibody therapy or even radiation.

  3. Fluorescence-Guided Probes of Aptamer-Targeted Gold Nanoparticles with Computed Tomography Imaging Accesses for in Vivo Tumor Resection.

    Science.gov (United States)

    Li, Cheng-Hung; Kuo, Tsung-Rong; Su, Hsin-Jan; Lai, Wei-Yun; Yang, Pan-Chyr; Chen, Jinn-Shiun; Wang, Di-Yan; Wu, Yi-Chun; Chen, Chia-Chun

    2015-10-28

    Recent development of molecular imaging probes for fluorescence-guided surgery has shown great progresses for determining tumor margin to execute the tissue resection. Here we synthesize the fluorescent gold nanoparticles conjugated with diatrizoic acid and nucleolin-targeted AS1411 aptamer. The nanoparticle conjugates exhibit high water-solubility, good biocompatibility, visible fluorescence and strong X-ray attenuation for computed tomography (CT) contrast enhancement. The fluorescent nanoparticle conjugates are applied as a molecular contrast agent to reveal the tumor location in CL1-5 tumor-bearing mice by CT imaging. Furthermore, the orange-red fluorescence emitting from the conjugates in the CL1-5 tumor can be easily visualized by the naked eyes. After the resection, the IVIS measurements show that the fluorescence signal of the nanoparticle conjugates in the tumor is greatly enhanced in comparison to that in the controlled experiment. Our work has shown potential application of functionalized nanoparticles as a dual-function imaging agent in clinical fluorescence-guided surgery.

  4. Bladder cancer diagnosis with fluorescence-image-guided optical coherence tomography

    Science.gov (United States)

    Wang, Z. G.; Durand, D. B.; Adler, H.; Pan, Y. T.

    2006-02-01

    A fluorescence-image-guided OCT (FIG-OCT) system is described, and its ability to enhance the sensitivity and specificity is examined in an animal bladder cancer model. Total 97 specimens were examined by fluorescence imaging, OCT and histological microscopy. The sensitivity and specificity of FIG-OCT is 100% and 93% respectively, compared to 79% and 53% for fluorescence imaging, while the OCT examination time has been dramatically decreased by 3~4 times. In combination of endoscopic OCT, FIG-OCT is a promising technique for effective early bladder cancer diagnosis.

  5. A Dual Reporter Iodinated Labeling Reagent for Cancer Positron Emission Tomography Imaging and Fluorescence-Guided Surgery

    Science.gov (United States)

    2018-01-01

    The combination of early diagnosis and complete surgical resection offers the greatest prospect of curative cancer treatment. An iodine-124/fluorescein-based dual-modality labeling reagent, 124I-Green, constitutes a generic tool for one-step installation of a positron emission tomography (PET) and a fluorescent reporter to any cancer-specific antibody. The resulting antibody conjugate would allow both cancer PET imaging and intraoperative fluorescence-guided surgery. 124I-Green was synthesized in excellent radiochemical yields of 92 ± 5% (n = 4) determined by HPLC with an improved one-pot three-component radioiodination reaction. The A5B7 carcinoembryonic antigen (CEA)-specific antibody was conjugated to 124I-Green. High tumor uptake of the dual-labeled A5B7 of 20.21 ± 2.70, 13.31 ± 0.73, and 10.64 ± 1.86%ID/g was observed in CEA-expressing SW1222 xenograft mouse model (n = 3) at 24, 48, and 72 h post intravenous injection, respectively. The xenografts were clearly visualized by both PET/CT and ex vivo fluorescence imaging. These encouraging results warrant the further translational development of 124I-Green for cancer PET imaging and fluorescence-guided surgery. PMID:29388770

  6. Anatomical image-guided fluorescence molecular tomography reconstruction using kernel method

    Science.gov (United States)

    Baikejiang, Reheman; Zhao, Yue; Fite, Brett Z.; Ferrara, Katherine W.; Li, Changqing

    2017-01-01

    Abstract. Fluorescence molecular tomography (FMT) is an important in vivo imaging modality to visualize physiological and pathological processes in small animals. However, FMT reconstruction is ill-posed and ill-conditioned due to strong optical scattering in deep tissues, which results in poor spatial resolution. It is well known that FMT image quality can be improved substantially by applying the structural guidance in the FMT reconstruction. An approach to introducing anatomical information into the FMT reconstruction is presented using the kernel method. In contrast to conventional methods that incorporate anatomical information with a Laplacian-type regularization matrix, the proposed method introduces the anatomical guidance into the projection model of FMT. The primary advantage of the proposed method is that it does not require segmentation of targets in the anatomical images. Numerical simulations and phantom experiments have been performed to demonstrate the proposed approach’s feasibility. Numerical simulation results indicate that the proposed kernel method can separate two FMT targets with an edge-to-edge distance of 1 mm and is robust to false-positive guidance and inhomogeneity in the anatomical image. For the phantom experiments with two FMT targets, the kernel method has reconstructed both targets successfully, which further validates the proposed kernel method. PMID:28464120

  7. Image-guided intraocular injection using multimodality optical coherence tomography and fluorescence confocal scanning laser ophthalmoscopy in rodent ophthalmological models

    Science.gov (United States)

    Terrones, Benjamin D.; Benavides, Oscar R.; Leeburg, Kelsey C.; Mehanathan, Sankarathi B.; Levine, Edward M.; Tao, Yuankai K.

    2018-02-01

    Intraocular injections are routinely performed for delivery of anti-VEGF and anti-inflammatory therapies in humans. While these injections are also performed in mice to develop novel models of ophthalmic diseases and screen novel therapeutics, the injection location and volume are not well-controlled and reproducible. We overcome limitations of conventional injections methods by developing a multimodality, long working distance, non-contact optical coherence tomography (OCT) and fluorescence confocal scanning laser ophthalmoscopy (cSLO) system for retinal imaging before and after injections. Our OCT+cSLO system combines a custom-built spectraldomain OCT engine (875+/-85 nm) with 125 kHz line-rate with a modified commercial cSLO with a maximum frame-rate of 30 fps (512 x 512 pix.). The system was designed for an overlapping OCT+cSLO field-of-view of 1.1 mm with a 7.76 mm working distance to the pupil. cSLO excitation light sources and filters were optimized for simultaneous GFP and tdTomato imaging. Lateral resolution was 3.02 µm for OCT and 2.74 μm for cSLO. Intravitreal injections of 5%, 10%, and 20% intralipid with Alex Fluor 488 were manually injected intraocularly in C57BL/6 mice. Post-injection imaging showed structural changes associated with retinal puncture, including the injection track, a retinal elevation, and detachment of the posterior hyaloid. OCT enables quantitative analysis of injection location and volumes whereas complementary cSLO improves specificity for identifying fluorescently labeled injected compounds and transgenic cells. The long working distance of our non-contact OCT+cSLO system is uniquely-suited for concurrent imaging with intraocular injections and may be applied for imaging of ophthalmic surgical dynamics and real-time image-guided injections.

  8. Multimodality optical coherence tomography and fluorescence confocal scanning laser ophthalmoscopy for image-guided feedback of intraocular injections in mouse models

    Science.gov (United States)

    Benavides, Oscar R.; Terrones, Benjamin D.; Leeburg, Kelsey C.; Mehanathan, Sankarathi B.; Levine, Edward M.; Tao, Yuankai K.

    2018-02-01

    Rodent models are robust tools for understanding human retinal disease and function because of their similarities with human physiology and anatomy and availability of genetic mutants. Optical coherence tomography (OCT) has been well-established for ophthalmic imaging in rodents and enables depth-resolved visualization of structures and image-based surrogate biomarkers of disease. Similarly, fluorescence confocal scanning laser ophthalmoscopy (cSLO) has demonstrated utility for imaging endogenous and exogenous fluorescence and scattering contrast in the mouse retina. Complementary volumetric scattering and en face fluorescence contrast from OCT and cSLO, respectively, enables cellular-resolution longitudinal imaging of changes in ophthalmic structure and function. We present a non-contact multimodal OCT+cSLO small animal imaging system with extended working distance to the pupil, which enables imaging during and after intraocular injection. While injections are routinely performed in mice to develop novel models of ophthalmic diseases and screen novel therapeutics, the location and volume delivered is not precisely controlled and difficult to reproduce. Animals were imaged using a custom-built OCT engine and scan-head combined with a modified commercial cSLO scan-head. Post-injection imaging showed structural changes associated with retinal puncture, including the injection track, a retinal elevation, and detachment of the posterior hyaloid. When combined with imagesegmentation, we believe OCT can be used to precisely identify injection locations and quantify injection volumes. Fluorescence cSLO can provide complementary contrast for either fluorescently labeled compounds or transgenic cells for improved specificity. Our non-contact OCT+cSLO system is uniquely-suited for concurrent imaging with intraocular injections, which may be used for real-time image-guided injections.

  9. Three-dimensional fluorescence lifetime tomography

    International Nuclear Information System (INIS)

    Godavarty, Anuradha; Sevick-Muraca, Eva M.; Eppstein, Margaret J.

    2005-01-01

    Near-infrared fluorescence tomography using molecularly targeted lifetime-sensitive, fluorescent contrast agents have applications for early-stage cancer diagnostics. Yet, although the measurement of fluorescent lifetime imaging microscopy (FLIM) is extensively used in microscopy and spectroscopy applications, demonstration of fluorescence lifetime tomography for medical imaging is limited to two-dimensional studies. Herein, the feasibility of three-dimensional fluorescence-lifetime tomography on clinically relevant phantom volumes is established, using (i) a gain-modulated intensified charge coupled device (CCD) and modulated laser diode imaging system, (ii) two fluorescent contrast agents, e.g., Indocyanine green and 3-3'-Diethylthiatricarbocyanine iodide differing in their fluorescence lifetime by 0.62 ns, and (iii) a two stage approximate extended Kalman filter reconstruction algorithm. Fluorescence measurements of phase and amplitude were acquired on the phantom surface under different target to background fluorescence absorption (70:1, 100:1) and fluorescence lifetime (1:1, 2.1:1) contrasts at target depths of 1.4-2 cm. The Bayesian tomography algorithm was employed to obtain three-dimensional images of lifetime and absorption owing to the fluorophores

  10. Ultrasound guided fluorescence molecular tomography with improved quantification by an attenuation compensated born-normalization and in vivo preclinical study of cancer

    International Nuclear Information System (INIS)

    Li, Baoqiang; Berti, Romain; Abran, Maxime; Lesage, Frédéric

    2014-01-01

    Ultrasound imaging, having the advantages of low-cost and non-invasiveness over MRI and X-ray CT, was reported by several studies as an adequate complement to fluorescence molecular tomography with the perspective of improving localization and quantification of fluorescent molecular targets in vivo. Based on the previous work, an improved dual-modality Fluorescence-Ultrasound imaging system was developed and then validated in imaging study with preclinical tumor model. Ultrasound imaging and a profilometer were used to obtain the anatomical prior information and 3D surface, separately, to precisely extract the tissue boundary on both sides of sample in order to achieve improved fluorescence reconstruction. Furthermore, a pattern-based fluorescence reconstruction on the detection side was incorporated to enable dimensional reduction of the dataset while keeping the useful information for reconstruction. Due to its putative role in the current imaging geometry and the chosen reconstruction technique, we developed an attenuation compensated Born-normalization method to reduce the attenuation effects and cancel off experimental factors when collecting quantitative fluorescence datasets over large area. Results of both simulation and phantom study demonstrated that fluorescent targets could be recovered accurately and quantitatively using this reconstruction mechanism. Finally, in vivo experiment confirms that the imaging system associated with the proposed image reconstruction approach was able to extract both functional and anatomical information, thereby improving quantification and localization of molecular targets

  11. In Vivo Diffuse Optical Tomography and Fluorescence Molecular Tomography

    Directory of Open Access Journals (Sweden)

    Mingze Li

    2010-01-01

    Full Text Available Diffuse optical tomography (DOT and fluorescence molecular tomography (FMT are two attractive imaging techniques for in vivo physiological and psychological research. They have distinct advantages such as non-invasiveness, non-ionizing radiation, high sensitivity and longitudinal monitoring. This paper reviews the key components of DOT and FMT. Light propagation model, mathematical reconstruction algorithm, imaging instrumentation and medical applications are included. Future challenges and perspective on optical tomography are discussed.

  12. Fluorescence molecular tomography in the presence of background fluorescence

    International Nuclear Information System (INIS)

    Soubret, Antoine; Ntziachristos, Vasilis

    2006-01-01

    Fluorescence molecular tomography is an emerging imaging technique that resolves the bio-distribution of engineered fluorescent probes developed for in vivo reporting of specific cellular and sub-cellular targets. The method can detect fluorochromes in picomole amounts or less, imaged through entire animals, but the detection sensitivity and imaging performance drop in the presence of background, non-specific fluorescence. In this study, we carried out a theoretical and an experimental investigation on the effect of background fluorescence on the measured signal and on the tomographic reconstruction. We further examined the performance of three subtraction methods based on physical models of photon propagation, using experimental data on phantoms and small animals. We show that the data pre-processing with subtraction schemes can improve image quality and quantification when non-specific background florescence is present

  13. X-ray microtome by fluorescence tomography

    CERN Document Server

    Simionovici, A S; Guenzler, F; Schrör, C; Snigirev, A; Snigireva, I; Tümmler, J; Weitkamp, T

    2001-01-01

    The X-ray fluorescence microtomography method is presented, which is capable of virtually slicing samples to obtain cross-sections of their inner structure. High precision experimental results of fluo-tomography in 'pencil-beam' geometry with up to 1.2 mu m resolution are described. Image reconstructions are based on either a simplified algebraic reconstruction method (ART) or the filtered back-projection method (FBP). Phantoms of inhomogeneous test objects as well as biological samples are successfully analyzed.

  14. Improving limited-projection-angle fluorescence molecular tomography using a co-registered x-ray computed tomography scan.

    Science.gov (United States)

    Radrich, Karin; Ale, Angelique; Ermolayev, Vladimir; Ntziachristos, Vasilis

    2012-12-01

    We examine the improvement in imaging performance, such as axial resolution and signal localization, when employing limited-projection-angle fluorescence molecular tomography (FMT) together with x-ray computed tomography (XCT) measurements versus stand-alone FMT. For this purpose, we employed living mice, bearing a spontaneous lung tumor model, and imaged them with FMT and XCT under identical geometrical conditions using fluorescent probes for cancer targeting. The XCT data was employed, herein, as structural prior information to guide the FMT reconstruction. Gold standard images were provided by fluorescence images of mouse cryoslices, providing the ground truth in fluorescence bio-distribution. Upon comparison of FMT images versus images reconstructed using hybrid FMT and XCT data, we demonstrate marked improvements in image accuracy. This work relates to currently disseminated FMT systems, using limited projection scans, and can be employed to enhance their performance.

  15. Radiative transport-based frequency-domain fluorescence tomography

    International Nuclear Information System (INIS)

    Joshi, Amit; Rasmussen, John C; Sevick-Muraca, Eva M; Wareing, Todd A; McGhee, John

    2008-01-01

    We report the development of radiative transport model-based fluorescence optical tomography from frequency-domain boundary measurements. The coupled radiative transport model for describing NIR fluorescence propagation in tissue is solved by a novel software based on the established Attila(TM) particle transport simulation platform. The proposed scheme enables the prediction of fluorescence measurements with non-contact sources and detectors at a minimal computational cost. An adjoint transport solution-based fluorescence tomography algorithm is implemented on dual grids to efficiently assemble the measurement sensitivity Jacobian matrix. Finally, we demonstrate fluorescence tomography on a realistic computational mouse model to locate nM to μM fluorophore concentration distributions in simulated mouse organs

  16. Field trials results of guided wave tomography

    International Nuclear Information System (INIS)

    Volker, Arno; Zon, Tim van; Leden, Edwin van der

    2015-01-01

    Corrosion is one of the industries major issues regarding the integrity of assets. Guided wave travel time tomography is a method capable of providing an absolute wall thickness map. This method is currently making the transition from the laboratory to the field. For this purpose a dedicated data acquisition system and special purpose EMAT sensor rings have been developed. The system can be deployed for permanent monitoring and inspections. Field trials have been conducted on various pipes with different diameters, containing either liquid or gas. The main focus has been on pipe supports. The results demonstrate the successful operation of the technology in the field. Expected corrosion damage was clearly visible on the produced results enabling asset owner to make calculated decisions on the pipelines safety, maintenance and operations

  17. Field trials results of guided wave tomography

    Science.gov (United States)

    Volker, Arno; van Zon, Tim; van der Leden, Edwin

    2015-03-01

    Corrosion is one of the industries major issues regarding the integrity of assets. Guided wave travel time tomography is a method capable of providing an absolute wall thickness map. This method is currently making the transition from the laboratory to the field. For this purpose a dedicated data acquisition system and special purpose EMAT sensor rings have been developed. The system can be deployed for permanent monitoring and inspections. Field trials have been conducted on various pipes with different diameters, containing either liquid or gas. The main focus has been on pipe supports. The results demonstrate the successful operation of the technology in the field. Expected corrosion damage was clearly visible on the produced results enabling asset owner to make calculated decisions on the pipelines safety, maintenance and operations.

  18. Fluorescence diffuse tomography of small animals with DsRed2 fluorescent protein

    Science.gov (United States)

    Turchin, I. V.; Plehanov, V. I.; Orlova, A. G.; Kamenskiy, V. A.; Kleshnin, M. S.; Shirmanova, M. V.; Shakhova, N. M.; Balalaeva, I. V.; Savitskiy, A. P.

    2006-05-01

    Fluorescent compounds are used as markers to diagnose oncological diseases, to study molecular processes typical for carcinogenesis, and to investigate metastasis formation and tumor regress under the influence of therapeutics. Different types of tomography, such as continuous wave (CW), frequency-domain (FD), and time-domain (TD) tomography, allow fluorescence imaging of tumors located deep in human or animal tissue. In this work, preliminary results of the frequency domain fluorescent diffuse tomography (FDT) method in application to DsRed2 protein as a fluorescent agent are presented. For the first step of our experiments, we utilized low-frequency amplitude modulation (1 kHz) of second harmonic of Nd: YAG (532 nm). The transilluminative configuration was used in the setup. The results of post mortem experiments with capsules containing DsRed2 inserted inside the esophagus of a 3-day-old hairless rat to simulate tumor are shown. An algorithm of processing fluorescent images based on calculating the zero of maximum curvature has been applied to detect fluorescent inclusion boundaries in the image. This work demonstrates the potential capability of the FDT method for imaging deep fluorescent tumors in human tissue or animal models of human cancer. Improvement of the setup can be accomplished by using high-frequency modulation (using a 110-MHz acoustooptical modulator).

  19. Diffuse fluorescence tomography of exo- and endogenously labeled tumors

    Science.gov (United States)

    Balalaeva, Irina V.; Turchin, Ilya V.; Orlova, Anna G.; Plekhanov, Vladimir I.; Shirmanova, Marina V.; Kleshnin, Michail S.; Fiks, Ilya I.; Zagainova, Elena V.; Kamensky, Vladislav A.

    2007-06-01

    Strong light scattering and absorption limit observation of the internal structure of biological tissue. Only special tools for turbid media imaging, such as optical diffuse tomography, enable noninvasive investigation of the internal biological tissues, including visualization and intravital monitoring of deep tumors. In this work the preliminary results of diffuse fluorescence tomography (DFT) of small animals are presented. Usage of exogenous fluorophores, targeted specifically at tumor cells, and fluorescent proteins expressed endogenously can significantly increase the contrast of obtained images. Fluorescent compounds of different nature, such as sulphonated aluminium phthalocyanine (Photosens), red fluorescing proteins and CdTe/CdSe-core/shell nanocrystals (quantum dots) were applied. We tested diffuse fluorescence tomography method at model media, in post mortem and in vivo experiments. The animal was scanned in transilluminative configuration by low-frequency modulated light (1 kHz) from Nd:YAG laser with second harmonic generation at wavelength of 532 nm or semiconductor laser at wavelength of 655 nm. Quantum dots or protein DsRed2 in glass capsules (inner diameter 2-3 mm) were placed post mortem inside the esophagus of 7-day-old hairless rats to simulate marked tumors. Photosens was injected intravenously to linear mice with metastazing Lewis lung carcinoma. The reconstruction algorithm, based on Algebraic Reconstruction Technique, was created and tested numerically in model experiments. High contrast images of tumor simulating capsules with DsRed2 concentrations about 10 -6 M and quantum dots about 5x10 -11 M have been obtained. Organ distribution of Photosens and its accumulation in tumors and surrounding tissues of animals has been examined. We have conducted the monitoring of tumors, exogenously labeled by photosensitizer. This work demonstrates potential capabilities of DFT method for intravital detection and monitoring of deep fluorescent

  20. Bessel beam fluorescence lifetime tomography of live embryos (Conference Presentation)

    Science.gov (United States)

    Xu, Dongli; Peng, Leilei

    2016-03-01

    Optical tomography allows isotropic 3D imaging of embryos. Scanning-laser optical tomography (SLOT) has superior light collecting efficiency than wide-field optical tomography, making it ideal for fluorescence imaging of live embryos. We previously reported an imaging system that combines SLOT with a novel Fourier-multiplexed fluorescence lifetime imaging (FmFLIM) technique named FmFLIM-SLOT. FmFLIM-SLOT performs multiplexed FLIM-FRET readout of multiple FRET sensors in live embryos. Here we report a recent effort on improving the spatial resolution of the FmFLIM-SLOT system in order to image complex biochemical processes in live embryos at the cellular level. Optical tomography has to compromise between resolution and the depth of view. In SLOT, the commonly-used focused Gaussian beam diverges quickly from the focal plane, making it impossible to achieve high resolution imaging in a large volume specimen. We thus introduce Bessel beam laser-scanning tomography, which illuminates the sample with a spatial-light-modulator-generated Bessel beam that has an extended focal depth. The Bessel beam is scanned across the whole specimen. Fluorescence projection images are acquired at equal angular intervals as the sample rotates. Reconstruction artifacts due to annular-rings of the Bessel beam are removed by a modified 3D filtered back projection algorithm. Furthermore, in combination of Fourier-multiplexing fluorescence lifetime imaging (FmFLIM) method, the Bessel FmFLIM-SLOT system is capable of perform 3D lifetime imaging of live embryos at cellular resolution. The system is applied to in-vivo imaging of transgenic Zebrafish embryos. Results prove that Bessel FmFLIM-SLOT is a promising imaging method in development biology research.

  1. Quantum process tomography by 2D fluorescence spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Pachón, Leonardo A. [Grupo de Física Atómica y Molecular, Instituto de Física, Facultad de Ciencias Exactas y Naturales, Universidad de Antioquia UdeA, Calle 70 No. 52-21, Medellín (Colombia); Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts 02138 (United States); Marcus, Andrew H. [Department of Chemistry and Biochemistry, Oregon Center for Optics, Institute of Molecular Biology, University of Oregon, Eugene, Oregon 97403 (United States); Aspuru-Guzik, Alán [Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts 02138 (United States)

    2015-06-07

    Reconstruction of the dynamics (quantum process tomography) of the single-exciton manifold in energy transfer systems is proposed here on the basis of two-dimensional fluorescence spectroscopy (2D-FS) with phase-modulation. The quantum-process-tomography protocol introduced here benefits from, e.g., the sensitivity enhancement ascribed to 2D-FS. Although the isotropically averaged spectroscopic signals depend on the quantum yield parameter Γ of the doubly excited-exciton manifold, it is shown that the reconstruction of the dynamics is insensitive to this parameter. Applications to foundational and applied problems, as well as further extensions, are discussed.

  2. Quantum process tomography by 2D fluorescence spectroscopy

    International Nuclear Information System (INIS)

    Pachón, Leonardo A.; Marcus, Andrew H.; Aspuru-Guzik, Alán

    2015-01-01

    Reconstruction of the dynamics (quantum process tomography) of the single-exciton manifold in energy transfer systems is proposed here on the basis of two-dimensional fluorescence spectroscopy (2D-FS) with phase-modulation. The quantum-process-tomography protocol introduced here benefits from, e.g., the sensitivity enhancement ascribed to 2D-FS. Although the isotropically averaged spectroscopic signals depend on the quantum yield parameter Γ of the doubly excited-exciton manifold, it is shown that the reconstruction of the dynamics is insensitive to this parameter. Applications to foundational and applied problems, as well as further extensions, are discussed

  3. Small-Animal Imaging Using Diffuse Fluorescence Tomography.

    Science.gov (United States)

    Davis, Scott C; Tichauer, Kenneth M

    2016-01-01

    Diffuse fluorescence tomography (DFT) has been developed to image the spatial distribution of fluorescence-tagged tracers in living tissue. This capability facilitates the recovery of any number of functional parameters, including enzymatic activity, receptor density, blood flow, and gene expression. However, deploying DFT effectively is complex and often requires years of know-how, especially for newer mutlimodal systems that combine DFT with conventional imaging systems. In this chapter, we step through the process of using MRI-DFT imaging of a receptor-targeted tracer in small animals.

  4. Fluorescent scanning x-ray tomography with synchrotron radiation

    Science.gov (United States)

    Takeda, Tohoru; Maeda, Toshikazu; Yuasa, Tetsuya; Akatsuka, Takao; Ito, Tatsuo; Kishi, Kenichi; Wu, Jin; Kazama, Masahiro; Hyodo, Kazuyuki; Itai, Yuji

    1995-02-01

    Fluorescent scanning (FS) x-ray tomography was developed to detect nonradioactive tracer materials (iodine and gadolinium) in a living object. FS x-ray tomography consists of a silicon (111) channel cut monochromator, an x-ray shutter, an x-ray slit system and a collimator for detection, a scanning table for the target organ, and an x-ray detector with pure germanium. The minimal detectable dose of iodine in this experiment was 100 ng in a volume of 2 mm3 and a linear relationship was shown between the photon counts of a fluorescent x ray and the concentration of iodine contrast material. A FS x-ray tomographic image was clearly obtained with a phantom.

  5. Frequency domain fluorescence diffuse tomography of small animals

    Science.gov (United States)

    Orlova, Anna G.; Turchin, Ilya V.; Kamensky, Vladislav A.; Plehanov, Vladimir I.; Balalaeva, Irina V.; Sergeeva, Ekaterina A.; Shirmanova, Marina V.; Kleshnin, Michail S.

    2007-05-01

    Fluorescent compounds for selective cancer cell marking are used for development of novel medical diagnostic methods, investigation of the influence of external factors on tumor growth, regress and metastasis. Only special tools for turbid media imaging, such as optical diffusion tomography permit noninvasive monitoring of fluorescent-labeled tumor alterations deep in animal tissue. In this work, the results of preliminary experiments utilizing frequency-domain fluorescent diffusion tomography (FD FDT) experimental setup in small animal are presented. Low-frequency modulated light (1 kHz) from Nd:YAG laser with second harmonic generation at the wavelength of 532 nm was used in the setup. The transilluminative planar configuration was used in the setup. A series of model experiments has been conducted and show good agreement between theoretical and experimental fluorescence intensity. Models of deep tumors were created by two methods: (1) glass capsules containing fluorophore solution were inserted into esophagus of small animals to simulate marked tumors; (2) a suspension of transfected HEΚ293-Turbo-RFP cells was subcutaneously injected to small animal. The conducted experiments have shown that FD FDT allows one to detect the presence of labeled tumor cells in small animals, to determine the volume of an experimental tumor, to perform 3D tumor reconstruction, as well as to conduct monitoring investigations. The obtained results demonstrate the potential capability of the FD FDT method for noninvasive whole-body imaging in cancer studies, diagnostics and therapy.

  6. Fluorescence diffuse tomography for tumor detection and monitoring

    Science.gov (United States)

    Balalaeva, Irina V.; Orlova, Anna G.; Shirmanova, Marina V.; Kibraeva, Elena A.; Zagainova, Elena V.; Turchin, Ilya V.

    2007-05-01

    Strong light scattering and absorption limit visualization of the internal structure of biological tissue. Only special tools for turbid media imaging, such as optical diffuse tomography, enable noninvasive investigation of the internal biological tissues, including visualization and intravital monitoring of deep tumors. In this work the preliminary results of fluorescence diffuse tomography (FDT) of small animals are presented. Using of exogenous fluorophores, targeted specifically at tumor cells, and fluorescent proteins expressed endogenously can significantly increase the contrast of obtained images. Fluorescent compounds of different nature, such as sulphonated aluminium phthalocyanine (Photosens), red fluorescing proteins and CdTe/CdSe-core/shell nanocrystals (quantum dots) were applied. The animal was scanned in the transilluminative configuration by low-frequency modulated light (1 kHz) from Nd:YAG laser with second harmonic generation at the wavelength of 532 nm or semiconductor laser at the wavelength of 655 nm. Photosens was injected intravenously into linear mice with metastazing Lewis lung carcinoma in dose 4 mg/kg. Quantum dots (5x10 -11 M) or protein DsRed2 (1-5x10 -6 M) in glass capsules (inner diameter 2-3 mm) were placed inside the esophagus of 7-day-old hairless rats (18-20 g) to simulate marked tumors. Cells of HEK-293 Phoenix line, transitory transfected with Turbo-RFP protein gene, were injected hypodermically to immunodeficient mice. This work demonstrates potential capabilities of FDT method for detection and monitoring of deep fluorescent-labeled tumors in animal models. Strong advantages of fluorescent proteins and quantum dots over the traditional photosensitizer for FDT imaging are shown.

  7. Fluorescence Molecular Tomography: Principles and Potential for Pharmaceutical Research

    Directory of Open Access Journals (Sweden)

    Florian Stuker

    2011-04-01

    Full Text Available Fluorescence microscopic imaging is widely used in biomedical research to study molecular and cellular processes in cell culture or tissue samples. This is motivated by the high inherent sensitivity of fluorescence techniques, the spatial resolution that compares favorably with cellular dimensions, the stability of the fluorescent labels used and the sophisticated labeling strategies that have been developed for selectively labeling target molecules. More recently, two and three-dimensional optical imaging methods have also been applied to monitor biological processes in intact biological organisms such as animals or even humans. These whole body optical imaging approaches have to cope with the fact that biological tissue is a highly scattering and absorbing medium. As a consequence, light propagation in tissue is well described by a diffusion approximation and accurate reconstruction of spatial information is demanding. While in vivo optical imaging is a highly sensitive method, the signal is strongly surface weighted, i.e., the signal detected from the same light source will become weaker the deeper it is embedded in tissue, and strongly depends on the optical properties of the surrounding tissue. Derivation of quantitative information, therefore, requires tomographic techniques such as fluorescence molecular tomography (FMT, which maps the three-dimensional distribution of a fluorescent probe or protein concentration. The combination of FMT with a structural imaging method such as X-ray computed tomography (CT or Magnetic Resonance Imaging (MRI will allow mapping molecular information on a high definition anatomical reference and enable the use of prior information on tissue’s optical properties to enhance both resolution and sensitivity. Today many of the fluorescent assays originally developed for studies in cellular systems have been successfully translated for experimental studies in animals. The opportunity of monitoring molecular

  8. Recommendations for fluorescence instrument qualification: the new ASTM Standard Guide.

    Science.gov (United States)

    DeRose, Paul C; Resch-Genger, Ute

    2010-03-01

    Aimed at improving quality assurance and quantitation for modern fluorescence techniques, ASTM International (ASTM) is about to release a Standard Guide for Fluorescence, reviewed here. The guide's main focus is on steady state fluorometry, for which available standards and instrument characterization procedures are discussed along with their purpose, suitability, and general instructions for use. These include the most relevant instrument properties needing qualification, such as linearity and spectral responsivity of the detection system, spectral irradiance reaching the sample, wavelength accuracy, sensitivity or limit of detection for an analyte, and day-to-day performance verification. With proper consideration of method-inherent requirements and limitations, many of these procedures and standards can be adapted to other fluorescence techniques. In addition, procedures for the determination of other relevant fluorometric quantities including fluorescence quantum yields and fluorescence lifetimes are briefly introduced. The guide is a clear and concise reference geared for users of fluorescence instrumentation at all levels of experience and is intended to aid in the ongoing standardization of fluorescence measurements.

  9. In vivo quantification of fluorescent molecular markers in real-time by ratio Imaging for diagnostic screening and image-guided surgery

    NARCIS (Netherlands)

    Bogaards, A.; Sterenborg, H. J. C. M.; Trachtenberg, J.; Wilson, B. C.; Lilge, L.

    2007-01-01

    Future applications of "molecular diagnostic screening" and "molecular image-guided surgery" will demand images of molecular markers with high resolution and high throughput (similar to >= 30 frames/second). MRI, SPECT, PET, optical fluorescence tomography, hyper-spectral fluorescence imaging, and

  10. Fluorescence guided surgery and tracer-dose, fact or fiction?

    International Nuclear Information System (INIS)

    KleinJan, Gijs H.; Olmos, Renato A.V.; Bunschoten, Anton; Berg, Nynke S. van den; Klop, W.M.C.; Horenblas, Simon; Poel, Henk G. van der; Wester, Hans-Juergen; Leeuwen, Fijs W.B. van

    2016-01-01

    Fluorescence guidance is an upcoming methodology to improve surgical accuracy. Challenging herein is the identification of the minimum dose at which the tracer can be detected with a clinical-grade fluorescence camera. Using a hybrid tracer such as indocyanine green (ICG)- 99m Tc-nanocolloid, it has become possible to determine the accumulation of tracer and correlate this to intraoperative fluorescence-based identification rates. In the current study, we determined the lower detection limit of tracer at which intraoperative fluorescence guidance was still feasible. Size exclusion chromatography (SEC) provided a laboratory set-up to analyze the chemical content and to simulate the migratory behavior of ICG-nanocolloid in tissue. Tracer accumulation and intraoperative fluorescence detection findings were derived from a retrospective analysis of 20 head-and-neck melanoma patients, 40 penile and 20 prostate cancer patients scheduled for sentinel node (SN) biopsy using ICG- 99m Tc-nanocolloid. In these patients, following tracer injection, single photon emission computed tomography fused with computed tomography (SPECT/CT) was used to identify the SN(s). The percentage injected dose (% ID), the amount of ICG (in nmol), and the concentration of ICG in the SNs (in μM) was assessed for SNs detected on SPECT/CT and correlated with the intraoperative fluorescence imaging findings. SEC determined that in the hybrid tracer formulation, 41 % (standard deviation: 12 %) of ICG was present in nanocolloid-bound form. In the SNs detected using fluorescence guidance a median of 0.88 % ID was present, compared to a median of 0.25 % ID in the non-fluorescent SNs (p-value < 0.001). The % ID values could be correlated to the amount ICG in a SN (range: 0.003-10.8 nmol) and the concentration of ICG in a SN (range: 0.006-64.6 μM). The ability to provide intraoperative fluorescence guidance is dependent on the amount and concentration of the fluorescent dye accumulated in the lesion(s) of

  11. Laplacian manifold regularization method for fluorescence molecular tomography

    Science.gov (United States)

    He, Xuelei; Wang, Xiaodong; Yi, Huangjian; Chen, Yanrong; Zhang, Xu; Yu, Jingjing; He, Xiaowei

    2017-04-01

    Sparse regularization methods have been widely used in fluorescence molecular tomography (FMT) for stable three-dimensional reconstruction. Generally, ℓ1-regularization-based methods allow for utilizing the sparsity nature of the target distribution. However, in addition to sparsity, the spatial structure information should be exploited as well. A joint ℓ1 and Laplacian manifold regularization model is proposed to improve the reconstruction performance, and two algorithms (with and without Barzilai-Borwein strategy) are presented to solve the regularization model. Numerical studies and in vivo experiment demonstrate that the proposed Gradient projection-resolved Laplacian manifold regularization method for the joint model performed better than the comparative algorithm for ℓ1 minimization method in both spatial aggregation and location accuracy.

  12. A new stereotactic apparatus guided by computed tomography

    International Nuclear Information System (INIS)

    Huk, W.J.

    1981-01-01

    The accurate information provided by computer tomography about existence, shape, and localization of intracranial neoplasms in an early phase and in inaccessible regions have improved the diagnostics greatly, so that these lie far ahead of the therapeutic possibilities for brain tumors. To reduce this wide margin we have developed a new targeting device which makes a stereotactic approach to central lesions under sight-control by computed tomography within the computed tomography-scanner possible. With the help of this simple device we are now able to perform stereotactic procedures for tumor biopsy guided by computed tomography, needling and drainage of abscesses and cysts, and finally for the implantation of radioactive material for the interstitial radiotherapy of inoperable cysts and tumors. (orig.) [de

  13. Singular value decomposition metrics show limitations of detector design in diffuse fluorescence tomography.

    Science.gov (United States)

    Leblond, Frederic; Tichauer, Kenneth M; Pogue, Brian W

    2010-11-29

    The spatial resolution and recovered contrast of images reconstructed from diffuse fluorescence tomography data are limited by the high scattering properties of light propagation in biological tissue. As a result, the image reconstruction process can be exceedingly vulnerable to inaccurate prior knowledge of tissue optical properties and stochastic noise. In light of these limitations, the optimal source-detector geometry for a fluorescence tomography system is non-trivial, requiring analytical methods to guide design. Analysis of the singular value decomposition of the matrix to be inverted for image reconstruction is one potential approach, providing key quantitative metrics, such as singular image mode spatial resolution and singular data mode frequency as a function of singular mode. In the present study, these metrics are used to analyze the effects of different sources of noise and model errors as related to image quality in the form of spatial resolution and contrast recovery. The image quality is demonstrated to be inherently noise-limited even when detection geometries were increased in complexity to allow maximal tissue sampling, suggesting that detection noise characteristics outweigh detection geometry for achieving optimal reconstructions.

  14. Fluorescent supramolecular micelles for imaging-guided cancer therapy

    Science.gov (United States)

    Sun, Mengmeng; Yin, Wenyan; Dong, Xinghua; Yang, Wantai; Zhao, Yuliang; Yin, Meizhen

    2016-02-01

    A novel smart fluorescent drug delivery system composed of a perylene diimide (PDI) core and block copolymer poly(d,l-lactide)-b-poly(ethyl ethylene phosphate) is developed and named as PDI-star-(PLA-b-PEEP)8. The biodegradable PDI-star-(PLA-b-PEEP)8 is a unimolecular micelle and can self-assemble into supramolecular micelles, called as fluorescent supramolecular micelles (FSMs), in aqueous media. An insoluble drug camptothecin (CPT) can be effectively loaded into the FSMs and exhibits pH-responsive release. Moreover, the FSMs with good biocompatibility can also be employed as a remarkable fluorescent probe for cell labelling because the maximum emission of PDI is beneficial for bio-imaging. The flow cytometry and confocal laser scanning microscopy analysis demonstrate that the micelles are easily endocytosed by cancer cells. In vitro and in vivo tumor growth-inhibitory studies reveal a better therapeutic effect of FSMs after CPT encapsulation when compared with the free CPT drug. The multifunctional FSM nanomedicine platform as a nanovehicle has great potential for fluorescence imaging-guided cancer therapy.A novel smart fluorescent drug delivery system composed of a perylene diimide (PDI) core and block copolymer poly(d,l-lactide)-b-poly(ethyl ethylene phosphate) is developed and named as PDI-star-(PLA-b-PEEP)8. The biodegradable PDI-star-(PLA-b-PEEP)8 is a unimolecular micelle and can self-assemble into supramolecular micelles, called as fluorescent supramolecular micelles (FSMs), in aqueous media. An insoluble drug camptothecin (CPT) can be effectively loaded into the FSMs and exhibits pH-responsive release. Moreover, the FSMs with good biocompatibility can also be employed as a remarkable fluorescent probe for cell labelling because the maximum emission of PDI is beneficial for bio-imaging. The flow cytometry and confocal laser scanning microscopy analysis demonstrate that the micelles are easily endocytosed by cancer cells. In vitro and in vivo tumor growth

  15. Fluorescence background subtraction technique for hybrid fluorescence molecular tomography/x-ray computed tomography imaging of a mouse model of early stage lung cancer.

    Science.gov (United States)

    Ale, Angelique; Ermolayev, Vladimir; Deliolanis, Nikolaos C; Ntziachristos, Vasilis

    2013-05-01

    The ability to visualize early stage lung cancer is important in the study of biomarkers and targeting agents that could lead to earlier diagnosis. The recent development of hybrid free-space 360-deg fluorescence molecular tomography (FMT) and x-ray computed tomography (XCT) imaging yields a superior optical imaging modality for three-dimensional small animal fluorescence imaging over stand-alone optical systems. Imaging accuracy was improved by using XCT information in the fluorescence reconstruction method. Despite this progress, the detection sensitivity of targeted fluorescence agents remains limited by nonspecific background accumulation of the fluorochrome employed, which complicates early detection of murine cancers. Therefore we examine whether x-ray CT information and bulk fluorescence detection can be combined to increase detection sensitivity. Correspondingly, we research the performance of a data-driven fluorescence background estimator employed for subtraction of background fluorescence from acquisition data. Using mice containing known fluorochromes ex vivo, we demonstrate the reduction of background signals from reconstructed images and sensitivity improvements. Finally, by applying the method to in vivo data from K-ras transgenic mice developing lung cancer, we find small tumors at an early stage compared with reconstructions performed using raw data. We conclude with the benefits of employing fluorescence subtraction in hybrid FMT-XCT for early detection studies.

  16. Recent developments in guided wave travel time tomography

    Energy Technology Data Exchange (ETDEWEB)

    Zon, Tim van; Volker, Arno [TNO, Stieltjesweg 1, P.O. box 155 2600 AD Delft (Netherlands)

    2014-02-18

    The concept of predictive maintenance using permanent sensors that monitor the integrity of an installation is an interesting addition to the current method of periodic inspections. Guided wave tomography had been developed to create a map of the wall thickness using the travel times of guided waves. It can be used for both monitoring and for inspection of pipe-segments that are difficult to access, for instance at the location of pipe-supports. An important outcome of the tomography is the minimum remaining wall thickness, as this is critical in the scheduling of a replacement of the pipe-segment. In order to improve the sizing accuracy we have improved the tomography scheme. A number of major improvements have been realized allowing to extend the application envelope to pipes with a larger wall thickness and to larger distances between the transducer rings. Simulation results indicate that the sizing accuracy has improved and that is now possible to have a spacing of 8 meter between the source-ring and the receiver-ring. Additionally a reduction of the number of sensors required might be possible as well.

  17. Three-dimensional in vivo fluorescence diffuse optical tomography of breast cancer in humans

    Science.gov (United States)

    Corlu, Alper; Choe, Regine; Durduran, Turgut; Rosen, Mark A.; Schweiger, Martin; Arridge, Simon R.; Schnall, Mitchell D.; Yodh, Arjun G.

    2007-05-01

    We present three-dimensional (3D) in vivo images of human breast cancer based on fluorescence diffuse optical tomography (FDOT). To our knowledge, this work represents the first reported 3D fluorescence tomography of human breast cancer in vivo. In our protocol, the fluorophore Indocyanine Green (ICG) is injected intravenously. Fluorescence excitation and detection are accomplished in the soft-compression, parallel-plane, transmission geometry using laser sources at 786 nm and spectrally filtered CCD detection. Phantom and in vivo studies confirm the signals are due to ICG fluorescence, rather than tissue autofluorescence and excitation light leakage. Fluorescence images of breast tumors were in good agreement with those of MRI, and with DOT based on endogenous contrast. Tumorto- normal tissue contrast based on ICG fluorescence was two-to-four-fold higher than contrast based on hemoglobin and scattering parameters. In total the measurements demonstrate that FDOT of breast cancer is feasible and promising.

  18. Compact instrument for fluorescence image-guided surgery

    Science.gov (United States)

    Wang, Xinghua; Bhaumik, Srabani; Li, Qing; Staudinger, V. Paul; Yazdanfar, Siavash

    2010-03-01

    Fluorescence image-guided surgery (FIGS) is an emerging technique in oncology, neurology, and cardiology. To adapt intraoperative imaging for various surgical applications, increasingly flexible and compact FIGS instruments are necessary. We present a compact, portable FIGS system and demonstrate its use in cardiovascular mapping in a preclinical model of myocardial ischemia. Our system uses fiber optic delivery of laser diode excitation, custom optics with high collection efficiency, and compact consumer-grade cameras as a low-cost and compact alternative to open surgical FIGS systems. Dramatic size and weight reduction increases flexibility and access, and allows for handheld use or unobtrusive positioning over the surgical field.

  19. Fast automatic segmentation of anatomical structures in x-ray computed tomography images to improve fluorescence molecular tomography reconstruction.

    Science.gov (United States)

    Freyer, Marcus; Ale, Angelique; Schulz, Ralf B; Zientkowska, Marta; Ntziachristos, Vasilis; Englmeier, Karl-Hans

    2010-01-01

    The recent development of hybrid imaging scanners that integrate fluorescence molecular tomography (FMT) and x-ray computed tomography (XCT) allows the utilization of x-ray information as image priors for improving optical tomography reconstruction. To fully capitalize on this capacity, we consider a framework for the automatic and fast detection of different anatomic structures in murine XCT images. To accurately differentiate between different structures such as bone, lung, and heart, a combination of image processing steps including thresholding, seed growing, and signal detection are found to offer optimal segmentation performance. The algorithm and its utilization in an inverse FMT scheme that uses priors is demonstrated on mouse images.

  20. Early Detection of Breast Cancer by Fluorescence Molecular Tomography

    National Research Council Canada - National Science Library

    Ntziachristos, Vasilis

    2007-01-01

    .... We have successfully completed all goals and achieved the three major aims of the proposal, i.e. i) the development of appropriate fluorescence imaging methods for highly reliable and quantitative fluorescence imaging ii...

  1. Multiple X-ray tomography using transmitted, scattered and fluorescent radiation

    International Nuclear Information System (INIS)

    Cesareo, R.; Brunetti, A.; Golosio, B.; Lopes, R.T.; Barroso, R.C.; Donativi, M.; Castellano, A.; Quarta, S.

    2003-01-01

    A multiple CT-scanner is described, which contemporaneously uses transmitted, scattered and fluorescent X-rays for Imaging. The scanner is characterized by a small size X-ray tube and by four detectors: a ''pencil'' X-ray NaI(Tl) for transmitted tomography, a larger size NaI(Tl) for 90 C o Compton tomography, a thermoelectrically cooled Si-PIN or CdZnTe for fluorescent imaging and a CdZnTe for Rayleigh (or diffraction) tomography. Examples of applications are shown

  2. Development of a guidance guide for dosimetry in computed tomography

    International Nuclear Information System (INIS)

    Fontes, Ladyjane Pereira

    2016-01-01

    Due to frequent questions from users of ionization chambers pencil type calibrated in the Instrument Calibration Laboratory of the Institute of Energy and Nuclear Research (LCI - IPEN), on how to properly apply the factors indicated in their calibration certificates, a guide was prepared guidance for dosimetry in computed tomography. The guide includes guidance prior knowledge of half value layer (HVL), as it is necessary to know the effective beam energy for application quality for correction factor (kq). The evaluation of HVL in TC scanners becomes a difficult task due to system geometry and therefore a survey was conducted of existing methodologies for the determination of HVL in clinical beams Computed Tomography, taking into account technical, practical and economic factors. In this work it was decided to test a Tandem System consists of absorbing covers made in the workshop of IPEN, based on preliminary studies due to low cost and good response. The Tandem system consists of five cylindrical absorbing layers of 1mm, 3mm, 5mm, 7mm and 10mm aluminum and 3 cylindrical absorbing covers 15mm, 25mm and acrylic 35mm (PMMA) coupled to the ionization chamber of commercial pencil type widely used in quality control tests in dosimetry in clinical beams Computed tomography. Through Tandem curves it was possible to assess HVL values and from the standard curve pencil-type ionization chamber, Kq find the appropriate beam. The elaborate Guide provides information on how to build the calibration curve on the basis of CSR, to find the Kq and information for construction Tandem curve, to find values close to CSR. (author)

  3. In vivo multiphoton tomography and fluorescence lifetime imaging of human brain tumor tissue.

    Science.gov (United States)

    Kantelhardt, Sven R; Kalasauskas, Darius; König, Karsten; Kim, Ella; Weinigel, Martin; Uchugonova, Aisada; Giese, Alf

    2016-05-01

    High resolution multiphoton tomography and fluorescence lifetime imaging differentiates glioma from adjacent brain in native tissue samples ex vivo. Presently, multiphoton tomography is applied in clinical dermatology and experimentally. We here present the first application of multiphoton and fluorescence lifetime imaging for in vivo imaging on humans during a neurosurgical procedure. We used a MPTflex™ Multiphoton Laser Tomograph (JenLab, Germany). We examined cultured glioma cells in an orthotopic mouse tumor model and native human tissue samples. Finally the multiphoton tomograph was applied to provide optical biopsies during resection of a clinical case of glioblastoma. All tissues imaged by multiphoton tomography were sampled and processed for conventional histopathology. The multiphoton tomograph allowed fluorescence intensity- and fluorescence lifetime imaging with submicron spatial resolution and 200 picosecond temporal resolution. Morphological fluorescence intensity imaging and fluorescence lifetime imaging of tumor-bearing mouse brains and native human tissue samples clearly differentiated tumor and adjacent brain tissue. Intraoperative imaging was found to be technically feasible. Intraoperative image quality was comparable to ex vivo examinations. To our knowledge we here present the first intraoperative application of high resolution multiphoton tomography and fluorescence lifetime imaging of human brain tumors in situ. It allowed in vivo identification and determination of cell density of tumor tissue on a cellular and subcellular level within seconds. The technology shows the potential of rapid intraoperative identification of native glioma tissue without need for tissue processing or staining.

  4. Frequency domain fluorescent diffuse tomography of small animals with DsRed2-expressed tumors

    Science.gov (United States)

    Turchin, Ilya V.; Savitsky, Alexander P.; Kamensky, Vladislav A.; Plehanov, Vladimir I.; Orlova, Anna G.; Sergeeva, Ekaterina A.; Kleshnin, Mikhail S.; Shirmanova, Marina V.

    2006-02-01

    The main applications of fluorescent proteins (FPs) are monitoring tumor growth, angiogenesis, metastases formation and effects of new classes of drugs. Different types of tomography allow fluorescence imaging of tumors located deep in human or animal tissue. These techniques were used for investigation of the distribution of near-infrared fluorescent probes, but only a few works are devoted to fluorescence tomography in visible light. In this work, preliminary results of the frequency domain fluorescent diffuse tomography (FD FDT) method in application to DsRed2 protein as a fluorescent agent are presented. For the first step of our experiments we utilized second harmonic generation of Nd:YAG laser (532 nm) modulated by low frequency (1 kHz) in the experimental setup. The transilluminative planar configuration was used in the setup. A series of model experiments has been conducted and show good agreement between theoretical and experimental fluorescence intensity. Post mortem experiments with capsules containing DsRed2 and scattering solution introduced into esophagus of rats to simulate tumor formation have been conducted. The results of these experiments show that sensitivity of the setup is sufficient to detect DsRed2 in concentrations similar to those in FP-expressed tumor, but the contrast is not enough high to separate fluorescence of DsRed2 and surrounding tissues. The setup can be significantly improved by utilizing high-frequency modulation (110 MHz using acousto-optical modulator) of the excitation light and precise phase measurements due to difference in fluorescence life-time of FPs and surrounding tissues. An algorithm of processing a fluorescent image based on calculating zero of maximum curvature was employed for detection of fluorescent inclusions boundaries in the image.

  5. Performance dependence of hybrid x-ray computed tomography/fluorescence molecular tomography on the optical forward problem.

    Science.gov (United States)

    Hyde, Damon; Schulz, Ralf; Brooks, Dana; Miller, Eric; Ntziachristos, Vasilis

    2009-04-01

    Hybrid imaging systems combining x-ray computed tomography (CT) and fluorescence tomography can improve fluorescence imaging performance by incorporating anatomical x-ray CT information into the optical inversion problem. While the use of image priors has been investigated in the past, little is known about the optimal use of forward photon propagation models in hybrid optical systems. In this paper, we explore the impact on reconstruction accuracy of the use of propagation models of varying complexity, specifically in the context of these hybrid imaging systems where significant structural information is known a priori. Our results demonstrate that the use of generically known parameters provides near optimal performance, even when parameter mismatch remains.

  6. Cone-Beam Computed Tomography-Guided Percutaneous Radiologic Gastrostomy

    International Nuclear Information System (INIS)

    Moehlenbruch, Markus; Nelles, Michael; Thomas, Daniel; Willinek, Winfried; Gerstner, Andreas; Schild, Hans H.; Wilhelm, Kai

    2010-01-01

    The purpose of this study was to investigate the feasibility of a flat-detector C-arm-guided radiographic technique (cone-beam computed tomography [CBCT]) for percutaneous radiologic gastrostomy (PRG) insertion. Eighteen patients (13 men and 5 women; mean age 62 years) in whom percutaneous endoscopic gastrostomy (PEG) had failed underwent CBCT-guided PRG insertion. PEG failure or unsuitability was caused by upper gastrointestinal tract obstruction in all cases. Indications for gastrostomy were esophageal and head and neck malignancies, respectively. Before the PRG procedure, initial C-arm CBCT scans were acquired. Three- and 2-dimensional soft-tissue reconstructions of the epigastrium region were generated on a dedicated workstation. Subsequently, gastropexy was performed with T-fasteners after CBCT-guided puncture of the stomach bubble, followed by insertion of an 14F balloon-retained catheter through a peel-away introducer. Puncture of the stomach bubble and PRG insertion was technically successful in all patients without alteration of the epigastric region. There was no malpositioning of the tube or other major periprocedural complications. In 2 patients, minor complications occurred during the first 30 days of follow-up (PRG malfunction: n = 1; slight infection: n = 1). Late complications, which were mainly tube disturbances, were observed in 2 patients. The mean follow-up time was 212 days. CBCT-guided PRG is a safe, well-tolerated, and successful method of gastrostomy insertion in patients in whom endoscopic gastrostomy is not feasible. CBCT provides detailed imaging of the soft tissue and surrounding structures of the epigastric region in one diagnostic tour and thus significantly improves the planning of PRG procedures.

  7. Computed tomography - guided cutting needle biopsy of pulmonary lesions

    International Nuclear Information System (INIS)

    Liao Shin Yu; Deheinzelin, Daniel; Younes, Riad N.; Chojniak, Rubens

    2002-01-01

    The purpose of this study was to report the experience of a radiology department in the use of computed tomography-guided cutting needle biopsy of pulmonary nodules, by evaluating diagnostic yield and incidence of complications. This is a retrospective analysis of 52 consecutive patients who underwent lung lesion biopsy guided by computed tomography, performed between May 1997 and May 2000. Thirty-five patients were male and 17 were female, with ages ranging from 5 to 85 years (median, 62 years). The size of the lesions ranged from 1.8 to 15 cm (median, 5.4 cm). In a total of 52 biopsies of lung lesions, 51 biopsies (98.1%) supplied appropriate material for histopathological diagnosis, with 9 diagnosed (17.3%) as benign and 42 (80.8%) as malignant lesions. Specific diagnosis was obtained in 44 (84.6%) biopsies: 4 benign (9.1%) and 40 (90.9%) malignant lesions. The sensitivity, specificity, and accuracy of the cutting needle biopsies for determining presence of malignancy were 96.8%, 100%, and 97.2%, respectively. Complications occurred in 9 cases (17.3%), including 6 cases (11.5%) of small pneumothorax, 1 (1.9%) of hemoptysis, 1 (1.9%) of pulmonary hematoma, and 1 (1.9%) of thoracic wall hematoma. All had spontaneous resolution. There were no complications requiring subsequent intervention. The high sensitivity and specificity of the method and the low rate of complications have established cutting needle biopsy as an efficient and safe tool for the diagnosis of lung lesions. In our hospital, cutting needle biopsy is considered a reliable procedure for the evaluation of indeterminate pulmonary nodules. (author)

  8. Diffuse optical tomography for breast cancer imaging guided by computed tomography: A feasibility study.

    Science.gov (United States)

    Baikejiang, Reheman; Zhang, Wei; Li, Changqing

    2017-01-01

    Diffuse optical tomography (DOT) has attracted attentions in the last two decades due to its intrinsic sensitivity in imaging chromophores of tissues such as hemoglobin, water, and lipid. However, DOT has not been clinically accepted yet due to its low spatial resolution caused by strong optical scattering in tissues. Structural guidance provided by an anatomical imaging modality enhances the DOT imaging substantially. Here, we propose a computed tomography (CT) guided multispectral DOT imaging system for breast cancer imaging. To validate its feasibility, we have built a prototype DOT imaging system which consists of a laser at the wavelength of 650 nm and an electron multiplying charge coupled device (EMCCD) camera. We have validated the CT guided DOT reconstruction algorithms with numerical simulations and phantom experiments, in which different imaging setup parameters, such as projection number of measurements and width of measurement patch, have been investigated. Our results indicate that an air-cooling EMCCD camera is good enough for the transmission mode DOT imaging. We have also found that measurements at six angular projections are sufficient for DOT to reconstruct the optical targets with 2 and 4 times absorption contrast when the CT guidance is applied. Finally, we have described our future research plan on integration of a multispectral DOT imaging system into a breast CT scanner.

  9. Guided wave tomography in anisotropic media using recursive extrapolation operators

    Science.gov (United States)

    Volker, Arno

    2018-04-01

    Guided wave tomography is an advanced technology for quantitative wall thickness mapping to image wall loss due to corrosion or erosion. An inversion approach is used to match the measured phase (time) at a specific frequency to a model. The accuracy of the model determines the sizing accuracy. Particularly for seam welded pipes there is a measurable amount of anisotropy. Moreover, for small defects a ray-tracing based modelling approach is no longer accurate. Both issues are solved by applying a recursive wave field extrapolation operator assuming vertical transverse anisotropy. The inversion scheme is extended by not only estimating the wall loss profile but also the anisotropy, local material changes and transducer ring alignment errors. This makes the approach more robust. The approach will be demonstrated experimentally on different defect sizes, and a comparison will be made between this new approach and an isotropic ray-tracing approach. An example is given in Fig. 1 for a 75 mm wide, 5 mm deep defect. The wave field extrapolation based tomography clearly provides superior results.

  10. Optical Coherence Tomography-Guided Decisions in Retinoblastoma Management.

    Science.gov (United States)

    Soliman, Sameh E; VandenHoven, Cynthia; MacKeen, Leslie D; Héon, Elise; Gallie, Brenda L

    2017-06-01

    Assess the role of handheld optical coherence tomography (OCT) in guiding management decisions during diagnosis, treatment, and follow-up of eyes affected by retinoblastoma. Retrospective, noncomparative, single-institution case series. All children newly diagnosed with retinoblastoma from January 2011 to December 2015 who had an OCT session during their active treatment at The Hospital for Sick Children (SickKids) in Toronto, Canada. The OCT sessions for fellow eyes of unilateral retinoblastoma without any suspicious lesion and those performed more than 6 months after the last treatment were excluded. Data collected included age at presentation, sex, family history, RB1 mutation status, 8th edition TNMH cancer staging and International Intraocular Retinoblastoma Classification (IIRC), and number of OCT sessions per eye. Details of each session were scored for indication-related details (informative or not) and assessed for guidance (directive or not), diagnosis (staging changed, new tumors found or excluded), treatment (modified, stopped, or modality shifted), or follow-up modified. Frequency of OCT-guided management decisions, stratified by indication and type of guidance (confirmatory vs. influential). Sixty-three eyes of 44 children had 339 OCT sessions over the course of clinical management (median number of OCT scans per eye, 5; range, 1-15). The age at presentation and presence of a heritable RB1 mutation significantly correlated with an increased number of OCT sessions. Indications included evaluation of post-treatment scar (55%) or fovea (16%), and posterior pole scanning for new tumors (11%). Of all sessions, 92% (312/339) were informative; 19 of 27 noninformative sessions had large, elevated lesions; of these, 14 of 19 were T2a or T2b (IIRC group C or D) eyes. In 94% (293/312) of the informative sessions, OCT directed treatment decisions (58%), diagnosis (16%), and follow-up (26%). Optical coherence tomography influenced and changed management from pre

  11. Deep-tissue reporter-gene imaging with fluorescence and optoacoustic tomography: a performance overview.

    Science.gov (United States)

    Deliolanis, Nikolaos C; Ale, Angelique; Morscher, Stefan; Burton, Neal C; Schaefer, Karin; Radrich, Karin; Razansky, Daniel; Ntziachristos, Vasilis

    2014-10-01

    A primary enabling feature of near-infrared fluorescent proteins (FPs) and fluorescent probes is the ability to visualize deeper in tissues than in the visible. The purpose of this work is to find which is the optimal visualization method that can exploit the advantages of this novel class of FPs in full-scale pre-clinical molecular imaging studies. Nude mice were stereotactically implanted with near-infrared FP expressing glioma cells to from brain tumors. The feasibility and performance metrics of FPs were compared between planar epi-illumination and trans-illumination fluorescence imaging, as well as to hybrid Fluorescence Molecular Tomography (FMT) system combined with X-ray CT and Multispectral Optoacoustic (or Photoacoustic) Tomography (MSOT). It is shown that deep-seated glioma brain tumors are possible to visualize both with fluorescence and optoacoustic imaging. Fluorescence imaging is straightforward and has good sensitivity; however, it lacks resolution. FMT-XCT can provide an improved rough resolution of ∼1 mm in deep tissue, while MSOT achieves 0.1 mm resolution in deep tissue and has comparable sensitivity. We show imaging capacity that can shift the visualization paradigm in biological discovery. The results are relevant not only to reporter gene imaging, but stand as cross-platform comparison for all methods imaging near infrared fluorescent contrast agents.

  12. Review of X-ray Tomography and X-ray Fluorescence Spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Shear, Trevor A. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-03-16

    This literature review will focus on both laboratory and synchrotron based X-ray tomography of materials and highlight the inner workings of these instruments. X-ray fluorescence spectroscopy will also be reviewed and applications of the tandem use of these techniques will be explored. The real world application of these techniques during the internship will also be discussed.

  13. Ultrasound-guided versus computed tomography-scan guided biopsy of pleural-based lung lesions.

    Science.gov (United States)

    Khosla, Rahul; McLean, Anna W; Smith, Jessica A

    2016-01-01

    Computed tomography (CT) guided biopsies have long been the standard technique to obtain tissue from the thoracic cavity and is traditionally performed by interventional radiologists. Ultrasound (US) guided biopsy of pleural-based lesions, performed by pulmonologists is gaining popularity and has the advantage of multi-planar imaging, real-time technique, and the absence of radiation exposure to patients. In this study, we aim to determine the diagnostic accuracy, the time to diagnosis after the initial consult placement, and the complications rates between the two different modalities. A retrospective study of electronic medical records was done of patients who underwent CT-guided biopsies and US-guided biopsies for pleural-based lesions between 2005 and 2014 and the data collected were analyzed for comparing the two groups. A total of 158 patients underwent 162 procedures during the study period. 86 patients underwent 89 procedures in the US group, and 72 patients underwent 73 procedures in the CT group. The overall yield in the US group was 82/89 (92.1%) versus 67/73 (91.8%) in the CT group (P = 1.0). Average days to the procedure was 7.2 versus 17.5 (P = 0.00001) in the US and CT group, respectively. Complication rate was higher in CT group 17/73 (23.3%) versus 1/89 (1.1%) in the US group (P guided biopsy is similar to that of CT-guided biopsy, with a lower complication rate and a significantly reduced time to the procedure.

  14. Computerized tomography-guided neurolytic splanchnic nerve block

    International Nuclear Information System (INIS)

    Henriquet, Franco; De Martini, Giuseppe; Roy, Maria Teresa; Pretrolesi, Fabio; Martinoli, Carlo; Cariati, Maurizio; Fiorentini, Franco.

    1997-01-01

    Computerized tomography-guided neurolytic splanchnic nerve block is a technique for relieving abdominal cancer pain; the goal is the alcoholic neurolytic interruption of the sensitive structures in retroperitoneal space. Computerized tomography yields accurate anatomical detailing and the course for needle placement and alcohol spread. January, 1993, to July, 1996, twenty-one bilateral splanchnic nerve blocks were performed through the posterior access. Forty-eight hours after alcoholism. 14 patients (66%) had complete pain regression; 52% of the patients needed no analgesics for 6 to 54 days and only 9 patients (42%) needed another low opioid therapy. Complications included hypotension and diarrhea in all cases. One had a cardiac arrest and diet 8 days after the procedure. There were no other complications. The whole procedure usually lasted 60 min (range: 45 to 90 min). Splanchnic nerve neurolysis is a useful treatment in the patients with severe chronic abdominal pain. It is used as a second line treatment when large lesions change celia anatomy and complicate the percutaneous block of the celiac plexus. Endosulfan, Malathion and Methyl parathion, on the metabolic rate of the estuarine clam, Villorita cyprinoides var. cochinensis, have been investigated. The animals exposed to the lower sublethal concentrations of Endosulfan, Malthion and Methyl parathion consumed oxygen at the rate of 1.60, 1.98 and 2.09 ml. 0 2 g - 1 h -1 respectively, while at the higher concentrations of the pesticides, consumption of oxygen by the animal dropped to nearly half the control value. When compared to Malathion and Methyl parathion. Endosulfan induced animals recorded a greater reduction in her percentage deviation (from control) of oxygen consumption, possibly due to hypoxia induced by the pollutants

  15. Time reversal optical tomography locates fluorescent targets in a turbid medium

    Science.gov (United States)

    Wu, Binlin; Cai, W.; Gayen, S. K.

    2013-03-01

    A fluorescence optical tomography approach that extends time reversal optical tomography (TROT) to locate fluorescent targets embedded in a turbid medium is introduced. It uses a multi-source illumination and multi-detector signal acquisition scheme, along with TR matrix formalism, and multiple signal classification (MUSIC) to construct pseudo-image of the targets. The samples consisted of a single or two small tubes filled with water solution of Indocyanine Green (ICG) dye as targets embedded in a 250 mm × 250 mm × 60 mm rectangular cell filled with Intralipid-20% suspension as the scattering medium. The ICG concentration was 1μM, and the Intralipid-20% concentration was adjusted to provide ~ 1-mm transport length for both excitation wavelength of 790 nm and fluorescence wavelength around 825 nm. The data matrix was constructed using the diffusely transmitted fluorescence signals for all scan positions, and the TR matrix was constructed by multiplying data matrix with its transpose. A pseudo spectrum was calculated using the signal subspace of the TR matrix. Tomographic images were generated using the pseudo spectrum. The peaks in the pseudo images provided locations of the target(s) with sub-millimeter accuracy. Concurrent transmission TROT measurements corroborated fluorescence-TROT findings. The results demonstrate that TROT is a fast approach that can be used to obtain accurate three-dimensional position information of fluorescence targets embedded deep inside a highly scattering medium, such as, a contrast-enhanced tumor in a human breast.

  16. FMT-XCT: in vivo animal studies with hybrid fluorescence molecular tomography-X-ray computed tomography.

    Science.gov (United States)

    Ale, Angelique; Ermolayev, Vladimir; Herzog, Eva; Cohrs, Christian; de Angelis, Martin Hrabé; Ntziachristos, Vasilis

    2012-06-01

    The development of hybrid optical tomography methods to improve imaging performance has been suggested over a decade ago and has been experimentally demonstrated in animals and humans. Here we examined in vivo performance of a camera-based hybrid fluorescence molecular tomography (FMT) system for 360° imaging combined with X-ray computed tomography (XCT). Offering an accurately co-registered, information-rich hybrid data set, FMT-XCT has new imaging possibilities compared to stand-alone FMT and XCT. We applied FMT-XCT to a subcutaneous 4T1 tumor mouse model, an Aga2 osteogenesis imperfecta model and a Kras lung cancer mouse model, using XCT information during FMT inversion. We validated in vivo imaging results against post-mortem planar fluorescence images of cryoslices and histology data. Besides offering concurrent anatomical and functional information, FMT-XCT resulted in the most accurate FMT performance to date. These findings indicate that addition of FMT optics into the XCT gantry may be a potent upgrade for small-animal XCT systems.

  17. Imaging performance of a hybrid x-ray computed tomography-fluorescence molecular tomography system using priors.

    Science.gov (United States)

    Ale, Angelique; Schulz, Ralf B; Sarantopoulos, Athanasios; Ntziachristos, Vasilis

    2010-05-01

    The performance is studied of two newly introduced and previously suggested methods that incorporate priors into inversion schemes associated with data from a recently developed hybrid x-ray computed tomography and fluorescence molecular tomography system, the latter based on CCD camera photon detection. The unique data set studied attains accurately registered data of high spatially sampled photon fields propagating through tissue along 360 degrees projections. Approaches that incorporate structural prior information were included in the inverse problem by adding a penalty term to the minimization function utilized for image reconstructions. Results were compared as to their performance with simulated and experimental data from a lung inflammation animal model and against the inversions achieved when not using priors. The importance of using priors over stand-alone inversions is also showcased with high spatial sampling simulated and experimental data. The approach of optimal performance in resolving fluorescent biodistribution in small animals is also discussed. Inclusion of prior information from x-ray CT data in the reconstruction of the fluorescence biodistribution leads to improved agreement between the reconstruction and validation images for both simulated and experimental data.

  18. Total Internal Reflection Fluorescence Microscopy Imaging-Guided Confocal Single-Molecule Fluorescence Spectroscopy

    OpenAIRE

    Zheng, Desheng; Kaldaras, Leonora; Lu, H. Peter

    2013-01-01

    We have developed an integrated spectroscopy system combining total internal reflection fluorescence microscopy imaging with confocal single-molecule fluorescence spectroscopy for two-dimensional interfaces. This spectroscopy approach is capable of both multiple molecules simultaneously sampling and in situ confocal fluorescence dynamics analyses of individual molecules of interest. We have demonstrated the calibration with fluorescent microspheres, and carried out single-molecule spectroscop...

  19. Multimodal optical coherence tomography and fluorescence lifetime imaging with interleaved excitation sources for simultaneous endogenous and exogenous fluorescence.

    Science.gov (United States)

    Shrestha, Sebina; Serafino, Michael J; Rico-Jimenez, Jesus; Park, Jesung; Chen, Xi; Zhaorigetu, Siqin; Walton, Brian L; Jo, Javier A; Applegate, Brian E

    2016-09-01

    Multimodal imaging probes a variety of tissue properties in a single image acquisition by merging complimentary imaging technologies. Exploiting synergies amongst the data, algorithms can be developed that lead to better tissue characterization than could be accomplished by the constituent imaging modalities taken alone. The combination of optical coherence tomography (OCT) with fluorescence lifetime imaging microscopy (FLIM) provides access to detailed tissue morphology and local biochemistry. The optical system described here merges 1310 nm swept-source OCT with time-domain FLIM having excitation at 355 and 532 nm. The pulses from 355 and 532 nm lasers have been interleaved to enable simultaneous acquisition of endogenous and exogenous fluorescence signals, respectively. The multimodal imaging system was validated using tissue phantoms. Nonspecific tagging with Alexa Flour 532 in a Watanbe rabbit aorta and active tagging of the LOX-1 receptor in human coronary artery, demonstrate the capacity of the system for simultaneous acquisition of OCT, endogenous FLIM, and exogenous FLIM in tissues.

  20. Photoacoustic tomography of human hepatic malignancies using intraoperative indocyanine green fluorescence imaging.

    Science.gov (United States)

    Miyata, Akinori; Ishizawa, Takeaki; Kamiya, Mako; Shimizu, Atsushi; Kaneko, Junichi; Ijichi, Hideaki; Shibahara, Junji; Fukayama, Masashi; Midorikawa, Yutaka; Urano, Yasuteru; Kokudo, Norihiro

    2014-01-01

    Recently, fluorescence imaging following the preoperative intravenous injection of indocyanine green has been used in clinical settings to identify hepatic malignancies during surgery. The aim of this study was to evaluate the ability of photoacoustic tomography using indocyanine green as a contrast agent to produce representative fluorescence images of hepatic tumors by visualizing the spatial distribution of indocyanine green on ultrasonographic images. Indocyanine green (0.5 mg/kg, intravenous) was preoperatively administered to 9 patients undergoing hepatectomy. Intraoperatively, photoacoustic tomography was performed on the surface of the resected hepatic specimens (n = 10) under excitation with an 800 nm pulse laser. In 4 hepatocellular carcinoma nodules, photoacoustic imaging identified indocyanine green accumulation in the cancerous tissue. In contrast, in one hepatocellular carcinoma nodule and five adenocarcinoma foci (one intrahepatic cholangiocarcinoma and 4 colorectal liver metastases), photoacoustic imaging delineated indocyanine green accumulation not in the cancerous tissue but rather in the peri-cancerous hepatic parenchyma. Although photoacoustic tomography enabled to visualize spatial distribution of ICG on ultrasonographic images, which was consistent with fluorescence images on cut surfaces of the resected specimens, photoacoustic signals of ICG-containing tissues decreased approximately by 40% even at 4 mm depth from liver surfaces. Photoacoustic tomography using indocyanine green also failed to identify any hepatocellular carcinoma nodules from the body surface of model mice with non-alcoholic steatohepatitis. In conclusion, photoacoustic tomography has a potential to enhance cancer detectability and differential diagnosis by ultrasonographic examinations and intraoperative fluorescence imaging through visualization of stasis of bile-excreting imaging agents in and/or around hepatic tumors. However, further technical advances are needed

  1. Photoacoustic tomography of human hepatic malignancies using intraoperative indocyanine green fluorescence imaging.

    Directory of Open Access Journals (Sweden)

    Akinori Miyata

    Full Text Available Recently, fluorescence imaging following the preoperative intravenous injection of indocyanine green has been used in clinical settings to identify hepatic malignancies during surgery. The aim of this study was to evaluate the ability of photoacoustic tomography using indocyanine green as a contrast agent to produce representative fluorescence images of hepatic tumors by visualizing the spatial distribution of indocyanine green on ultrasonographic images. Indocyanine green (0.5 mg/kg, intravenous was preoperatively administered to 9 patients undergoing hepatectomy. Intraoperatively, photoacoustic tomography was performed on the surface of the resected hepatic specimens (n = 10 under excitation with an 800 nm pulse laser. In 4 hepatocellular carcinoma nodules, photoacoustic imaging identified indocyanine green accumulation in the cancerous tissue. In contrast, in one hepatocellular carcinoma nodule and five adenocarcinoma foci (one intrahepatic cholangiocarcinoma and 4 colorectal liver metastases, photoacoustic imaging delineated indocyanine green accumulation not in the cancerous tissue but rather in the peri-cancerous hepatic parenchyma. Although photoacoustic tomography enabled to visualize spatial distribution of ICG on ultrasonographic images, which was consistent with fluorescence images on cut surfaces of the resected specimens, photoacoustic signals of ICG-containing tissues decreased approximately by 40% even at 4 mm depth from liver surfaces. Photoacoustic tomography using indocyanine green also failed to identify any hepatocellular carcinoma nodules from the body surface of model mice with non-alcoholic steatohepatitis. In conclusion, photoacoustic tomography has a potential to enhance cancer detectability and differential diagnosis by ultrasonographic examinations and intraoperative fluorescence imaging through visualization of stasis of bile-excreting imaging agents in and/or around hepatic tumors. However, further technical

  2. Human thyroid specimen imaging by fluorescent x-ray computed tomography with synchrotron radiation

    Science.gov (United States)

    Takeda, Tohoru; Yu, Quanwen; Yashiro, Toru; Yuasa, Tetsuya; Hasegawa, Yasuo; Itai, Yuji; Akatsuka, Takao

    1999-09-01

    Fluorescent x-ray computed tomography (FXCT) is being developed to detect non-radioactive contrast materials in living specimens. The FXCT system consists of a silicon (111) channel cut monochromator, an x-ray slit and a collimator for fluorescent x ray detection, a scanning table for the target organ and an x-ray detector for fluorescent x-ray and transmission x-ray. To reduce Compton scattering overlapped on the fluorescent K(alpha) line, incident monochromatic x-ray was set at 37 keV. The FXCT clearly imaged a human thyroid gland and iodine content was estimated quantitatively. In a case of hyperthyroidism, the two-dimensional distribution of iodine content was not uniform, and thyroid cancer had a small amount of iodine. FXCT can be used to detect iodine within thyroid gland quantitatively and to delineate its distribution.

  3. Development of Ultrasonic Modulation Probe for Fluorescence Tomography Based on Acousto-Optic Effect

    Directory of Open Access Journals (Sweden)

    Trinh Quang Duc

    2011-01-01

    Full Text Available We have developed an ultrasonic probe for fluorescence modulation to image fluorescence within biological tissues. The probe consists of a focused ultrasonic transducer mounted on actuators for mechanical fan scanning, which can be used in contact with the measuring object aiming for clinical application. The mechanical fan scanning employed in the probe has a beneficial feature of portability. As a result, fluorescent beads, which were localized with the diameter of 2 mm at 20 mm depth in a pork meat tissue, were detected with resolution of 3 mm. The system performance denotes the feasibility of development towards the final goal of ultrasonic fluorescence modulation tomography for clinical applications.

  4. Experimental Results of Guided Wave Travel Time Tomography

    Science.gov (United States)

    Volker, Arno; Mast, Arjan; Bloom, Joost

    2010-02-01

    Corrosion is one of the industries major issues regarding the integrity of assets. Currently inspections are conducted at regular intervals to ensure a sufficient integrity level of these assets. Both economical and social requirements are pushing the industry to even higher levels of availability, reliability and safety of installations. The concept of predictive maintenance using permanent sensors that monitor the integrity of an installation is an interesting addition to the current method of periodic inspections reducing uncertainty and extending inspection intervals. Guided wave travel time tomography is a promising method to monitor the wall thickness quantitatively over large areas. Obviously the robustness and reliability of such a monitoring system is of paramount importance. Laboratory experiments have been carried out on a 10″ pipe with a nominal wall thickness of 8 mm. Multiple, inline defects have been created with a realistic morphology. The depth of the defects was increased stepwise from 0.5 mm to 2 mm. Additionally the influences of the presence of liquid inside the pipe and surface roughness have been evaluated as well. Experimental results show that this method is capable of providing quantitative wall thickness information over a distance of 4 meter, with a sufficient accuracy such that results can be used for trending. The method has no problems imaging multiple defects.

  5. Compression of Born ratio for fluorescence molecular tomography/x-ray computed tomography hybrid imaging: methodology and in vivo validation.

    Science.gov (United States)

    Mohajerani, Pouyan; Ntziachristos, Vasilis

    2013-07-01

    The 360° rotation geometry of the hybrid fluorescence molecular tomography/x-ray computed tomography modality allows for acquisition of very large datasets, which pose numerical limitations on the reconstruction. We propose a compression method that takes advantage of the correlation of the Born-normalized signal among sources in spatially formed clusters to reduce the size of system model. The proposed method has been validated using an ex vivo study and an in vivo study of a nude mouse with a subcutaneous 4T1 tumor, with and without inclusion of a priori anatomical information. Compression rates of up to two orders of magnitude with minimum distortion of reconstruction have been demonstrated, resulting in large reduction in weight matrix size and reconstruction time.

  6. Ultrasonic guided wave tomography for wall thickness mapping in pipes

    Science.gov (United States)

    Willey, Carson L.

    Corrosion and erosion damage pose fundamental challenges to operation of oil and gas infrastructure. In order to manage the life of critical assets, plant operators must implement inspection programs aimed at assessing the severity of wall thickness loss (WTL) in pipelines, vessels, and other structures. Maximum defect depth determines the residual life of these structures and therefore represents one of the key parameters for robust damage mitigation strategies. In this context, continuous monitoring with permanently installed sensors has attracted significant interest and currently is the subject of extensive research worldwide. Among the different monitoring approaches being considered, significant promise is offered by the combination of guided ultrasonic wave technology with the principles of model based inversion under the paradigm of what is now referred to as guided wave tomography (GWT). Guided waves are attractive because they propagate inside the wall of a structure over a large distance. This can yield significant advantages over conventional pulse-echo thickness gage sensors that provide insufficient area coverage -- typically limited to the sensor footprint. While significant progress has been made in the application of GWT to plate-like structures, extension of these methods to pipes poses a number of fundamental challenges that have prevented the development of sensitive GWT methods. This thesis focuses on these challenges to address the complex guided wave propagation in pipes and to account for parametric uncertainties that are known to affect model based inversion and which are unavoidable in real field applications. The main contribution of this work is the first demonstration of a sensitive GWT method for accurately mapping the depth of defects in pipes. This is achieved by introducing a novel forward model that can extract information related to damage from the complex waveforms measured by pairs of guided wave transducers mounted on the pipe

  7. Computed tomography-guided percutaneous gastrostomy: initial experience at a cancer center

    Energy Technology Data Exchange (ETDEWEB)

    Tyng, Chiang Jeng; Santos, Erich Frank Vater; Guerra, Luiz Felipe Alves; Bitencourt, Almir Galvao Vieira; Barbosa, Paula Nicole Vieira Pinto; Chojniak, Rubens [A. C. Camargo Cancer Center, Sao Paulo, SP (Brazil); Universidade Federal do Espirito Santo (HUCAM/UFES), Vitoria, ES (Brazil). Hospital Universitario Cassiano Antonio de Morais. Radiologia e Diagnostico por Imagem

    2017-03-15

    Gastrostomy is indicated for patients with conditions that do not allow adequate oral nutrition. To reduce the morbidity and costs associated with the procedure, there is a trend toward the use of percutaneous gastrostomy, guided by endoscopy, fluoroscopy, or, most recently, computed tomography. The purpose of this paper was to review the computed tomography-guided gastrostomy procedure, as well as the indications for its use and the potential complications. (author)

  8. Computed tomography-guided percutaneous gastrostomy: initial experience at a cancer center

    International Nuclear Information System (INIS)

    Tyng, Chiang Jeng; Santos, Erich Frank Vater; Guerra, Luiz Felipe Alves; Bitencourt, Almir Galvao Vieira; Barbosa, Paula Nicole Vieira Pinto; Chojniak, Rubens; Universidade Federal do Espirito Santo

    2017-01-01

    Gastrostomy is indicated for patients with conditions that do not allow adequate oral nutrition. To reduce the morbidity and costs associated with the procedure, there is a trend toward the use of percutaneous gastrostomy, guided by endoscopy, fluoroscopy, or, most recently, computed tomography. The purpose of this paper was to review the computed tomography-guided gastrostomy procedure, as well as the indications for its use and the potential complications. (author)

  9. A tumor-targeted polymer theranostics platform for positron emission tomography and fluorescence imaging

    Czech Academy of Sciences Publication Activity Database

    Koziolová, Eva; Goel, S.; Chytil, Petr; Janoušková, Olga; Barnhart, T. E.; Cai, W.; Etrych, Tomáš

    2017-01-01

    Roč. 9, č. 30 (2017), s. 10906-10918 ISSN 2040-3364 R&D Projects: GA ČR(CZ) GA15-02986S; GA MZd(CZ) NV16-28594A; GA MŠk(CZ) LO1507 Institutional support: RVO:61389013 Keywords : N-(2-hydroxypropyl)methacrylamide (HPMA) copolymers * positron emission tomography ( PET ) * fluorescence imaging Subject RIV: CD - Macromolecular Chemistry OBOR OECD: Polymer science Impact factor: 7.367, year: 2016

  10. Fundus auto fluorescence and spectral domain ocular coherence tomography in the early detection of chloroquine retinopathy

    OpenAIRE

    Megan B. Goodman; Ari Ziskind

    2015-01-01

    Purpose: To determine the sensitivity of spectral domain ocular coherence tomography (SD-OCT) and fundus auto fluorescence (FAF) images as a screening test to detect early changes in the retina prior to the onset of chloroquine retinopathy. Method: The study was conducted using patients taking chloroquine (CQ), referred by the Rheumatology Department to the Ophthalmology Department at Tygerberg Academic Hospital. Group A consisted of 59 patients on CQ for less than 5 years, and Group B co...

  11. Depth-resolved imaging of colon tumor using optical coherence tomography and fluorescence laminar optical tomography (Conference Presentation)

    Science.gov (United States)

    Tang, Qinggong; Frank, Aaron; Wang, Jianting; Chen, Chao-wei; Jin, Lily; Lin, Jon; Chan, Joanne M.; Chen, Yu

    2016-03-01

    Early detection of neoplastic changes remains a critical challenge in clinical cancer diagnosis and treatment. Many cancers arise from epithelial layers such as those of the gastrointestinal (GI) tract. Current standard endoscopic technology is unable to detect those subsurface lesions. Since cancer development is associated with both morphological and molecular alterations, imaging technologies that can quantitative image tissue's morphological and molecular biomarkers and assess the depth extent of a lesion in real time, without the need for tissue excision, would be a major advance in GI cancer diagnostics and therapy. In this research, we investigated the feasibility of multi-modal optical imaging including high-resolution optical coherence tomography (OCT) and depth-resolved high-sensitivity fluorescence laminar optical tomography (FLOT) for structural and molecular imaging. APC (adenomatous polyposis coli) mice model were imaged using OCT and FLOT and the correlated histopathological diagnosis was obtained. Quantitative structural (the scattering coefficient) and molecular imaging parameters (fluorescence intensity) from OCT and FLOT images were developed for multi-parametric analysis. This multi-modal imaging method has demonstrated the feasibility for more accurate diagnosis with 87.4% (87.3%) for sensitivity (specificity) which gives the most optimal diagnosis (the largest area under receiver operating characteristic (ROC) curve). This project results in a new non-invasive multi-modal imaging platform for improved GI cancer detection, which is expected to have a major impact on detection, diagnosis, and characterization of GI cancers, as well as a wide range of epithelial cancers.

  12. Guided mass spectrum labelling in atom probe tomography

    Energy Technology Data Exchange (ETDEWEB)

    Haley, D., E-mail: daniel.haley@materials.ox.ac.uk [Max-Planck-Institut für Eisenforschung, Max-Plack Straße 1, Düsseldorf (Germany); Department of Materials, University of Oxford, Parks Road, Oxford OX1 3PH (United Kingdom); Choi, P.; Raabe, D. [Max-Planck-Institut für Eisenforschung, Max-Plack Straße 1, Düsseldorf (Germany)

    2015-12-15

    Atom probe tomography (APT) is a valuable near-atomic scale imaging technique, which yields mass spectrographic data. Experimental correctness can often pivot on the identification of peaks within a dataset, this is a manual process where subjectivity and errors can arise. The limitations of manual procedures complicate APT experiments for the operator and furthermore are a barrier to technique standardisation. In this work we explore the capabilities of computer-guided ranging to aid identification and analysis of mass spectra. We propose a fully robust algorithm for enumeration of the possible identities of detected peak positions, which assists labelling. Furthermore, a simple ranking scheme is developed to allow for evaluation of the likelihood of each possible identity being the likely assignment from the enumerated set. We demonstrate a simple, yet complete work-chain that allows for the conversion of mass-spectra to fully identified APT spectra, with the goal of minimising identification errors, and the inter-operator variance within APT experiments. This work chain is compared to current procedures via experimental trials with different APT operators, to determine the relative effectiveness and precision of the two approaches. It is found that there is little loss of precision (and occasionally gain) when participants are given computer assistance. We find that in either case, inter-operator precision for ranging varies between 0 and 2 “significant figures” (2σ confidence in the first n digits of the reported value) when reporting compositions. Intra-operator precision is weakly tested and found to vary between 1 and 3 significant figures, depending upon species composition levels. Finally it is suggested that inconsistencies in inter-operator peak labelling may be the largest source of scatter when reporting composition data in APT. - Highlights: • Demonstration of a complete, but simple, automation chain for APT spectra analysis. • Algorithm for

  13. Guided mass spectrum labelling in atom probe tomography

    International Nuclear Information System (INIS)

    Haley, D.; Choi, P.; Raabe, D.

    2015-01-01

    Atom probe tomography (APT) is a valuable near-atomic scale imaging technique, which yields mass spectrographic data. Experimental correctness can often pivot on the identification of peaks within a dataset, this is a manual process where subjectivity and errors can arise. The limitations of manual procedures complicate APT experiments for the operator and furthermore are a barrier to technique standardisation. In this work we explore the capabilities of computer-guided ranging to aid identification and analysis of mass spectra. We propose a fully robust algorithm for enumeration of the possible identities of detected peak positions, which assists labelling. Furthermore, a simple ranking scheme is developed to allow for evaluation of the likelihood of each possible identity being the likely assignment from the enumerated set. We demonstrate a simple, yet complete work-chain that allows for the conversion of mass-spectra to fully identified APT spectra, with the goal of minimising identification errors, and the inter-operator variance within APT experiments. This work chain is compared to current procedures via experimental trials with different APT operators, to determine the relative effectiveness and precision of the two approaches. It is found that there is little loss of precision (and occasionally gain) when participants are given computer assistance. We find that in either case, inter-operator precision for ranging varies between 0 and 2 “significant figures” (2σ confidence in the first n digits of the reported value) when reporting compositions. Intra-operator precision is weakly tested and found to vary between 1 and 3 significant figures, depending upon species composition levels. Finally it is suggested that inconsistencies in inter-operator peak labelling may be the largest source of scatter when reporting composition data in APT. - Highlights: • Demonstration of a complete, but simple, automation chain for APT spectra analysis. • Algorithm for

  14. Use of multiphoton tomography and fluorescence lifetime imaging to investigate skin pigmentation in vivo

    Science.gov (United States)

    Dancik, Yuri; Favre, Amandine; Loy, Chong Jin; Zvyagin, Andrei V.; Roberts, Michael S.

    2013-02-01

    There is a growing body of literature showing the usefulness of multiphoton tomography (MPT) and fluorescence lifetime imaging for in situ characterization of skin constituents and the ensuing development of noninvasive diagnostic tools against skin diseases. Melanin and pigmentation-associated skin cancers constitute some of the major applications. We show that MPT and fluorescence lifetime imaging can be used to measure changes in cutaneous melanin concentration and that these can be related to the visible skin color. Melanin in the skin of African, Indian, Caucasian, and Asian volunteers is detected on the basis of its emission wavelength and fluorescence lifetimes in solution and in a melanocyte-keratinocyte cell culture. Fluorescence intensity is used to characterize the melanin content and distribution as a function of skin type and depth into the skin (stratum granulosum and stratum basale). The measured fluorescence intensities in given skin types agree with melanin amounts reported by others using biopsies. Our results suggest that spatial distribution of melanin in skin can be studied using MPT and fluorescence lifetime imaging, but further studies are needed to ascertain that the method can resolve melanin amount in smaller depth intervals.

  15. Toward robust high resolution fluorescence tomography: a hybrid row-action edge preserving regularization

    Science.gov (United States)

    Behrooz, Ali; Zhou, Hao-Min; Eftekhar, Ali A.; Adibi, Ali

    2011-02-01

    Depth-resolved localization and quantification of fluorescence distribution in tissue, called Fluorescence Molecular Tomography (FMT), is highly ill-conditioned as depth information should be extracted from limited number of surface measurements. Inverse solvers resort to regularization algorithms that penalize Euclidean norm of the solution to overcome ill-posedness. While these regularization algorithms offer good accuracy, their smoothing effects result in continuous distributions which lack high-frequency edge-type features of the actual fluorescence distribution and hence limit the resolution offered by FMT. We propose an algorithm that penalizes the total variation (TV) norm of the solution to preserve sharp transitions and high-frequency components in the reconstructed fluorescence map while overcoming ill-posedness. The hybrid algorithm is composed of two levels: 1) An Algebraic Reconstruction Technique (ART), performed on FMT data for fast recovery of a smooth solution that serves as an initial guess for the iterative TV regularization, 2) A time marching TV regularization algorithm, inspired by the Rudin-Osher-Fatemi TV image restoration, performed on the initial guess to further enhance the resolution and accuracy of the reconstruction. The performance of the proposed method in resolving fluorescent tubes inserted in a liquid tissue phantom imaged by a non-contact CW trans-illumination FMT system is studied and compared to conventional regularization schemes. It is observed that the proposed method performs better in resolving fluorescence inclusions at higher depths.

  16. Functional imaging in bulk tissue specimens using optical emission tomography: fluorescence preservation during optical clearing

    International Nuclear Information System (INIS)

    Sakhalkar, H S; Dewhirst, M; Oliver, T; Cao, Y; Oldham, M

    2007-01-01

    Optical emission computed tomography (optical-ECT) is a technique for imaging the three-dimensional (3D) distribution of fluorescent probes in biological tissue specimens with high contrast and spatial resolution. In optical-ECT, functional information can be imaged by (i) systemic application of functional labels (e.g. fluorophore labelled proteins) and/or (ii) endogenous expression of fluorescent reporter proteins (e.g. red fluorescent protein (RFP), green fluorescent protein (GFP)) in vivo. An essential prerequisite for optical-ECT is optical clearing, a procedure where tissue specimens are made transparent to light by sequential perfusion with fixing, dehydrating and clearing agents. In this study, we investigate clearing protocols involving a selection of common fixing (4% buffered paraformaldehyde (PFA), methanol and ethanol), dehydrating (methanol and ethanol) and clearing agents (methyl salicylate and benzyl-alcohol-benzyl-benzoate (BABB)) in order to determine a 'fluorescence friendly' clearing procedure. Cell culture experiments were employed to optimize the sequence of chemical treatments that best preserve fluorescence. Texas red (TxRed), fluorescein isothiocyanate (FITC), RFP and GFP were tested as fluorophores and fluorescent reporter proteins of interest. Fluorescent and control cells were imaged on a microscope using a DSred2 and FITC filter set. The most promising clearing protocols of cell culture experiments were applied to whole xenograft tumour specimens, to test their effectiveness in large unsectioned samples. Fluorescence of TxRed/FITC fluorophores was not found to be significantly affected by any of the test clearing protocols. RFP and GFP fluorescence, however, was found to be significantly greater when cell fixation was in ethanol. Fixation in either PFA or methanol resulted in diminished fluorescence. After ethanol fixation, the RFP and GFP fluorescence proved remarkably robust to subsequent exposure to either methyl salicylate or BABB

  17. Functional imaging in bulk tissue specimens using optical emission tomography: fluorescence preservation during optical clearing

    Energy Technology Data Exchange (ETDEWEB)

    Sakhalkar, H S [Department of Radiation Oncology, Duke University Medical Center, Durham, NC 27710 (United States); Dewhirst, M [Department of Radiation Oncology, Duke University Medical Center, Durham, NC 27710 (United States); Oliver, T [Department of Cell Biology, Duke University Medical Center, Durham, NC 27710 (United States); Cao, Y [Department of Radiation Oncology, Duke University Medical Center, Durham, NC 27710 (United States); Oldham, M [Department of Radiation Oncology Physics, and Biomedical Engineering, Duke University Medical Center, Durham, NC 27710 (United States)

    2007-04-21

    Optical emission computed tomography (optical-ECT) is a technique for imaging the three-dimensional (3D) distribution of fluorescent probes in biological tissue specimens with high contrast and spatial resolution. In optical-ECT, functional information can be imaged by (i) systemic application of functional labels (e.g. fluorophore labelled proteins) and/or (ii) endogenous expression of fluorescent reporter proteins (e.g. red fluorescent protein (RFP), green fluorescent protein (GFP)) in vivo. An essential prerequisite for optical-ECT is optical clearing, a procedure where tissue specimens are made transparent to light by sequential perfusion with fixing, dehydrating and clearing agents. In this study, we investigate clearing protocols involving a selection of common fixing (4% buffered paraformaldehyde (PFA), methanol and ethanol), dehydrating (methanol and ethanol) and clearing agents (methyl salicylate and benzyl-alcohol-benzyl-benzoate (BABB)) in order to determine a 'fluorescence friendly' clearing procedure. Cell culture experiments were employed to optimize the sequence of chemical treatments that best preserve fluorescence. Texas red (TxRed), fluorescein isothiocyanate (FITC), RFP and GFP were tested as fluorophores and fluorescent reporter proteins of interest. Fluorescent and control cells were imaged on a microscope using a DSred2 and FITC filter set. The most promising clearing protocols of cell culture experiments were applied to whole xenograft tumour specimens, to test their effectiveness in large unsectioned samples. Fluorescence of TxRed/FITC fluorophores was not found to be significantly affected by any of the test clearing protocols. RFP and GFP fluorescence, however, was found to be significantly greater when cell fixation was in ethanol. Fixation in either PFA or methanol resulted in diminished fluorescence. After ethanol fixation, the RFP and GFP fluorescence proved remarkably robust to subsequent exposure to either methyl salicylate

  18. Computer tomography guided lung biopsy using interactive breath-hold control

    DEFF Research Database (Denmark)

    Ashraf, Haseem; Krag-Andersen, Shella; Naqibullah, Matiullah

    2017-01-01

    Background: Interactive breath-hold control (IBC) may improve the accuracy and decrease the complication rate of computed tomography (CT)-guided lung biopsy, but this presumption has not been proven in a randomized study. Methods: Patients admitted for CT-guided lung biopsy were randomized...

  19. Non-invasive imaging of skin cancer with fluorescence lifetime imaging using two photon tomography

    Science.gov (United States)

    Patalay, Rakesh; Talbot, Clifford; Alexandrov, Yuriy; Munro, Ian; Breunig, Hans Georg; König, Karsten; Warren, Sean; Neil, Mark A. A.; French, Paul M. W.; Chu, Anthony; Stamp, Gordon W.; Dunsby, Christopher

    2011-07-01

    Multispectral fluorescence lifetime imaging (FLIM) using two photon microscopy as a non-invasive technique for the diagnosis of skin lesions is described. Skin contains fluorophores including elastin, keratin, collagen, FAD and NADH. This endogenous contrast allows tissue to be imaged without the addition of exogenous agents and allows the in vivo state of cells and tissues to be studied. A modified DermaInspect® multiphoton tomography system was used to excite autofluorescence at 760 nm in vivo and on freshly excised ex vivo tissue. This instrument simultaneously acquires fluorescence lifetime images in four spectral channels between 360-655 nm using time-correlated single photon counting and can also provide hyperspectral images. The multispectral fluorescence lifetime images were spatially segmented and binned to determine lifetimes for each cell by fitting to a double exponential lifetime model. A comparative analysis between the cellular lifetimes from different diagnoses demonstrates significant diagnostic potential.

  20. In vivo fluorescence enhanced optical tomography reconstruction of lung cancer of non immersed small animals

    Science.gov (United States)

    Hervé, L.; Koenig, A.; Da Silva, A.; Berger, M.; Boutet, J.; Dinten, J. M.; Peltié, P.; Rizo, P.

    2007-02-01

    Fluorescence enhanced diffuse optical tomography (fDOT) is envisioned to be useful to collect functional information from small animal models. For oncology applications, cancer-targeted fluorescent markers can be used as a surrogate of the cancer activity. We are developing a continuous wave fDOT bench intended to be integrated in systems dedicated to whole body small animal fluorescence analyses. The focus is currently put on the reconstruction of non immersed small animals imaged by a CCD camera. The reconstruction stage already corrects the tissue heterogeneity artifacts through the computation of an optical heterogeneity map. We will show how this formalism coupled with the determination of the animal boundaries performed by a laser scanner, can be used to manage non contact acquisitions. The time of reconstruction for a 10 × 9 laser source positions, 45 × 40 detector elements and 14 × 11 × 14 mesh voxels is typically 10 minutes on a 3GHz PCs corresponding to the acquisition time allowing the two tasks to be performed in parallel. The system is validated on an in vivo experiment performed on three healthy nude mice and a mouse bearing a lung tumor at 10, 12 and 14 days after implantation allowing the follow up of the disease. The 3D fluorescence reconstructions of this mouse are presented and the total fluorescence amounts are compared.

  1. Combined X-ray fluorescence and absorption computed tomography using a synchrotron beam

    International Nuclear Information System (INIS)

    Hall, C

    2013-01-01

    X-ray computed tomography (CT) and fluorescence X-ray computed tomography (FXCT) using synchrotron sources are both useful tools in biomedical imaging research. Synchrotron CT (SRCT) in its various forms is considered an important technique for biomedical imaging since the phase coherence of SR beams can be exploited to obtain images with high contrast resolution. Using a synchrotron as the source for FXCT ensures a fluorescence signal that is optimally detectable by exploiting the beam monochromaticity and polarisation. The ability to combine these techniques so that SRCT and FXCT images are collected simultaneously, would bring distinct benefits to certain biomedical experiments. Simultaneous image acquisition would alleviate some of the registration difficulties which comes from collecting separate data, and it would provide increased information about the sample: functional X-ray images from the FXCT, with the morphological information from the SRCT. A method is presented for generating simultaneous SRCT and FXCT images. Proof of principle modelling has been used to show that it is possible to recover a fluorescence image of a point-like source from an SRCT apparatus by suitably modulating the illuminating planar X-ray beam. The projection image can be successfully used for reconstruction by removing the static modulation from the sinogram in the normal flat and dark field processing. Detection of the modulated fluorescence signal using an energy resolving detector allows the position of a fluorescent marker to be obtained using inverse reconstruction techniques. A discussion is made of particular reconstruction methods which might be applied by utilising both the CT and FXCT data.

  2. Computerized Tomography and its Applications : a Guided Tour

    NARCIS (Netherlands)

    Roerdink, J.B.T.M.

    1992-01-01

    We present a review of the mathematical principles of computerized tomography. Topics treated include the role of the Radon transform and related transforms, inversion formulas, uniqueness, ill-posedness and stability, practical reconstruction algorithms, and various generalizations such as

  3. Correlative cryo-fluorescence light microscopy and cryo-electron tomography of Streptomyces.

    Science.gov (United States)

    Koning, Roman I; Celler, Katherine; Willemse, Joost; Bos, Erik; van Wezel, Gilles P; Koster, Abraham J

    2014-01-01

    Light microscopy and electron microscopy are complementary techniques that in a correlative approach enable identification and targeting of fluorescently labeled structures in situ for three-dimensional imaging at nanometer resolution. Correlative imaging allows electron microscopic images to be positioned in a broader temporal and spatial context. We employed cryo-correlative light and electron microscopy (cryo-CLEM), combining cryo-fluorescence light microscopy and cryo-electron tomography, on vitrified Streptomyces bacteria to study cell division. Streptomycetes are mycelial bacteria that grow as long hyphae and reproduce via sporulation. On solid media, Streptomyces subsequently form distinct aerial mycelia where cell division leads to the formation of unigenomic spores which separate and disperse to form new colonies. In liquid media, only vegetative hyphae are present divided by noncell separating crosswalls. Their multicellular life style makes them exciting model systems for the study of bacterial development and cell division. Complex intracellular structures have been visualized with transmission electron microscopy. Here, we describe the methods for cryo-CLEM that we applied for studying Streptomyces. These methods include cell growth, fluorescent labeling, cryo-fixation by vitrification, cryo-light microscopy using a Linkam cryo-stage, image overlay and relocation, cryo-electron tomography using a Titan Krios, and tomographic reconstruction. Additionally, methods for segmentation, volume rendering, and visualization of the correlative data are described. © 2014 Elsevier Inc. All rights reserved.

  4. Non-stationary reconstruction for dynamic fluorescence molecular tomography with extended kalman filter.

    Science.gov (United States)

    Liu, Xin; Wang, Hongkai; Yan, Zhuangzhi

    2016-11-01

    Dynamic fluorescence molecular tomography (FMT) plays an important role in drug delivery research. However, the majority of current reconstruction methods focus on solving the stationary FMT problems. If the stationary reconstruction methods are applied to the time-varying fluorescence measurements, the reconstructed results may suffer from a high level of artifacts. In addition, based on the stationary methods, only one tomographic image can be obtained after scanning one circle projection data. As a result, the movement of fluorophore in imaged object may not be detected due to the relative long data acquisition time (typically >1 min). In this paper, we apply extended kalman filter (EKF) technique to solve the non-stationary fluorescence tomography problem. Especially, to improve the EKF reconstruction performance, the generalized inverse of kalman gain is calculated by a second-order iterative method. The numerical simulation, phantom, and in vivo experiments are performed to evaluate the performance of the method. The experimental results indicate that by using the proposed EKF-based second-order iterative (EKF-SOI) method, we cannot only clearly resolve the time-varying distributions of fluorophore within imaged object, but also greatly improve the reconstruction time resolution (~2.5 sec/frame) which makes it possible to detect the movement of fluorophore during the imaging processes.

  5. Role of hexaminolevulinate-guided fluorescence cystoscopy in bladder cancer

    DEFF Research Database (Denmark)

    Malmström, Per-Uno; Grabe, Magnus; Haug, Erik Skaaheim

    2012-01-01

    Hexaminolevulinate (HAL) is an optical imaging agent used with fluorescence cystoscopy (FC) for the detection of non-muscle-invasive bladder cancer (NMIBC). Guidelines from the European Association of Urology (EAU) and a recent, more detailed European expert consensus statement agree that HAL...

  6. Full-direct method for imaging pharmacokinetic parameters in dynamic fluorescence molecular tomography

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Guanglei, E-mail: guangleizhang@bjtu.edu.cn [Department of Biomedical Engineering, School of Medicine, Tsinghua University, Beijing 100084 (China); Department of Biomedical Engineering, School of Computer and Information Technology, Beijing Jiaotong University, Beijing 100044 (China); Pu, Huangsheng; Liu, Fei; Bai, Jing [Department of Biomedical Engineering, School of Medicine, Tsinghua University, Beijing 100084 (China); He, Wei [China Institute of Sport Science, Beijing 100061 (China); Luo, Jianwen, E-mail: luo-jianwen@tsinghua.edu.cn [Department of Biomedical Engineering, School of Medicine, Tsinghua University, Beijing 100084 (China); Center for Biomedical Imaging Research, School of Medicine, Tsinghua University, Beijing 100084 (China)

    2015-02-23

    Images of pharmacokinetic parameters (also known as parametric images) in dynamic fluorescence molecular tomography (FMT) can provide three-dimensional metabolic information for biological studies and drug development. However, the ill-posed nature of FMT and the high temporal variation of fluorophore concentration together make it difficult to obtain accurate parametric images in small animals in vivo. In this letter, we present a method to directly reconstruct the parametric images from the boundary measurements based on hybrid FMT/X-ray computed tomography (XCT) system. This method can not only utilize structural priors obtained from the XCT system to mitigate the ill-posedness of FMT but also make full use of the temporal correlations of boundary measurements to model the high temporal variation of fluorophore concentration. The results of numerical simulation and mouse experiment demonstrate that the proposed method leads to significant improvements in the reconstruction quality of parametric images.

  7. An optical method for reducing green fluorescence from urine during fluorescence-guided cystoscopy

    DEFF Research Database (Denmark)

    Lindvold, Lars René; Hermann, Gregers G

    2016-01-01

    Photodynamic diagnosis (PDD) of bladder tumour tissue significantly improves endoscopic diagnosis and treatment of bladder cancer in rigid cystoscopes in the operating theatre and thus reduces tumour recurrence. PDD comprises the use of blue light, which unfortunately excites green fluorescence...... this light source also is useful for exciting autofluorescence in healthy bladder mucosa. This autofluorescence then provides a contrast to the sensitized fluorescence (PDD) of tumours in the bladder....

  8. An optical method for reducing green fluorescence from urine during fluorescence-guided cystoscopy

    Science.gov (United States)

    Lindvold, Lars R.; Hermann, Gregers G.

    2016-12-01

    Photodynamic diagnosis (PDD) of bladder tumour tissue significantly improves endoscopic diagnosis and treatment of bladder cancer in rigid cystoscopes in the operating theatre and thus reduces tumour recurrence. PDD comprises the use of blue light, which unfortunately excites green fluorescence from urine. As this green fluorescence confounds the desired red fluorescence of the PDD, methods for avoiding this situation particularly in cystoscopy using flexible cystoscopes are desirable. In this paper we demonstrate how a tailor made high power LED light source at 525 nm can be used for fluorescence assisted tumour detection using both a flexible and rigid cystoscope used in the outpatient department (OPD) and operating room (OR) respectively. It is demonstrated both in vitro and in vivo how this light source can significantly reduce the green fluorescence problem with urine. At the same time this light source also is useful for exciting autofluorescence in healthy bladder mucosa. This autofluorescence then provides a contrast to the sensitized fluorescence (PDD) of tumours in the bladder.

  9. A three-step reconstruction method for fluorescence molecular tomography based on compressive sensing

    DEFF Research Database (Denmark)

    Zhu, Yansong; Jha, Abhinav K.; Dreyer, Jakob K.

    2017-01-01

    Fluorescence molecular tomography (FMT) is a promising tool for real time in vivo quantification of neurotransmission (NT) as we pursue in our BRAIN initiative effort. However, the acquired image data are noisy and the reconstruction problem is ill-posed. Further, while spatial sparsity of the NT...... matrix coherence. The resultant image data are input to a homotopy-based reconstruction strategy that exploits sparsity via ℓ1 regularization. The reconstructed image is then input to a maximum-likelihood expectation maximization (MLEM) algorithm that retains the sparseness of the input estimate...... and improves upon the quantitation by accurate Poisson noise modeling. The proposed reconstruction method was evaluated in a three-dimensional simulated setup with fluorescent sources in a cuboidal scattering medium with optical properties simulating human brain cortex (reduced scattering coefficient: 9.2 cm-1...

  10. Efficient L1 regularization-based reconstruction for fluorescent molecular tomography using restarted nonlinear conjugate gradient.

    Science.gov (United States)

    Shi, Junwei; Zhang, Bin; Liu, Fei; Luo, Jianwen; Bai, Jing

    2013-09-15

    For the ill-posed fluorescent molecular tomography (FMT) inverse problem, the L1 regularization can protect the high-frequency information like edges while effectively reduce the image noise. However, the state-of-the-art L1 regularization-based algorithms for FMT reconstruction are expensive in memory, especially for large-scale problems. An efficient L1 regularization-based reconstruction algorithm based on nonlinear conjugate gradient with restarted strategy is proposed to increase the computational speed with low memory consumption. The reconstruction results from phantom experiments demonstrate that the proposed algorithm can obtain high spatial resolution and high signal-to-noise ratio, as well as high localization accuracy for fluorescence targets.

  11. Occlusal overload investigations by noninvasive technology: fluorescence microscopy and en-face optical coherence tomography

    Science.gov (United States)

    Marcauteanu, Corina; Negrutiu, Meda; Sinescu, Cosmin; Demjan, Enikö; Hughes, Michael; Bradu, Adrian; Dobre, George; Podoleanu, Adrian G.

    2009-07-01

    The aim of this study is the early detection and monitoring of occlusal overload in bruxing patients. En-Face Optical coherence tomography (eF-OCT) and fluorescence microscopy (FM) were used for the imaging of several anterior teeth extracted from patients with light active bruxism. We found a characteristic pattern of enamel cracks, that reached the tooth surface. We concluded that the combination of the en-Face OCT and FM is a promising non-invasive alternative technique for reliable monitoring of occlusal overload.

  12. Reconstruction for limited-projection fluorescence molecular tomography based on projected restarted conjugate gradient normal residual.

    Science.gov (United States)

    Cao, Xu; Zhang, Bin; Liu, Fei; Wang, Xin; Bai, Jing

    2011-12-01

    Limited-projection fluorescence molecular tomography (FMT) can greatly reduce the acquisition time, which is suitable for resolving fast biology processes in vivo but suffers from severe ill-posedness because of the reconstruction using only limited projections. To overcome the severe ill-posedness, we report a reconstruction method based on the projected restarted conjugate gradient normal residual. The reconstruction results of two phantom experiments demonstrate that the proposed method is feasible for limited-projection FMT. © 2011 Optical Society of America

  13. Image-guided cancer surgery using near-infrared fluorescence

    Science.gov (United States)

    Vahrmeijer, Alexander L.; Hutteman, Merlijn; van der Vorst, Joost R.; van de Velde, C.J.H.; Frangioni, John V.

    2013-01-01

    Paradigm shifts in surgery arise when surgeons are empowered to perform surgery faster, better, and/or less expensively. Optical imaging that exploits invisible near-infrared fluorescent light has the potential to improve cancer surgery outcomes while minimizing anesthesia time and lowering healthcare costs. Because of this, the last few years have witnessed an explosion of proof-of-concept clinical trials in the field. In this review, we introduce the concept of near-infrared fluorescence imaging for cancer surgery, review the clinical trial literature to date, outline the key issues pertaining to imaging system and contrast agent optimization, discuss limitations and leverage, and provide a framework for making the technology available for the routine care of cancer patients in the near future. PMID:23881033

  14. A guide for approval of x-ray fluorescence analysis devices

    International Nuclear Information System (INIS)

    1990-01-01

    This guide has been written to assist manufacturers, distributors and users of x-ray fluorescence analysis devices in the preparation of a submission to the Atomic Energy Control Board (AECB) in support of a request for approval of an x-ray fluorescence analysis device. Prior to the issuance of a Radioisotope licence authorizing the use or possession of an x-ray fluorescence analysis device in Canada, the design and construction of the device must be approved by the AECB. The AECB assessment is limited to the radiation safety aspects of use and packaging for transportation

  15. Patch-based anisotropic diffusion scheme for fluorescence diffuse optical tomography--part 2: image reconstruction.

    Science.gov (United States)

    Correia, Teresa; Koch, Maximilian; Ale, Angelique; Ntziachristos, Vasilis; Arridge, Simon

    2016-02-21

    Fluorescence diffuse optical tomography (fDOT) provides 3D images of fluorescence distributions in biological tissue, which represent molecular and cellular processes. The image reconstruction problem is highly ill-posed and requires regularisation techniques to stabilise and find meaningful solutions. Quadratic regularisation tends to either oversmooth or generate very noisy reconstructions, depending on the regularisation strength. Edge preserving methods, such as anisotropic diffusion regularisation (AD), can preserve important features in the fluorescence image and smooth out noise. However, AD has limited ability to distinguish an edge from noise. We propose a patch-based anisotropic diffusion regularisation (PAD), where regularisation strength is determined by a weighted average according to the similarity between patches around voxels within a search window, instead of a simple local neighbourhood strategy. However, this method has higher computational complexity and, hence, we wavelet compress the patches (PAD-WT) to speed it up, while simultaneously taking advantage of the denoising properties of wavelet thresholding. Furthermore, structural information can be incorporated into the image reconstruction with PAD-WT to improve image quality and resolution. In this case, the weights used to average voxels in the image are calculated using the structural image, instead of the fluorescence image. The regularisation strength depends on both structural and fluorescence images, which guarantees that the method can preserve fluorescence information even when it is not structurally visible in the anatomical images. In part 1, we tested the method using a denoising problem. Here, we use simulated and in vivo mouse fDOT data to assess the algorithm performance. Our results show that the proposed PAD-WT method provides high quality and noise free images, superior to those obtained using AD.

  16. Image navigation as a means to expand the boundaries of fluorescence-guided surgery.

    Science.gov (United States)

    Brouwer, Oscar R; Buckle, Tessa; Bunschoten, Anton; Kuil, Joeri; Vahrmeijer, Alexander L; Wendler, Thomas; Valdés-Olmos, Renato A; van der Poel, Henk G; van Leeuwen, Fijs W B

    2012-05-21

    Hybrid tracers that are both radioactive and fluorescent help extend the use of fluorescence-guided surgery to deeper structures. Such hybrid tracers facilitate preoperative surgical planning using (3D) scintigraphic images and enable synchronous intraoperative radio- and fluorescence guidance. Nevertheless, we previously found that improved orientation during laparoscopic surgery remains desirable. Here we illustrate how intraoperative navigation based on optical tracking of a fluorescence endoscope may help further improve the accuracy of hybrid surgical guidance. After feeding SPECT/CT images with an optical fiducial as a reference target to the navigation system, optical tracking could be used to position the tip of the fluorescence endoscope relative to the preoperative 3D imaging data. This hybrid navigation approach allowed us to accurately identify marker seeds in a phantom setup. The multispectral nature of the fluorescence endoscope enabled stepwise visualization of the two clinically approved fluorescent dyes, fluorescein and indocyanine green. In addition, the approach was used to navigate toward the prostate in a patient undergoing robot-assisted prostatectomy. Navigation of the tracked fluorescence endoscope toward the target identified on SPECT/CT resulted in real-time gradual visualization of the fluorescent signal in the prostate, thus providing an intraoperative confirmation of the navigation accuracy.

  17. Evaluation of dental enamel caries assessment using Quantitative Light Induced Fluorescence and Optical Coherence Tomography.

    Science.gov (United States)

    Maia, Ana Marly Araújo; de Freitas, Anderson Zanardi; de L Campello, Sergio; Gomes, Anderson Stevens Leônidas; Karlsson, Lena

    2016-06-01

    An in vitro study of morphological alterations between sound dental structure and artificially induced white spot lesions in human teeth, was performed through the loss of fluorescence by Quantitative Light-Induced Fluorescence (QLF) and the alterations of the light attenuation coefficient by Optical Coherence Tomography (OCT). To analyze the OCT images using a commercially available system, a special algorithm was applied, whereas the QLF images were analyzed using the software available in the commercial system employed. When analyzing the sound region against white spot lesions region by QLF, a reduction in the fluorescence intensity was observed, whilst an increase of light attenuation by the OCT system occurred. Comparison of the percentage of alteration between optical properties of sound and artificial enamel caries regions showed that OCT processed images through the attenuation of light enhanced the tooth optical alterations more than fluorescence detected by QLF System. QLF versus OCT imaging of enamel caries: a photonics assessment. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. Quantitative performance characterization of three-dimensional noncontact fluorescence molecular tomography

    Science.gov (United States)

    Favicchio, Rosy; Psycharakis, Stylianos; Schönig, Kai; Bartsch, Dusan; Mamalaki, Clio; Papamatheakis, Joseph; Ripoll, Jorge; Zacharakis, Giannis

    2016-02-01

    Fluorescent proteins and dyes are routine tools for biological research to describe the behavior of genes, proteins, and cells, as well as more complex physiological dynamics such as vessel permeability and pharmacokinetics. The use of these probes in whole body in vivo imaging would allow extending the range and scope of current biomedical applications and would be of great interest. In order to comply with a wide variety of application demands, in vivo imaging platform requirements span from wide spectral coverage to precise quantification capabilities. Fluorescence molecular tomography (FMT) detects and reconstructs in three dimensions the distribution of a fluorophore in vivo. Noncontact FMT allows fast scanning of an excitation source and noninvasive measurement of emitted fluorescent light using a virtual array detector operating in free space. Here, a rigorous process is defined that fully characterizes the performance of a custom-built horizontal noncontact FMT setup. Dynamic range, sensitivity, and quantitative accuracy across the visible spectrum were evaluated using fluorophores with emissions between 520 and 660 nm. These results demonstrate that high-performance quantitative three-dimensional visible light FMT allowed the detection of challenging mesenteric lymph nodes in vivo and the comparison of spectrally distinct fluorescent reporters in cell culture.

  19. Comparison tomography relocation hypocenter grid search and guided grid search method in Java island

    International Nuclear Information System (INIS)

    Nurdian, S. W.; Adu, N.; Palupi, I. R.; Raharjo, W.

    2016-01-01

    The main data in this research is earthquake data recorded from 1952 to 2012 with 9162 P wave and 2426 events are recorded by 30 stations located around Java island. Relocation hypocenter processed using grid search and guidded grid search method. Then the result of relocation hypocenter become input for tomography pseudo bending inversion process. It can be used to identification the velocity distribution in subsurface. The result of relocation hypocenter by grid search and guided grid search method after tomography process shown in locally and globally. In locally area grid search method result is better than guided grid search according to geological reseach area. But in globally area the result of guided grid search method is better for a broad area because the velocity variation is more diverse than the other one and in accordance with local geological research conditions. (paper)

  20. Computed tomography-guided percutaneous core needle biopsy of deep seated bone lesions in two dogs

    International Nuclear Information System (INIS)

    Mori, T.; Sakaida, M.; Yamada, M.; Akiyama, H.; Takai, Y.; Sakai, H.; Maruo, K.

    2006-01-01

    Computed Tomography (CT)-guided percutaneous core needle biopsies were undertaken for the diagnosis of osteosarcoma in the pelvis (case 1) and myeloma (case 2) in the seventh lumber vertebra which were difficult to targeted by palpation, ultrasound or fluoroscopy. In both cases, enough tissue for pathological diagnosis were obtained without any complication. CT-guided biopsy was thought to be a safe, easy and effective technique for the evaluation of the deep seated bone lesion

  1. Fluorescent x-ray computed tomography with synchrotron radiation using fan collimator

    Science.gov (United States)

    Takeda, Tohoru; Akiba, Masahiro; Yuasa, Tetsuya; Kazama, Masahiro; Hoshino, Atsunori; Watanabe, Yuuki; Hyodo, Kazuyuki; Dilmanian, F. Avraham; Akatsuka, Takao; Itai, Yuji

    1996-04-01

    We describe a new system of fluorescent x-ray computed tomography applied to image nonradioactive contrast materials in vivo. The system operates on the basis of computed tomography (CT) of the first generation. The experiment was also simulated using the Monte Carlo method. The research was carried out at the BLNE-5A bending-magnet beam line of the Tristan Accumulation Ring in Kek, Japan. An acrylic cylindrical phantom containing five paraxial channels of 5 and 4 mm diameters was imaged. The channels were filled with a diluted iodine-based contrast material, with iodine concentrations of 2 mg/ml and 500 (mu) g/ml. Spectra obtained with the system's high purity germanium (HPGe) detector separated clearly the K(alpha ) and K(beta 1) x-ray fluorescent lines, and the Compton scattering. CT images were reconstructed from projections generated by integrating the counts in these spectral lines. The method had adequate sensitivity and detection power, as shown by the experiment and predicted by the simulations, to show the iodine content of the phantom channels, which corresponded to 1 and 4 (mu) g iodine content per pixel in the reconstructed images.

  2. Fluorescent X-ray computed tomography using synchrotron radiation for imaging nonradioactive tracer materials

    Energy Technology Data Exchange (ETDEWEB)

    Akiba, Masahiro; Yuasa, Tetsuya; Uchida, Akira; Akatsuka, Takao [Yamagata Univ., Yonezawa (Japan). Electrical and Information of Engineering; Takeda, Tohoru; Hyodo, Kazuyuki; Itai, Yuji

    1997-09-01

    We describe a system of fluorescent X-ray computed tomography using synchrotron radiation (SR-FXCT) to image nonradioactive contrast materials. The system operates on the basis of computed tomography (CT) scanned by the pencil beam. In the previous experiment, we have imaged an acrylic cylindrical phantom with cross-shaped channel, filled with a diluted iodine-based tracer material of 200 {mu}g/ml. This research is aimed to improve image quality, to select the optimum energy of the incident X-ray, to confirm quantitative evaluation of the image, and to demonstrate FXCT image for living body. First, we simulated output energy profile by the Monte Carlo simulation and confirmed to predetermine the incident X-ray energy at 37 keV, in order to separate the fluorescent photons from background scattering components. Next, the imaging experiment was performed by using conventional CT algorithm under the optimum parameter at the Tristan Accumulation Ring, KEK, Japan. An acrylic phantom containing five paraxial channels of 5 and 4 mm in diameter, could be imaged; where each channel was respectively filled with diluted iodine-based contrast materials of 50, 100, 200 and 500 {mu}g/ml. From the reconstructed image, we confirmed quantitativity in the FXCT image. Finally, a rat`s brain was imaged in vitro by FXCT and monochromatic transmission CT. The comparison between these results showed that the iodine-rich region in the FXCT image corresponded with that in the monochromatic transmission CT image. (author)

  3. Study of continuous-wave domain fluorescence diffuse optical tomography for quality control on agricultural produce

    Energy Technology Data Exchange (ETDEWEB)

    Nadhira, Vebi, E-mail: vebi@tf.itb.ac.id; Kurniadi, Deddy, E-mail: vebi@tf.itb.ac.id; Juliastuti, E., E-mail: vebi@tf.itb.ac.id; Sutiswan, Adeline, E-mail: vebi@tf.itb.ac.id [Instrumentation and Control Research Group, Faculty of Industrial Technology, Institute Technology of Bandung, Ganesha 10 40132 Bandung (Indonesia)

    2014-03-24

    The importance of monitoring the quality of vegetables and fruits is prosperity by giving a competitive advantage for producer and providing a more healthy food for consumer. Diffuse Optical Tomography (DOT) is offering the possibility to detect the internal defects of the agricultural produce quality. Fluorescence diffuse optical tomography (FDOT) is the development of DOT, offering the possibilities to improve spatial resolution and to contrast image. The purpose of this research is to compare FDOT and DOT in forward analysis with continuous wave approach. The scattering and absorbing parameters of potatoes are used to represent the real condition. The object was illuminated by the NIR source from some positions on the boundary of object. A set of NIR detector are placed on the peripheral position of the object to measure the intensity of propagated or emitted light. In the simulation, we varied a condition of object then we analyzed the sensitivity of forward problem. The result of this study shows that FDOT has a better sensitivity than DOT and a better potential to monitor internal defects of agricultural produce because of the contrast value between optical and fluorescence properties of agricultural produce normal tissue and defects.

  4. Fluorescence diffuse optical tomography: benefits of using the time-resolved modality

    International Nuclear Information System (INIS)

    Ducros, Nicolas

    2009-01-01

    Fluorescence diffuse optical tomography enables the three-dimensional reconstruction of fluorescence markers injected within a biological tissue, with light in the near infrared range. The simple continuous modality uses steady excitation light and operates from the measurements at different positions of the attenuation of the incident beam. This technique is low-cost, non-ionizing, and easy to handle, but subject to low resolution for thick tissues due to diffusion. Hopefully, the time-resolved modality, which provides the time of flight of any detected photon, could overcome this limitation and pave the way to clinical applications. This thesis aims at determining the best way to exploit the time resolved information and at quantifying the advantages of this modality over the standard continuous wave one. Model deviations must be carefully limited when ill-posed problems as fluorescence diffuse optical tomography are considered. As a result, we have first addressed the modelling part of the problem. We have shown that the photons density models to good approximation the measurable quantity that is the quantity measured by an actual acquisition set-up. Then, the moment-based reconstruction scheme has been thoroughly evaluated by means of a theoretical analysis of the moments properties. It was found that the moment-based approach requires high photon counts to be profitable compared to the continuous wave modality. Last, a novel wavelet-based approach, which enables an improved reconstruction quality, has been introduced. This approach has shown good ability to exploit the temporal information at lower photon counts. (author) [fr

  5. Fluorescent x-ray computed tomography to visualize specific material distribution

    Science.gov (United States)

    Takeda, Tohoru; Yuasa, Tetsuya; Hoshino, Atsunori; Akiba, Masahiro; Uchida, Akira; Kazama, Masahiro; Hyodo, Kazuyuki; Dilmanian, F. Avraham; Akatsuka, Takao; Itai, Yuji

    1997-10-01

    Fluorescent x-ray computed tomography (FXCT) is being developed to detect non-radioactive contrast materials in living specimens. The FXCT systems consists of a silicon channel cut monochromator, an x-ray slit and a collimator for detection, a scanning table for the target organ and an x-ray detector for fluorescent x-ray and transmission x-ray. To reduce Compton scattering overlapped on the K(alpha) line, incident monochromatic x-ray was set at 37 keV. At 37 keV Monte Carlo simulation showed almost complete separation between Compton scattering and the K(alpha) line. Actual experiments revealed small contamination of Compton scattering on the K(alpha) line. A clear FXCT image of a phantom was obtained. Using this system the minimal detectable dose of iodine was 30 ng in a volume of 1 mm3, and a linear relationship was demonstrated between photon counts of fluorescent x-rays and the concentration of iodine contrast material. The use of high incident x-ray energy allows an increase in the signal to noise ratio by reducing the Compton scattering on the K(alpha) line.

  6. Three-dimensional simultaneous optical coherence tomography and confocal fluorescence microscopy for investigation of lung tissue.

    Science.gov (United States)

    Gaertner, Maria; Cimalla, Peter; Meissner, Sven; Kuebler, Wolfgang M; Koch, Edmund

    2012-07-01

    Although several strategies exist for a minimal-invasive treatment of patients with lung failure, the mortality rate of acute respiratory distress syndrome still reaches 30% at minimum. This striking number indicates the necessity of understanding lung dynamics on an alveolar level. To investigate the dynamical behavior on a microscale, we used three-dimensional geometrical and functional imaging to observe tissue parameters including alveolar size and length of embedded elastic fibers during ventilation. We established a combined optical coherence tomography (OCT) and confocal fluorescence microscopy system that is able to monitor the distension of alveolar tissue and elastin fibers simultaneously within three dimensions. The OCT system can laterally resolve a 4.9 μm line pair feature and has an approximately 11 μm full-width-half-maximum axial resolution in air. confocal fluorescence microscopy visualizes molecular properties of the tissue with a resolution of 0.75 μm (laterally), and 5.9 μm (axially) via fluorescence detection of the dye sulforhodamine B specifically binding to elastin. For system evaluation, we used a mouse model in situ to perform lung distension by application of different constant pressure values within the physiological regime. Our method enables the investigation of alveolar dynamics by helping to reveal basic processes emerging during artificial ventilation and breathing.

  7. Computed tomography-guided percutaneous biopsy of pancreatic masses using pneumodissection

    Directory of Open Access Journals (Sweden)

    Chiang Jeng Tyng

    2013-06-01

    Full Text Available Objective To describe the technique of computed tomography-guided percutaneous biopsy of pancreatic tumors with pneumodissection. Materials and Methods In the period from June 2011 to May 2012, seven computed tomography-guided percutaneous biopsies of pancreatic tumors utilizing pneumodissection were performed in the authors' institution. All the procedures were performed with an automatic biopsy gun and coaxial system with Tru-core needles. The biopsy specimens were histologically assessed. Results In all the cases the pancreatic mass could not be directly approached by computed tomography without passing through major organs and structures. The injection of air allowed the displacement of adjacent structures and creation of a safe coaxial needle pathway toward the lesion. Biopsy was successfully performed in all the cases, yielding appropriate specimens for pathological analysis. Conclusion Pneumodissection is a safe, inexpensive and technically easy approach to perform percutaneous biopsy in selected cases where direct access to the pancreatic tumor is not feasible.

  8. Computed tomography-guided percutaneous biopsy of pancreatic masses using pneumodissection

    International Nuclear Information System (INIS)

    Tyng, Chiang Jeng; Bitencourt, Almir Galvao Vieira; Almeida, Maria Fernanda Arruda; Barbosa, Paula Nicole Vieira; Martins, Eduardo Bruno Lobato; Junior, Joao Paulo Kawaoka Matushita; Chojniak, Rubens; Coimbra, Felipe Jose Fernandez

    2013-01-01

    Objective: to describe the technique of computed tomography-guided percutaneous biopsy of pancreatic tumors with pneumodissection. Materials and methods: in the period from June 2011 to May 2012, seven computed tomography guided percutaneous biopsies of pancreatic tumors utilizing pneumodissection were performed in the authors' institution. All the procedures were performed with an automatic biopsy gun and coaxial system with Tru-core needles. The biopsy specimens were histologically assessed. Results: in all the cases the pancreatic mass could not be directly approached by computed tomography without passing through major organs and structures. The injection of air allowed the displacement of adjacent structures and creation of a safe coaxial needle pathway toward the lesion. Biopsy was successfully performed in all the cases, yielding appropriate specimens for pathological analysis. Conclusion: Pneumodissection is a safe, inexpensive and technically easy approach to perform percutaneous biopsy in selected cases where direct access to the pancreatic tumor is not feasible. (author)

  9. Multi-spectral and fluorescence diffuse optical tomography of breast cancer

    Science.gov (United States)

    Corlu, Alper

    Multi-spectral and fluorescence diffuse optical tomography (DOT) techniques are explored and applied to image human breast cancer in vivo. Image reconstruction algorithms that utilize first and second order gradient information are described in detail. Breast DOT requires large computational memory and long run times. To this end, parallel computation techniques were developed appropriate to each reconstruction algorithm. A parallel plate DOT instrument developed for breast cancer imaging is described. The system relies heavily on continuous-wave (CW) transmission measurements and utilizes frequency domain (FD) measurements on the reemission side. However, traditional DOT image reconstruction methods based on CW measurements fail to separate tissue absorption and scattering uniquely. In this manuscript, multi-spectral DOT is shown to be capable of minimizing cross-talk and retrieving spectral parameters almost uniquely when the measurement wavelengths are optimized. A theoretical framework to select optimum wavelengths is provided, and tested with computer simulations. Results from phantom spectroscopy experiments and in vivo patient measurements support the notion that multi-spectral methods are superior to traditional DOT image reconstruction schemes. The same breast DOT instrument is improved and utilized to obtain the first in vivo images of human breast cancer based on fluorescence DOT (FDOT). To this end the fluorophore Indocyanine Green (ICG) is injected intravenously and fluorescence excitation and detection are accomplished in the soft-compression, parallel-plane, transmission geometry using laser sources at 786 nm and spectrally filtered CCD detection. Careful phantom and in vivo measurements are carried on to assure that the signals are due to ICG fluorescence, rather than tissue autofluorescence and excitation light leakage. An in vivo measurement protocol is designed to maximize the ICG contrast by acquiring full fluorescence tomographic scan during

  10. Feasibility of Computed Tomography-Guided Methods for Spatial Normalization of Dopamine Transporter Positron Emission Tomography Image.

    Science.gov (United States)

    Kim, Jin Su; Cho, Hanna; Choi, Jae Yong; Lee, Seung Ha; Ryu, Young Hoon; Lyoo, Chul Hyoung; Lee, Myung Sik

    2015-01-01

    Spatial normalization is a prerequisite step for analyzing positron emission tomography (PET) images both by using volume-of-interest (VOI) template and voxel-based analysis. Magnetic resonance (MR) or ligand-specific PET templates are currently used for spatial normalization of PET images. We used computed tomography (CT) images acquired with PET/CT scanner for the spatial normalization for [18F]-N-3-fluoropropyl-2-betacarboxymethoxy-3-beta-(4-iodophenyl) nortropane (FP-CIT) PET images and compared target-to-cerebellar standardized uptake value ratio (SUVR) values with those obtained from MR- or PET-guided spatial normalization method in healthy controls and patients with Parkinson's disease (PD). We included 71 healthy controls and 56 patients with PD who underwent [18F]-FP-CIT PET scans with a PET/CT scanner and T1-weighted MR scans. Spatial normalization of MR images was done with a conventional spatial normalization tool (cvMR) and with DARTEL toolbox (dtMR) in statistical parametric mapping software. The CT images were modified in two ways, skull-stripping (ssCT) and intensity transformation (itCT). We normalized PET images with cvMR-, dtMR-, ssCT-, itCT-, and PET-guided methods by using specific templates for each modality and measured striatal SUVR with a VOI template. The SUVR values measured with FreeSurfer-generated VOIs (FSVOI) overlaid on original PET images were also used as a gold standard for comparison. The SUVR values derived from all four structure-guided spatial normalization methods were highly correlated with those measured with FSVOI (P normalization methods provided reliable striatal SUVR values comparable to those obtained with MR-guided methods. CT-guided methods can be useful for analyzing dopamine transporter PET images when MR images are unavailable.

  11. A Comparison of Endoscopic Ultrasound Guided Biopsy and Positron Emission Tomography with Integrated Computed Tomography in Lung Cancer Staging

    DEFF Research Database (Denmark)

    Larsen, Stine Schmidt; Vilmann, P; Krasnik, K

    2009-01-01

    BACKGROUND AND STUDY AIMS: Exact staging of patients with non-small-cell lung cancer (NSCLC) is important to improve selection of resectable and curable patients for surgery. Positron emission tomography with integrated computed tomography (PET/CT) and endoscopic ultrasound guided fine needle...... aspiration biopsy (EUS-FNA) are new and promising methods, but indications in lung cancer staging are controversial. Only few studies have compared the 2 methods. The aim of this study was to assess and compare the diagnostic values of PET/CT and EUS-FNA for diagnosing advanced lung cancer in patients, who...... had both procedures performed. PATIENTS AND METHODS: 27 patients considered to be potential candidates for resection of NSCLC underwent PET/CT and EUS-FNA. Diagnoses were confirmed either by open thoracotomy, mediastinoscopy or clinical follow-up. Advanced lung cancer was defined as tumour...

  12. Fluorescence guided lymph node biopsy in large animals using direct image projection device

    Science.gov (United States)

    Ringhausen, Elizabeth; Wang, Tylon; Pitts, Jonathan; Akers, Walter J.

    2016-03-01

    The use of fluorescence imaging for aiding oncologic surgery is a fast growing field in biomedical imaging, revolutionizing open and minimally invasive surgery practices. We have designed, constructed, and tested a system for fluorescence image acquisition and direct display on the surgical field for fluorescence guided surgery. The system uses a near-infrared sensitive CMOS camera for image acquisition, a near-infra LED light source for excitation, and DLP digital projector for projection of fluorescence image data onto the operating field in real time. Instrument control was implemented in Matlab for image capture, processing of acquired data and alignment of image parameters with the projected pattern. Accuracy of alignment was evaluated statistically to demonstrate sensitivity to small objects and alignment throughout the imaging field. After verification of accurate alignment, feasibility for clinical application was demonstrated in large animal models of sentinel lymph node biopsy. Indocyanine green was injected subcutaneously in Yorkshire pigs at various locations to model sentinel lymph node biopsy in gynecologic cancers, head and neck cancer, and melanoma. Fluorescence was detected by the camera system during operations and projected onto the imaging field, accurately identifying tissues containing the fluorescent tracer at up to 15 frames per second. Fluorescence information was projected as binary green regions after thresholding and denoising raw intensity data. Promising results with this initial clinical scale prototype provided encouraging results for the feasibility of optical projection of acquired luminescence during open oncologic surgeries.

  13. A Conjugate of Pentamethine Cyanine and 18F as a Positron Emission Tomography/Near-Infrared Fluorescence Probe for Multimodality Tumor Imaging

    Directory of Open Access Journals (Sweden)

    Fei-Fei An

    2017-06-01

    Full Text Available The novel synthesis of a dual-modality, pentamethine cyanine (Cy5 fluorescent, 18F positron emission tomography (PET imaging probe is reported. The probe shows a large extinction coefficient and large quantum yield in the biologically transparent, near-infrared window (650–900 nm for in vivo fluorescent imaging. This fluorophore bears the isotope, 18F, giving a 18F-PET/near-infrared fluorescent (NIRF, bi-modal imaging probe, that combines the long-term stability of NIRF and the unlimited penetration depth of PET imaging. The bi-modal probe is labeled with 18F in a quick, one-step reaction, which is important in working with the rapid decay of 18F. The bi-modal probe bears a free carboxyl group, highlighting a PET/NIRF synthon that can be conjugated onto many advanced biomolecules for biomarker-specific in vivo dual-modal PET/NIR tumor imaging, confocal histology, and utility in multi-fluorophore, fluorescence-guided surgery. Its potential in vivo biocompatibility is explored in a quick proof-of-principal in vivo study. The dye is delivered to A549 xenograft flank-tumors to generate PET and NIRF signals at the tumor site. The tumor distribution is confirmed in ex vivo gamma counting and imaging. Pentamethine cyanine (Cy5 has the ability to preferentially accumulate in tumor xenografts. We substitute the PET/NIRF probe for Cy5, and explore this phenomenon.

  14. Real-time Fluorescence Image-Guided Oncologic Surgery

    Science.gov (United States)

    Mondal, Suman B.; Gao, Shengkui; Zhu, Nan; Liang, Rongguang; Gruev, Viktor; Achilefu, Samuel

    2014-01-01

    Medical imaging plays a critical role in cancer diagnosis and planning. Many of these patients rely on surgical intervention for curative outcomes. This requires a careful identification of the primary and microscopic tumors, and the complete removal of cancer. Although there have been efforts to adapt traditional imaging modalities for intraoperative image guidance, they suffer from several constraints such as large hardware footprint, high operation cost, and disruption of the surgical workflow. Because of the ease of image acquisition, relatively low cost devices and intuitive operation, optical imaging methods have received tremendous interests for use in real-time image-guided surgery. To improve imaging depth under low interference by tissue autofluorescence, many of these applications utilize light in the near-infra red (NIR) wavelengths, which is invisible to human eyes. With the availability of a wide selection of tumor-avid contrast agents, advancements in imaging sensors, electronic and optical designs, surgeons are able to combine different attributes of NIR optical imaging techniques to improve treatment outcomes. The emergence of diverse commercial and experimental image guidance systems, which are in various stages of clinical translation, attests to the potential high impact of intraoperative optical imaging methods to improve speed of oncologic surgery with high accuracy and minimal margin positivity. PMID:25287689

  15. Optimization and performance evaluation of a conical mirror based fluorescence molecular tomography imaging system

    Science.gov (United States)

    Zhao, Yue; Zhang, Wei; Zhu, Dianwen; Li, Changqing

    2016-03-01

    We performed numerical simulations and phantom experiments with a conical mirror based fluorescence molecular tomography (FMT) imaging system to optimize its performance. With phantom experiments, we have compared three measurement modes in FMT: the whole surface measurement mode, the transmission mode, and the reflection mode. Our results indicated that the whole surface measurement mode performed the best. Then, we applied two different neutral density (ND) filters to improve the measurement's dynamic range. The benefits from ND filters are not as much as predicted. Finally, with numerical simulations, we have compared two laser excitation patterns: line and point. With the same excitation position number, we found that the line laser excitation had slightly better FMT reconstruction results than the point laser excitation. In the future, we will implement Monte Carlo ray tracing simulations to calculate multiple reflection photons, and create a look-up table accordingly for calibration.

  16. The lymphatic mechanisms of brain cleaning: application of optical coherence tomography and fluorescence microscopy

    Science.gov (United States)

    Glushkovskaya-Semyachkina, O.; Abdurashitov, A.; Fedosov, I.; Namykin, A.; Pavlov, A.; Shirokov, A.; Shushunova, N.; Sindeeva, O.; Khorovodov, A.; Ulanova, M.; Sagatova, V.; Agranovich, I.; Bodrova, A.; Kurths, J.

    2018-04-01

    Here we studied the role of cerebral lymphatic system in the brain clearing using intraparenchymal injection of Evans Blue and gold nanorods assessed by optical coherent tomography and fluorescence microscopy. Our data clearly show that the cerebral lymphatic system plays an important role in the brain cleaning via meningeal lymphatic vessels but not cerebral veins. Meningeal lymphatic vessels transport fluid from the brain into the deep cervical node, which is the first anatomical "station" for lymph outflow from the brain. The lymphatic processes underlying brain clearing are more slowly vs. peripheral lymphatics. These results shed light on the lymphatic mechanisms responsible for brain clearing as well as interaction between the intra- and extracranial lymphatic compartment.

  17. A penalized linear and nonlinear combined conjugate gradient method for the reconstruction of fluorescence molecular tomography.

    Science.gov (United States)

    Shang, Shang; Bai, Jing; Song, Xiaolei; Wang, Hongkai; Lau, Jaclyn

    2007-01-01

    Conjugate gradient method is verified to be efficient for nonlinear optimization problems of large-dimension data. In this paper, a penalized linear and nonlinear combined conjugate gradient method for the reconstruction of fluorescence molecular tomography (FMT) is presented. The algorithm combines the linear conjugate gradient method and the nonlinear conjugate gradient method together based on a restart strategy, in order to take advantage of the two kinds of conjugate gradient methods and compensate for the disadvantages. A quadratic penalty method is adopted to gain a nonnegative constraint and reduce the illposedness of the problem. Simulation studies show that the presented algorithm is accurate, stable, and fast. It has a better performance than the conventional conjugate gradient-based reconstruction algorithms. It offers an effective approach to reconstruct fluorochrome information for FMT.

  18. Molecular imaging needles: dual-modality optical coherence tomography and fluorescence imaging of labeled antibodies deep in tissue

    Science.gov (United States)

    Scolaro, Loretta; Lorenser, Dirk; Madore, Wendy-Julie; Kirk, Rodney W.; Kramer, Anne S.; Yeoh, George C.; Godbout, Nicolas; Sampson, David D.; Boudoux, Caroline; McLaughlin, Robert A.

    2015-01-01

    Molecular imaging using optical techniques provides insight into disease at the cellular level. In this paper, we report on a novel dual-modality probe capable of performing molecular imaging by combining simultaneous three-dimensional optical coherence tomography (OCT) and two-dimensional fluorescence imaging in a hypodermic needle. The probe, referred to as a molecular imaging (MI) needle, may be inserted tens of millimeters into tissue. The MI needle utilizes double-clad fiber to carry both imaging modalities, and is interfaced to a 1310-nm OCT system and a fluorescence imaging subsystem using an asymmetrical double-clad fiber coupler customized to achieve high fluorescence collection efficiency. We present, to the best of our knowledge, the first dual-modality OCT and fluorescence needle probe with sufficient sensitivity to image fluorescently labeled antibodies. Such probes enable high-resolution molecular imaging deep within tissue. PMID:26137379

  19. A generic, geometric cocalibration method for a combined system of fluorescence molecular tomography and microcomputed tomography with arbitrarily shaped objects

    International Nuclear Information System (INIS)

    Fu Jianwei; Yang Xiaoquan; Wang Kan; Luo Qingming; Gong Hui

    2011-01-01

    Purpose: A combined system of fluorescence molecular tomography and microcomputed tomography (FMT and mCT) can provide molecular and anatomical information of small animals in a single study with intrinsically coregistered images. The anatomical information provided by the mCT subsystem is commonly used as a reference to locate the fluorophore distribution or as a priori structural information to improve the performance of FMT. Therefore, the transformation between the coordinate systems of the subsystem needs to be determined in advanced. Methods: A cocalibration method for the combined system of FMT and mCT is proposed. First, linear models are adopted to describe the galvano mirrors and the charge-coupled device (CCD) camera in the FMT subsystem. Second, the position and orientation of the galvano mirrors are determined with the input voltages of the galvano mirrors and the markers, whose positions are predetermined. The position, orientation and normalized pixel size of the CCD camera are obtained by analysing the projections of a point-like marker at different positions. Finally, the orientation and position of sources and the corresponding relationship between the detectors and their projections on the image plane are predicted. Because the positions of the markers are acquired with mCT, the registration of the FMT and mCT could be realized by direct image fusion. Results: The accuracy and consistency of this method in the presence of noise is evaluated by computer simulation. Next, a practical implementation for an experimental FMT and mCT system is carried out and validated. The maximum prediction error of the source positions on the surface of a cylindrical phantom is within 0.375 mm and that of the projections of a point-like marker is within 0.629 pixel. Finally, imaging experiments of the fluorophore distribution in a cylindrical phantom and a phantom with a complex shape demonstrate the feasibility of the proposed method. Conclusions: This method is

  20. Adaptation and focusing of optode configurations for fluorescence optical tomography by experimental design methods.

    Science.gov (United States)

    Freiberger, Manuel; Clason, Christian; Scharfetter, Hermann

    2010-01-01

    Fluorescence tomography excites a fluorophore inside a sample by light sources on the surface. From boundary measurements of the fluorescent light, the distribution of the fluorophore is reconstructed. The optode placement determines the quality of the reconstructions in terms of, e.g., resolution and contrast-to-noise ratio. We address the adaptation of the measurement setup. The redundancy of the measurements is chosen as a quality criterion for the optodes and is computed from the Jacobian of the mathematical formulation of light propagation. The algorithm finds a subset with minimum redundancy in the measurements from a feasible pool of optodes. This allows biasing the design in order to favor reconstruction results inside a given region. Two different variations of the algorithm, based on geometric and arithmetic averaging, are compared. Both deliver similar optode configurations. The arithmetic averaging is slightly more stable, whereas the geometric averaging approach shows a better conditioning of the sensitivity matrix and mathematically corresponds more closely with entropy optimization. Adapted illumination and detector patterns are presented for an initial set of 96 optodes placed on a cylinder with focusing on different regions. Examples for the attenuation of fluorophore signals from regions outside the focus are given.

  1. A time-domain fluorescence diffusion optical tomography system for breast tumor diagnosis

    Science.gov (United States)

    Zhang, Wei; Gao, Feng; Wu, LinHui; Ma, Wenjuan; Yang, Fang; Zhou, Zhongxing; Zhang, Limin; Zhao, Huijuan

    2011-02-01

    A prototype time-domain fluorescence diffusion optical tomography (FDOT) system using near-infrared light is presented. The system employs two pulsed light sources, 32 source fibers and 32 detection channels, working separately for acquiring the temporal distribution of the photon flux on the tissue surface. The light sources are provided by low power picosecond pulsed diode lasers at wavelengths of 780 nm and 830 nm, and a 1×32-fiber-optic-switch sequentially directs light sources to the object surface through 32 source fibers. The light signals re-emitted from the object are collected by 32 detection fibers connected to four 8×1 fiber-optic-switch and then routed to four time-resolved measuring channels, each of which consists of a collimator, a filter wheel, a photomultiplier tube (PMT) photon-counting head and a time-correlated single photon counting (TCSPC) channel. The performance and efficacy of the designed multi-channel PMT-TCSPC system are assessed by reconstructing the fluorescent yield and lifetime images of a solid phantom.

  2. Enhanced spatial resolution in fluorescence molecular tomography using restarted L1-regularized nonlinear conjugate gradient algorithm.

    Science.gov (United States)

    Shi, Junwei; Liu, Fei; Zhang, Guanglei; Luo, Jianwen; Bai, Jing

    2014-04-01

    Owing to the high degree of scattering of light through tissues, the ill-posedness of fluorescence molecular tomography (FMT) inverse problem causes relatively low spatial resolution in the reconstruction results. Unlike L2 regularization, L1 regularization can preserve the details and reduce the noise effectively. Reconstruction is obtained through a restarted L1 regularization-based nonlinear conjugate gradient (re-L1-NCG) algorithm, which has been proven to be able to increase the computational speed with low memory consumption. The algorithm consists of inner and outer iterations. In the inner iteration, L1-NCG is used to obtain the L1-regularized results. In the outer iteration, the restarted strategy is used to increase the convergence speed of L1-NCG. To demonstrate the performance of re-L1-NCG in terms of spatial resolution, simulation and physical phantom studies with fluorescent targets located with different edge-to-edge distances were carried out. The reconstruction results show that the re-L1-NCG algorithm has the ability to resolve targets with an edge-to-edge distance of 0.1 cm at a depth of 1.5 cm, which is a significant improvement for FMT.

  3. Validating Intravascular Imaging with Serial Optical Coherence Tomography and Confocal Fluorescence Microscopy.

    Science.gov (United States)

    Tardif, Pier-Luc; Bertrand, Marie-Jeanne; Abran, Maxime; Castonguay, Alexandre; Lefebvre, Joël; Stähli, Barbara E; Merlet, Nolwenn; Mihalache-Avram, Teodora; Geoffroy, Pascale; Mecteau, Mélanie; Busseuil, David; Ni, Feng; Abulrob, Abedelnasser; Rhéaume, Éric; L'Allier, Philippe; Tardif, Jean-Claude; Lesage, Frédéric

    2016-12-15

    Atherosclerotic cardiovascular diseases are characterized by the formation of a plaque in the arterial wall. Intravascular ultrasound (IVUS) provides high-resolution images allowing delineation of atherosclerotic plaques. When combined with near infrared fluorescence (NIRF), the plaque can also be studied at a molecular level with a large variety of biomarkers. In this work, we present a system enabling automated volumetric histology imaging of excised aortas that can spatially correlate results with combined IVUS/NIRF imaging of lipid-rich atheroma in cholesterol-fed rabbits. Pullbacks in the rabbit aortas were performed with a dual modality IVUS/NIRF catheter developed by our group. Ex vivo three-dimensional (3D) histology was performed combining optical coherence tomography (OCT) and confocal fluorescence microscopy, providing high-resolution anatomical and molecular information, respectively, to validate in vivo findings. The microscope was combined with a serial slicer allowing for the imaging of the whole vessel automatically. Colocalization of in vivo and ex vivo results is demonstrated. Slices can then be recovered to be tested in conventional histology.

  4. Intravascular atherosclerotic imaging with combined fluorescence and optical coherence tomography probe based on a double-clad fiber combiner

    Science.gov (United States)

    Liang, Shanshan; Saidi, Arya; Jing, Joe; Liu, Gangjun; Li, Jiawen; Zhang, Jun; Sun, Changsen; Narula, Jagat; Chen, Zhongping

    2012-07-01

    We developed a multimodality fluorescence and optical coherence tomography probe based on a double-clad fiber (DCF) combiner. The probe is composed of a DCF combiner, grin lens, and micromotor in the distal end. An integrated swept-source optical coherence tomography and fluorescence intensity imaging system was developed based on the combined probe for the early diagnoses of atherosclerosis. This system is capable of real-time data acquisition and processing as well as image display. For fluorescence imaging, the inflammation of atherosclerosis and necrotic core formed with the annexin V-conjugated Cy5.5 were imaged. Ex vivo imaging of New Zealand white rabbit arteries demonstrated the capability of the combined system.

  5. Optical coherence tomography in guided surgery of GI cancer

    Science.gov (United States)

    Zagaynova, Elena V.; Abelevich, Alexander I.; Zagaynov, Vladimir E.; Gladkova, Natalia D.; Denisenko, Arkady N.; Feldchtein, Felix I.; Snopova, Ludmila B.; Kutis, Irina S.

    2005-04-01

    Optical Coherence Tomography (OCT) is a new high spatial resolution, real-time optical imaging modality, known from prior pilot studies for its high sensitivity to invasive cancer. We reported our results in an OCT feasibility study for accurate determination of the proximal border for esophageal carcinoma and the distal border for rectal carcinoma. The OCT study enrolled 19 patients with rectal adenocarcinoma and 24 patients with distal esophageal carcinoma (14 squamous cell carcinomas, 10 adenocarcinomas). During pre-surgery planning endoscopy we performed in vivo OCT imaging of the tumor border at four dial clock axes (12, 3, 6 and 9 o"clock). The OCT border then was marked by an electrocoagulator, or by a methylene blue tattoo. A cold biopsy (from the esophagus) was performed at visual and OCT borders and compared with visual and OCT readings. 27 post-surgery excised specimens were analyzed. OCT borders matched the histopathology in 94% cases in the rectum and 83.3% in the esophagus. In the cases of a mismatch between the OCT and histology borders, a deep tumor invasion occurred in the muscle layer (esophagus, rectum). Because of its high sensitivity to mucosal cancer, OCT can be used for pre-surgery planning and surgery guidance of the proximal border for esophageal carcinoma and the distal border for rectal carcinoma. However, deep invasion in the rectum or esophageal wall has to be controlled by alternative diagnostic modalities.

  6. Imaging of pharmacokinetic rates of indocyanine green in mouse liver with a hybrid fluorescence molecular tomography/x-ray computed tomography system.

    Science.gov (United States)

    Zhang, Guanglei; Liu, Fei; Zhang, Bin; He, Yun; Luo, Jianwen; Bai, Jing

    2013-04-01

    Pharmacokinetic rates have the potential to provide quantitative physiological and pathological information for biological studies and drug development. Fluorescence molecular tomography (FMT) is an attractive imaging tool for three-dimensionally resolving fluorophore distribution in small animals. In this letter, pharmacokinetic rates of indocyanine green (ICG) in mouse liver are imaged with a hybrid FMT and x-ray computed tomography (XCT) system. A recently developed FMT method using structural priors from an XCT system is adopted to improve the quality of FMT reconstruction. In the in vivo experiments, images of uptake and excretion rates of ICG in mouse liver are obtained, which can be used to quantitatively evaluate liver function. The accuracy of the results is validated by a fiber-based fluorescence measurement system.

  7. Quantification of thickness loss in a liquid-loaded plate using ultrasonic guided wave tomography

    Science.gov (United States)

    Rao, Jing; Ratassepp, Madis; Fan, Zheng

    2017-12-01

    Ultrasonic guided wave tomography (GWT) provides an attractive solution to map thickness changes from remote locations. It is based on the velocity-to-thickness mapping employing the dispersive characteristics of selected guided modes. This study extends the application of GWT on a liquid-loaded plate. It is a more challenging case than the application on a free plate, due to energy of the guided waves leaking into the liquid. In order to ensure the accuracy of thickness reconstruction, advanced forward models are developed to consider attenuation effects using complex velocities. The reconstruction of the thickness map is based on the frequency-domain full waveform inversion (FWI) method, and its accuracy is discussed using different frequencies and defect dimensions. Validation experiments are carried out on a water-loaded plate with an irregularly shaped defect using S0 guided waves, showing excellent performance of the reconstruction algorithm.

  8. Three-dimensional digitizer (neuronavigator): new equipment for computed tomography-guided stereotaxic surgery.

    Science.gov (United States)

    Watanabe, E; Watanabe, T; Manaka, S; Mayanagi, Y; Takakura, K

    1987-06-01

    A new device was invented as an adjunct for computed tomography (CT)-guided stereotaxic or open neurosurgery. It is composed of a multijoint three-dimensional digitizer (sensor arm) and a microcomputer, which indicates the place of the sensor arm tip on preoperative CT images. Computed tomography scan is performed preoperatively with three markers placed on the nasion and ears. At surgery, after fixing the patient's head and the sensor arm, sampling of the standard points was done to translate the position of the tip of the sensor arm onto the CT images displayed on a computer screen. In this way positional data from conventional preoperative CT scan can be directly transferred into the surgical field. This system has the unique feature of introducing CT-guided stereotaxis into conventional open neurosurgery.

  9. Cranial radiotherapy guided by computed tomography with or without fields conformation in pediatric

    International Nuclear Information System (INIS)

    Fernandez, Diego; Caussa, Lucas; Murina, Patricia; Zunino, Silvia

    2007-01-01

    Many malignancies in children can be cured by radiotherapy, acute toxicity and the significant effect of delayed treatment are worrying for the patient, family and society. Therefore, the end of the pediatric radiotherapy is to maintain or improve the cure rate of cancer, diminishing the aftermath of treatment. The goal of this study is to measure differences in doses to the healthy tissue of the central nervous system with two radiotherapy techniques, both guided by computed tomography [es

  10. Computed tomography-guided core-needle biopsy of lung lesions: an oncology center experience

    Energy Technology Data Exchange (ETDEWEB)

    Guimaraes, Marcos Duarte; Fonte, Alexandre Calabria da; Chojniak, Rubens, E-mail: marcosduarte@yahoo.com.b [Hospital A.C. Camargo, Sao Paulo, SP (Brazil). Dept. of Radiology and Imaging Diagnosis; Andrade, Marcony Queiroz de [Hospital Alianca, Salvador, BA (Brazil); Gross, Jefferson Luiz [Hospital A.C. Camargo, Sao Paulo, SP (Brazil). Dept. of Chest Surgery

    2011-03-15

    Objective: The present study is aimed at describing the experience of an oncology center with computed tomography guided core-needle biopsy of pulmonary lesions. Materials and Methods: Retrospective analysis of 97 computed tomography-guided core-needle biopsy of pulmonary lesions performed in the period between 1996 and 2004 in a Brazilian reference oncology center (Hospital do Cancer - A.C. Camargo). Information regarding material appropriateness and the specific diagnoses were collected and analyzed. Results: Among 97 lung biopsies, 94 (96.9%) supplied appropriate specimens for histological analyses, with 71 (73.2%) cases being diagnosed as malignant lesions and 23 (23.7%) diagnosed as benign lesions. Specimens were inappropriate for analysis in three cases. The frequency of specific diagnosis was 83 (85.6%) cases, with high rates for both malignant lesions with 63 (88.7%) cases and benign lesions with 20 (86.7%). As regards complications, a total of 12 cases were observed as follows: 7 (7.2%) cases of hematoma, 3 (3.1%) cases of pneumothorax and 2 (2.1%) cases of hemoptysis. Conclusion: Computed tomography-guided core needle biopsy of lung lesions demonstrated high rates of material appropriateness and diagnostic specificity, and low rates of complications in the present study. (author)

  11. Development of tumor-targeted near infrared probes for fluorescence guided surgery.

    Science.gov (United States)

    Kelderhouse, Lindsay E; Chelvam, Venkatesh; Wayua, Charity; Mahalingam, Sakkarapalayam; Poh, Scott; Kularatne, Sumith A; Low, Philip S

    2013-06-19

    Complete surgical resection of malignant disease is the only reliable method to cure cancer. Unfortunately, quantitative tumor resection is often limited by a surgeon's ability to locate all malignant disease and distinguish it from healthy tissue. Fluorescence-guided surgery has emerged as a tool to aid surgeons in the identification and removal of malignant lesions. While nontargeted fluorescent dyes have been shown to passively accumulate in some tumors, the resulting tumor-to-background ratios are often poor, and the boundaries between malignant and healthy tissues can be difficult to define. To circumvent these problems, our laboratory has developed high affinity tumor targeting ligands that bind to receptors that are overexpressed on cancer cells and deliver attached molecules selectively into these cells. In this study, we explore the use of two tumor-specific targeting ligands (i.e., folic acid that targets the folate receptor (FR) and DUPA that targets prostate specific membrane antigen (PSMA)) to deliver near-infrared (NIR) fluorescent dyes specifically to FR and PSMA expressing cancers, thereby rendering only the malignant cells highly fluorescent. We report here that all FR- and PSMA-targeted NIR probes examined bind cultured cancer cells in the low nanomolar range. Moreover, upon intravenous injection into tumor-bearing mice with metastatic disease, these same ligand-NIR dye conjugates render receptor-expressing tumor tissues fluorescent, enabling their facile resection with minimal contamination from healthy tissues.

  12. Multimodality Imaging Probe for Positron Emission Tomography and Fluorescence Imaging Studies

    Directory of Open Access Journals (Sweden)

    Suresh K. Pandey

    2014-05-01

    Full Text Available Our goal is to develop multimodality imaging agents for use in cell tracking studies by positron emission tomography (PET and optical imaging (OI. For this purpose, bovine serum albumin (BSA was complexed with biotin (histologic studies, 5(6- carboxyfluorescein, succinimidyl ester (FAM SE (OI studies, and diethylenetriamine pentaacetic acid (DTPA for chelating gallium 68 (PET studies. For synthesis of BSA-biotin-FAM-DTPA, BSA was coupled to (+-biotin N-hydroxysuccinimide ester (biotin-NHSI. BSA- biotin was treated with DTPA-anhydride and biotin-BSA-DTPA was reacted with FAM. The biotin-BSA-DTPA-FAM was reacted with gallium chloride 3 to 5 mCi eluted from the generator using 0.1 N HCl and was passed through basic resin (AG 11 A8 and 150 mCi (100 μL, pH 7–8 was incubated with 0.1 mg of FAM conjugate (100 μL at room temperature for 15 minutes to give 66Ga-BSA-biotin-DTPA-FAM. A shaved C57 black mouse was injected with FAM conjugate (50 μL at one flank and FAM-68Ga (50 μL, 30 mCi at the other. Immediately after injection, the mouse was placed in a fluorescence imaging system (Kodak In-Vivo F, Bruker Biospin Co., Woodbridge, CT and imaged (Λex: 465 nm, Λem: 535 nm, time: 8 seconds, Xenon Light Source, Kodak. The same mouse was then placed under an Inveon microPET scanner (Siemens Medical Solutions, Knoxville, TN injected (intravenously with 25 μCi of 18F and after a half-hour (to allow sufficient bone uptake was imaged for 30 minutes. Molecular weight determined using matrix-associated laser desorption ionization (MALDI for the BSA sample was 66,485 Da and for biotin-BSA was 67,116 Da, indicating two biotin moieties per BSA molecule; for biotin-BSA-DTPA was 81,584 Da, indicating an average of 30 DTPA moieties per BSA molecule; and for FAM conjugate was 82,383 Da, indicating an average of 1.7 fluorescent moieties per BSA molecule. Fluorescence imaging clearly showed localization of FAM conjugate and FAM-68Ga at respective flanks of the mouse

  13. Uncommon primary tumors of the orbit diagnosed by computed tomography-guided core needle biopsy: report of two cases

    Energy Technology Data Exchange (ETDEWEB)

    Tyng, Chiang Jeng; Matushita Junior, Joao Paulo Kawaoka; Bitencourt, Almir Galvao Vieira; Amoedo, Mauricio Kauark; Barbosa, Paula Nicole Vieira; Chojniak, Rubens, E-mail: almirgvb@yahoo.com.br [A.C.Camargo Cancer Center, Sao Paulo, SP (Brazil). Dept. de Imagem; Neves, Flavia Branco Cerqueira Serra [Hospital do Servidor Publico Estadual, Sao Paulo, SP (Brazil). Div. de Oftalmologia

    2014-11-15

    Computed tomography-guided percutaneous biopsy is a safe and effective alternative method for evaluating selected intra-orbital lesions where the preoperative diagnosis is important for the therapeutic planning. The authors describe two cases of patients with uncommon primary orbital tumors whose diagnosis was obtained by means of computed tomography-guided core needle biopsy, with emphasis on the technical aspects of the procedure. (author)

  14. Self-prior strategy for organ reconstruction in fluorescence molecular tomography.

    Science.gov (United States)

    Zhou, Yuan; Chen, Maomao; Su, Han; Luo, Jianwen

    2017-10-01

    The purpose of this study is to propose a strategy for organ reconstruction in fluorescence molecular tomography (FMT) without prior information from other imaging modalities, and to overcome the high cost and ionizing radiation caused by the traditional structural prior strategy. The proposed strategy is designed as an iterative architecture to solve the inverse problem of FMT. In each iteration, a short time Fourier transform (STFT) based algorithm is used to extract the self-prior information in the space-frequency energy spectrum with the assumption that the regions with higher fluorescence concentration have larger energy intensity, then the cost function of the inverse problem is modified by the self-prior information, and lastly an iterative Laplacian regularization algorithm is conducted to solve the updated inverse problem and obtains the reconstruction results. Simulations and in vivo experiments on liver reconstruction are carried out to test the performance of the self-prior strategy on organ reconstruction. The organ reconstruction results obtained by the proposed self-prior strategy are closer to the ground truth than those obtained by the iterative Tikhonov regularization (ITKR) method (traditional non-prior strategy). Significant improvements are shown in the evaluation indexes of relative locational error (RLE), relative error (RE) and contrast-to-noise ratio (CNR). The self-prior strategy improves the organ reconstruction results compared with the non-prior strategy and also overcomes the shortcomings of the traditional structural prior strategy. Various applications such as metabolic imaging and pharmacokinetic study can be aided by this strategy.

  15. Positron Emission Tomography Computed Tomography: A Guide for the General Radiologist.

    Science.gov (United States)

    Beadsmoore, Clare; Newman, David; MacIver, Duncan; Pawaroo, Davina

    2015-11-01

    Cancer remains a leading cause of death in Canada and worldwide. Whilst advances in anatomical imaging to detect and monitor malignant disease have continued over the last few decades, limitations remain. Functional imaging, such as positron emission tomography (PET), has improved the sensitivity and specificity in detecting malignant disease. In combination with computed tomography (CT), PET is now commonly used in the oncology setting and is an integral part of many cancer patients' pathways. Although initially the CT component of the study was purely for attenuation of the PET imaging and to provide anatomical coregistration, many centers now combine the PET study with a diagnostic quality contrast enhanced CT to provide one stop staging, thus refining the patient's pathway. The commonest tracer used in everyday practice is FDG (F18-fluorodeoxyglucose). There are many more tracers in routine clinical practice and those with emerging roles, such as 11C-choline, useful in the imaging of prostate cancer; 11C-methionine, useful in imaging brain tumours; C11-acetate, used in imaging hepatocellular carcinomas; 18F-FLT, which can be used as a marker of cellular proliferation in various malignancies; and F18-DOPA and various 68Ga-somatostatin analogues, used in patients with neuroendocrine tumours. In this article we concentrate on FDG PETCT as this is the most commonly available and widely utilised tracer now used to routinely stage a number of cancers. PETCT alters the stage in approximately one-third of patients compared to anatomical imaging alone. Increasingly, PETCT is being used to assess early metabolic response to treatment. Metabolic response can be seen much earlier than a change in the size/volume of the disease which is measured by standard CT imaging. This can aid treatment decisions in both in terms of modifying therapy and in addition to providing important prognostic information. Furthermore, it is helpful in patients with distorted anatomy from surgery

  16. Guided-wave tomography imaging plate defects by laser-based ultrasonic techniques

    Energy Technology Data Exchange (ETDEWEB)

    Park, Jun Pil; Lim, Ju Young; Cho, Youn Ho [School of Mechanical Engineering, Pusan National University, Pusan (Korea, Republic of)

    2014-12-15

    Contact-guided-wave tests are impractical for investigating specimens with limited accessibility and rough surfaces or complex geometric features. A non-contact setup with a laser-ultrasonic transmitter and receiver is quite attractive for guided-wave inspection. In the present work, we developed a non-contact guided-wave tomography technique using the laser-ultrasonic technique in a plate. A method for Lamb-wave generation and detection in an aluminum plate with a pulsed laser-ultrasonic transmitter and Michelson-interferometer receiver was developed. The defect shape and area in the images obtained using laser scanning, showed good agreement with the actual defect. The proposed approach can be used as a non-contact online inspection and monitoring technique.

  17. Polarized X-ray excitation for scatter reduction in X-ray fluorescence computed tomography.

    Science.gov (United States)

    Vernekohl, Don; Tzoumas, Stratis; Zhao, Wei; Xing, Lei

    2018-05-25

    X-ray fluorescence computer tomography (XFCT) is a new molecular imaging modality which uses X-ray excitation to stimulate the emission of fluorescent photons in high atomic number contrast agents. Scatter contamination is one of the main challenges in XFCT imaging which limits the molecular sensitivity. When polarized X-rays are used, it is possible to reduce the scatter contamination significantly by placing detectors perpendicular to the polarization direction. This study quantifies scatter contamination for polarized and unpolarized X-ray excitation and determines the advantages of scatter reduction. The amount of scatter in preclinical XFCT is quantified in Monte Carlo simulations. The fluorescent X-rays are emitted isotropically, while scattered X-rays propagate in polarization direction. The magnitude of scatter contamination is studied in XFCT simulations of a mouse phantom. In this study, the contrast agent gold is examined as an example but a scatter reduction from polarized excitation is also expected for other elements. The scatter reduction capability is examined for different polarization intensities with a monoenergetic X-ray excitation energy of 82 keV. The study evaluates two different geometrical shapes of CZT detectors which are modeled with an energy resolution of 1 keV FWHM at an X-ray energy of 80 keV. Benefits of a detector placement perpendicular to the polarization direction are shown in iterative and analytic image reconstruction including scatter correction. The contrast to noise ratio (CNR) and the normalized mean square error (NMSE) are analyzed and compared for the reconstructed images. A substantial scatter reduction for common detector sizes was achieved for 100% and 80% linear polarization while lower polarization intensities provide a decreased scatter reduction. By placing the detector perpendicular to the polarization direction, a scatter reduction by factor up to 5.5 can be achieved for common detector sizes. The image

  18. Recent advances in near-infrared fluorescence-guided imaging surgery using indocyanine green.

    Science.gov (United States)

    Namikawa, Tsutomu; Sato, Takayuki; Hanazaki, Kazuhiro

    2015-12-01

    Near-infrared (NIR) fluorescence imaging has better tissue penetration, allowing for the effective rejection of excitation light and detection deep inside organs. Indocyanine green (ICG) generates NIR fluorescence after illumination by an NIR ray, enabling real-time intraoperative visualization of superficial lymphatic channels and vessels transcutaneously. The HyperEye Medical System (HEMS) can simultaneously detect NIR rays under room light to provide color imaging, which enables visualization under bright light. Thus, NIR fluorescence imaging using ICG can provide for excellent diagnostic accuracy in detecting sentinel lymph nodes in cancer and microvascular circulation in various ischemic diseases, to assist us with intraoperative decision making. Including HEMS in this system could further improve the sentinel lymph node mapping and intraoperative identification of blood supply in reconstructive organs and ischemic diseases, making it more attractive than conventional imaging. Moreover, the development of new laparoscopic imaging systems equipped with NIR will allow fluorescence-guided surgery in a minimally invasive setting. Future directions, including the conjugation of NIR fluorophores to target specific cancer markers might be realistic technology with diagnostic and therapeutic benefits.

  19. Fundus auto fluorescence and spectral domain ocular coherence tomography in the early detection of chloroquine retinopathy

    Directory of Open Access Journals (Sweden)

    Megan B. Goodman

    2015-08-01

    Full Text Available Purpose: To determine the sensitivity of spectral domain ocular coherence tomography (SD-OCT and fundus auto fluorescence (FAF images as a screening test to detect early changes in the retina prior to the onset of chloroquine retinopathy. Method: The study was conducted using patients taking chloroquine (CQ, referred by the Rheumatology Department to the Ophthalmology Department at Tygerberg Academic Hospital. Group A consisted of 59 patients on CQ for less than 5 years, and Group B consisted of 53 patients on CQ for more than 5 years. A 200 × 200 macula thickness map, 5-line raster SD-OCT on a Carl Zeiss Meditec Cirrus HD-OCT and FAF images on a Carl Zeiss Meditec Visucam 500 were recorded for 223 eyes. Images were reviewed independently, and then those of Groups A and B compared. Results: There were no statistically significant differences between Groups A and B. The criteria included the internal limiting membrane and the retinal pigment epithelium (ILM-RPE thickness, interdigitation zone integrity (p = 0.891, df = 1, χ² = 0.1876, ellipsoid zone integrity (p = 0.095, df = 2, χ² = 4.699 and FAF image irregularities (p = 0.479, df = 1, χ²= 4995978. Conclusion: The inclusion of SD-OCT and FAF as objective tests into the prescribed screening guidelines does not appear to simplify the detection of subclinical injury in patients on chloroquine treatment.

  20. Laboratory Scale X-ray Fluorescence Tomography: Instrument Characterization and Application in Earth and Environmental Science.

    Science.gov (United States)

    Laforce, Brecht; Vermeulen, Bram; Garrevoet, Jan; Vekemans, Bart; Van Hoorebeke, Luc; Janssen, Colin; Vincze, Laszlo

    2016-03-15

    A new laboratory scale X-ray fluorescence (XRF) imaging instrument, based on an X-ray microfocus tube equipped with a monocapillary optic, has been developed to perform XRF computed tomography experiments with both higher spatial resolution (20 μm) and a better energy resolution (130 eV @Mn-K(α)) than has been achieved up-to-now. This instrument opens a new range of possible applications for XRF-CT. Next to the analytical characterization of the setup by using well-defined model/reference samples, demonstrating its capabilities for tomographic imaging, the XRF-CT microprobe has been used to image the interior of an ecotoxicological model organism, Americamysis bahia. This had been exposed to elevated metal (Cu and Ni) concentrations. The technique allowed the visualization of the accumulation sites of copper, clearly indicating the affected organs, i.e. either the gastric system or the hepatopancreas. As another illustrative application, the scanner has been employed to investigate goethite spherules from the Cretaceous-Paleogene boundary, revealing the internal elemental distribution of these valuable distal ejecta layer particles.

  1. Image reconstruction of fluorescent molecular tomography based on the tree structured Schur complement decomposition

    Directory of Open Access Journals (Sweden)

    Wang Jiajun

    2010-05-01

    Full Text Available Abstract Background The inverse problem of fluorescent molecular tomography (FMT often involves complex large-scale matrix operations, which may lead to unacceptable computational errors and complexity. In this research, a tree structured Schur complement decomposition strategy is proposed to accelerate the reconstruction process and reduce the computational complexity. Additionally, an adaptive regularization scheme is developed to improve the ill-posedness of the inverse problem. Methods The global system is decomposed level by level with the Schur complement system along two paths in the tree structure. The resultant subsystems are solved in combination with the biconjugate gradient method. The mesh for the inverse problem is generated incorporating the prior information. During the reconstruction, the regularization parameters are adaptive not only to the spatial variations but also to the variations of the objective function to tackle the ill-posed nature of the inverse problem. Results Simulation results demonstrate that the strategy of the tree structured Schur complement decomposition obviously outperforms the previous methods, such as the conventional Conjugate-Gradient (CG and the Schur CG methods, in both reconstruction accuracy and speed. As compared with the Tikhonov regularization method, the adaptive regularization scheme can significantly improve ill-posedness of the inverse problem. Conclusions The methods proposed in this paper can significantly improve the reconstructed image quality of FMT and accelerate the reconstruction process.

  2. Direct reconstruction of pharmacokinetic parameters in dynamic fluorescence molecular tomography by the augmented Lagrangian method

    Science.gov (United States)

    Zhu, Dianwen; Zhang, Wei; Zhao, Yue; Li, Changqing

    2016-03-01

    Dynamic fluorescence molecular tomography (FMT) has the potential to quantify physiological or biochemical information, known as pharmacokinetic parameters, which are important for cancer detection, drug development and delivery etc. To image those parameters, there are indirect methods, which are easier to implement but tend to provide images with low signal-to-noise ratio, and direct methods, which model all the measurement noises together and are statistically more efficient. The direct reconstruction methods in dynamic FMT have attracted a lot of attention recently. However, the coupling of tomographic image reconstruction and nonlinearity of kinetic parameter estimation due to the compartment modeling has imposed a huge computational burden to the direct reconstruction of the kinetic parameters. In this paper, we propose to take advantage of both the direct and indirect reconstruction ideas through a variable splitting strategy under the augmented Lagrangian framework. Each iteration of the direct reconstruction is split into two steps: the dynamic FMT image reconstruction and the node-wise nonlinear least squares fitting of the pharmacokinetic parameter images. Through numerical simulation studies, we have found that the proposed algorithm can achieve good reconstruction results within a small amount of time. This will be the first step for a combined dynamic PET and FMT imaging in the future.

  3. Performance Enhancement of Pharmacokinetic Diffuse Fluorescence Tomography by Use of Adaptive Extended Kalman Filtering.

    Science.gov (United States)

    Wang, Xin; Wu, Linhui; Yi, Xi; Zhang, Yanqi; Zhang, Limin; Zhao, Huijuan; Gao, Feng

    2015-01-01

    Due to both the physiological and morphological differences in the vascularization between healthy and diseased tissues, pharmacokinetic diffuse fluorescence tomography (DFT) can provide contrast-enhanced and comprehensive information for tumor diagnosis and staging. In this regime, the extended Kalman filtering (EKF) based method shows numerous advantages including accurate modeling, online estimation of multiparameters, and universal applicability to any optical fluorophore. Nevertheless the performance of the conventional EKF highly hinges on the exact and inaccessible prior knowledge about the initial values. To address the above issues, an adaptive-EKF scheme is proposed based on a two-compartmental model for the enhancement, which utilizes a variable forgetting-factor to compensate the inaccuracy of the initial states and emphasize the effect of the current data. It is demonstrated using two-dimensional simulative investigations on a circular domain that the proposed adaptive-EKF can obtain preferable estimation of the pharmacokinetic-rates to the conventional-EKF and the enhanced-EKF in terms of quantitativeness, noise robustness, and initialization independence. Further three-dimensional numerical experiments on a digital mouse model validate the efficacy of the method as applied in realistic biological systems.

  4. Topical MMP beacon enabled fluorescence-guided resection of oral carcinoma

    Science.gov (United States)

    Burgess, Laura; Chen, Juan; Wolter, Nikolaus E.; Wilson, Brian; Zheng, Gang

    2016-01-01

    Each year almost 300,000 individuals worldwide are diagnosed with oral cancer, more than 90% of these being oral carcinoma [N. Engl. J. Med. 328, 184 19938417385]. Surgical resection is the standard of care, but accurate delineation of the tumor boundaries is challenging, resulting in either under-resection with risk of local recurrence or over-resection with increased functional loss and negative impact on quality of life. This study evaluates, in two pre-clinical in vivo tumor models, the potential of fluorescence-guided resection using molecular beacons activated by metalloproteinases, which are frequently upregulated in human oral cancer. In both models there was rapid (beacon activation upon local application, allowing clear fluoresecence imaging in vivo and confirmed by ex vivo fluorescence microscopy and HPLC, with minimal activation in normal oral tissues. Although the tissue penetration was limited using topical application, these findings support further development of this approach towards translation to first-in-human trials. PMID:27231609

  5. The feasibility study on 3-dimensional fluorescent x-ray computed tomography using the pinhole effect for biomedical applications.

    Science.gov (United States)

    Sunaguchi, Naoki; Yuasa, Tetsuya; Hyodo, Kazuyuki; Zeniya, Tsutomu

    2013-01-01

    We propose a 3-dimensional fluorescent x-ray computed tomography (CT) pinhole collimator, aimed at providing molecular imaging with quantifiable measures and sub-millimeter spatial resolution. In this study, we demonstrate the feasibility of this concept and investigate imaging properties such as spatial resolution, contrast resolution and quantifiable measures, by imaging physical phantoms using a preliminary imaging system developed with monochromatic synchrotron x rays constructed at the BLNE-7A experimental line at KEK, Japan.

  6. Review of fluorescence guided surgery systems: identification of key performance capabilities beyond indocyanine green imaging

    Science.gov (United States)

    DSouza, Alisha V.; Lin, Huiyun; Henderson, Eric R.; Samkoe, Kimberley S.; Pogue, Brian W.

    2016-08-01

    There is growing interest in using fluorescence imaging instruments to guide surgery, and the leading options for open-field imaging are reviewed here. While the clinical fluorescence-guided surgery (FGS) field has been focused predominantly on indocyanine green (ICG) imaging, there is accelerated development of more specific molecular tracers. These agents should help advance new indications for which FGS presents a paradigm shift in how molecular information is provided for resection decisions. There has been a steady growth in commercially marketed FGS systems, each with their own differentiated performance characteristics and specifications. A set of desirable criteria is presented to guide the evaluation of instruments, including: (i) real-time overlay of white-light and fluorescence images, (ii) operation within ambient room lighting, (iii) nanomolar-level sensitivity, (iv) quantitative capabilities, (v) simultaneous multiple fluorophore imaging, and (vi) ergonomic utility for open surgery. In this review, United States Food and Drug Administration 510(k) cleared commercial systems and some leading premarket FGS research systems were evaluated to illustrate the continual increase in this performance feature base. Generally, the systems designed for ICG-only imaging have sufficient sensitivity to ICG, but a fraction of the other desired features listed above, with both lower sensitivity and dynamic range. In comparison, the emerging research systems targeted for use with molecular agents have unique capabilities that will be essential for successful clinical imaging studies with low-concentration agents or where superior rejection of ambient light is needed. There is no perfect imaging system, but the feature differences among them are important differentiators in their utility, as outlined in the data and tables here.

  7. Review of fluorescence guided surgery systems: identification of key performance capabilities beyond indocyanine green imaging

    Science.gov (United States)

    DSouza, Alisha V.; Lin, Huiyun; Henderson, Eric R.; Samkoe, Kimberley S.; Pogue, Brian W.

    2016-01-01

    Abstract. There is growing interest in using fluorescence imaging instruments to guide surgery, and the leading options for open-field imaging are reviewed here. While the clinical fluorescence-guided surgery (FGS) field has been focused predominantly on indocyanine green (ICG) imaging, there is accelerated development of more specific molecular tracers. These agents should help advance new indications for which FGS presents a paradigm shift in how molecular information is provided for resection decisions. There has been a steady growth in commercially marketed FGS systems, each with their own differentiated performance characteristics and specifications. A set of desirable criteria is presented to guide the evaluation of instruments, including: (i) real-time overlay of white-light and fluorescence images, (ii) operation within ambient room lighting, (iii) nanomolar-level sensitivity, (iv) quantitative capabilities, (v) simultaneous multiple fluorophore imaging, and (vi) ergonomic utility for open surgery. In this review, United States Food and Drug Administration 510(k) cleared commercial systems and some leading premarket FGS research systems were evaluated to illustrate the continual increase in this performance feature base. Generally, the systems designed for ICG-only imaging have sufficient sensitivity to ICG, but a fraction of the other desired features listed above, with both lower sensitivity and dynamic range. In comparison, the emerging research systems targeted for use with molecular agents have unique capabilities that will be essential for successful clinical imaging studies with low-concentration agents or where superior rejection of ambient light is needed. There is no perfect imaging system, but the feature differences among them are important differentiators in their utility, as outlined in the data and tables here. PMID:27533438

  8. X-ray nanoprobes and diffraction-limited storage rings: opportunities and challenges of fluorescence tomography of biological specimens

    Energy Technology Data Exchange (ETDEWEB)

    Jonge, Martin D. de, E-mail: martin.dejonge@synchrotron.org.au [Australian Synchrotron, 800 Blackburn Road, Clayton, Victoria 3168 (Australia); Ryan, Christopher G. [CSIRO Earth Science and Research Engineering, Clayton, Victoria 3168 (Australia); Jacobsen, Chris J. [Advanced Photon Source, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, IL 60439 (United States); Department of Physics, Chemistry of Life Processes Institute, Northwestern University, 2170 Campus Drive, Evanston, IL 60208 (United States); Chemistry of Life Processes Institute, Northwestern University, 2170 Campus Drive, Evanston, IL 60208 (United States)

    2014-08-27

    Nanoscale X-ray scanning microscopes, or X-ray nanoprobes, will benefit greatly from diffraction-limited storage rings. Here the requirements for nanoscale fluorescence tomography are explored to gain insight into the scientific opportunities and technical challenges that such sources offer. X-ray nanoprobes require coherent illumination to achieve optic-limited resolution, and so will benefit directly from diffraction-limited storage rings. Here, the example of high-resolution X-ray fluorescence tomography is focused on as one of the most voracious demanders of coherent photons, since the detected signal is only a small fraction of the incident flux. Alternative schemes are considered for beam delivery, sample scanning and detectors. One must consider as well the steps before and after the X-ray experiment: sample preparation and examination conditions, and analysis complexity due to minimum dose requirements and self-absorption. By understanding the requirements and opportunities for nanoscale fluorescence tomography, one gains insight into the R&D challenges in optics and instrumentation needed to fully exploit the source advances that diffraction-limited storage rings offer.

  9. A dual-targeting upconversion nanoplatform for two-color fluorescence imaging-guided photodynamic therapy.

    Science.gov (United States)

    Wang, Xu; Yang, Cheng-Xiong; Chen, Jia-Tong; Yan, Xiu-Ping

    2014-04-01

    The targetability of a theranostic probe is one of the keys to assuring its theranostic efficiency. Here we show the design and fabrication of a dual-targeting upconversion nanoplatform for two-color fluorescence imaging-guided photodynamic therapy (PDT). The nanoplatform was prepared from 3-aminophenylboronic acid functionalized upconversion nanocrystals (APBA-UCNPs) and hyaluronated fullerene (HAC60) via a specific diol-borate condensation. The two specific ligands of aminophenylboronic acid and hyaluronic acid provide synergistic targeting effects, high targetability, and hence a dramatically elevated uptake of the nanoplatform by cancer cells. The high generation yield of (1)O2 due to multiplexed Förster resonance energy transfer between APBA-UCNPs (donor) and HAC60 (acceptor) allows effective therapy. The present nanoplatform shows great potential for highly selective tumor-targeted imaging-guided PDT.

  10. Spontaneous Coronary Dissection: “Live Flash” Optical Coherence Tomography Guided Angioplasty

    Science.gov (United States)

    Bento, Angela Pimenta; Fernandes, Renato Gil dos Santos Pinto; Neves, David Cintra Henriques Silva; Patrício, Lino Manuel Ribeiro; de Aguiar, José Eduardo Chambel

    2016-01-01

    Optical Coherence tomography (OCT) is a light-based imaging modality which shows tremendous potential in the setting of coronary imaging. Spontaneous coronary artery dissection (SCAD) is an infrequent cause of acute coronary syndrome (ACS). The diagnosis of SCAD is made mainly with invasive coronary angiography, although adjunctive imaging modalities such as computed tomography angiography, IVUS, and OCT may increase the diagnostic yield. The authors describe a clinical case of a young woman admitted with the diagnosis of ACS. The ACS was caused by SCAD detected in the coronary angiography and the angioplasty was guided by OCT. OCT use in the setting of SCAD has been already described and the true innovation in this case was this unique use of OCT. The guidance of angioplasty with live and short images was very useful as it allowed clearly identifying the position of the guidewires at any given moment without the use of prohibitive amounts of contrast. PMID:26989520

  11. L-shell x-ray fluorescence computed tomography (XFCT) imaging of Cisplatin

    International Nuclear Information System (INIS)

    Bazalova, Magdalena; Ahmad, Moiz; Pratx, Guillem; Xing, Lei

    2014-01-01

    X-ray fluorescence computed tomography (XFCT) imaging has been focused on the detection of K-shell x-rays. The potential utility of L-shell x-ray XFCT is, however, not well studied. Here we report the first Monte Carlo (MC) simulation of preclinical L-shell XFCT imaging of Cisplatin. We built MC models for both L- and K-shell XFCT with different excitation energies (15 and 30 keV for L-shell and 80 keV for K-shell XFCT). Two small-animal sized imaging phantoms of 2 and 4 cm diameter containing a series of objects of 0.6 to 2.7 mm in diameter at 0.7 to 16 mm depths with 10 to 250 µg mL −1  concentrations of Pt are used in the study. Transmitted and scattered x-rays were collected with photon-integrating transmission detector and photon-counting detector arc, respectively. Collected data were rearranged into XFCT and transmission CT sinograms for image reconstruction. XFCT images were reconstructed with filtered back-projection and with iterative maximum-likelihood expectation maximization without and with attenuation correction. While K-shell XFCT was capable of providing an accurate measurement of Cisplatin concentration, its sensitivity was 4.4 and 3.0 times lower than that of L-shell XFCT with 15 keV excitation beam for the 2 cm and 4 cm diameter phantom, respectively. With the inclusion of excitation and fluorescence beam attenuation correction, we found that L-shell XFCT was capable of providing fairly accurate information of Cisplatin concentration distribution. With a dose of 29 and 58 mGy, clinically relevant Cisplatin Pt concentrations of 10 µg mg −1  could be imaged with L-shell XFCT inside a 2 cm and 4 cm diameter object, respectively. (paper)

  12. Endobronchial Ultrasound-Guided Transbronchial Needle Aspiration for Staging of Patients with Non-Small Cell Lung Cancer without Mediastinal Involvement at Positron Emission Tomography-Computed Tomography

    DEFF Research Database (Denmark)

    Naur, Therese Maria Henriette; Konge, Lars; Clementsen, Paul Frost

    2017-01-01

    BACKGROUND: Staging of lung cancer is essential to the treatment, which is curative only in cases of localized disease. Previous studies have suggested that endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) is unnecessary when positron emission tomography-computed tomog...

  13. Fluorescence-guided surgery and intervention - An AAPM emerging technology blue paper.

    Science.gov (United States)

    Pogue, Brian W; Zhu, Timothy C; Ntziachristos, Vasilis; Paulsen, Keith D; Wilson, Brian C; Pfefer, Joshua; Nordstrom, Robert J; Litorja, Maritoni; Wabnitz, Heidrun; Chen, Yu; Gioux, Sylvain; Tromberg, Bruce J; Yodh, Arjun G

    2018-04-10

    Fluorescence-guided surgery (FGS) and other interventions are rapidly evolving as a class of technologically driven interventional approaches in which many surgical specialties visualize fluorescent molecular tracers or biomarkers through associated cameras or oculars to guide clinical decisions on pathological lesion detection and excision/ablation. The technology has been commercialized for some specific applications, but also presents technical challenges unique to optical imaging that could confound the utility of some interventional procedures where real-time decisions must be made. Accordingly, the AAPM has initiated the publication of this Blue Paper of The Emerging Technology Working Group (TETAWG) and the creation of a Task Group from the Therapy Physics Committee within the Treatment Delivery Subcommittee. In describing the relevant issues, this document outlines the key parameters, stakeholders, impacts, and outcomes of clinical FGS technology and its applications. The presentation is not intended to be conclusive, but rather to inform the field of medical physics and stimulate the discussions needed in the field with respect to a seemingly low-risk imaging technology that has high potential for significant therapeutic impact. This AAPM Task Group is working toward consensus around guidelines and standards for advancing the field safely and effectively. © 2018 American Association of Physicists in Medicine.

  14. Nerve-Highlighting Fluorescent Contrast Agents for Image-Guided Surgery

    Directory of Open Access Journals (Sweden)

    Summer L. Gibbs-Strauss

    2011-03-01

    Full Text Available Nerve damage is the major morbidity of many surgeries, resulting in chronic pain, loss of function, or both. The sparing of nerves during surgical procedures is a vexing problem because surrounding tissue often obscures them. To date, systemically administered nerve-highlighting contrast agents that can be used for nerve-sparing image-guided surgery have not been reported. In the current study, physicochemical and optical properties of 4,4‘-[(2-methoxy-1,4-phenylenedi-(1E-2,1-ethenediyl]bis-benzenamine (BMB and a newly synthesized, red-shifted derivative 4-[(1E-2-[4-[(1E-2-[4-aminophenyl]ethenyl]-3-methoxyphenyl]ethenyl]-benzonitrile (GE3082 were characterized in vitro and in vivo. Both agents crossed the blood-nerve barrier and blood-brain barrier and rendered myelinated nerves fluorescent after a single systemic injection. Although both BMB and GE3082 also exhibited significant uptake in white adipose tissue, GE3082 underwent a hypsochromic shift in adipose tissue that provided a means to eliminate the unwanted signal using hyperspectral deconvolution. Dose and kinetic studies were performed in mice to determine the optimal dose and drug-imaging interval. The results were confirmed in rat and pig, with the latter used to demonstrate, for the first time, simultaneous fluorescence imaging of blood vessels and nerves during surgery using the FLARE™ (Fluorescence-Assisted Resection and Exploration imaging system. These results lay the foundation for the development of ideal nerve-highlighting fluorophores for image-guided surgery.

  15. Comparison between the indocyanine green fluorescence and blue dye methods for sentinel lymph node biopsy using novel fluorescence image-guided resection equipment in different types of hospitals.

    Science.gov (United States)

    He, Kunshan; Chi, Chongwei; Kou, Deqiang; Huang, Wenhe; Wu, Jundong; Wang, Yabing; He, Lifang; Ye, Jinzuo; Mao, Yamin; Zhang, Guo-Jun; Wang, Jiandong; Tian, Jie

    2016-12-01

    Sentinel lymph node biopsy (SLNB) has become a standard of care to detect axillary lymph metastasis in early-stage breast cancer patients with clinically negative axillary lymph nodes. Current SLNB detection modalities comprising a blue dye, a radioactive tracer, or a combination of both have advantages as well as disadvantages. Thus, near-infrared fluorescence imaging using indocyanine green (ICG) has recently been regarded as a novel method that has generated interest for SLNB around the world. However, the lack of appropriate fluorescence imaging systems has hindered further research and wide application of this method. Therefore, we developed novel fluorescence image-guided resection equipment (FIRE) to detect sentinel lymph nodes (SLNs). Moreover, to compare the ICG fluorescence imaging method with the blue dye method and to explore the universal feasibility of the former, a different type of hospital study was conducted. Ninety-nine eligible patients participated in the study at 3 different types of hospitals. After subcutaneous ICG allergy testing, all the patients were subcutaneously injected with methylene blue and ICG into the subareolar area. Consequently, 276 SLNs (range 1-7) were identified in 98 subjects (detection rate: 99%) by using the ICG fluorescence imaging method. In contrast, the blue dye method only identified 202 SLNs (range 1-7) in 91 subjects (detection rate: 91.92%). Besides, the results of the fluorescence imaging method were similar in the 3 hospitals. Our findings indicate the universal feasibility of the ICG fluorescence imaging method for SLNB using the fluorescence image-guided resection equipment in early breast cancer detection. Copyright © 2016 Elsevier Inc. All rights reserved.

  16. Comparison of the accuracy of cone beam computed tomography and medical computed tomography: implications for clinical diagnostics with guided surgery.

    Science.gov (United States)

    Abboud, Marcus; Calvo-Guirado, Jose Luis; Orentlicher, Gary; Wahl, Gerhard

    2013-01-01

    This study compared the accuracy of cone beam computed tomography (CBCT) and medical-grade CT in the context of evaluating the diagnostic value and accuracy of fiducial marker localization for reference marker-based guided surgery systems. Cadaver mandibles with attached radiopaque gutta-percha markers, as well as glass balls and composite cylinders of known dimensions, were measured manually with a highly accurate digital caliper. The objects were then scanned using a medical-grade CT scanner (Philips Brilliance 64) and five different CBCT scanners (Sirona Galileos, Morita 3D Accuitomo 80, Vatech PaX-Reve3D, 3M Imtech Iluma, and Planmeca ProMax 3D). The data were then imported into commercially available software, and measurements were made of the scanned markers and objects. CT and CBCT measurements were compared to each other and to the caliper measurements. The difference between the CBCT measurements and the caliper measurements was larger than the difference between the CT measurements and the caliper measurements. Measurements of the cadaver mandible and the geometric reference markers were highly accurate with CT. The average absolute errors of the human mandible measurements were 0.03 mm for CT and 0.23 mm for CBCT. The measurement errors of the geometric objects based on CT ranged between 0.00 and 0.12 mm, compared to an error range between 0.00 and 2.17 mm with the CBCT scanners. CT provided the most accurate images in this study, closely followed by one CBCT of the five tested. Although there were differences in the distance measurements of the hard tissue of the human mandible between CT and CBCT, these differences may not be of clinical significance for most diagnostic purposes. The fiducial marker localization error caused by some CBCT scanners may be a problem for guided surgery systems.

  17. Computed tomography-guided percutaneous biopsy of bone lesions: rate of diagnostic success and complications

    International Nuclear Information System (INIS)

    Maciel, Macello Jose Sampaio; Tyng, Chiang Jeng; Barbosa, Paula Nicole Vieira Pinto; Bitencourt, Almir Galvao Vieira; Matushita Junior, Joao Paulo Kawaoka; Zurstrassen, Charles Edouard; Chung, Wu Tu; Chojniak, Rubens

    2014-01-01

    Objective: To determine the rates of diagnostic success and complications of computed tomography (CT)-guided percutaneous biopsy of bone lesions suspected for malignancy. Materials and Methods: Retrospective study including 186 cases of CT-guided percutaneous biopsies of bone lesions in the period from January, 2010 to December, 2012. All the specimens were obtained with 8-10 gauge needles. The following data were collected: demographics, previous history of malignancy, data related to the lesion, to the procedure, and to histological results. Results: Most patients were women (57%), and the mean age was 53.0 ± 16.4 years. In 139 cases (74.6%), there was diagnostic suspicion of metastasis and the most common primary tumors were breast (32.1%) and prostate (11.8%). The bones most commonly involved were spine (36.0%), hip (32.8%) and long bones (18.3%). Complications occurred in only three cases (1.6%) including bone fracture, paraesthesia with functional impairment, and needle breakage requiring surgical removal. The specimens collected from 183 lesions (98.4%) were considered appropriate for diagnosis. Malignant results were more frequently found in patients who had a suspected secondary lesion and history of known malignancy (p < 0.001), and in patients who underwent PET/CT-guided procedures (p = 0.011). Conclusion: CT-guided percutaneous biopsy is a safe and effective procedure for the diagnosis of suspicious bone lesions. (author)

  18. Incidental finding of a left over guide wire on a positron emission tomography

    International Nuclear Information System (INIS)

    Yap, Kok Hooi; Lee, Phong Teck; Buch, Mamta; Rammohan, Kandadai Seshadri

    2012-01-01

    The Seldinger technique is commonly used cannulate vessels for radiographical procedures. Loss of a guide wire into the circulation is a rare and preventable complication. It is often noticed by chance during routine radiographs. However, there is a lack of reported cases of incidental fin dings of leftover guide wire on a PET scan. An intravascular foreign body should be retrieved as soon as the diagnosis is made, to prevent complications such as embolisation or vascular damage by fractured wires. Interventional radiology is the method of choice for retrieval. We report a rare case of the coincidental finding of a lost guide wire on a PET scan. A 37 year old man presented with psychotic episodes, thigh weakness, weight gain, increased appetite and leg cramps. He was subsequently diagnosed with cushing syndrome secondary to ectopic adrenocorticotropic secretion from a right lung tumour. He subsequently underwent a staging positron emission tomography (PET) scan. The lung tumour had no uptake on PET bit had increased activity uptake on octreotide scanning. These appearances were suggestive of with carcinoid tumour. The PET scan also revealed an incidental finding of a leftover guide wire used during peripheral inserted central catheter (PICC) recently. The wire extended from right atrium to inferior vena cava. It also showed a high uptake in the adrenal glands, indicating hyperplasia, which was most likely due to adrenocorticotropic hormone stimulation. He underwent a percutaneous wire retrieval via the right femoral vein in a cardiac catheterisation laboratory and was transferred to a thoracic surgical unit for lung tumor resection

  19. Incidental finding of a left over guide wire on a positron emission tomography

    Energy Technology Data Exchange (ETDEWEB)

    Yap, Kok Hooi; Lee, Phong Teck; Buch, Mamta; Rammohan, Kandadai Seshadri

    2012-12-15

    The Seldinger technique is commonly used cannulate vessels for radiographical procedures. Loss of a guide wire into the circulation is a rare and preventable complication. It is often noticed by chance during routine radiographs. However, there is a lack of reported cases of incidental fin dings of leftover guide wire on a PET scan. An intravascular foreign body should be retrieved as soon as the diagnosis is made, to prevent complications such as embolisation or vascular damage by fractured wires. Interventional radiology is the method of choice for retrieval. We report a rare case of the coincidental finding of a lost guide wire on a PET scan. A 37 year old man presented with psychotic episodes, thigh weakness, weight gain, increased appetite and leg cramps. He was subsequently diagnosed with cushing syndrome secondary to ectopic adrenocorticotropic secretion from a right lung tumour. He subsequently underwent a staging positron emission tomography (PET) scan. The lung tumour had no uptake on PET bit had increased activity uptake on octreotide scanning. These appearances were suggestive of with carcinoid tumour. The PET scan also revealed an incidental finding of a leftover guide wire used during peripheral inserted central catheter (PICC) recently. The wire extended from right atrium to inferior vena cava. It also showed a high uptake in the adrenal glands, indicating hyperplasia, which was most likely due to adrenocorticotropic hormone stimulation. He underwent a percutaneous wire retrieval via the right femoral vein in a cardiac catheterisation laboratory and was transferred to a thoracic surgical unit for lung tumor resection.

  20. Computed tomography-guided percutaneous biopsy of bone lesions: rate of diagnostic success and complications

    Energy Technology Data Exchange (ETDEWEB)

    Maciel, Macello Jose Sampaio; Tyng, Chiang Jeng; Barbosa, Paula Nicole Vieira Pinto; Bitencourt, Almir Galvao Vieira; Matushita Junior, Joao Paulo Kawaoka; Zurstrassen, Charles Edouard; Chung, Wu Tu; Chojniak, Rubens, E-mail: macellomaciel@me.com [A.C.Camargo Cancer Center, Sao Paulo, SP (Brazil)

    2014-09-15

    Objective: To determine the rates of diagnostic success and complications of computed tomography (CT)-guided percutaneous biopsy of bone lesions suspected for malignancy. Materials and Methods: Retrospective study including 186 cases of CT-guided percutaneous biopsies of bone lesions in the period from January, 2010 to December, 2012. All the specimens were obtained with 8-10 gauge needles. The following data were collected: demographics, previous history of malignancy, data related to the lesion, to the procedure, and to histological results. Results: Most patients were women (57%), and the mean age was 53.0 ± 16.4 years. In 139 cases (74.6%), there was diagnostic suspicion of metastasis and the most common primary tumors were breast (32.1%) and prostate (11.8%). The bones most commonly involved were spine (36.0%), hip (32.8%) and long bones (18.3%). Complications occurred in only three cases (1.6%) including bone fracture, paraesthesia with functional impairment, and needle breakage requiring surgical removal. The specimens collected from 183 lesions (98.4%) were considered appropriate for diagnosis. Malignant results were more frequently found in patients who had a suspected secondary lesion and history of known malignancy (p < 0.001), and in patients who underwent PET/CT-guided procedures (p = 0.011). Conclusion: CT-guided percutaneous biopsy is a safe and effective procedure for the diagnosis of suspicious bone lesions. (author)

  1. EpCAM as multi-tumour target for near-infrared fluorescence guided surgery

    International Nuclear Information System (INIS)

    Driel, P. B. A. A. van; Boonstra, M. C.; Prevoo, H. A. J. M.; Giessen, M. van de; Snoeks, T. J. A.; Tummers, Q. R. J. G.; Keereweer, S.; Cordfunke, R. A.; Fish, A.; Eendenburg, J. D. H. van; Lelieveldt, B. P. F.; Dijkstra, J.; Velde, C. J. H. van de; Kuppen, P. J. K.; Vahrmeijer, A. L.; Löwik, C. W. G. M.; Sier, C. F. M.

    2016-01-01

    Evaluation of resection margins during cancer surgery can be challenging, often resulting in incomplete tumour removal. Fluorescence-guided surgery (FGS) aims to aid the surgeon to visualize tumours and resection margins during surgery. FGS relies on a clinically applicable imaging system in combination with a specific tumour-targeting contrast agent. In this study EpCAM (epithelial cell adhesion molecule) is evaluated as target for FGS in combination with the novel Artemis imaging system. The NIR fluorophore IRDye800CW was conjugated to the well-established EpCAM specific monoclonal antibody 323/A3 and an isotype IgG1 as control. The anti-EpCAM/800CW conjugate was stable in serum and showed preserved binding capacity as evaluated on EpCAM positive and negative cell lines, using flow cytometry and cell-based plate assays. Four clinically relevant orthotopic tumour models, i.e. colorectal cancer, breast cancer, head and neck cancer, and peritonitis carcinomatosa, were used to evaluate the performance of the anti-EpCAM agent with the clinically validated Artemis imaging system. The Pearl Impulse small animal imaging system was used as reference. The specificity of the NIRF signal was confirmed using bioluminescence imaging and green-fluorescent protein. All tumour types could clearly be delineated and resected 72 h after injection of the imaging agent. Using NIRF imaging millimetre sized tumour nodules were detected that were invisible for the naked eye. Fluorescence microscopy demonstrated the distribution and tumour specificity of the anti-EpCAM agent. This study shows the potential of an EpCAM specific NIR-fluorescent agent in combination with a clinically validated intraoperative imaging system to visualize various tumours during surgery

  2. Integrin-Targeted Hybrid Fluorescence Molecular Tomography/X-ray Computed Tomography for Imaging Tumor Progression and Early Response in Non-Small Cell Lung Cancer

    Directory of Open Access Journals (Sweden)

    Xiaopeng Ma

    2017-01-01

    Full Text Available Integrins play an important role in tumor progression, invasion and metastasis. Therefore we aimed to evaluate a preclinical imaging approach applying ανβ3 integrin targeted hybrid Fluorescence Molecular Tomography/X-ray Computed Tomography (FMT-XCT for monitoring tumor progression as well as early therapy response in a syngeneic murine Non-Small Cell Lung Cancer (NSCLC model. Lewis Lung Carcinomas were grown orthotopically in C57BL/6 J mice and imaged in-vivo using a ανβ3 targeted near-infrared fluorescence (NIRF probe. ανβ3-targeted FMT-XCT was able to track tumor progression. Cilengitide was able to substantially block the binding of the NIRF probe and suppress the imaging signal. Additionally mice were treated with an established chemotherapy regimen of Cisplatin and Bevacizumab or with a novel MEK inhibitor (Refametinib for 2 weeks. While μCT revealed only a moderate slowdown of tumor growth, ανβ3 dependent signal decreased significantly compared to non-treated mice already at one week post treatment. ανβ3 targeted imaging might therefore become a promising tool for assessment of early therapy response in the future.

  3. Preclinical, fluorescence and diffuse optical tomography: non-contact instrumentation, modeling and time-resolved 3D reconstruction

    International Nuclear Information System (INIS)

    Nouizi, F.

    2011-09-01

    Time-Resolved Diffuse Optical Tomography (TR-DOT) is a new non-invasive imaging technique increasingly used in the clinical and preclinical fields. It yields optical absorption and scattering maps of the explored organs, and related physiological parameters. Time-Resolved Fluorescence Diffuse Optical Tomography (TR-FDOT) is based on the detection of fluorescence photons. It provides spatio-temporal maps of fluorescent probe concentrations and life times, and allows access to metabolic and molecular imaging which is important for diagnosis and therapeutic monitoring, particularly in oncology. The main goal of this thesis was to reconstruct 3D TR-DOT/TR-FDOT images of small animals using time-resolved optical technology. Data were acquired using optical fibers fixed around the animal without contact with its surface. The work was achieved in four steps: 1)- Setting up an imaging device to record the 3D coordinates of an animal's surface; 2)- Modeling the no-contact approach to solve the forward problem; 3)- Processing of the measured signals taking into account the impulse response of the device; 4)- Implementation of a new image reconstruction method based on a selection of carefully chosen points. As a result, good-quality 3D optical images were obtained owing to reduced cross-talk between absorption and scattering. Moreover, the computation time was cut down, compared to full-time methods using whole temporal profiles. (author)

  4. Iodinated oil-loaded, fluorescent mesoporous silica-coated iron oxide nanoparticles for magnetic resonance imaging/computed tomography/fluorescence trimodal imaging

    Directory of Open Access Journals (Sweden)

    Xue S

    2014-05-01

    Full Text Available Sihan Xue,1 Yao Wang,1 Mengxing Wang,2 Lu Zhang,1 Xiaoxia Du,2 Hongchen Gu,1 Chunfu Zhang1,31School of Biomedical Engineering and Med-X Research Institute, Shanghai Jiao Tong University, 2Shanghai Key Laboratory of Magnetic Resonance, Department of Physics, East China Normal University, 3State Key Laboratory of Oncogenes and Related Genes, Shanghai Cancer Institute, School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai, People’s Republic of ChinaAbstract: In this study, a novel magnetic resonance imaging (MRI/computed tomography (CT/fluorescence trifunctional probe was prepared by loading iodinated oil into fluorescent mesoporous silica-coated superparamagnetic iron oxide nanoparticles (i-fmSiO4@SPIONs. Fluorescent mesoporous silica-coated superparamagnetic iron oxide nanoparticles (fmSiO4@SPIONs were prepared by growing fluorescent dye-doped silica onto superparamagnetic iron oxide nanoparticles (SPIONs directed by a cetyltrimethylammonium bromide template. As prepared, fmSiO4@SPIONs had a uniform size, a large surface area, and a large pore volume, which demonstrated high efficiency for iodinated oil loading. Iodinated oil loading did not change the sizes of fmSiO4@SPIONs, but they reduced the MRI T2 relaxivity (r2 markedly. I-fmSiO4@SPIONs were stable in their physical condition and did not demonstrate cytotoxic effects under the conditions investigated. In vitro studies indicated that the contrast enhancement of MRI and CT, and the fluorescence signal intensity of i-fmSiO4@SPION aqueous suspensions and macrophages, were intensified with increased i-fmSiO4@SPION concentrations in suspension and cell culture media. Moreover, for the in vivo study, the accumulation of i-fmSiO4@SPIONs in the liver could also be detected by MRI, CT, and fluorescence imaging. Our study demonstrated that i-fmSiO4@SPIONs had great potential for MRI/C/fluorescence trimodal imaging.Keywords: multifunctional probe, SPIONs, mesoporous silica

  5. Guiding flying-spot laser transepithelial phototherapeutic keratectomy with optical coherence tomography.

    Science.gov (United States)

    Li, Yan; Yokogawa, Hideaki; Tang, Maolong; Chamberlain, Winston; Zhang, Xinbo; Huang, David

    2017-04-01

    To analyze transepithelial phototherapeutic keratectomy (PTK) results using optical coherence tomography (OCT) and develop a model to guide the laser dioptric and depth settings. Casey Eye Institute, Portland, Oregon, USA. Prospective nonrandomized case series. Patients with superficial corneal opacities and irregularities had transepithelial PTK with a flying-spot excimer laser by combining wide-zone myopic and hyperopic astigmatic ablations. Optical coherence tomography was used to calculate corneal epithelial lenticular masking effects, guide refractive laser settings, and measure opacity removal. The laser ablation efficiency and the refractive outcome were investigated using multivariate linear regression models. Twenty-six eyes of 20 patients received PTK to remove opacities and irregular astigmatism due to scar, dystrophy, radial keratotomy, or previous corneal surgeries. The uncorrected distance visual acuity and corrected distance visual acuity were significantly improved (P laser ablation depths were 31.3% (myopic ablation) and 63.0% (hyperopic ablation) deeper than the manufacturer's nomogram. The spherical equivalent of the corneal epithelial lenticular masking effect was 0.73 diopter ± 0.61 (SD). The refractive outcome highly correlated to the laser settings and epithelial lenticular masking effect (Pearson R = 0.96, P < .01). The ablation rate of granular dystrophy opacities appeared to be slower. Smoothing ablation under masking fluid was needed to prevent focal steep islands in these cases. The OCT-measured ablation depth efficiency could guide opacity removal. The corneal epithelial lenticular masking effect could refine the spherical refractive nomogram to achieve a better refractive outcome after transepithelial ablation. Copyright © 2017 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.

  6. Reconstruction method for fluorescent X-ray computed tomography by least-squares method using singular value decomposition

    Science.gov (United States)

    Yuasa, T.; Akiba, M.; Takeda, T.; Kazama, M.; Hoshino, A.; Watanabe, Y.; Hyodo, K.; Dilmanian, F. A.; Akatsuka, T.; Itai, Y.

    1997-02-01

    We describe a new attenuation correction method for fluorescent X-ray computed tomography (FXCT) applied to image nonradioactive contrast materials in vivo. The principle of the FXCT imaging is that of computed tomography of the first generation. Using monochromatized synchrotron radiation from the BLNE-5A bending-magnet beam line of Tristan Accumulation Ring in KEK, Japan, we studied phantoms with the FXCT method, and we succeeded in delineating a 4-mm-diameter channel filled with a 500 /spl mu/g I/ml iodine solution in a 20-mm-diameter acrylic cylindrical phantom. However, to detect smaller iodine concentrations, attenuation correction is needed. We present a correction method based on the equation representing the measurement process. The discretized equation system is solved by the least-squares method using the singular value decomposition. The attenuation correction method is applied to the projections by the Monte Carlo simulation and the experiment to confirm its effectiveness.

  7. Quantitative X ray analysis system. User's manual and guide to X ray fluorescence technique

    International Nuclear Information System (INIS)

    2009-01-01

    This guide covers trimmed and re-arranged version 3.6 of the Quantitative X ray Analysis System (QXAS) software package that includes the most frequently used methods of quantitative analysis. QXAS is a comprehensive quantitative analysis package that has been developed by the IAEA through research and technical contracts. Additional development has also been carried out in the IAEA Laboratories in Seibersdorf where QXAS was extensively tested. New in this version of the manual are the descriptions of the Voigt-profile peak fitting, the backscatter fundamental parameters' and emission-transmission methods of chemical composition analysis, an expanded chapter on the X ray fluorescence physics, and completely revised and increased number of practical examples of utilization of the QXAS software package. The analytical data accompanying this manual were collected in the IAEA Seibersdorf Laboratories in the years 2006/2007

  8. Computed tomography fluoroscopy-guided placement of iliosacral screws in patients with unstable posterior pelvic fractures

    International Nuclear Information System (INIS)

    Iguchi, Toshihiro; Ogawa, Ken-Ichi; Doi, Takeshi; Munetomo, Kazuo; Miyasho, Koji; Hiraki, Takao; Kanazawa, Susumu; Ozaki, Toshifumi

    2010-01-01

    The purpose of this study was to evaluate retrospectively the safety and effectiveness of the computed tomography (CT) fluoroscopy-guided placement of iliosacral screws in patients with unstable posterior pelvic fractures. Six patients (four women and two men; mean age 55.8 years; range 35-77 years) with unstable posterior pelvic fractures underwent iliosacral screw placement under CT fluoroscopy guidance between November 2007 and August 2008. Unstable pelvic ring injury (AO types B and C) was the indication for this procedure. In all the six patients except one, CT fluoroscopy-guided placement had been technically successful. In one patient, a second screw had been inserted, with a tilt to the caudal site, and slightly advanced into the extrasacral body; afterward, it could be exchanged safely for a shorter screw. Five patients and one patient underwent placement of two screws and one screw, respectively. The mean duration of the procedure was 15.0 min (range 9-30 min) per screw; the duration was 12.3 min and 18.2 min for the first and second screws, respectively. No complications requiring treatment occurred during or after the procedure. The mean clinical and radiologic follow-up period was 14 months (range 6-21 months). All pelvic injuries had healed satisfactorily, without complication, and all patients are now doing well clinically and can walk. CT fluoroscopy-guided placement of iliosacral screws is a safe and effective treatment in patients with unstable posterior pelvic fractures. (orig.)

  9. User-guided segmentation for volumetric retinal optical coherence tomography images

    Science.gov (United States)

    Yin, Xin; Chao, Jennifer R.; Wang, Ruikang K.

    2014-01-01

    Abstract. Despite the existence of automatic segmentation techniques, trained graders still rely on manual segmentation to provide retinal layers and features from clinical optical coherence tomography (OCT) images for accurate measurements. To bridge the gap between this time-consuming need of manual segmentation and currently available automatic segmentation techniques, this paper proposes a user-guided segmentation method to perform the segmentation of retinal layers and features in OCT images. With this method, by interactively navigating three-dimensional (3-D) OCT images, the user first manually defines user-defined (or sketched) lines at regions where the retinal layers appear very irregular for which the automatic segmentation method often fails to provide satisfactory results. The algorithm is then guided by these sketched lines to trace the entire 3-D retinal layer and anatomical features by the use of novel layer and edge detectors that are based on robust likelihood estimation. The layer and edge boundaries are finally obtained to achieve segmentation. Segmentation of retinal layers in mouse and human OCT images demonstrates the reliability and efficiency of the proposed user-guided segmentation method. PMID:25147962

  10. Ultrasound guided electrical impedance tomography for 2D free-interface reconstruction

    Science.gov (United States)

    Liang, Guanghui; Ren, Shangjie; Dong, Feng

    2017-07-01

    The free-interface detection problem is normally seen in industrial or biological processes. Electrical impedance tomography (EIT) is a non-invasive technique with advantages of high-speed and low cost, and is a promising solution for free-interface detection problems. However, due to the ill-posed and nonlinear characteristics, the spatial resolution of EIT is low. To deal with the issue, an ultrasound guided EIT is proposed to directly reconstruct the geometric configuration of the target free-interface. In the method, the position of the central point of the target interface is measured by a pair of ultrasound transducers mounted at the opposite side of the objective domain, and then the position measurement is used as the prior information for guiding the EIT-based free-interface reconstruction. During the process, a constrained least squares framework is used to fuse the information from different measurement modalities, and the Lagrange multiplier-based Levenberg-Marquardt method is adopted to provide the iterative solution of the constraint optimization problem. The numerical results show that the proposed ultrasound guided EIT method for the free-interface reconstruction is more accurate than the single modality method, especially when the number of valid electrodes is limited.

  11. Ultrasound guided electrical impedance tomography for 2D free-interface reconstruction

    International Nuclear Information System (INIS)

    Liang, Guanghui; Ren, Shangjie; Dong, Feng

    2017-01-01

    The free-interface detection problem is normally seen in industrial or biological processes. Electrical impedance tomography (EIT) is a non-invasive technique with advantages of high-speed and low cost, and is a promising solution for free-interface detection problems. However, due to the ill-posed and nonlinear characteristics, the spatial resolution of EIT is low. To deal with the issue, an ultrasound guided EIT is proposed to directly reconstruct the geometric configuration of the target free-interface. In the method, the position of the central point of the target interface is measured by a pair of ultrasound transducers mounted at the opposite side of the objective domain, and then the position measurement is used as the prior information for guiding the EIT-based free-interface reconstruction. During the process, a constrained least squares framework is used to fuse the information from different measurement modalities, and the Lagrange multiplier-based Levenberg–Marquardt method is adopted to provide the iterative solution of the constraint optimization problem. The numerical results show that the proposed ultrasound guided EIT method for the free-interface reconstruction is more accurate than the single modality method, especially when the number of valid electrodes is limited. (paper)

  12. Amphiphilic semiconducting polymer as multifunctional nanocarrier for fluorescence/photoacoustic imaging guided chemo-photothermal therapy.

    Science.gov (United States)

    Jiang, Yuyan; Cui, Dong; Fang, Yuan; Zhen, Xu; Upputuri, Paul Kumar; Pramanik, Manojit; Ding, Dan; Pu, Kanyi

    2017-11-01

    Chemo-photothermal nanotheranostics has the advantage of synergistic therapeutic effect, providing opportunities for optimized cancer therapy. However, current chemo-photothermal nanotheranostic systems generally comprise more than three components, encountering the potential issues of unstable nanostructures and unexpected conflicts in optical and biophysical properties among different components. We herein synthesize an amphiphilic semiconducting polymer (PEG-PCB) and utilize it as a multifunctional nanocarrier to simplify chemo-photothermal nanotheranostics. PEG-PCB has a semiconducting backbone that not only serves as the diagnostic component for near-infrared (NIR) fluorescence and photoacoustic (PA) imaging, but also acts as the therapeutic agent for photothermal therapy. In addition, the hydrophobic backbone of PEG-PCB provides strong hydrophobic and π-π interactions with the aromatic anticancer drug such as doxorubicin for drug encapsulation and delivery. Such a trifunctionality of PEG-PCB eventually results in a greatly simplified nanotheranostic system with only two components but multimodal imaging and therapeutic capacities, permitting effective NIR fluorescence/PA imaging guided chemo-photothermal therapy of cancer in living mice. Our study thus provides a molecular engineering approach to integrate essential properties into one polymer for multimodal nanotheranostics. Copyright © 2017 Elsevier Ltd. All rights reserved.

  13. Image-Guided Radiotherapy for Liver Cancer Using Respiratory-Correlated Computed Tomography and Cone-Beam Computed Tomography

    International Nuclear Information System (INIS)

    Guckenberger, Matthias; Sweeney, Reinhart A.; Wilbert, Juergen; Krieger, Thomas; Richter, Anne; Baier, Kurt; Mueller, Gerd; Sauer, Otto; Flentje, Michael

    2008-01-01

    Purpose: To evaluate a novel four-dimensional (4D) image-guided radiotherapy (IGRT) technique in stereotactic body RT for liver tumors. Methods and Materials: For 11 patients with 13 intrahepatic tumors, a respiratory-correlated 4D computed tomography (CT) scan was acquired at treatment planning. The target was defined using CT series reconstructed at end-inhalation and end-exhalation. The liver was delineated on these two CT series and served as a reference for image guidance. A cone-beam CT scan was acquired after patient positioning; the blurred diaphragm dome was interpreted as a probability density function showing the motion range of the liver. Manual contour matching of the liver structures from the planning 4D CT scan with the cone-beam CT scan was performed. Inter- and intrafractional uncertainties of target position and motion range were evaluated, and interobserver variability of the 4D-IGRT technique was tested. Results: The workflow of 4D-IGRT was successfully practiced in all patients. The absolute error in the liver position and error in relation to the bony anatomy was 8 ± 4 mm and 5 ± 2 mm (three-dimensional vector), respectively. Margins of 4-6 mm were calculated for compensation of the intrafractional drifts of the liver. The motion range of the diaphragm dome was reproducible within 5 mm for 11 of 13 lesions, and the interobserver variability of the 4D-IGRT technique was small (standard deviation, 1.5 mm). In 4 patients, the position of the intrahepatic lesion was directly verified using a mobile in-room CT scanner after application of intravenous contrast. Conclusion: The results of our study have shown that 4D image guidance using liver contour matching between respiratory-correlated CT and cone-beam CT scans increased the accuracy compared with stereotactic positioning and compared with IGRT without consideration of breathing motion

  14. Surgical strategy for malignant gliomas involving pyramidal tracts guided by functional neuronavigation and 5-ALA fluorescence navigation

    International Nuclear Information System (INIS)

    Sato, Ken-ichi; Ito, Tamio; Seo, Yoshinobu; Sunohara, Tadashi; Maeda, Masana; Sasaki, Takehiko; Nakagawara, Jyoji; Nakamura, Hirohiko

    2009-01-01

    For patients with malignant glioma invading pyramidal tracts, maximal resections are difficult to accomplish while preserving their motor function. We used tractography-integrated functional neuronavigation and 5-aminolevulinic acid (5-ALA) fluorescence-guided resection for removal of malignant gliomas involving pyramidal tract. In this study, we analyzed postoperative motor function and extent of resection in a series of patients who underwent surgery in our department. Ten patients with malignant glioma invading pyramidal tracts underwent radical surgery. To preserve pyramidal tracts, we developed a functional neuronavigation-guided fence-post procedure to avoid the problem of brain shift, a disadvantage of the existing neuronavigation systems. Furthermore we have achieved precise resection of tumors using 5-ALA fluorescence navigation. Intraoperatively, tumor fluorescence was visualized using a modified operating microscope. All fluorescing tumor tissue was resected. Motor function was preserved after appropriate tumor resection in all cases. Postoperatively, improvement of motor weakness was observed in seven patients, whereas transient mild motor weakness occurred in two patients. Gross total removals were accomplished in seven patients, and subtotal removal was accomplished in one patient, and partial removal was accomplished in two patients. Combined use of tractography-integrated functional neuronavigation and 5-ALA fluorescence-guided resection contributes to maximal safe resection of malignant gliomas with pyramidal tract involvement. (author)

  15. Fluoroscopy-Guided Percutaneous Lung Biopsy: A Valuable Alternative to Computed Tomography

    International Nuclear Information System (INIS)

    Kurban, L.A.; Gomersall, L.; Weir, J.; Wade, P.

    2008-01-01

    Background: Computed tomography (CT) fluoroscopy nowadays is the most preferred method of guidance to perform percutaneous lung biopsy of pulmonary masses. Conventional fluoroscopy is an increasingly forgotten technique that still can be used to perform lung biopsies, with many advantages. Purpose: To compare the accuracy, safety, and effective dose (ED) of conventional fluoroscopy-guided needle lung biopsy (FNLB) with CT-guided needle lung biopsy procedures (CTNLB) reported in the literature. Material and Methods: 100 consecutive patients who underwent FNLB were reviewed retrospectively. Using the final histological diagnoses and the clinical and radiological course of the disease as references, the accuracy and sensitivity of FNLB were calculated. The complication rates of FNLB were assessed. Using computer software (XDOSE), the ED was calculated. The accuracy, complication rates, and the ED of FNLB were compared with CTNLB reported in the literature. Results: The overall accuracy rate and sensitivity of FNLB were both 87%, which are comparable to the range of accuracies reported in the literature for CTNLB (74-97%). The complication rates of FNLB were also comparable to the complication rates reported for CTNLB. The commonest complication was pneumothorax, at a rate of 25%. The ED of FNLB was small, significantly lower than reported in the literature for CT-guided procedures. The mean ED of FNLB was 0.029 mSv, which is approximately equivalent to one chest X-ray. Conclusion: Conventional fluoroscopy is an accurate, safe, and low-dose alternative modality to CT to obtain an image-guided histological diagnosis of pulmonary lesions

  16. Computed tomography-guided needle biopsy of lung lesions in fourteen cats and dogs

    International Nuclear Information System (INIS)

    Yoshida, K.; Mori, T.; Yamada, M.; Sakaida, M.; Yonemaru, K.; Murakami, M.; Sakai, H.; Maruo, K.

    2007-01-01

    Computed tomography (CT)-guided fine-needle aspirates (FNA) or core biopsies of lung lesions were performed in nine dogs and five cats. A clinical diagnosis was obtained in twelve of fourteen animals (85%), namely 80% FNA and 100% core biopsies. Eight animals had other mass (es) apart from the lung, and five were diagnosed to metastases. In only one case, the lung mass was histopathologically diagnosed as a malignant primary tumor. Iatrogenic complications through the lung biopsies were noted in four animals, and three showed mild pneumothorax on CT images and one was bleeding from the needle. However, between fifteen and thirty minutes after the biopsy, no animal indicated signs of pneumothorax or hemorrhage

  17. Imaging osteoarthritis in the knee joints using x-ray guided diffuse optical tomography

    Science.gov (United States)

    Zhang, Qizhi; Yuan, Zhen; Sobel, Eric S.; Jiang, Huabei

    2010-02-01

    In our previous studies, near-infrared (NIR) diffuse optical tomography (DOT) had been successfully applied to imaging osteoarthritis (OA) in the finger joints where significant difference in optical properties of the joint tissues was evident between healthy and OA finger joints. Here we report for the first time that large joints such as the knee can also be optically imaged especially when DOT is combined with x-ray tomosynthesis where the 3D image of the bones from x-ray is incorporated into the DOT reconstruction as spatial a priori structural information. This study demonstrates that NIR light can image large joints such as the knee in addition to finger joints, which will drastically broaden the clinical utility of our x-ray guided DOT technique for OA diagnosis.

  18. Predicting the "usefulness" of 5-ALA-derived tumor fluorescence for fluorescence-guided resections in pediatric brain tumors

    DEFF Research Database (Denmark)

    Stummer, Walter; Rodrigues, Floriano; Schucht, Philippe

    2014-01-01

    fluorescence was "useful", i.e., leading to changes in surgical strategy or identification of residual tumor. Recursive partitioning analysis (RPA) was used for defining cohorts with high or low likelihoods for useful fluorescence. RESULTS: Data on 78 patients ..., 25 %) and pilocytic astrocytomas (two of 13; 15 %). RPA of pre-operative factors showed tumors with supratentorial location, strong contrast enhancement and first operation to have a likelihood of useful fluorescence of 64.3 %, as opposed to infratentorial tumors with first surgery (23...

  19. Guided access cavity preparation using cone-beam computed tomography and optical surface scans - an ex vivo study

    DEFF Research Database (Denmark)

    Buchgreitz, J; Buchgreitz, M; Mortensen, D

    2016-01-01

    AIM: To evaluate ex vivo, the accuracy of a preparation procedure planned for teeth with pulp canal obliteration (PCO) using a guide rail concept based on a cone-beam computed tomography (CBCT) scan merged with an optical surface scan. METHODOLOGY: A total of 48 teeth were mounted in acrylic bloc...

  20. The using of megavoltage computed tomography in image-guided brachytherapy for cervical cancer: A case report

    Energy Technology Data Exchange (ETDEWEB)

    Tharavichitkul, Ekkasit; Janla-or, Suwapim; Wanwilairat, Somsak; Chakrabandhu, Somvilai; Klunklin, Pitchayaponne; Onchan, Wimrak; Supawongwattana, Bongkot; Chitapanarux, Imjai [Division of Therapeutic Radiology and Oncology, Dept. of Radiology, Faculty of Medicine, Chiang Mai University, Chiang Mai (Thailand); Galalae, Razvan M. [Faculty of Medicine, Christian-Albrecht University (Campus Kiel), Kiel (Germany)

    2015-06-15

    We present a case of cervical cancer treated by concurrent chemoradiation. In radiation therapy part, the combination of the whole pelvic helical tomotherapy plus image-guided brachytherapy with megavoltage computed tomography of helical tomotherapy was performed. We propose this therapeutic approach could be considered in a curative setting in some problematic situation as our institution.

  1. Prior image constrained scatter correction in cone-beam computed tomography image-guided radiation therapy.

    Science.gov (United States)

    Brunner, Stephen; Nett, Brian E; Tolakanahalli, Ranjini; Chen, Guang-Hong

    2011-02-21

    X-ray scatter is a significant problem in cone-beam computed tomography when thicker objects and larger cone angles are used, as scattered radiation can lead to reduced contrast and CT number inaccuracy. Advances have been made in x-ray computed tomography (CT) by incorporating a high quality prior image into the image reconstruction process. In this paper, we extend this idea to correct scatter-induced shading artifacts in cone-beam CT image-guided radiation therapy. Specifically, this paper presents a new scatter correction algorithm which uses a prior image with low scatter artifacts to reduce shading artifacts in cone-beam CT images acquired under conditions of high scatter. The proposed correction algorithm begins with an empirical hypothesis that the target image can be written as a weighted summation of a series of basis images that are generated by raising the raw cone-beam projection data to different powers, and then, reconstructing using the standard filtered backprojection algorithm. The weight for each basis image is calculated by minimizing the difference between the target image and the prior image. The performance of the scatter correction algorithm is qualitatively and quantitatively evaluated through phantom studies using a Varian 2100 EX System with an on-board imager. Results show that the proposed scatter correction algorithm using a prior image with low scatter artifacts can substantially mitigate scatter-induced shading artifacts in both full-fan and half-fan modes.

  2. Computed tomography-guided percutaneous catheter drainage of primary and secondary iliopsoas abscesses

    International Nuclear Information System (INIS)

    Cantasdemir, M.; Kara, B.; Cebi, D.; Selcuk, N.D.; Numan, F.

    2003-01-01

    AIM: To report our experience with computed tomography (CT)-guided percutaneous catheter drainage (PCD) of iliopsoas abscesses. MATERIALS AND METHODS: Twenty-two iliopsoas abscesses in 21 patients (11 women, 10 men) aged between 18 and 66 years (mean 36 years) were treated with PCD. Abdominal CT demonstrated the iliopsoas abscesses, which were definitively determined by Gram staining and aspirate cultures. Twenty of the 22 iliopsoas abscesses were primary and two were secondary. All PCD procedures were performed under local anaesthesia using a single-step trocar technique (n=19) or Seldinger technique (n=3). RESULTS: PCD was an effective treatment in 21 out of the 22 iliopsoas abscesses. Recurrence was seen in three abscesses as minimal residual collections. Two of them resolved spontaneously with anti-tuberculous regimen. One required percutaneous needle aspiration. The procedure failed in a diabetic patient with a secondary abscess, who died due to sepsis. The length of time that catheters remained in place ranged from 21 to 75 days (mean 59.7 days). Complications included catheter dislocation in four abscesses, which required removal of dislocated catheters and indwelling new ones. CONCLUSION: CT-guided PCD is a safe and effective front-line treatment of iliopsoas abscesses. Surgery should be reserved for failure of PCD and presence of contraindications to PCD

  3. Computer tomography urography assisted real-time ultrasound-guided percutaneous nephrolithotomy on renal calculus.

    Science.gov (United States)

    Fang, You-Qiang; Wu, Jie-Ying; Li, Teng-Cheng; Zheng, Hao-Feng; Liang, Guan-Can; Chen, Yan-Xiong; Hong, Xiao-Bin; Cai, Wei-Zhong; Zang, Zhi-Jun; Di, Jin-Ming

    2017-06-01

    This study aimed to assess the role of pre-designed route on computer tomography urography (CTU) in the ultrasound-guided percutaneous nephrolithotomy (PCNL) for renal calculus.From August 2013 to May 2016, a total of 100 patients diagnosed with complex renal calculus in our hospital were randomly divided into CTU group and control group (without CTU assistance). CTU was used to design a rational route for puncturing in CTU group. Ultrasound was used in both groups to establish a working trace in the operation areas. Patients' perioperative parameters and postoperative complications were recorded.All operations were successfully performed, without transferring to open surgery. Time of channel establishment in CTU group (6.5 ± 4.3 minutes) was shorter than the control group (10.0 ± 6.7 minutes) (P = .002). In addition, there was shorter operation time, lower rates of blood transfusion, secondary operation, and less establishing channels. The incidence of postoperative complications including residual stones, sepsis, severe hemorrhage, and perirenal hematoma was lower in CTU group than in control group.Pre-designing puncture route on CTU images would improve the puncturing accuracy, lessen establishing channels as well as improve the security in the ultrasound-guided PCNL for complex renal calculus, but at the cost of increased radiation exposure.

  4. Efficacy of computed tomography guided radiofrequency ablation forosteoid osteomas in 31 patients

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jung Hoon; Ahn, Joong Mo; Lee, Joon Woo; Lee, Guen Young; Lee, Eu Gene; Oh, Joo Han; Cho, Hwan Seong; Kang, Heung Sik [Seoul National University Bundang Hospital, Seongnam (Korea, Republic of)

    2015-04-15

    To present the clinical outcome of computed tomography (CT) guided radiofrequency ablation (RFA) for osteoid osteoma. Thirty-one patients (M:F = 23:8, mean age: 20 years, range: 4-54 years) who underwent RFA for clinically suspected osteoid osteoma from May 2004 to December 2013 were retrospectively reviewed. RFA was done in all cases under CT guidance by one of three radiologists in our department. Electronic medical records and images were retrospectively reviewed in all patients. Lesions were located in femur (n = 20), tibia (n = 5), fibula (n = 2), humerus (n = 3), talus (n = 2), and calcaneus (n = 1). On discharge, 27 of 33 cases showed complete remission of pain (82%). One major complication (compartment syndrome) and 2 minor complications (reactive synovitis, minimal skin burn at electrode insertion site) were observed. On the last follow-up (0-78 months, mean: 12.6 months) 27 of 33 cases were successfully treated (82%) and had no more complaints. 3 cases presented remaining pain (9%). In 3 cases relapse occurred (9%) and RFA was repeated in 1 case. The repeated treatment was successful. CT-guided RFA is an effective method for the treatment of osteoid osteoma.

  5. Just-in-time tomography (JiTT): a new concept for image-guided radiation therapy

    Energy Technology Data Exchange (ETDEWEB)

    Pang, G; Rowlands, J A [Toronto-Sunnybrook Regional Cancer Centre, 2075 Bayview Avenue, Toronto M4N 3M5 (Canada); Imaging Research, Sunnybrook and Women' s College Health Sciences Centre, Departments of Radiation Oncology and Medical Biophysics, University of Toronto, Toronto (Canada)

    2005-11-07

    Soft-tissue target motion is one of the main concerns in high-precision radiation therapy. Cone beam computed tomography (CBCT) has been developed recently to image soft-tissue targets in the treatment room and guide the radiation therapy treatment. However, due to its relatively long image acquisition time the CBCT approach cannot provide images of the target at the instant of the treatment and thus it is not adequate for imaging targets with intrafraction motion. In this note, a new approach for image-guided radiation therapy-just-in-time tomography (JiTT)-is proposed. Differing from CBCT, JiTT takes much less time to generate the needed tomographical, beam's-eye-view images of the treatment target at the right moment to guide the radiation therapy treatment. (note)

  6. Just-in-time tomography (JiTT): a new concept for image-guided radiation therapy

    International Nuclear Information System (INIS)

    Pang, G; Rowlands, J A

    2005-01-01

    Soft-tissue target motion is one of the main concerns in high-precision radiation therapy. Cone beam computed tomography (CBCT) has been developed recently to image soft-tissue targets in the treatment room and guide the radiation therapy treatment. However, due to its relatively long image acquisition time the CBCT approach cannot provide images of the target at the instant of the treatment and thus it is not adequate for imaging targets with intrafraction motion. In this note, a new approach for image-guided radiation therapy-just-in-time tomography (JiTT)-is proposed. Differing from CBCT, JiTT takes much less time to generate the needed tomographical, beam's-eye-view images of the treatment target at the right moment to guide the radiation therapy treatment. (note)

  7. Success rates for computed tomography-guided musculoskeletal biopsies performed using a low-dose technique

    International Nuclear Information System (INIS)

    Motamedi, Kambiz; Levine, Benjamin D.; Seeger, Leanne L.; McNitt-Gray, Michael F.

    2014-01-01

    To evaluate the success rate of a low-dose (50 % mAs reduction) computed tomography (CT) biopsy technique. This protocol was adopted based on other successful reduced-CT radiation dose protocols in our department, which were implemented in conjunction with quality improvement projects. The technique included a scout view and initial localizing scan with standard dose. Additional scans obtained for further guidance or needle adjustment were acquired by reducing the tube current-time product (mAs) by 50 %. The radiology billing data were searched for CT-guided musculoskeletal procedures performed over a period of 8 months following the initial implementation of the protocol. These were reviewed for the type of procedure and compliance with the implemented protocol. The compliant CT-guided biopsy cases were then retrospectively reviewed for patient demographics, tumor pathology, and lesion size. Pathology results were compared to the ultimate diagnoses and were categorized as diagnostic, accurate, or successful. Of 92 CT-guided procedures performed during this period, two were excluded as they were not biopsies (one joint injection and one drainage), 19 were excluded due to non-compliance (operators neglected to follow the protocol), and four were excluded due to lack of available follow-up in our electronic medical records. A total of 67 compliant biopsies were performed in 63 patients (two had two biopsies, and one had three biopsies). There were 32 males and 31 females with an average age of 50 (range, 15-84 years). Of the 67 biopsies, five were non-diagnostic and inaccurate and thus unsuccessful (7 %); five were diagnostic but inaccurate and thus unsuccessful (7 %); 57 were diagnostic and accurate thus successful (85 %). These results were comparable with results published in the radiology literature. The success rate of CT-guided biopsies using a low-dose protocol is comparable to published rates for conventional dose biopsies. The implemented low-dose protocol

  8. Success rates for computed tomography-guided musculoskeletal biopsies performed using a low-dose technique

    Energy Technology Data Exchange (ETDEWEB)

    Motamedi, Kambiz; Levine, Benjamin D.; Seeger, Leanne L.; McNitt-Gray, Michael F. [UCLA Health System, Radiology, Los Angeles, CA (United States)

    2014-11-15

    To evaluate the success rate of a low-dose (50 % mAs reduction) computed tomography (CT) biopsy technique. This protocol was adopted based on other successful reduced-CT radiation dose protocols in our department, which were implemented in conjunction with quality improvement projects. The technique included a scout view and initial localizing scan with standard dose. Additional scans obtained for further guidance or needle adjustment were acquired by reducing the tube current-time product (mAs) by 50 %. The radiology billing data were searched for CT-guided musculoskeletal procedures performed over a period of 8 months following the initial implementation of the protocol. These were reviewed for the type of procedure and compliance with the implemented protocol. The compliant CT-guided biopsy cases were then retrospectively reviewed for patient demographics, tumor pathology, and lesion size. Pathology results were compared to the ultimate diagnoses and were categorized as diagnostic, accurate, or successful. Of 92 CT-guided procedures performed during this period, two were excluded as they were not biopsies (one joint injection and one drainage), 19 were excluded due to non-compliance (operators neglected to follow the protocol), and four were excluded due to lack of available follow-up in our electronic medical records. A total of 67 compliant biopsies were performed in 63 patients (two had two biopsies, and one had three biopsies). There were 32 males and 31 females with an average age of 50 (range, 15-84 years). Of the 67 biopsies, five were non-diagnostic and inaccurate and thus unsuccessful (7 %); five were diagnostic but inaccurate and thus unsuccessful (7 %); 57 were diagnostic and accurate thus successful (85 %). These results were comparable with results published in the radiology literature. The success rate of CT-guided biopsies using a low-dose protocol is comparable to published rates for conventional dose biopsies. The implemented low-dose protocol

  9. Computed tomography guided needle biopsy: experience from 1,300 procedures

    Energy Technology Data Exchange (ETDEWEB)

    Chojniak, Rubens; Isberner, Rony Klaus; Viana, Luciana Marinho; Yu, Liao Shin; Aita, Alessandro Amorim; Soares, Fernando Augusto [Hospital do Cancer A.C. Camargo, Sao Paulo, SP (Brazil). Dept. de Radiologia e Patologia

    2006-01-15

    Context and objective: computed tomography (CT) guided biopsy is widely accepted as effective and safe for diagnosis in many settings. Accuracy depends on target organ and needle type. Cutting needles present advantages over fine needles. This study presents experience from CT guided biopsies performed at an oncology center. Design and setting: retrospective study at Hospital do Cancer A. C. Camargo, Sao Paulo.Methods: 1,300 consecutive CT guided biopsies performed between July 1994 and February 2000 were analyzed. Nodules or masses were suspected as primary malignancy in 845 cases (65%) or metastatic lesion in 455 (35%). 628 lesions were thoracic, 281 abdominal, 208 retroperitoneal, 134 musculoskeletal and 49 head/neck. All biopsies were performed by one radiologist or under his supervision: 765 (59%) with 22-gauge fine-needle/aspiration technique and 535 (41%) with automated 16 or 18-gauge cutting-needle biopsy. Results: adequate samples were obtained in 70-92% of fine-needle and 93-100% of cutting-needle biopsies. The specific diagnosis rates were 54-67% for fine-needle and 82-100% for cutting-needle biopsies, according to biopsy site. For any site, sample adequacy and specific diagnosis rate were always better for cutting-needle biopsy. Among 530 lung biopsies, there were 84 pneumothorax (16%) and two hemothorax (0.3%) cases, with thoracic drainage in 24 (4.9%). Among abdominal and retroperitoneal biopsies, there were two cases of major bleeding and one of peritonitis. Conclusion: both types of needle showed satisfactory results, but cutting-needle biopsy should be used when specific diagnosis is desired without greater incidence of complications. (author)

  10. Tomography

    International Nuclear Information System (INIS)

    1985-01-01

    Already widely accepted in medicine, tomography can also be useful in industry. The theory behind tomography and a demonstration of the technique to inspect a motorcycle carburetor is presented. To demonstrate the potential of computer assisted tomography (CAT) to accurately locate defects in three dimensions, a sectioned 5 cm gate valve with a shrink cavity made visible by the sectioning was tomographically imaged using a Co-60 source. The tomographic images revealed a larger cavity below the sectioned surface. The position of this cavity was located with an in-plane and axial precision of approximately +-1 mm. The volume of the cavity was estimated to be approximately 40 mm 3

  11. 5-ALA Fluorescence Image Guided Resection of Glioblastoma Multiforme: A Meta-Analysis of the Literature

    Directory of Open Access Journals (Sweden)

    Samy Eljamel

    2015-05-01

    Full Text Available Background: Glioblastoma multiforme (GBM is one of the most deadly cancers in humans. Despite recent advances in anti-cancer therapies, most patients with GBM die from local disease progression. Fluorescence image guided surgical resection (FIGR was recently advocated to enhance local control of GBM. This is meta-analyses of 5-aminolevulinic (5-ALA induced FIGR. Materials: Review of the literature produced 503 potential publications; only 20 of these fulfilled the inclusion criteria of this analysis, including a total of 565 patients treated with 5-ALA-FIGR reporting on its outcomes and 800 histological samples reporting 5-ALA-FIGR sensitivity and specificity. Results: The mean gross total resection (GTR rate was 75.4% (95% CI: 67.4–83.5, p < 0.001. The mean time to tumor progression (TTP was 8.1 months (95% CI: 4.7–12, p < 0.001. The mean overall survival gain reported was 6.2 months (95% CI: −1–13, p < 0.001. The specificity was 88.9% (95% CI: 83.9–93.9, p < 0.001 and the sensitivity was 82.6% (95% CI: 73.9–91.9, p < 0.001. Conclusion: 5-ALA-FIGR in GBM is highly sensitive and specific, and imparts significant benefits to patients in terms of improved GTR and TTP.

  12. Prevention of bladder tumor implantion after fluorescence-guided TUR with photodynamic therapy

    Science.gov (United States)

    Berrahmoune, Saoussen; Bezdetnaya, Lina; de Witte, Peter; Leroux, Agnès; Dumas, Dominique; Guillemin, François; D'Hallewin, Marie Ange

    2009-06-01

    The prevalence of bladder cancer is very high, due to its high recurrence rate in superficial bladder cancer (30 to 85%), which is the staging of approximately 80% of the patients at first diagnosis. Risk of recurrence and progression is associated with grade, stage, presence of concomitant carcinoma in situ, size and number of lesions, as well as time to first recurrence. Recurrences can be partly attributed to new occurrences but also to residual tumors after resection. Incomplete tumor removal has been observed in 30 to 50% of TUR's, especially when dealing with T1 or poorly visible malignant or pre-malignant disease1. Fluorescence guided resection with 5 amino levulinic acid (ALA) or its hexyl ester derivative (Hexvix, has now unequivocally been demonstrated to increase detection rate and a growing number of studies indicate this has a positive impact on recurrence and progression ratesImplantation of viable tumor cells, dispersed during resection, is a third factor influencing bladder cancer recurrence. The aim of early intravesical therapy is to interfere with cell viability and thus reduce implantation risks.

  13. Automated microaxial tomography of cell nuclei after specific labelling by fluorescence in situ hybridisation

    Czech Academy of Sciences Publication Activity Database

    Kozubek, Michal; Skalníková, M.; Matula, Pe.; Bártová, Eva; Rauch, J.; Neuhaus, F.; Eipel, H.; Hasmann, M.

    2002-01-01

    Roč. 33, 7-8 (2002), s. 655-665 ISSN 0968-4328 Institutional research plan: CEZ:AV0Z5004920 Keywords : microaxial tomography * automated microscopy * high-resolution cytometry Subject RIV: BO - Biophysics Impact factor: 1.537, year: 2002

  14. Dual source and dual detector arrays tetrahedron beam computed tomography for image guided radiotherapy

    International Nuclear Information System (INIS)

    Kim, Joshua; Zhang, Tiezhi; Lu, Weiguo

    2014-01-01

    Cone-beam computed tomography (CBCT) is an important online imaging modality for image guided radiotherapy. But suboptimal image quality and the lack of a real-time stereoscopic imaging function limit its implementation in advanced treatment techniques, such as online adaptive and 4D radiotherapy. Tetrahedron beam computed tomography (TBCT) is a novel online imaging modality designed to improve on the image quality provided by CBCT. TBCT geometry is flexible, and multiple detector and source arrays can be used for different applications. In this paper, we describe a novel dual source–dual detector TBCT system that is specially designed for LINAC radiation treatment machines. The imaging system is positioned in-line with the MV beam and is composed of two linear array x-ray sources mounted aside the electrical portal imaging device and two linear arrays of x-ray detectors mounted below the machine head. The detector and x-ray source arrays are orthogonal to each other, and each pair of source and detector arrays forms a tetrahedral volume. Four planer images can be obtained from different view angles at each gantry position at a frame rate as high as 20 frames per second. The overlapped regions provide a stereoscopic field of view of approximately 10–15 cm. With a half gantry rotation, a volumetric CT image can be reconstructed having a 45 cm field of view. Due to the scatter rejecting design of the TBCT geometry, the system can potentially produce high quality 2D and 3D images with less radiation exposure. The design of the dual source–dual detector system is described, and preliminary results of studies performed on numerical phantoms and simulated patient data are presented. (paper)

  15. Dual source and dual detector arrays tetrahedron beam computed tomography for image guided radiotherapy

    Science.gov (United States)

    Kim, Joshua; Lu, Weiguo; Zhang, Tiezhi

    2014-02-01

    Cone-beam computed tomography (CBCT) is an important online imaging modality for image guided radiotherapy. But suboptimal image quality and the lack of a real-time stereoscopic imaging function limit its implementation in advanced treatment techniques, such as online adaptive and 4D radiotherapy. Tetrahedron beam computed tomography (TBCT) is a novel online imaging modality designed to improve on the image quality provided by CBCT. TBCT geometry is flexible, and multiple detector and source arrays can be used for different applications. In this paper, we describe a novel dual source-dual detector TBCT system that is specially designed for LINAC radiation treatment machines. The imaging system is positioned in-line with the MV beam and is composed of two linear array x-ray sources mounted aside the electrical portal imaging device and two linear arrays of x-ray detectors mounted below the machine head. The detector and x-ray source arrays are orthogonal to each other, and each pair of source and detector arrays forms a tetrahedral volume. Four planer images can be obtained from different view angles at each gantry position at a frame rate as high as 20 frames per second. The overlapped regions provide a stereoscopic field of view of approximately 10-15 cm. With a half gantry rotation, a volumetric CT image can be reconstructed having a 45 cm field of view. Due to the scatter rejecting design of the TBCT geometry, the system can potentially produce high quality 2D and 3D images with less radiation exposure. The design of the dual source-dual detector system is described, and preliminary results of studies performed on numerical phantoms and simulated patient data are presented.

  16. US-guided diffuse optical tomography for breast lesions: the reliability of clinical experience

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Min Jung; Kim, Ji Youn; Youn, Jung Hyun; Kim, Myung Hyun; Koo, Hye Ryoung; Kim, Soo Jin; Sohn, Yu-Mee; Moon, Hee Jung; Kim, Eun-Kyung [Yonsei University College of Medicine, Institute of Radiological Science, Seoul (Korea, Republic of); Yonsei University College of Medicine, Department of Radiology, Seoul (Korea, Republic of)

    2011-07-15

    To prospectively assess the reliability of US-guided diffuse optical tomography (US-DOT) using interobserver agreement for the diagnosis of breast lesions with individual real-time imaging and to assess the interobserver agreement of conventional sonography (US) combined with US-DOT for differentiation between benignity and malignancy breast lesions. An Institutional Review Board approved this study, and all subjects provided written informed consent. 122 breast lesions in 111 patients evaluated with US-guided core biopsy were included. Assessments with US and US-DOT for cases subjected to biopsy were obtained by two radiologists using individual real-time imaging prior to biopsy and were prospectively recorded by each performer. With DOT, the total haemoglobin concentration (THC) for each breast lesion was measured. Histopathological results from US-guided biopsies were used as a reference standard. To assess measurement interobserver agreement, the intraclass correlation coefficient (ICC) and the Bland-Altman plot were used for THC in US-DOT and the kappa values and ROC analysis were used to evaluate the diagnostic performances of the US BI-RADS final assessment in US and combined US and US-DOT. Of 122 US-guided core biopsied lesions, 83 (68.0%) were diagnosed as benign, and 39 (32.0%) as malignant. Excellent correlation was seen in the THC in US-DOT (ICC score 0.796; 95% confidence interval, 0.708-0.857). The interobserver agreement in BI-RADS final assessment with US and US-DOT (almost perfect; {kappa} = 0.8618) was improved compared with that of US (substantial agreement, {kappa} = 0.6574). However, the overall areas under the ROC curve did not show significant differences between US and combined US and US-DOT, 0.8894 and 0.8975, respectively (P = 0.981). The reliability of THC in US-DOT showed excellent correlation in overall real-time performance. Although the inter-observer agreement for BI-RADS final assessment of US was improved by using US-DOT, the

  17. Computed-tomography-guided anatomic standardization for quantitative assessment of dopamine transporter SPECT

    Energy Technology Data Exchange (ETDEWEB)

    Yokoyama, Kota [National Center of Neurology and Psychiatry, Department of Radiology, Tokyo (Japan); National Center of Neurology and Psychiatry, Integrative Brain Imaging Center, Tokyo (Japan); Imabayashi, Etsuko; Matsuda, Hiroshi [National Center of Neurology and Psychiatry, Integrative Brain Imaging Center, Tokyo (Japan); Sumida, Kaoru; Sone, Daichi; Kimura, Yukio; Sato, Noriko [National Center of Neurology and Psychiatry, Department of Radiology, Tokyo (Japan); Mukai, Youhei; Murata, Miho [National Center of Neurology and Psychiatry, Department of Neurology, Tokyo (Japan)

    2017-03-15

    For the quantitative assessment of dopamine transporter (DAT) using [{sup 123}I]FP-CIT single-photon emission computed tomography (SPECT) (DaTscan), anatomic standardization is preferable for achieving objective and user-independent quantification of striatal binding using a volume-of-interest (VOI) template. However, low accumulation of DAT in Parkinson's disease (PD) would lead to a deformation error when using a DaTscan-specific template without any structural information. To avoid this deformation error, we applied computed tomography (CT) data obtained using SPECT/CT equipment to anatomic standardization. We retrospectively analyzed DaTscan images of 130 patients with parkinsonian syndromes (PS), including 80 PD and 50 non-PD patients. First we segmented gray matter from CT images using statistical parametric mapping 12 (SPM12). These gray-matter images were then anatomically standardized using the diffeomorphic anatomical registration using exponentiated Lie algebra (DARTEL) algorithm. Next, DaTscan images were warped with the same parameters used in the CT anatomic standardization. The target striatal VOIs for decreased DAT in PD were generated from the SPM12 group comparison of 20 DaTscan images from each group. We applied these VOIs to DaTscan images of the remaining patients in both groups and calculated the specific binding ratios (SBRs) using nonspecific counts in a reference area. In terms of the differential diagnosis of PD and non-PD groups using SBR, we compared the present method with two other methods, DaTQUANT and DaTView, which have already been released as software programs for the quantitative assessment of DaTscan images. The SPM12 group comparison showed a significant DAT decrease in PD patients in the bilateral whole striatum. Of the three methods assessed, the present CT-guided method showed the greatest power for discriminating PD and non-PD groups, as it completely separated the two groups. CT-guided anatomic standardization using

  18. 3D imaging of vapour and liquid inclusions from the Mole Granite, Australia, using helical fluorescence tomography

    Energy Technology Data Exchange (ETDEWEB)

    Cauzid, J. [European Synchrotron Radiation Facility, 6 rue Jules Horowitz, BP 220, 38043 Grenoble Cedex (France)], E-mail: jean.cauzid@esrf.fr; Philippot, P. [Geobiosphere Actuelle et Primitive, Institut de Physique du Globe de Paris, CNRS and Universite Denis Diderot, Case 89, 4 place Jussieu, 75252 Paris Cedex 05 (France); Bleuet, P. [European Synchrotron Radiation Facility, 6 rue Jules Horowitz, BP 220, 38043 Grenoble Cedex (France); Simionovici, A. [Laboratoire de Geophysique Interne et Tectonophysique, BP 53, 38041 Grenoble Cedex 9 (France); Somogyi, A. [Synchrotron Soleil, DiffAbs beamline, Saint-Aubin, BP 48, 91192 Gif-sur-Yvette Cedex (France); Golosio, B. [Instituto di Matematica e Fisica, Universita di Sassari, 2 via Vienna, 07100 Sassari (Italy)

    2007-08-15

    World class Cu resources are concentrated in porphyry and epithermal ore deposits. Their formation remains partially understood, however, due to a lack of constraints on the partitioning properties of trace elements in general, and Cu in particular, between vapour and liquid phases evolved from boiling fluids at depth in the Earth's crust. Immiscible liquid and vapour fluid inclusions coexisting in a single quartz grain have been imaged in three dimensions by X-ray Fluorescence Computed Tomography (XFCT). Elemental spatial distributions confirm that Cu, and to a lesser extent As, partition into the vapour phase, whereas Mn, Fe, Zn, Br, Rb, Sr and Pb concentrate in the liquid inclusion. High resolution mapping of the vapour inclusions revealed that Cu is heterogeneously distributed at the scale of a single inclusion and is mostly concentrated as tiny daughter crystals.

  19. Optical design of an optical coherence tomography and multispectral fluorescence imaging endoscope to detect early stage ovarian cancer

    Science.gov (United States)

    Tate, Tyler; Keenan, Molly; Swan, Elizabeth; Black, John; Utzinger, Urs; Barton, Jennifer

    2014-12-01

    The five year survival rate for ovarian cancer is over 90% if early detection occurs, yet no effective early screening method exists. We have designed and are constructing a dual modality Optical Coherence Tomography (OCT) and Multispectral Fluorescence Imaging (MFI) endoscope to optically screen the Fallopian tube and ovary for early stage cancer. The endoscope reaches the ovary via the natural pathway of the vagina, cervix, uterus and Fallopian tube. In order to navigate the Fallopian tube the endoscope must have an outer diameter of 600 μm, be highly flexible, steerable, tracking and nonperforating. The imaging systems consists of six optical subsystems, two from OCT and four from MFI. The optical subsystems have independent and interrelated design criteria. The endoscope will be tested on realistic tissue models and ex vivo tissue to prove feasibility of future human trials. Ultimately the project aims to provide women the first effective ovarian cancer screening technique.

  20. 3D imaging of vapour and liquid inclusions from the Mole Granite, Australia, using helical fluorescence tomography

    Science.gov (United States)

    Cauzid, J.; Philippot, P.; Bleuet, P.; Simionovici, A.; Somogyi, A.; Golosio, B.

    2007-08-01

    World class Cu resources are concentrated in porphyry and epithermal ore deposits. Their formation remains partially understood, however, due to a lack of constraints on the partitioning properties of trace elements in general, and Cu in particular, between vapour and liquid phases evolved from boiling fluids at depth in the Earth's crust. Immiscible liquid and vapour fluid inclusions coexisting in a single quartz grain have been imaged in three dimensions by X-ray Fluorescence Computed Tomography (XFCT). Elemental spatial distributions confirm that Cu, and to a lesser extent As, partition into the vapour phase, whereas Mn, Fe, Zn, Br, Rb, Sr and Pb concentrate in the liquid inclusion. High resolution mapping of the vapour inclusions revealed that Cu is heterogeneously distributed at the scale of a single inclusion and is mostly concentrated as tiny daughter crystals.

  1. Efficacy of Lower-Body Shielding in Computed Tomography Fluoroscopy-Guided Interventions

    International Nuclear Information System (INIS)

    Mahnken, Andreas H.; Sedlmair, Martin; Ritter, Christine; Banckwitz, Rosemarie; Flohr, Thomas

    2012-01-01

    Purpose: Computed tomography (CT) fluoroscopy-guided interventions pose relevant radiation exposure to the interventionalist. The goal of this study was to analyze the efficacy of lower-body shielding as a simple structural method for decreasing radiation dose to the interventionalist without limiting access to the patient. Material and Methods: All examinations were performed with a 128-slice dual source CT scanner (12 × 1.2-mm collimation; 120 kV; and 20, 40, 60, and 80 mAs) and an Alderson-Rando phantom. Scatter radiation was measured with an ionization chamber and a digital dosimeter at standardized positions and heights with and without a lower-body lead shield (0.5-mm lead equivalent; Kenex, Harlow, UK). Dose decreases were computed for the different points of measurement. Results: On average, lower-body shielding decreased scatter radiation by 38.2% within a 150-cm radius around the shielding. This decrease is most significant close to the gantry opening and at low heights of 50 and 100 cm above the floor with a maximum decrease of scatter radiation of 95.9% close to the scanner’s isocentre. With increasing distance to the gantry opening, the effect decreased. There is almost no dose decrease effect at ≥150 above the floor. Scatter radiation and its decrease were linearly correlated with the tube current-time product (r 2 = 0.99), whereas percent scatter radiation decrease was independent of the tube current-time product. Conclusion: Lower-body shielding is an effective way to decrease radiation exposure to the interventionalist and should routinely be used in CT fluoroscopy-guided interventions.

  2. Co-registration of fluorescence diffuse optical tomography (fDOT) with positron emission tomography (PET) and development of multi-angle fDOT

    International Nuclear Information System (INIS)

    Tong, X.

    2012-01-01

    This thesis concerns the image processing of fluorescence diffuse optical tomography (fDOT), following two axes: fDOT image co-registration with PET (positron emission tomography) image and improvement of fDOT image reconstructions using mirrors to collect additional projections. It is presented in two parts:In the first part, an automatic method to co-register the fDOT images with PET images has been developed to correlate all the information from each modality. This co-registration method is based on automatic detection of fiducial markers (FM) present in both modalities. The particularity of this method is the use of optical surface image obtained in fDOT imaging system, which serves to identify the Z position of FM in optical images. We tested this method on a model of mice bearing tumor xenografts of MEN2A cancer cells that mimic a human medullary thyroid carcinoma, after a double injection of radiotracer [ 18 F] 2-fluoro-2-Deoxy-D-glucose (FDG) for PET imaging and optical fluorescent infrared tracer Sentidye. With the accuracy of our method, we can demonstrate that the signal of Sentidye is present both in the tumor and surrounding vessels.The fDOT reconstruction image quality is degraded along the Z axis due to a limited number of projections for reconstruction. In the second part, the work is oriented towards a new method of fDOT image reconstruction with a new multi-angle data acquisition system in placing two mirrors on each side of the animal. This work was conducted in collaboration with the CS Department of University College London (UCL), a partner of the European project FMT-XCT. TOAST software developed by this team was used as source code for the reconstruction algorithm, and was modified to adapt to the concerned problem. After several tests on the adjustment of program parameters, we applied this method on a phantom that simulating the biological tissue and on mice. The results showed an improvement in the reconstructed image of a semi

  3. Three-dimensional organization of pKi-67: a comparative fluorescence and electron tomography study using FluoroNanogold.

    Science.gov (United States)

    Cheutin, Thierry; O'Donohue, Marie-Françoise; Beorchia, Adrien; Klein, Christophe; Kaplan, Hervé; Ploton, Dominique

    2003-11-01

    The monoclonal antibody (MAb) Ki-67 is routinely used in clinical studies to estimate the growth fraction of tumors. However, the role of pKi-67, the protein detected by the Ki-67 MAb, remains elusive, although some biochemical data strongly suggest that it might organize chromatin. To better understand the functional organization of pKi-67, we studied its three-dimensional distribution in interphase cells by confocal microscopy and electron tomography. FluoroNanogold, a single probe combining a dense marker with a fluorescent dye, was used to investigate pKi-67 organization at the optical and ultrastructural levels. Observation by confocal microscopy followed by 3D reconstruction showed that pKi-67 forms a shell around the nucleoli. Double labeling experiments revealed that pKi-67 co-localizes with perinucleolar heterochromatin. Electron microscopy studies confirmed this close association and demonstrated that pKi-67 is located neither in the fibrillar nor in the granular components of the nucleolus. Finally, spatial analyses by electron tomography showed that pKi-67 forms cords 250-300 nm in diameter, which are themselves composed of 30-50-nm-thick fibers. These detailed comparative in situ analyses strongly suggest the involvement of pKi-67 in the higher-order organization of perinucleolar chromatin.

  4. Surgical positioning of orthodontic mini-implants with guides fabricated on models replicated with cone-beam computed tomography.

    Science.gov (United States)

    Kim, Seong-Hun; Choi, Yong-Suk; Hwang, Eui-Hwan; Chung, Kyu-Rhim; Kook, Yoon-Ah; Nelson, Gerald

    2007-04-01

    This article illustrates a new surgical guide system that uses cone-beam computed tomography (CBCT) images to replicate dental models; surgical guides for the proper positioning of orthodontic mini-implants were fabricated on the replicas, and the guides were used for precise placement. The indications, efficacy, and possible complications of this method are discussed. Patients who were planning to have orthodontic mini-implant treatment were recruited for this study. A CBCT system (PSR 9000N, Asahi Roentgen, Kyoto, Japan) was used to acquire virtual slices of the posterior maxilla that were 0.1 to 0.15 mm thick. Color 3-dimensional rapid prototyping was used to differentiate teeth, alveolus, and maxillary sinus wall. A surgical guide for the mini-implant was fabricated on the replica model. Proper positioning for mini-implants on the posterior maxilla was determined by viewing the CBCT images. The surgical guide was placed on the clinical site, and it allowed precise pilot drilling and accurate placement of the mini-implant. CBCT imaging allows remarkably lower radiation doses and thinner acquisition slices compared with medical computed tomography. Virtually reproduced replica models enable precise planning for mini-implant positions in anatomically complex sites.

  5. Image-guided modified deep anterior lamellar keratoplasty (DALK) corneal transplant using intraoperative optical coherence tomography

    Science.gov (United States)

    Tao, Yuankai K.; LaBarbera, Michael; Ehlers, Justis P.; Srivastava, Sunil K.; Dupps, William J.

    2015-03-01

    Deep anterior lamellar keratoplasty (DALK) is an alternative to full-thickness corneal transplant and has advantages including the absence of allograft rejection; shortened duration of topical corticosteroid treatment and reduced associated risk of glaucoma, cataract, or infection; and enables use of grafts with poor endothelial quality. DALK begins by performing a trephination of approximately 80% stromal thickness, as measured by pachymetry. After removal of the anterior stoma, a needle is inserted into the residual stroma to inject air or viscoelastic to dissect Descemet's membrane. These procedures are inherently difficult and intraoperative rates of Descemet's membrane perforation between 4-39% have been reported. Optical coherence tomography (OCT) provides high-resolution images of tissue microstructures in the cornea, including Descemet's membrane, and allows quantitation of corneal layer thicknesses. Here, we use crosssectional intraoperative OCT (iOCT) measurements of corneal thickness during surgery and a novel micrometeradjustable biopsy punch to precision-cut the stroma down to Descemet's membrane. Our prototype cutting tool allows us to establish a dissection plane at the corneal endothelium interface, mitigates variability in cut-depths as a result of tremor, reduces procedure complexity, and reduces complication rates. iOCT-guided modified DALK procedures were performed on 47 cadaveric porcine eyes by non-experts and achieved a perforation rate of ~5% with a mean corneal dissection time care.

  6. Creating vascular models by postprocessing computed tomography angiography images: a guide for anatomical education.

    Science.gov (United States)

    Govsa, Figen; Ozer, Mehmet Asim; Sirinturk, Suzan; Eraslan, Cenk; Alagoz, Ahmet Kemal

    2017-08-01

    A new application of teaching anatomy includes the use of computed tomography angiography (CTA) images to create clinically relevant three-dimensional (3D) printed models. The purpose of this article is to review recent innovations on the process and the application of 3D printed models as a tool for using under and post-graduate medical education. Images of aortic arch pattern received by CTA were converted into 3D images using the Google SketchUp free software and were saved in stereolithography format. Using a 3D printer (Makerbot), a model mode polylactic acid material was printed. A two-vessel left aortic arch was identified consisting of the brachiocephalic trunk and left subclavian artery. The life-like 3D models were rotated 360° in all axes in hand. The early adopters in education and clinical practices have embraced the medical imaging-guided 3D printed anatomical models for their ability to provide tactile feedback and a superior appreciation of visuospatial relationship between the anatomical structures. Printed vascular models are used to assist in preoperative planning, develop intraoperative guidance tools, and to teach patients surgical trainees in surgical practice.

  7. [Fluoroscopy dose reduction of computed tomography guided chest interventional radiology using real-time iterative reconstruction].

    Science.gov (United States)

    Hasegawa, Hiroaki; Mihara, Yoshiyuki; Ino, Kenji; Sato, Jiro

    2014-11-01

    The purpose of this study was to evaluate the radiation dose reduction to patients and radiologists in computed tomography (CT) guided examinations for the thoracic region using CT fluoroscopy. Image quality evaluation of the real-time filtered back-projection (RT-FBP) images and the real-time adaptive iterative dose reduction (RT-AIDR) images was carried out on noise and artifacts that were considered to affect the CT fluoroscopy. The image standard deviation was improved in the fluoroscopy setting with less than 30 mA on 120 kV. With regard to the evaluation of artifact visibility and the amount generated by the needle attached to the chest phantom, there was no significant difference between the RT-FBP images with 120 kV, 20 mA and the RT-AIDR images with low-dose conditions (greater than 80 kV, 30 mA and less than 120 kV, 20 mA). The results suggest that it is possible to reduce the radiation dose by approximately 34% at the maximum using RT-AIDR while maintaining image quality equivalent to the RT-FBP images with 120 V, 20 mA.

  8. Percutaneous computed tomography-guided ethanol injection in aldosterone-producing adrenocortical adenoma

    International Nuclear Information System (INIS)

    Rossi, R.; Savastano, S.; Tommaselli, A.P.

    1995-01-01

    The feasibility, safety and effectiveness of percutaneous computed tomography-guided ethanol injection (PEI-CT) was investigated in a patient affected by aldosterone-producing adenoma (APA). A 42-year-old male patient with typical features of hyperaldosteronism presented a solitary left adrenal adenoma measuring 2 cm, with a normal contralateral gland, evidenced by both CT scan and adrenal [ 75 Se-19]-nor-cholesterol scintigraphy. After normalization of potassium plasma levels, 4 ml of sterile 95% ethanol with 0.5 ml of 80% iothalamate sodium was injected. The procedure was completed in about 30 min. No severe pain or local complication was noted. Five hour after PEI, a fourfold and a twofold increase in aldosterone and cortisol plasma levels were observed, respectively. After 11 days on a normal sodium and potassium diet, normal potassium plasma levels and reduced aldosterone plasma levels were present, with reappearance of an aldosterone postural response. Plasma renin activity and aldosterone plasma levels normalized 1 month later, with reappearance also of a plasma renin activity postural response and maintenance of normal potassium plasma levels on a high sodium and normal potassium diet. The patient has remained hypertensive, although lower antihypertensive drug dosages have been employed. After 17 months, normal biochemical, hormonal and morphological findings were present. The authors suggested PEI-CT as a further alternative approach to surgery in the management of carefully selected patients with APA. 15 refs., 2 figs., 1 tab

  9. Artifact reduction method in ultrasound-guided diffuse optical tomography using exogenous contrast agents

    Science.gov (United States)

    Ardeshirpour, Yasaman; Biswal, Nrusingh; Aguirre, Andres; Zhu, Quing

    2011-04-01

    In diffuse optical tomography (DOT), a typical perturbation approach requires two sets of measurements obtained at the lesion breast (lesion or target site) and a contra-lateral location of the normal breast (reference site) for image reconstruction. For patients who have a small amount of breast tissue, the chest-wall underneath the breast tissue at both sites affects the imaging results. In this group of patients, the perturbation, which is the difference between measurements obtained at the lesion and reference sites, may include the information of background mismatch which can generate artifacts or affect the reconstructed quantitative absorption coefficient of the lesion. Also, for patients who have a single breast due to prior surgery, the contra-lateral reference is not available. To improve the DOT performance or overcome its limitation, we introduced a new method based on an exogenous contrast agent and demonstrate its performance using animal models. Co-registered ultrasound was used to guide the lesion localization. The results have shown that artifacts caused by background mismatch can be reduced significantly by using this new method.

  10. Tomography

    International Nuclear Information System (INIS)

    Barrett, H.H.; Gordon, S.; Swindell, W.

    1980-01-01

    Apparatus is described for generating a two-dimensional back-projected image of a slice of an object in tomography. The apparatus uses optical techniques to perform the functions of filtering and back projection. Central to the technique is a cylindrical drum which rotates at a fast rate and whose rotational axis tilts at a slower rate. The novel method overcomes the problem of image blurring due to motion which occurs in many tomographic techniques. It also has the advantages of being less expensive and simpler compared to tomography using digital processing techniques which require fast computers. (UK)

  11. Optical coherent tomography and fluorescent microscopy for the study of meningeal lymphatic systems

    Science.gov (United States)

    Semyachkina-Glushkovskaya, O.; Abdurashitov, A.; Namykin, A.; Fedosov, I.; Pavlov, A.; Karavaev, A.; Sindeeva, O.; Shirokov, A.; Ulanova, M.; Shushunova, N.; Khorovodov, A.; Agranovich, I.; Bodrova, A.; Sagatova, M.; Shareef, Ali Esmat; Saranceva, E.; Dvoryatkina, M.; Tuchin, V.

    2018-04-01

    The development of novel technologies for the imaging of meningeal lymphatic vessels is one of the amazing trends of biophotonics thanks to discovery of brain lymphatics over several years ago. However, there is the limited technologies exist for the study of lymphatics in vivo because lymphatic vessels are transparent with a low speed flow of lymph. Here we demonstrate the successful application of fluorescent microscopy for the imaging of lymphatic system in the mouse brain in vivo.

  12. A Google Glass navigation system for ultrasound and fluorescence dual-mode image-guided surgery

    Science.gov (United States)

    Zhang, Zeshu; Pei, Jing; Wang, Dong; Hu, Chuanzhen; Ye, Jian; Gan, Qi; Liu, Peng; Yue, Jian; Wang, Benzhong; Shao, Pengfei; Povoski, Stephen P.; Martin, Edward W.; Yilmaz, Alper; Tweedle, Michael F.; Xu, Ronald X.

    2016-03-01

    Surgical resection remains the primary curative intervention for cancer treatment. However, the occurrence of a residual tumor after resection is very common, leading to the recurrence of the disease and the need for re-resection. We develop a surgical Google Glass navigation system that combines near infrared fluorescent imaging and ultrasonography for intraoperative detection of sites of tumor and assessment of surgical resection boundaries, well as for guiding sentinel lymph node (SLN) mapping and biopsy. The system consists of a monochromatic CCD camera, a computer, a Google Glass wearable headset, an ultrasonic machine and an array of LED light sources. All the above components, except the Google Glass, are connected to a host computer by a USB or HDMI port. Wireless connection is established between the glass and the host computer for image acquisition and data transport tasks. A control program is written in C++ to call OpenCV functions for image calibration, processing and display. The technical feasibility of the system is tested in both tumor simulating phantoms and in a human subject. When the system is used for simulated phantom resection tasks, the tumor boundaries, invisible to the naked eye, can be clearly visualized with the surgical Google Glass navigation system. This system has also been used in an IRB approved protocol in a single patient during SLN mapping and biopsy in the First Affiliated Hospital of Anhui Medical University, demonstrating the ability to successfully localize and resect all apparent SLNs. In summary, our tumor simulating phantom and human subject studies have demonstrated the technical feasibility of successfully using the proposed goggle navigation system during cancer surgery.

  13. Fluorescence-guided surgery of human colon cancer increases complete resection resulting in cures in an orthotopic nude mouse model.

    Science.gov (United States)

    Metildi, Cristina A; Kaushal, Sharmeela; Snyder, Cynthia S; Hoffman, Robert M; Bouvet, Michael

    2013-01-01

    We inquired if fluorescence-guided surgery (FGS) could improve surgical outcomes in fluorescent orthotopic nude mouse models of human colon cancer. We established fluorescent orthotopic mouse models of human colon cancer expressing a fluorescent protein. Tumors were resected under bright light surgery (BLS) or FGS. Pre- and post-operative images with the OV-100 Small Animal Imaging System (Olympus Corp, Tokyo Japan) were obtained to assess the extent of surgical resection. All mice with primary tumor that had undergone FGS had complete resection compared with 58% of mice in the BLS group (P = 0.001). FGS resulted in decreased recurrence compared with BLS (33% versus 62%, P = 0.049) and lengthened disease-free median survival from 9 to >36 wk. The median overall survival increased from 16 wk in the BLS group to 31 weeks in the FGS group. FGS resulted in a cure in 67% of mice (alive without evidence of tumor at >6 mo after surgery) compared with only 37% of mice that underwent BLS (P = 0.049). Surgical outcomes in orthotopic nude mouse models of human colon cancer were significantly improved with FGS. The present study can be translated to the clinic by various effective methods of fluorescently labeling tumors. Copyright © 2013 Elsevier Inc. All rights reserved.

  14. Efficacy and safety of balloon pulmonary angioplasty for chronic thromboembolic pulmonary hypertension guided by cone-beam computed tomography and electrocardiogram-gated area detector computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Ogo, Takeshi, E-mail: ogo.takeshi.hp@mail.ncvc.go.jp [Division of Pulmonary Circulation, Department of Cardiovascular Medicine, National Cerebral and Cardiovascular Centre, Osaka (Japan); Department of Advanced Mediccal Research for Pulmonary Hypertension, National Cerebral and Cardiovascular Centre, Osaka (Japan); Fukuda, Tetsuya [Department of Radiology, National Cerebral and Cardiovascular Centre, Osaka (Japan); Tsuji, Akihiro; Fukui, Shigefumi; Ueda, Jin [Division of Pulmonary Circulation, Department of Cardiovascular Medicine, National Cerebral and Cardiovascular Centre, Osaka (Japan); Sanda, Yoshihiro [Department of Cardiovascular Medicine, National Cerebral and Cardiovascular Centre, Osaka (Japan); Morita, Yoshiaki [Department of Radiology, National Cerebral and Cardiovascular Centre, Osaka (Japan); Asano, Ryotaro; Konagai, Nao [Division of Pulmonary Circulation, Department of Cardiovascular Medicine, National Cerebral and Cardiovascular Centre, Osaka (Japan); Yasuda, Satoshi [Department of Cardiovascular Medicine, National Cerebral and Cardiovascular Centre, Osaka (Japan)

    2017-04-15

    Highlights: • Recent advancement in CT enables distal CTEpH lesions to be visualized. • We investigated the efficacy and safety of BPA guided by CBCT or ECG-gated area detector CT. • BPA guided by CBCT or ECG-gated area detector CT is effective and safe in patients with CTEpH . • These new advanced CT techniques may be useful in pre-BPA target lesion assessment. - Abstract: Background: Chronic thromboembolic pulmonary hypertension (CTEPH) is a disease characterized by chronic obstructive thrombus and pulmonary hypertension. Balloon pulmonary angioplasty (BPA), an emerging alternative catheter-based treatment for inoperable patients with CTEPH, has not yet been standardised, especially for lesion assessment in distal pulmonary arteries. Recent advancement in computed tomography enables distal CTEPH lesions to be visualized. Methods: We retrospectively studied 80 consecutive patients with inoperable CTEPH who received BPA guided by cone-beam computed tomography (CT) (CBCT) or electrocardiogram (ECG)-gated area detector CT (ADCT) for target lesion assessment. We collected clinical and hemodynamic data, including procedural complications, before BPA and at 3 months and 1 year after BPA. Results: Three hundred eight-five BPA sessions (4.8 sessions/patient) were performed for the lesions of subsegmental arteries (1155 lesions), segmental arteries (738 lesions), and lobar arteries (4 lesions) identified by CBCT or ECG-gated ADCT. Significant improvements in the symptoms, 6-min walk distance, brain natriuretic peptide level, exercise capacity, and haemodynamics were observed 3 months and 1 year after BPA. No cases of death or cardiogenic shock with a low rate of severe wire perforation (0.3%) and severe reperfusion oedema (0.3%) were observed. Conclusions: BPA guided by CBCT or ECG-gated ADCT is effective and remarkably safe in patients with CTEPH . These new advanced CT techniques may be useful in pre-BPA target lesion assessment.

  15. Efficacy and safety of balloon pulmonary angioplasty for chronic thromboembolic pulmonary hypertension guided by cone-beam computed tomography and electrocardiogram-gated area detector computed tomography

    International Nuclear Information System (INIS)

    Ogo, Takeshi; Fukuda, Tetsuya; Tsuji, Akihiro; Fukui, Shigefumi; Ueda, Jin; Sanda, Yoshihiro; Morita, Yoshiaki; Asano, Ryotaro; Konagai, Nao; Yasuda, Satoshi

    2017-01-01

    Highlights: • Recent advancement in CT enables distal CTEpH lesions to be visualized. • We investigated the efficacy and safety of BPA guided by CBCT or ECG-gated area detector CT. • BPA guided by CBCT or ECG-gated area detector CT is effective and safe in patients with CTEpH . • These new advanced CT techniques may be useful in pre-BPA target lesion assessment. - Abstract: Background: Chronic thromboembolic pulmonary hypertension (CTEPH) is a disease characterized by chronic obstructive thrombus and pulmonary hypertension. Balloon pulmonary angioplasty (BPA), an emerging alternative catheter-based treatment for inoperable patients with CTEPH, has not yet been standardised, especially for lesion assessment in distal pulmonary arteries. Recent advancement in computed tomography enables distal CTEPH lesions to be visualized. Methods: We retrospectively studied 80 consecutive patients with inoperable CTEPH who received BPA guided by cone-beam computed tomography (CT) (CBCT) or electrocardiogram (ECG)-gated area detector CT (ADCT) for target lesion assessment. We collected clinical and hemodynamic data, including procedural complications, before BPA and at 3 months and 1 year after BPA. Results: Three hundred eight-five BPA sessions (4.8 sessions/patient) were performed for the lesions of subsegmental arteries (1155 lesions), segmental arteries (738 lesions), and lobar arteries (4 lesions) identified by CBCT or ECG-gated ADCT. Significant improvements in the symptoms, 6-min walk distance, brain natriuretic peptide level, exercise capacity, and haemodynamics were observed 3 months and 1 year after BPA. No cases of death or cardiogenic shock with a low rate of severe wire perforation (0.3%) and severe reperfusion oedema (0.3%) were observed. Conclusions: BPA guided by CBCT or ECG-gated ADCT is effective and remarkably safe in patients with CTEPH . These new advanced CT techniques may be useful in pre-BPA target lesion assessment.

  16. Tomography

    International Nuclear Information System (INIS)

    Allan, C.J.; Keller, N.A.; Lupton, L.R.; Taylor, T.; Tonner, P.D.

    1984-10-01

    Tomography is a non-intrusive imaging technique being developed at CRNL as an industrial tool for generating quantitative cross-sectional density maps of objects. Of most interest is tomography's ability to: distinguish features within complex geometries where other NDT techniques fail because of the complexity of the geometry; detect/locate small density changes/defects within objects, e.g. void fraction measurements within thick-walled vessels, shrink cavities in castings, etc.; provide quantitative data that can be used in analyses, e.g. of complex processes, or fracture mechanics; and provide objective quantitative data that can be used for (computer-based) quality assurance decisions, thereby reducing and in some cases eliminating the present subjectivity often encountered in NDT. The CRNL program is reviewed and examples are presented to illustrate the potential and the limitations of the technology

  17. Efficacy and safety of balloon pulmonary angioplasty for chronic thromboembolic pulmonary hypertension guided by cone-beam computed tomography and electrocardiogram-gated area detector computed tomography.

    Science.gov (United States)

    Ogo, Takeshi; Fukuda, Tetsuya; Tsuji, Akihiro; Fukui, Shigefumi; Ueda, Jin; Sanda, Yoshihiro; Morita, Yoshiaki; Asano, Ryotaro; Konagai, Nao; Yasuda, Satoshi

    2017-04-01

    Chronic thromboembolic pulmonary hypertension (CTEPH) is a disease characterized by chronic obstructive thrombus and pulmonary hypertension. Balloon pulmonary angioplasty (BPA), an emerging alternative catheter-based treatment for inoperable patients with CTEPH, has not yet been standardised, especially for lesion assessment in distal pulmonary arteries. Recent advancement in computed tomography enables distal CTEPH lesions to be visualized. We retrospectively studied 80 consecutive patients with inoperable CTEPH who received BPA guided by cone-beam computed tomography (CT) (CBCT) or electrocardiogram (ECG)-gated area detector CT (ADCT) for target lesion assessment. We collected clinical and hemodynamic data, including procedural complications, before BPA and at 3 months and 1year after BPA. Three hundred eight-five BPA sessions (4.8 sessions/patient) were performed for the lesions of subsegmental arteries (1155 lesions), segmental arteries (738 lesions), and lobar arteries (4 lesions) identified by CBCT or ECG-gated ADCT. Significant improvements in the symptoms, 6-min walk distance, brain natriuretic peptide level, exercise capacity, and haemodynamics were observed 3 months and 1year after BPA. No cases of death or cardiogenic shock with a low rate of severe wire perforation (0.3%) and severe reperfusion oedema (0.3%) were observed. BPA guided by CBCT or ECG-gated ADCT is effective and remarkably safe in patients with CTEPH . These new advanced CT techniques may be useful in pre-BPA target lesion assessment. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  18. 3D ion velocity distribution function measurement in an electric thruster using laser induced fluorescence tomography

    Science.gov (United States)

    Elias, P. Q.; Jarrige, J.; Cucchetti, E.; Cannat, F.; Packan, D.

    2017-09-01

    Measuring the full ion velocity distribution function (IVDF) by non-intrusive techniques can improve our understanding of the ionization processes and beam dynamics at work in electric thrusters. In this paper, a Laser-Induced Fluorescence (LIF) tomographic reconstruction technique is applied to the measurement of the IVDF in the plume of a miniature Hall effect thruster. A setup is developed to move the laser axis along two rotation axes around the measurement volume. The fluorescence spectra taken from different viewing angles are combined using a tomographic reconstruction algorithm to build the complete 3D (in phase space) time-averaged distribution function. For the first time, this technique is used in the plume of a miniature Hall effect thruster to measure the full distribution function of the xenon ions. Two examples of reconstructions are provided, in front of the thruster nose-cone and in front of the anode channel. The reconstruction reveals the features of the ion beam, in particular on the thruster axis where a toroidal distribution function is observed. These findings are consistent with the thruster shape and operation. This technique, which can be used with other LIF schemes, could be helpful in revealing the details of the ion production regions and the beam dynamics. Using a more powerful laser source, the current implementation of the technique could be improved to reduce the measurement time and also to reconstruct the temporal evolution of the distribution function.

  19. Value of computed tomography for evaluating the injection site in endosonography-guided celiac plexus neurolysis

    International Nuclear Information System (INIS)

    Sakamoto, Hiroki; Kitano, Masayuki; Nishio, Takeshi; Takeyama, Yoshifumi; Yasuda, Chikao; Kudo, Masatoshi

    2006-01-01

    Endosonography-guided celiac plexus neurolysis (EUS-CPN) safely and effectively relieves pain associated with intra-abdominal malignancies when the neurolytic is accurately injected. We applied contrast medium to evaluate the ethanol injection sites in patients who received EUS-CPN due to abdominal pain caused by malignancies. We injected, under the guidance of endoscopic ultrasonography (EUS), ethanol containing 10% contrast medium into the celiac plexus of patients with intra-abdominal pain due to malignancies. Immediately after the endoscopic therapy, patients underwent computed tomography (CT) to confirm the injection site. Images of distribution of injected solutions were classified into three groups. Injected solution dispersed in unilateral and bilateral anterocrural space was defined as ''unilateral injection'' or bilateral injection'', respectively. Injected solution located out of the anterocrural space was defined as ''inappropriate injection''. Pre- and postprocedure pain was assessed using a standard analog scale. Before and 2, 4, 8, 12, and 16 weeks after the procedure, pain scores were evaluated. From April 2003 to May 2005, 13 patients were enrolled in this study. Improvement of pain score in the ''bilateral injection'' and ''unilateral injection'' groups was significantly superior to the change in the ''inappropriate injection'' group. Although EUS-CPN was effective in eight of 13 patients (61.5%), additional EUS-CPN to the ''inappropriate injection group'' increased the response rate to 84.6%. Injection of ethanol to the anterocrural space by EUS-CPN produced adequate pain relief. Immediate examination by CT for confirmation of injection sites after EUS-CPN would increase the likelihood of induction of pain relief. (author)

  20. Evaluation of a cone beam computed tomography geometry for image guided small animal irradiation

    International Nuclear Information System (INIS)

    Yang, Yidong; Armour, Michael; Wang, Ken Kang-Hsin; Gandhi, Nishant; Wong, John; Iordachita, Iulian; Siewerdsen, Jeffrey

    2015-01-01

    The conventional imaging geometry for small animal cone beam computed tomography (CBCT) is that a detector panel rotates around the head-to-tail axis of an imaged animal (‘tubular’ geometry). Another unusual but possible imaging geometry is that the detector panel rotates around the anterior-to-posterior axis of the animal (‘pancake’ geometry). The small animal radiation research platform developed at Johns Hopkins University employs the pancake geometry where a prone-positioned animal is rotated horizontally between an x-ray source and detector panel. This study is to assess the CBCT image quality in the pancake geometry and investigate potential methods for improvement. We compared CBCT images acquired in the pancake geometry with those acquired in the tubular geometry when the phantom/animal was placed upright simulating the conventional CBCT geometry. Results showed signal-to-noise and contrast-to-noise ratios in the pancake geometry were reduced in comparison to the tubular geometry at the same dose level. But the overall spatial resolution within the transverse plane of the imaged cylinder/animal was better in the pancake geometry. A modest exposure increase to two folds in the pancake geometry can improve image quality to a level close to the tubular geometry. Image quality can also be improved by inclining the animal, which reduces streak artifacts caused by bony structures. The major factor resulting in the inferior image quality in the pancake geometry is the elevated beam attenuation along the long axis of the phantom/animal and consequently increased scatter-to-primary ratio in that orientation. Not withstanding, the image quality in the pancake-geometry CBCT is adequate to support image guided animal positioning, while providing unique advantages of non-coplanar and multiple mice irradiation. This study also provides useful knowledge about the image quality in the two very different imaging geometries, i.e. pancake and tubular geometry

  1. Evaluation of a cone beam computed tomography geometry for image guided small animal irradiation.

    Science.gov (United States)

    Yang, Yidong; Armour, Michael; Wang, Ken Kang-Hsin; Gandhi, Nishant; Iordachita, Iulian; Siewerdsen, Jeffrey; Wong, John

    2015-07-07

    The conventional imaging geometry for small animal cone beam computed tomography (CBCT) is that a detector panel rotates around the head-to-tail axis of an imaged animal ('tubular' geometry). Another unusual but possible imaging geometry is that the detector panel rotates around the anterior-to-posterior axis of the animal ('pancake' geometry). The small animal radiation research platform developed at Johns Hopkins University employs the pancake geometry where a prone-positioned animal is rotated horizontally between an x-ray source and detector panel. This study is to assess the CBCT image quality in the pancake geometry and investigate potential methods for improvement. We compared CBCT images acquired in the pancake geometry with those acquired in the tubular geometry when the phantom/animal was placed upright simulating the conventional CBCT geometry. Results showed signal-to-noise and contrast-to-noise ratios in the pancake geometry were reduced in comparison to the tubular geometry at the same dose level. But the overall spatial resolution within the transverse plane of the imaged cylinder/animal was better in the pancake geometry. A modest exposure increase to two folds in the pancake geometry can improve image quality to a level close to the tubular geometry. Image quality can also be improved by inclining the animal, which reduces streak artifacts caused by bony structures. The major factor resulting in the inferior image quality in the pancake geometry is the elevated beam attenuation along the long axis of the phantom/animal and consequently increased scatter-to-primary ratio in that orientation. Not withstanding, the image quality in the pancake-geometry CBCT is adequate to support image guided animal positioning, while providing unique advantages of non-coplanar and multiple mice irradiation. This study also provides useful knowledge about the image quality in the two very different imaging geometries, i.e. pancake and tubular geometry, respectively.

  2. SU-E-T-20: A Novel Hybrid CBCT, Bioluminescence and Fluorescence Tomography System for Preclinical Radiation Research

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, B; Eslami, S; Iordachita, I [Johns Hopkins University, Baltimore, Maryland (United States); Yang, Y [University of Miami School of Medicine, Miami, FL (United States); Patterson, M [Hamilton Regional Cancer Ctr., Hamilton, ON (Canada); Wong, J [Johns Hopkins University, Baltimore, MD (United States); Wang, K [Johns Hopkins Hospital, Baltimore, MD (United States)

    2014-06-01

    Purpose: A novel standalone bioluminescence and fluorescence tomography (BLT and FT) system equipped with high resolution CBCT has been built in our group. In this work, we present the system calibration method and validate our system in both phantom and in vivo environment. Methods: The CBCT is acquired by rotating the animal stage while keeping the x-ray source and detector panel static. The optical signal is reflected by the 3-mirror system to a multispectral filter set and then delivered to the CCD camera with f/1.4 lens mounted. Nine fibers passing through the stage and in contact with the mouse skin serve as the light sources for diffuse optical tomography (DOT) and FT. The anatomical information and optical properties acquired from the CBCT and DOT, respectively, are used as the priori information to improve the BLT/FT reconstruction accuracy. Flat field correction for the optical system was acquired at multiple wavelengths. A home-built phantom is used to register the optical and CBCT coordinates. An absolute calibration relating the CCD photon counts rate to the light fluence rate emitted at animal surface was developed to quantify the bioluminescence power or fluorophore concentration. Results: An optical inhomogeneous phantom with 2 light sources (3mm separation) imbedded is used to test the system. The optical signal is mapped onto the mesh generated from CBCT for optical reconstruction. Our preliminary results show that the center of mass can be reconstructed within 2.8mm accuracy. A live mouse with the light source imbedded is also used to validate our system. Liver or lung metastatic luminescence tumor model will be used for further testing. Conclusion: This hybrid system transforms preclinical research to a level that even sub-palpable volume of cells can be imaged rapidly and non-invasively, which largely extends the scope of radiobiological research. The research is supported by the NCI grant R01CA158100-01.

  3. Imaging retinal degeneration in mice by combining Fourier domain optical coherence tomography and fluorescent scanning laser ophthalmoscopy

    Science.gov (United States)

    Hossein-Javaheri, Nima; Molday, Laurie L.; Xu, Jing; Molday, Robert S.; Sarunic, Marinko V.

    2009-02-01

    Visualization of the internal structures of the retina is critical for clinical diagnosis and monitoring of pathology as well as for medical research investigating the root causes of retinal degeneration. Optical Coherence Tomography (OCT) is emerging as the preferred technique for non-contact sub-surface depth-resolved imaging of the retina. The high resolution cross sectional images acquired in vivo by OCT can be compared to histology to visually delineate the retinal layers. The recent demonstration of the significant sensitivity increase obtained through use of Fourier domain (FD) detection with OCT has been used to facilitate high speed scanning for volumetric reconstruction of the retina in software. The images acquired by OCT are purely structural, relying on refractive index differences in the tissue for contrast, and do not provide information on the molecular content of the sample. We have constructed a FDOCT prototype and combined it with a fluorescent Scanning Laser Ophthalmoscope (fSLO) to permit real time alignment of the field of view on the retina. The alignment of the FDOCT system to the specimen is crucial for the registration of measurements taken throughout longitudinal studies. In addition, fluorescence detection has been integrated with the SLO to enable the en face localization of a molecular contrast signal, which is important for retinal angiography, and also for detection of autofluorescence associated with some forms of retinal degeneration, for example autofluorescence lipofuscin accumulations are associated with Stargardt's Macular Dystrophy. The integrated FD OCT/fSLO system was investigated for imaging the retina of the mice in vivo.

  4. Systematic study of target localization for bioluminescence tomography guided radiation therapy

    Science.gov (United States)

    Yu, Jingjing; Zhang, Bin; Iordachita, Iulian I.; Reyes, Juvenal; Lu, Zhihao; Brock, Malcolm V.; Patterson, Michael S.; Wong, John W.

    2016-01-01

    Purpose: To overcome the limitation of CT/cone-beam CT (CBCT) in guiding radiation for soft tissue targets, the authors developed a spectrally resolved bioluminescence tomography (BLT) system for the small animal radiation research platform. The authors systematically assessed the performance of the BLT system in terms of target localization and the ability to resolve two neighboring sources in simulations, tissue-mimicking phantom, and in vivo environments. Methods: Multispectral measurements acquired in a single projection were used for the BLT reconstruction. The incomplete variables truncated conjugate gradient algorithm with an iterative permissible region shrinking strategy was employed as the optimization scheme to reconstruct source distributions. Simulation studies were conducted for single spherical sources with sizes from 0.5 to 3 mm radius at depth of 3–12 mm. The same configuration was also applied for the double source simulation with source separations varying from 3 to 9 mm. Experiments were performed in a standalone BLT/CBCT system. Two self-illuminated sources with 3 and 4.7 mm separations placed inside a tissue-mimicking phantom were chosen as the test cases. Live mice implanted with single-source at 6 and 9 mm depth, two sources at 3 and 5 mm separation at depth of 5 mm, or three sources in the abdomen were also used to illustrate the localization capability of the BLT system for multiple targets in vivo. Results: For simulation study, approximate 1 mm accuracy can be achieved at localizing center of mass (CoM) for single-source and grouped CoM for double source cases. For the case of 1.5 mm radius source, a common tumor size used in preclinical study, their simulation shows that for all the source separations considered, except for the 3 mm separation at 9 and 12 mm depth, the two neighboring sources can be resolved at depths from 3 to 12 mm. Phantom experiments illustrated that 2D bioluminescence imaging failed to distinguish two sources

  5. Systematic study of target localization for bioluminescence tomography guided radiation therapy

    Energy Technology Data Exchange (ETDEWEB)

    Yu, Jingjing [Department of Radiation Oncology and Molecular Radiation Sciences, Johns Hopkins University, Baltimore, Maryland 21231 and School of Physics and Information Technology, Shaanxi Normal University, Shaanxi 710119 (China); Zhang, Bin; Reyes, Juvenal; Wong, John W.; Wang, Ken Kang-Hsin, E-mail: kwang27@jhmi.edu [Department of Radiation Oncology and Molecular Radiation Sciences, Johns Hopkins University, Baltimore, Maryland 21231 (United States); Iordachita, Iulian I. [Laboratory for Computational Sensing and Robotics, Johns Hopkins University, Baltimore, Maryland 21218 (United States); Lu, Zhihao [Department of Oncology and Department of Surgery, Johns Hopkins University, Baltimore, Maryland 21231 and Key laboratory of Carcinogenesis and Translational Research, Department of GI Oncology, Peking University, Beijing Cancer Hospital and Institute, Beijing 100142 (China); Brock, Malcolm V. [Department of Oncology and Department of Surgery, Johns Hopkins University, Baltimore, Maryland 21231 (United States); Patterson, Michael S. [Department of Medical Physics and Applied Radiation Sciences, McMaster University, Hamilton, Ontario L8S 4L8 (Canada)

    2016-05-15

    Purpose: To overcome the limitation of CT/cone-beam CT (CBCT) in guiding radiation for soft tissue targets, the authors developed a spectrally resolved bioluminescence tomography (BLT) system for the small animal radiation research platform. The authors systematically assessed the performance of the BLT system in terms of target localization and the ability to resolve two neighboring sources in simulations, tissue-mimicking phantom, and in vivo environments. Methods: Multispectral measurements acquired in a single projection were used for the BLT reconstruction. The incomplete variables truncated conjugate gradient algorithm with an iterative permissible region shrinking strategy was employed as the optimization scheme to reconstruct source distributions. Simulation studies were conducted for single spherical sources with sizes from 0.5 to 3 mm radius at depth of 3–12 mm. The same configuration was also applied for the double source simulation with source separations varying from 3 to 9 mm. Experiments were performed in a standalone BLT/CBCT system. Two self-illuminated sources with 3 and 4.7 mm separations placed inside a tissue-mimicking phantom were chosen as the test cases. Live mice implanted with single-source at 6 and 9 mm depth, two sources at 3 and 5 mm separation at depth of 5 mm, or three sources in the abdomen were also used to illustrate the localization capability of the BLT system for multiple targets in vivo. Results: For simulation study, approximate 1 mm accuracy can be achieved at localizing center of mass (CoM) for single-source and grouped CoM for double source cases. For the case of 1.5 mm radius source, a common tumor size used in preclinical study, their simulation shows that for all the source separations considered, except for the 3 mm separation at 9 and 12 mm depth, the two neighboring sources can be resolved at depths from 3 to 12 mm. Phantom experiments illustrated that 2D bioluminescence imaging failed to distinguish two sources

  6. Preliminary Results of Emergency Computed Tomography-Guided Ventricular Drain Placement-Precision for the Most Difficult Cases.

    Science.gov (United States)

    Nowacki, Andreas; Wagner, Franca; Söll, Nicole; Hakim, Arsany; Beck, Jürgen; Raabe, Andreas; Z'Graggen, Werner J

    2018-04-05

    External ventricular drainage (EVD) catheter placement is one of the most commonly performed neurosurgical procedures. The study's objective was to compare a computed tomography (CT) bolt scan-guided approach for the placement of EVDs with conventional landmark-based insertion. In this retrospective case-control study, we analyzed patients undergoing bolt-kit EVD catheter placement, either CT-guided or landmark-based, between 2013 and 2016. The CT bolt scan-guided approach was based on a dose-reduced CT scan after bolt fixation with immediate image reconstruction along the axis of the bolt to evaluate the putative insertion axis. If needed, angulation of the bolt was corrected and the procedure repeated before the catheter was inserted. Primary endpoint was the accuracy of insertion. Secondary endpoints were the overall number of attempts, duration of intervention, complication rates, and cumulative radiation dose. In total, 34 patients were included in the final analysis. In the group undergoing CT-guided placement, the average ventricle width was significantly smaller (P = 0.04) and average midline shift significantly more pronounced (P = 0.01). CT-guided placement resulted in correct positioning of the catheter in the ipsilateral frontal horn in all 100% of the cases compared with landmark-guided insertion (63%; P = 0.01). Application of the CT-guided approach increased the number of total CT scans (3.6 ± 1.9) and the overall radiation dose (3.34 ± 1.61 mSv) compared with the freehand insertion group (1.84 ± 2.0 mSv and 1.55 ± 1.66 mSv). No differences were found for the other secondary outcome parameters. CT-guided bolt-kit EVD catheter placement is feasible and accurate in the most difficult cases. Copyright © 2018 Elsevier Inc. All rights reserved.

  7. Portable Intraoperative Computed Tomography Scan in Image-Guided Surgery for Brain High-grade Gliomas: Analysis of Technical Feasibility and Impact on Extent of Tumor Resection.

    Science.gov (United States)

    Barbagallo, Giuseppe M V; Palmucci, Stefano; Visocchi, Massimiliano; Paratore, Sabrina; Attinà, Giancarlo; Sortino, Giuseppe; Albanese, Vincenzo; Certo, Francesco

    2016-03-01

    Intraoperative magnetic resonance imaging is the gold standard among image-guided techniques for glioma surgery. Scant data are available on the role of intraoperative computed tomography (i-CT) in high-grade glioma (HGG) surgery. To verify the technical feasibility and usefulness of portable i-CT in image-guided surgical resection of HGGs. This is a retrospective series control analysis of prospectively collected data. Twenty-five patients (Group A) with HGGs underwent surgery using i-CT and 5-aminolevulinic acid (5-ALA) fluorescence. A second cohort of 25 patients (Group B) underwent 5-ALA fluorescence-guided surgery but without i-CT. We used a portable 8-slice CT scanner and, in both groups, neuronavigation. Extent of tumor resection (ETOR) and pre- and postoperative Karnofsky performance status (KPS) scores were measured; the impact of i-CT on overall survival (OS) and progression-free survival (PFS) was also analyzed. In 8 patients (32%) in Group A, i-CT revealed residual tumor, and in 4 of them it helped to also resect pathological tissue detached from the main tumor. EOTR in these 8 patients was 97.3% (96%-98.6%). In Group B, residual tumor was found in 6 patients, whose tumor's mean resection was 98% (93.5-99.7). The Student t test did not show statistically significant differences in EOTR in the 2 groups. The KPS score decreased from 67 to 69 after surgery in Group A and from 74 to 77 in Group B (P = .07 according to the Student t test). Groups A and B did not show statistically significant differences in OS and PFS (P = .61 and .46, respectively, by the log-rank test). No statistically significant differences in EOTR, KPS, PFS, and OS were observed in the 2 groups. However, i-CT helped to verify EOTR and to update the neuronavigator with real-time images, as well as to identify and resect pathological tissue in multifocal tumors. i-CT is a feasible and effective alternative to intraoperative magnetic resonance imaging. Portable i-CT can provide useful

  8. Assessing pharmacokinetics of indocyanine green-loaded nanoparticle in tumor with a dynamic diffuse fluorescence tomography system

    Science.gov (United States)

    Zhang, Yanqi; Yin, Guoyan; Zhao, Huijuan; Ma, Wenjuan; Gao, Feng; Zhang, Limin

    2018-02-01

    Real-time and continuous monitoring of drug release in vivo is an important task in pharmaceutical development. Here, we devoted to explore a real-time continuous study of the pharmacokinetics of free indocyanine green (ICG) and ICG loaded in the shell-sheddable nanoparticles in tumor based on a dynamic diffuse fluorescence tomography (DFT) system: A highly-sensitive dynamic DFT system of CT-scanning mode generates informative and instantaneous sampling datasets; An analysis procedure extracts the pharmacokinetic parameters from the reconstructed time curves of the mean ICG concentration in tumor, using the Gauss-Newton scheme based on two-compartment model. Compared with the pharmacokinetic parameters of free ICG in tumor, the ICG loaded in the shell-sheddable nanoparticles shows efficient accumulation in tumor. The results demonstrate our proposed dynamic-DFT can provide an integrated and continuous view of the drug delivery of the injected agents in different formulations, which is helpful for the development of diagnosis and therapy for tumors.

  9. Imaging breast adipose and fibroglandular tissue molecular signatures by using hybrid MRI-guided near-infrared spectral tomography

    Science.gov (United States)

    Brooksby, Ben; Pogue, Brian W.; Jiang, Shudong; Dehghani, Hamid; Srinivasan, Subhadra; Kogel, Christine; Tosteson, Tor D.; Weaver, John; Poplack, Steven P.; Paulsen, Keith D.

    2006-06-01

    Magnetic resonance (MR)-guided near-infrared spectral tomography was developed and used to image adipose and fibroglandular breast tissue of 11 normal female subjects, recruited under an institutional review board-approved protocol. Images of hemoglobin, oxygen saturation, water fraction, and subcellular scattering were reconstructed and show that fibroglandular fractions of both blood and water are higher than in adipose tissue. Variation in adipose and fibroglandular tissue composition between individuals was not significantly different across the scattered and dense breast categories. Combined MR and near-infrared tomography provides fundamental molecular information about these tissue types with resolution governed by MR T1 images. hemoglobin | magnetic resonance imaging | water | fat | oxygen saturation

  10. C-arm cone beam computed tomography needle path overlay for fluoroscopic guided vertebroplasty.

    Science.gov (United States)

    Tam, Alda L; Mohamed, Ashraf; Pfister, Marcus; Chinndurai, Ponraj; Rohm, Esther; Hall, Andrew F; Wallace, Michael J

    2010-05-01

    Retrospective review. To report our early clinical experience using C-arm cone beam computed tomography (C-arm CBCT) with fluoroscopic overlay for needle guidance during vertebroplasty. C-arm CBCT is advanced three-dimensional (3-D) imaging technology that is currently available on state-of-the-art flat panel based angiography systems. The imaging information provided by C-arm CBCT allows for the acquisition and reconstruction of "CT-like" images in flat panel based angiography/interventional suites. As part of the evolution of this technology, enhancements allowing the overlay of cross-sectional imaging information can now be integrated with real time fluoroscopy. We report our early clinical experience with C-arm CBCT with fluoroscopic overlay for needle guidance during vertebroplasty. This is a retrospective review of 10 consecutive oncology patients who underwent vertebroplasty of 13 vertebral levels using C-arm CBCT with fluoroscopic overlay for needle guidance from November 2007 to December 2008. Procedural data including vertebral level, approach (transpedicular vs. extrapedicular), access (bilateral vs. unilateral) and complications were recorded. Technical success with the overlay technology was assessed based on accuracy which consisted of 4 measured parameters: distance from target to needle tip, distance from planned path to needle tip, distance from midline to needle tip, and distance from the anterior 1/3 of the vertebral body to needle tip. Success within each parameter required that the distance between the needle tip and parameter being evaluated be no more than 5 mm on multiplanar CBCT or fluoroscopy. Imaging data for 12 vertebral levels was available for review. All vertebral levels were treated using unilateral access and 9 levels were treated with an extrapedicular approach. Technical success rates were 92% for both distance from planned path and distance from midline to final needle tip, 100% when distance from needle tip to the anterior 1

  11. Development of a guidance guide for dosimetry in computed tomography; Desenvolvimento de um guia orientativo para dosimetria em tomografia computadorizada

    Energy Technology Data Exchange (ETDEWEB)

    Fontes, Ladyjane Pereira

    2016-07-01

    Due to frequent questions from users of ionization chambers pencil type calibrated in the Instrument Calibration Laboratory of the Institute of Energy and Nuclear Research (LCI - IPEN), on how to properly apply the factors indicated in their calibration certificates, a guide was prepared guidance for dosimetry in computed tomography. The guide includes guidance prior knowledge of half value layer (HVL), as it is necessary to know the effective beam energy for application quality for correction factor (kq). The evaluation of HVL in TC scanners becomes a difficult task due to system geometry and therefore a survey was conducted of existing methodologies for the determination of HVL in clinical beams Computed Tomography, taking into account technical, practical and economic factors. In this work it was decided to test a Tandem System consists of absorbing covers made in the workshop of IPEN, based on preliminary studies due to low cost and good response. The Tandem system consists of five cylindrical absorbing layers of 1mm, 3mm, 5mm, 7mm and 10mm aluminum and 3 cylindrical absorbing covers 15mm, 25mm and acrylic 35mm (PMMA) coupled to the ionization chamber of commercial pencil type widely used in quality control tests in dosimetry in clinical beams Computed tomography. Through Tandem curves it was possible to assess HVL values and from the standard curve pencil-type ionization chamber, Kq find the appropriate beam. The elaborate Guide provides information on how to build the calibration curve on the basis of CSR, to find the Kq and information for construction Tandem curve, to find values close to CSR. (author)

  12. Cone-beam computed tomography fusion and navigation for real-time positron emission tomography-guided biopsies and ablations: a feasibility study.

    Science.gov (United States)

    Abi-Jaoudeh, Nadine; Mielekamp, Peter; Noordhoek, Niels; Venkatesan, Aradhana M; Millo, Corina; Radaelli, Alessandro; Carelsen, Bart; Wood, Bradford J

    2012-06-01

    To describe a novel technique for multimodality positron emission tomography (PET) fusion-guided interventions that combines cone-beam computed tomography (CT) with PET/CT before the procedure. Subjects were selected among patients scheduled for a biopsy or ablation procedure. The lesions were not visible with conventional imaging methods or did not have uniform uptake on PET. Clinical success was defined by adequate histopathologic specimens for molecular profiling or diagnosis and by lack of enhancement on follow-up imaging for ablation procedures. Time to target (time elapsed between the completion of the initial cone-beam CT scan and first tissue sample or treatment), total procedure time (time from the moment the patient was on the table until the patient was off the table), and number of times the needle was repositioned were recorded. Seven patients underwent eight procedures (two ablations and six biopsies). Registration and procedures were completed successfully in all cases. Clinical success was achieved in all biopsy procedures and in one of the two ablation procedures. The needle was repositioned once in one biopsy procedure only. On average, the time to target was 38 minutes (range 13-54 min). Total procedure time was 95 minutes (range 51-240 min, which includes composite ablation). On average, fluoroscopy time was 2.5 minutes (range 1.3-6.2 min). An integrated cone-beam CT software platform can enable PET-guided biopsies and ablation procedures without the need for additional specialized hardware. Copyright © 2012 SIR. Published by Elsevier Inc. All rights reserved.

  13. Characterizing the Utility and Limitations of Repurposing an Open-Field Optical Imaging Device for Fluorescence-Guided Surgery in Head and Neck Cancer Patients.

    Science.gov (United States)

    Moore, Lindsay S; Rosenthal, Eben L; Chung, Thomas K; de Boer, Esther; Patel, Neel; Prince, Andrew C; Korb, Melissa L; Walsh, Erika M; Young, E Scott; Stevens, Todd M; Withrow, Kirk P; Morlandt, Anthony B; Richman, Joshua S; Carroll, William R; Zinn, Kurt R; Warram, Jason M

    2017-02-01

    The purpose of this study was to assess the potential of U.S. Food and Drug Administration-cleared devices designed for indocyanine green-based perfusion imaging to identify cancer-specific bioconjugates with overlapping excitation and emission wavelengths. Recent clinical trials have demonstrated potential for fluorescence-guided surgery, but the time and cost of the approval process may impede clinical translation. To expedite this translation, we explored the feasibility of repurposing existing optical imaging devices for fluorescence-guided surgery. Consenting patients (n = 15) scheduled for curative resection were enrolled in a clinical trial evaluating the safety and specificity of cetuximab-IRDye800 (NCT01987375). Open-field fluorescence imaging was performed preoperatively and during the surgical resection. Fluorescence intensity was quantified using integrated instrument software, and the tumor-to-background ratio characterized fluorescence contrast. In the preoperative clinic, the open-field device demonstrated potential to guide preoperative mapping of tumor borders, optimize the day of surgery, and identify occult lesions. Intraoperatively, the device demonstrated robust potential to guide surgical resections, as all peak tumor-to-background ratios were greater than 2 (range, 2.2-14.1). Postresection wound bed fluorescence was significantly less than preresection tumor fluorescence (P open-field imaging device was successfully repurposed to distinguish cancer from normal tissue in the preoperative clinic and throughout surgical resection. This study illuminated the potential for existing open-field optical imaging devices with overlapping excitation and emission spectra to be used for fluorescence-guided surgery. © 2017 by the Society of Nuclear Medicine and Molecular Imaging.

  14. Chlorophyll fluorescence analysis: a guide to good practice and understanding some new applications.

    Science.gov (United States)

    Murchie, E H; Lawson, T

    2013-10-01

    Chlorophyll fluorescence is a non-invasive measurement of photosystem II (PSII) activity and is a commonly used technique in plant physiology. The sensitivity of PSII activity to abiotic and biotic factors has made this a key technique not only for understanding the photosynthetic mechanisms but also as a broader indicator of how plants respond to environmental change. This, along with low cost and ease of collecting data, has resulted in the appearance of a large array of instrument types for measurement and calculated parameters which can be bewildering for the new user. Moreover, its accessibility can lead to misuse and misinterpretation when the underlying photosynthetic processes are not fully appreciated. This review is timely because it sits at a point of renewed interest in chlorophyll fluorescence where fast measurements of photosynthetic performance are now required for crop improvement purposes. Here we help the researcher make choices in terms of protocols using the equipment and expertise available, especially for field measurements. We start with a basic overview of the principles of fluorescence analysis and provide advice on best practice for taking pulse amplitude-modulated measurements. We also discuss a number of emerging techniques for contemporary crop and ecology research, where we see continual development and application of analytical techniques to meet the new challenges that have arisen in recent years. We end the review by briefly discussing the emerging area of monitoring fluorescence, chlorophyll fluorescence imaging, field phenotyping, and remote sensing of crops for yield and biomass enhancement.

  15. Tomography

    International Nuclear Information System (INIS)

    Brown, B.H.; Barber, D.C.; Freeston, I.L.

    1983-01-01

    Tomography images of a body are constructed by placing a plurality of surface electrodes at spaced intervals on the body, causing currents to flow in the body (e.g. by applying a potential between each pair of electrodes in turn, or by induction), and measuring the potential between pairs of electrodes, calculating the potential expected in each case on the assumption that the body consists of a medium of uniform impedance, plotting the isopotentials corresponding to the calculated results to create a uniform image of the body, obtaining the ratio between the measured potential and the calculated potential in each case, and modifying the image in accordance with the respective ratios by increasing the assumed impedance along an isopotential in proportion to a ratio greater than unity or decreasing the assumed impedance in proportion to a ratio less than unity. The modified impedances along the isopotentials for each pair of electrodes are superimposed. The calculations are carried out using a computer and the plotting is carried out by a visual display unit and/or a print-out unit. (author)

  16. TGP, an extremely stable, non-aggregating fluorescent protein created by structure-guided surface engineering

    OpenAIRE

    Close, Devin W.; Don Paul, Craig; Langan, Patricia S.; Wilce, Matthew C.J.; Traore, Daouda A.K.; Halfmann, Randal; Rocha, Reginaldo C.; Waldo, Geoffery S.; Payne, Riley J.; Rucker, Joseph B.; Prescott, Mark; Bradbury, Andrew R.M.

    2015-01-01

    In this paper we describe the engineering and X-ray crystal structure of Thermal Green Protein (TGP), an extremely stable, highly soluble, non-aggregating green fluorescent protein. TGP is a soluble variant of the fluorescent protein eCGP123, which despite being highly stable, has proven to be aggregation-prone. The X-ray crystal structure of eCGP123, also determined within the context of this paper, was used to carry out rational surface engineering to improve its solubility, leading to TGP....

  17. Photosensitizer conjugated iron oxide nanoparticles for simultaneous in vitro magneto-fluorescent imaging guided photodynamic therapy.

    Science.gov (United States)

    Nafiujjaman, Md; Revuri, Vishnu; Nurunnabi, Md; Cho, Kwang Jae; Lee, Yong-Kyu

    2015-04-04

    In this study, photosensitizer conjugated iron oxide nanoparticles were strategically designed and prepared for simultaneous PDT and dual-mode fluorescence/MR imaging. The MRI contrast agent Fe3O4 was modified by APTES to functionalize the surface and further to link with heparin-pheophorbide-A conjugates.

  18. Image Guided Radiation Therapy Using Synthetic Computed Tomography Images in Brain Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Price, Ryan G. [Department of Radiation Oncology, Henry Ford Health System, Detroit, Michigan (United States); Department of Radiation Oncology, Wayne State University School of Medicine, Detroit, Michigan (United States); Kim, Joshua P.; Zheng, Weili [Department of Radiation Oncology, Henry Ford Health System, Detroit, Michigan (United States); Chetty, Indrin J. [Department of Radiation Oncology, Henry Ford Health System, Detroit, Michigan (United States); Department of Radiation Oncology, Wayne State University School of Medicine, Detroit, Michigan (United States); Glide-Hurst, Carri, E-mail: churst2@hfhs.org [Department of Radiation Oncology, Henry Ford Health System, Detroit, Michigan (United States); Department of Radiation Oncology, Wayne State University School of Medicine, Detroit, Michigan (United States)

    2016-07-15

    Purpose: The development of synthetic computed tomography (CT) (synCT) derived from magnetic resonance (MR) images supports MR-only treatment planning. We evaluated the accuracy of synCT and synCT-generated digitally reconstructed radiographs (DRRs) relative to CT and determined their performance for image guided radiation therapy (IGRT). Methods and Materials: Magnetic resonance simulation (MR-SIM) and CT simulation (CT-SIM) images were acquired of an anthropomorphic skull phantom and 12 patient brain cancer cases. SynCTs were generated using fluid attenuation inversion recovery, ultrashort echo time, and Dixon data sets through a voxel-based weighted summation of 5 tissue classifications. The DRRs were generated from the phantom synCT, and geometric fidelity was assessed relative to CT-generated DRRs through bounding box and landmark analysis. An offline retrospective analysis was conducted to register cone beam CTs (n=34) to synCTs and CTs using automated rigid registration in the treatment planning system. Planar MV and KV images (n=37) were rigidly registered to synCT and CT DRRs using an in-house script. Planar and volumetric registration reproducibility was assessed and margin differences were characterized by the van Herk formalism. Results: Bounding box and landmark analysis of phantom synCT DRRs were within 1 mm of CT DRRs. Absolute planar registration shift differences ranged from 0.0 to 0.7 mm for phantom DRRs on all treatment platforms and from 0.0 to 0.4 mm for volumetric registrations. For patient planar registrations, the mean shift differences were 0.4 ± 0.5 mm (range, −0.6 to 1.6 mm), 0.0 ± 0.5 mm (range, −0.9 to 1.2 mm), and 0.1 ± 0.3 mm (range, −0.7 to 0.6 mm) for the superior-inferior (S-I), left-right (L-R), and anterior-posterior (A-P) axes, respectively. The mean shift differences in volumetric registrations were 0.6 ± 0.4 mm (range, −0.2 to 1.6 mm), 0.2 ± 0.4 mm (range, −0.3 to 1.2 mm), and 0.2 ± 0

  19. Image Guided Radiation Therapy Using Synthetic Computed Tomography Images in Brain Cancer

    International Nuclear Information System (INIS)

    Price, Ryan G.; Kim, Joshua P.; Zheng, Weili; Chetty, Indrin J.; Glide-Hurst, Carri

    2016-01-01

    Purpose: The development of synthetic computed tomography (CT) (synCT) derived from magnetic resonance (MR) images supports MR-only treatment planning. We evaluated the accuracy of synCT and synCT-generated digitally reconstructed radiographs (DRRs) relative to CT and determined their performance for image guided radiation therapy (IGRT). Methods and Materials: Magnetic resonance simulation (MR-SIM) and CT simulation (CT-SIM) images were acquired of an anthropomorphic skull phantom and 12 patient brain cancer cases. SynCTs were generated using fluid attenuation inversion recovery, ultrashort echo time, and Dixon data sets through a voxel-based weighted summation of 5 tissue classifications. The DRRs were generated from the phantom synCT, and geometric fidelity was assessed relative to CT-generated DRRs through bounding box and landmark analysis. An offline retrospective analysis was conducted to register cone beam CTs (n=34) to synCTs and CTs using automated rigid registration in the treatment planning system. Planar MV and KV images (n=37) were rigidly registered to synCT and CT DRRs using an in-house script. Planar and volumetric registration reproducibility was assessed and margin differences were characterized by the van Herk formalism. Results: Bounding box and landmark analysis of phantom synCT DRRs were within 1 mm of CT DRRs. Absolute planar registration shift differences ranged from 0.0 to 0.7 mm for phantom DRRs on all treatment platforms and from 0.0 to 0.4 mm for volumetric registrations. For patient planar registrations, the mean shift differences were 0.4 ± 0.5 mm (range, −0.6 to 1.6 mm), 0.0 ± 0.5 mm (range, −0.9 to 1.2 mm), and 0.1 ± 0.3 mm (range, −0.7 to 0.6 mm) for the superior-inferior (S-I), left-right (L-R), and anterior-posterior (A-P) axes, respectively. The mean shift differences in volumetric registrations were 0.6 ± 0.4 mm (range, −0.2 to 1.6 mm), 0.2 ± 0.4 mm (range, −0.3 to 1.2 mm), and 0.2 ± 0

  20. TGP, an extremely stable, non-aggregating fluorescent protein created by structure-guided surface engineering

    Science.gov (United States)

    Close, Devin W.; Don Paul, Craig; Langan, Patricia S.; Wilce, Matthew C.J.; Traore, Daouda A.K.; Halfmann, Randal; Rocha, Reginaldo C.; Waldo, Geoffery S.; Payne, Riley J.; Rucker, Joseph B.; Prescott, Mark; Bradbury, Andrew R.M.

    2014-01-01

    In this paper we describe the engineering and X-ray crystal structure of Thermal Green Protein (TGP), an extremely stable, highly soluble, non-aggregating green fluorescent protein. TGP is a soluble variant of the fluorescent protein eCGP123, which despite being highly stable, has proven to be aggregation-prone. The X-ray crystal structure of eCGP123, also determined within the context of this paper, was used to carry out rational surface engineering to improve its solubility, leading to TGP. The approach involved simultaneously eliminating crystal lattice contacts while increasing the overall negative charge of the protein. Despite intentional disruption of lattice contacts and introduction of high entropy glutamate side chains, TGP crystallized readily in a number of different conditions and the X-ray crystal structure of TGP was determined to 1.9 Å resolution. The structural reasons for the enhanced stability of TGP and eCGP123 are discussed. We demonstrate the utility of using TGP as a fusion partner in various assays and significantly, in amyloid assays in which the standard fluorescent protein, EGFP, is undesirable because of aberrant oligomerization. PMID:25287913

  1. Thermal green protein, an extremely stable, nonaggregating fluorescent protein created by structure-guided surface engineering.

    Science.gov (United States)

    Close, Devin W; Paul, Craig Don; Langan, Patricia S; Wilce, Matthew C J; Traore, Daouda A K; Halfmann, Randal; Rocha, Reginaldo C; Waldo, Geoffery S; Payne, Riley J; Rucker, Joseph B; Prescott, Mark; Bradbury, Andrew R M

    2015-07-01

    In this article, we describe the engineering and X-ray crystal structure of Thermal Green Protein (TGP), an extremely stable, highly soluble, non-aggregating green fluorescent protein. TGP is a soluble variant of the fluorescent protein eCGP123, which despite being highly stable, has proven to be aggregation-prone. The X-ray crystal structure of eCGP123, also determined within the context of this paper, was used to carry out rational surface engineering to improve its solubility, leading to TGP. The approach involved simultaneously eliminating crystal lattice contacts while increasing the overall negative charge of the protein. Despite intentional disruption of lattice contacts and introduction of high entropy glutamate side chains, TGP crystallized readily in a number of different conditions and the X-ray crystal structure of TGP was determined to 1.9 Å resolution. The structural reasons for the enhanced stability of TGP and eCGP123 are discussed. We demonstrate the utility of using TGP as a fusion partner in various assays and significantly, in amyloid assays in which the standard fluorescent protein, EGFP, is undesirable because of aberrant oligomerization. © 2014 Wiley Periodicals, Inc.

  2. Percutaneous transthoracic computed tomography-guided AICD insertion in a patient with extracardiac Fontan conduit.

    LENUS (Irish Health Repository)

    Murphy, Darra T

    2011-02-01

    Percutaneous pulmonary venous atrial puncture was performed under computed tomography guidance to successfully place an automated implantable cardiac defibrillator into a 26-year-old patient with extracardiac Fontan conduit who had presented with two out-of-hospital cardiac arrests. The procedure avoided the need for lead placement at thoracotomy.

  3. Osteoid osteomas in common and in technically challenging locations treated with computed tomography-guided percutaneous radiofrequency ablation

    International Nuclear Information System (INIS)

    Mylona, Sophia; Patsoura, Sofia; Karapostolakis, Georgios; Galani, Panagiota; Pomoni, Anastasia; Thanos, Loukas

    2010-01-01

    To evaluate the efficacy of computed tomography (CT)-guided radiofrequency (RF) ablation for the treatment of osteoid osteomas in common and in technically challenging locations. Twenty-three patients with osteoid osteomas in common (nine cases) and technically challenging [14 cases: intra-articular (n = 7), spinal (n = 5), metaphyseal (n = 2)] positions were treated with CT-guided RF ablation. Therapy was performed under conscious sedation with a seven-array expandable RF electrode for 8-10 min at 80-110 C and power of 90-110 W. The patients went home under instruction. A brief pain inventory (BPI) score was calculated before and after (1 day, 4 weeks, 6 months and 1 year) treatment. All procedures were technically successful. Primary clinical success was 91.3% (21 of total 23 patients), despite the lesions' locations. BPI score was dramatically reduced after the procedure, and the decrease in BPI score was significant (P < 0.001, paired t-test; n - 1 = 22) for all periods during follow up. Two patients had persistent pain after 1 month and were treated successfully with a second procedure (secondary success rate 100%). No immediate or delayed complications were observed. CT-guided RF ablation is safe and highly effective for treatment of osteoid osteomas, even in technically difficult positions. (orig.)

  4. Computed tomography-guided interstitial high dose rate brachytherapy for centrally located liver tumours: a single institution study

    Energy Technology Data Exchange (ETDEWEB)

    Tselis, Nikolaos; Chatzikonstantinou, Georgios; Zamboglou, Nikolaos [Klinikum Offenbach, Department of Radiation Oncology, Offenbach am Main (Germany); Kolotas, Christos [Hirslanden Medical Center, Institute for Radiotherapy, Aarau (Switzerland); Milickovic, Natasa; Baltas, Dimos [Klinikum Offenbach, Department of Medical Physics and Engineering, Offenbach am Main (Germany)

    2013-08-15

    To evaluate the clinical outcome of computed tomography (CT)-guided interstitial (IRT) high-dose-rate (HDR) brachytherapy (BRT) in the treatment of unresectable primary and secondary liver malignancies. This report updates and expands our previously described experience with this treatment technique. Forty-one patients with 50 tumours adjacent to the liver hilum and bile duct bifurcation were treated in 59 interventions of CT-guided IRT HDR BRT. The tumours were larger than 4 cm with a median volume of 84 cm{sup 3} (38-1,348 cm{sup 3}). The IRT HDR BRT delivered a median total physical dose of 20.0 Gy (7.0-32.0 Gy) in twice daily fractions of median 7.0 Gy (4.0-10.0 Gy) in 19 patients and in once daily fractions of median 8.0 Gy (7.0-14.0 Gy) in 22 patients. With a median follow-up of 12.4 months, the local control for metastatic hepatic tumours was 89 %, 73 % and 63 % at 6, 12 and 18 months respectively. The local control for primary hepatic tumours was 90 %, 81 % and 50 % at 6, 12 and 18 months respectively. Severe side effects occurred in 5.0 % of interventions with no treatment-related deaths. CT-guided IRT HDR BRT is a promising procedure for the radiation treatment of centrally located liver malignancies. (orig.)

  5. 3D artificial bones for bone repair prepared by computed tomography-guided fused deposition modeling for bone repair.

    Science.gov (United States)

    Xu, Ning; Ye, Xiaojian; Wei, Daixu; Zhong, Jian; Chen, Yuyun; Xu, Guohua; He, Dannong

    2014-09-10

    The medical community has expressed significant interest in the development of new types of artificial bones that mimic natural bones. In this study, computed tomography (CT)-guided fused deposition modeling (FDM) was employed to fabricate polycaprolactone (PCL)/hydroxyapatite (HA) and PCL 3D artificial bones to mimic natural goat femurs. The in vitro mechanical properties, in vitro cell biocompatibility, and in vivo performance of the artificial bones in a long load-bearing goat femur bone segmental defect model were studied. All of the results indicate that CT-guided FDM is a simple, convenient, relatively low-cost method that is suitable for fabricating natural bonelike artificial bones. Moreover, PCL/HA 3D artificial bones prepared by CT-guided FDM have more close mechanics to natural bone, good in vitro cell biocompatibility, biodegradation ability, and appropriate in vivo new bone formation ability. Therefore, PCL/HA 3D artificial bones could be potentially be of use in the treatment of patients with clinical bone defects.

  6. Percutaneous computed tomography-guided core needle biopsy of soft tissue tumors: results and correlation with surgical specimen analysis

    Energy Technology Data Exchange (ETDEWEB)

    Chojniak, Rubens; Grigio, Henrique Ramos; Bitencourt, Almir Galvao Vieira; Pinto, Paula Nicole Vieira; Tyng, Chiang J.; Cunha, Isabela Werneck da; Aguiar Junior, Samuel; Lopes, Ademar, E-mail: chojniak@uol.com.br [Hospital A.C. Camargo, Sao Paulo, SP (Brazil)

    2012-09-15

    Objective: To evaluate the efficacy of percutaneous computed tomography (CT)-guided core needle biopsy of soft tissue tumors in obtaining appropriate samples for histological analysis, and compare its diagnosis with the results of the surgical pathology as available. Materials and Methods: The authors reviewed medical records, imaging and histological reports of 262 patients with soft-tissue tumors submitted to CT-guided core needle biopsy in an oncologic reference center between 2003 and 2009. Results: Appropriate samples were obtained in 215 (82.1%) out of the 262 patients. The most prevalent tumors were sarcomas (38.6%), metastatic carcinomas (28.8%), benign mesenchymal tumors (20.5%) and lymphomas (9.3%). Histological grading was feasible in 92.8% of sarcoma patients, with the majority of them (77.9%) being classified as high grade tumors. Out of the total sample, 116 patients (44.3%) underwent surgical excision and diagnosis confirmation. Core biopsy demonstrated 94.6% accuracy in the identification of sarcomas, with 96.4% sensitivity and 89.5% specificity. A significant intermethod agreement about histological grading was observed between core biopsy and surgical resection (p < 0.001; kappa = 0.75). Conclusion: CT-guided core needle biopsy demonstrated a high diagnostic accuracy in the evaluation of soft tissue tumors as well as in the histological grading of sarcomas, allowing an appropriate therapeutic planning (author)

  7. Feasibility of optimizing the dose distribution in lung tumors using fluorine-18-fluorodeoxyglucose positron emission tomography and single photon emission computed tomography guided dose prescriptions

    International Nuclear Information System (INIS)

    Das, S.K.; Miften, M.M.; Zhou, S.; Bell, M.; Munley, M.T.; Whiddon, C.S.; Craciunescu, O.; Baydush, A.H.; Wong, T.; Rosenman, J.G.; Dewhirst, M.W.; Marks, L.B.

    2004-01-01

    The information provided by functional images may be used to guide radiotherapy planning by identifying regions that require higher radiation dose. In this work we investigate the dosimetric feasibility of delivering dose to lung tumors in proportion to the fluorine-18-fluorodeoxyglucose activity distribution from positron emission tomography (FDG-PET). The rationale for delivering dose in proportion to the tumor FDG-PET activity distribution is based on studies showing that FDG uptake is correlated to tumor cell proliferation rate, which is shown to imply that this dose delivery strategy is theoretically capable of providing the same duration of local control at all voxels in tumor. Target dose delivery was constrained by single photon emission computed tomography (SPECT) maps of normal lung perfusion, which restricted irradiation of highly perfused lung and imposed dose-function constraints. Dose-volume constraints were imposed on all other critical structures. All dose-volume/function constraints were considered to be soft, i.e., critical structure doses corresponding to volume/function constraint levels were minimized while satisfying the target prescription, thus permitting critical structure doses to minimally exceed dose constraint levels. An intensity modulation optimization methodology was developed to deliver this radiation, and applied to two lung cancer patients. Dosimetric feasibility was assessed by comparing spatially normalized dose-volume histograms from the nonuniform dose prescription (FDG-PET proportional) to those from a uniform dose prescription with equivalent tumor integral dose. In both patients, the optimization was capable of delivering the nonuniform target prescription with the same ease as the uniform target prescription, despite SPECT restrictions that effectively diverted dose from high to low perfused normal lung. In one patient, both prescriptions incurred similar critical structure dosages, below dose-volume/function limits

  8. Reliability of implant placement with stereolithographic surgical guides generated from computed tomography: clinical data from 94 implants.

    Science.gov (United States)

    Ersoy, Ahmet Ersan; Turkyilmaz, Ilser; Ozan, Oguz; McGlumphy, Edwin A

    2008-08-01

    Dental implant placement requires precise planning with regard to anatomic limitations and restorative goals. The aim of this study was to evaluate the match between the positions and axes of the planned and placed implants using stereolithographic (SLA) surgical guides. Ninety-four implants were placed using SLA surgical guides generated from computed tomography (CT) between 2005 and 2006. Radiographic templates were used for all subjects during CT imaging. After obtaining three-dimensional CT images, each implant was virtually placed on the CT images. SLA surgical guides, fabricated using an SLA machine with a laser beam to polymerize the liquid photo-polymerized resin, were used during implant placement. A new CT scan was taken for each subject following implant placement. Special software was used to fuse the images of the planned and placed implants, and the locations and axes were compared. Compared to the planned implants, the placed implants showed angular deviation of 4.9 degrees+/-2.36 degrees, whereas the mean linear deviation was 1.22+/-0.85 mm at the implant neck and 1.51+/-1 mm at the implant apex. Compared to the implant planning, the angular deviation and linear deviation at the neck and apex of the placed maxillary implants were 5.31 degrees+/-0.36 degrees, 1.04+/-0.56 mm, and 1.57+/-0.97 mm, respectively, whereas corresponding figures for placed mandibular implants were 4.44 degrees+/-0.31 degrees, 1.42+/-1.05 mm, and 1.44+/-1.03 mm, respectively. SLA surgical guides using CT data may be reliable in implant placement and make flapless implant placement possible.

  9. Magnetic resonance tomography-guided interventional procedure for diagnosis of prostate cancer

    International Nuclear Information System (INIS)

    Schernthaner, M.; Helbich, T.H.; Fueger, B.J.; Memarsadeghi, M.; Stiglbauer, A.; Linhart, H.G.; Doan, A.; Pinker, K.; Brader, P.; Margreiter, M.

    2011-01-01

    In recent years magnetic resonance imaging (MRI) has been increasingly established in the diagnosis of prostate cancer in addition to transrectal ultrasonography (TRUS). The use of T2-weighted imaging allows an exact delineation of the zonal anatomy of the prostate and its surrounding structures. Other MR imaging tools, such as dynamic contrast-enhanced T1-weighted imaging or diffusion-weighted imaging allow an inference of the biochemical characteristics (multiparametric MRI). Prostate cancer, which could only be diagnosed using MR imaging or lesions suspected as being prostate cancer, which are localized in the anterior aspect of the prostate and were missed with repetitive TRUS biopsy, need to undergo MR guided biopsy. Recent studies have shown a good correlation between MR imaging and histopathology of specimens collected by MR-guided biopsy. Improved lesion targeting is therefore possible with MR-guided biopsy. So far data suggest that MR-guided biopsy of the prostate is a promising alternative diagnostic tool to TRUS-guided biopsy. (orig.) [de

  10. Magnetic resonance imaging-guided attenuation and scatter corrections in three-dimensional brain positron emission tomography

    CERN Document Server

    Zaidi, H; Slosman, D O

    2003-01-01

    Reliable attenuation correction represents an essential component of the long chain of modules required for the reconstruction of artifact-free, quantitative brain positron emission tomography (PET) images. In this work we demonstrate the proof of principle of segmented magnetic resonance imaging (MRI)-guided attenuation and scatter corrections in 3D brain PET. We have developed a method for attenuation correction based on registered T1-weighted MRI, eliminating the need of an additional transmission (TX) scan. The MR images were realigned to preliminary reconstructions of PET data using an automatic algorithm and then segmented by means of a fuzzy clustering technique which identifies tissues of significantly different density and composition. The voxels belonging to different regions were classified into air, skull, brain tissue and nasal sinuses. These voxels were then assigned theoretical tissue-dependent attenuation coefficients as reported in the ICRU 44 report followed by Gaussian smoothing and additio...

  11. Microscope-integrated intraoperative optical coherence tomography-guided small-incision lenticule extraction: New surgical technique.

    Science.gov (United States)

    Sharma, Namrata; Urkude, Jayanand; Chaniyara, Manthan; Titiyal, Jeewan S

    2017-10-01

    We describe the surgical technique of microscope-integrated intraoperative optical coherence tomography (OCT)-guided small-incision lenticule extraction. The technique enables manual tracking of surgical instruments and identification of the desired dissection plane. It also helps discern the relation between the dissector and the intrastromal lenticule. The dissection plane becomes hyperreflective on dissection, ensuring complete separation of the intrastromal lenticule from the overlying and underlying stroma. Inadvertent posterior plane entry, cap-lenticule adhesion, incomplete separation of the lenticule, creation of a false plane, and lenticule remnants may be recognized intraoperatively so corrective steps can be taken immediately. In cases with a hazy overlying cap, microscope-integrated intraoperative OCT enables localization and extraction of the lenticule. The technique is helpful for inexperienced surgeons, especially in cases with low amplitudes of refractive errors, ie, thin lenticules. Copyright © 2017 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.

  12. Computed tomography-guided bupivacaine and corticosteroid injection for the treatment of symptomatic calcification in the great toe tendon

    Directory of Open Access Journals (Sweden)

    Karatoprak O

    2014-04-01

    Full Text Available Omer Karatoprak,1 Sinan Karaca,2 Mehmet Nuri Erdem,3 Ozgur Karaman,2 Azmi Hamzaoglu41Department of Orthopedic Surgery, Kadikoy Florence Nightingale Hospital, Istanbul, Turkey; 2Department of Orthopedic Surgery, Fatih Sultan Mehmet Training and Research Hospital Atasehir, Istanbul, Turkey; 3Department of Orthopedics and Traumatology, Kolan International Hospital Sisli, Istanbul, Turkey; 4Department of Orthopedic Surgery, Istanbul Florence Nightingale Hospital, Istanbul TurkeyBackground: Calcification in the great toe tendon is a rare disorder that is characterized by the deposition of calcium on degenerative collagen fibrils.Case presentations: In this report, we present two cases of calcific tendonitis: one in the adductor hallucis and the other in the flexor hallucis longus tendon. We preferred computed tomography-guided steroid injection in our cases because of pain unresponsive to conservative treatment. Patients were free of symptoms at the follow-up visit, 4 weeks after injection.Conclusion: Calcification of the hallux tendons is a rare disorder. Treatment of tendonitis consists of nonsteroidal anti-inflammatory drugs. Local anesthetic and steroid injection may be considered in cases unresponsive to conservative treatment. Because of the anatomic location of tendons, injection could be difficult. Computed tomography guidance may improve the success rate of injections.Keywords: bupivacaine, calcification, great toe tendons, corticosteroid injection

  13. Computed tomography-guided percutaneous biopsy of pancreatic masses using pneumodissection; Biopsia percutanea de massas pancreaticas guiada por tomografia computadorizada com pneumodisseccao

    Energy Technology Data Exchange (ETDEWEB)

    Tyng, Chiang Jeng; Bitencourt, Almir Galvao Vieira; Almeida, Maria Fernanda Arruda; Barbosa, Paula Nicole Vieira; Martins, Eduardo Bruno Lobato; Junior, Joao Paulo Kawaoka Matushita; Chojniak, Rubens, E-mail: chiangjengtyng@gmail.com [Hospital A.C. Camargo, Sao Paulo, SP (Brazil). Dept. de Imagem; Coimbra, Felipe Jose Fernandez [Hospital A.C. Camargo, Sao Paulo, SP (Brazil). Dept. de Cirurgia Abdominal

    2013-05-15

    Objective: to describe the technique of computed tomography-guided percutaneous biopsy of pancreatic tumors with pneumodissection. Materials and methods: in the period from June 2011 to May 2012, seven computed tomography guided percutaneous biopsies of pancreatic tumors utilizing pneumodissection were performed in the authors' institution. All the procedures were performed with an automatic biopsy gun and coaxial system with Tru-core needles. The biopsy specimens were histologically assessed. Results: in all the cases the pancreatic mass could not be directly approached by computed tomography without passing through major organs and structures. The injection of air allowed the displacement of adjacent structures and creation of a safe coaxial needle pathway toward the lesion. Biopsy was successfully performed in all the cases, yielding appropriate specimens for pathological analysis. Conclusion: Pneumodissection is a safe, inexpensive and technically easy approach to perform percutaneous biopsy in selected cases where direct access to the pancreatic tumor is not feasible. (author)

  14. Cone-Beam Computed Tomography for Image-Guided Radiation Therapy of Prostate Cancer

    Science.gov (United States)

    2008-01-01

    imaging in small- animal on-Medical Physics, Vol. 34, No. 12, December 2007cology models,” Mol. Imag. 3, 55–62 2004. 8E. B. Walters, K. Panda , J. A...publication 8 October 2007; published 28 November 2007 Cone-beam microcomputed tomography microCT is one of the most popular choices for small animal ...imaging which is becoming an important tool for studying animal models with transplanted diseases. Region-of-interest ROI imaging techniques in CT, which

  15. Magnetic resonance imaging-guided attenuation correction of positron emission tomography data in PET/MRI

    OpenAIRE

    Izquierdo-Garcia, David; Catana, Ciprian

    2016-01-01

    Attenuation correction (AC) is one of the most important challenges in the recently introduced combined positron emission tomography/magnetic resonance imaging (PET/MR) scanners. PET/MR AC (MR-AC) approaches aim to develop methods that allow accurate estimation of the linear attenuation coefficients (LACs) of the tissues and other components located in the PET field of view (FoV). MR-AC methods can be divided into three main categories: segmentation-, atlas- and PET-based. This review aims to...

  16. [Value of the optical coherence tomography in the treatment guided of the stent failure. Case report].

    Science.gov (United States)

    Macías, Enrico; Tellez, Alejandro; Ochoa, Jorge; Ortíz, José E

    2014-01-01

    Since the advent of bare metal and drug-eluting stents, the surgical revascularization have declined considerably, however the thrombosis and in-stent restenosis are important complications of these devices. There are several factors that predispose to thrombosis and in-stent restenosis. Conventional angiography has serious limitations to determine the causes of stent failure. Optical coherence tomography is a very sensitive technique to determine the cause of thrombosis and in-stent restenosis. Copyright © 2013 Instituto Nacional de Cardiología Ignacio Chávez. Published by Masson Doyma México S.A. All rights reserved.

  17. Validating atlas-guided DOT: a comparison of diffuse optical tomography informed by atlas and subject-specific anatomies.

    Science.gov (United States)

    Cooper, Robert J; Caffini, Matteo; Dubb, Jay; Fang, Qianqian; Custo, Anna; Tsuzuki, Daisuke; Fischl, Bruce; Wells, William; Dan, Ippeita; Boas, David A

    2012-09-01

    We describe the validation of an anatomical brain atlas approach to the analysis of diffuse optical tomography (DOT). Using MRI data from 32 subjects, we compare the diffuse optical images of simulated cortical activation reconstructed using a registered atlas with those obtained using a subject's true anatomy. The error in localization of the simulated cortical activations when using a registered atlas is due to a combination of imperfect registration, anatomical differences between atlas and subject anatomies and the localization error associated with diffuse optical image reconstruction. When using a subject-specific MRI, any localization error is due to diffuse optical image reconstruction only. In this study we determine that using a registered anatomical brain atlas results in an average localization error of approximately 18 mm in Euclidean space. The corresponding error when the subject's own MRI is employed is 9.1 mm. In general, the cost of using atlas-guided DOT in place of subject-specific MRI-guided DOT is a doubling of the localization error. Our results show that despite this increase in error, reasonable anatomical localization is achievable even in cases where the subject-specific anatomy is unavailable. Copyright © 2012 Elsevier Inc. All rights reserved.

  18. Computed tomography- and fluoroscopy-guided percutaneous screw fixation of low-grade isthmic spondylolisthesis in adults: a new technique

    Energy Technology Data Exchange (ETDEWEB)

    Amoretti, Nicolas; Huwart, Laurent; Browaeys, Patrick; Nouri, Yasir; Ibba, Caroline [Hopital Archet 2, Centre Hospitalo-Universitaire de Nice, Department of Radiology, Nice (France); Hauger, Olivier [Hopital Pellegrin, Centre Hospitalo-Universitaire de Bordeaux, Department of Radiology, Bordeaux (France); Marcy, Pierre-Yves [Antoine Lacassagne Cancer Research Institute, Department of Radiology, Nice (France); Boileau, Pascal [Hopital Archet 2, Centre Hospitalo-Universitaire de Nice, Department of Orthopedic Surgery, Nice (France)

    2012-12-15

    To evaluate the feasibility of computed tomography (CT)- and fluoroscopy-guided percutaneous screw fixation for the treatment of low-grade isthmic spondylolisthesis in adults. Ten consecutive adult patients (four men and six women; mean age: 57.1 [range, 44-78 years]) were prospectively treated by percutaneous screw fixation for low-grade (six grade 1 and four grade 2) isthmic spondylolisthesis of L5. For each patient, two 4.0-mm Asnis III cannulated screws were placed to fix the pars interarticularis defects. All procedures were performed under local anaesthesia by using CT and fluoroscopy guidance. Post-operative outcome was assessed using the visual analogue scale and Oswestry Disability Index (ODI) scores. The procedure time ranged from 45 to 60 min. The mean screw length was 27 mm (range, 24-32 mm). The VAS and ODI measurements {+-} SD decreased from 7.8 {+-} 0.9 preoperatively to 1.5 {+-} 1.1 at the last 2-year follow-up, and from 62.3 {+-} 17.2 to 15.1 {+-} 6.0, respectively (P < 0.001 in both cases). Neither slip progression nor screw failure was noted. This feasibility study showed that CT- and fluoroscopy-guided percutaneous screw fixation could be a rapid, safe and effective method of treating low-grade isthmic spondylolisthesis. (orig.)

  19. Chest Computed Tomography (CT) Immediately after CT-Guided Transthoracic Needle Aspiration Biopsy as a Predictor of Overt Pneumothorax

    Science.gov (United States)

    Noh, Tae June; Lee, Chang Hoon; Kang, Young Ae; Kwon, Sung-Youn; Yoon, Ho-Il; Kim, Tae Jung; Lee, Kyung Won; Lee, Jae Ho

    2009-01-01

    Background/Aims This study examined the correlation between pneumothorax detected by immediate post-transthoracic needle aspiration-biopsy (TTNB) chest computed tomography (CT) and overt pneumothorax detected by chest PA, and investigated factors that might influence the correlation. Methods Adult patients who had undergone CT-guided TTNB for lung lesions from May 2003 to June 2007 at Seoul National University Bundang Hospital were included. Immediate post-TTNB CT and chest PA follow-up at 4 and 16 hours after CT-guided TTNB were performed in 934 patients. Results Pneumothorax detected by immediate chest CT (CT-pneumothorax) was found in 237 (25%) and overt pneumothorax was detected by chest PA follow-up in 92 (38.8%) of the 237 patients. However, overt pneumothorax was found in 18 (2.6%) of the 697 patients without CT-pneumothorax. The width and depth of CT-pneumothorax were predictive risk factors for overt pneumothorax. Conclusions CT-pneumothorax is very sensitive for predicting overt pneumothorax, and the width and depth on CT-pneumothorax are reliable risk factors for predicting overt pneumothorax. PMID:19949733

  20. Computed tomography- and fluoroscopy-guided percutaneous screw fixation of low-grade isthmic spondylolisthesis in adults: a new technique

    International Nuclear Information System (INIS)

    Amoretti, Nicolas; Huwart, Laurent; Browaeys, Patrick; Nouri, Yasir; Ibba, Caroline; Hauger, Olivier; Marcy, Pierre-Yves; Boileau, Pascal

    2012-01-01

    To evaluate the feasibility of computed tomography (CT)- and fluoroscopy-guided percutaneous screw fixation for the treatment of low-grade isthmic spondylolisthesis in adults. Ten consecutive adult patients (four men and six women; mean age: 57.1 [range, 44-78 years]) were prospectively treated by percutaneous screw fixation for low-grade (six grade 1 and four grade 2) isthmic spondylolisthesis of L5. For each patient, two 4.0-mm Asnis III cannulated screws were placed to fix the pars interarticularis defects. All procedures were performed under local anaesthesia by using CT and fluoroscopy guidance. Post-operative outcome was assessed using the visual analogue scale and Oswestry Disability Index (ODI) scores. The procedure time ranged from 45 to 60 min. The mean screw length was 27 mm (range, 24-32 mm). The VAS and ODI measurements ± SD decreased from 7.8 ± 0.9 preoperatively to 1.5 ± 1.1 at the last 2-year follow-up, and from 62.3 ± 17.2 to 15.1 ± 6.0, respectively (P < 0.001 in both cases). Neither slip progression nor screw failure was noted. This feasibility study showed that CT- and fluoroscopy-guided percutaneous screw fixation could be a rapid, safe and effective method of treating low-grade isthmic spondylolisthesis. (orig.)

  1. Fluorescence cytology with 5-aminolevulinic acid in EUS-guided FNA as a method for differentiating between malignant and benign lesions (with video).

    Science.gov (United States)

    Ikeura, Tsukasa; Takaoka, Makoto; Uchida, Kazushige; Shimatani, Masaaki; Miyoshi, Hideaki; Kato, Kota; Ohe, Chisato; Uemura, Yoshiko; Kaibori, Masaki; Kwon, A-Hon; Okazaki, Kazuichi

    2015-01-01

    EUS-guided FNA (EUS-FNA) has been increasingly performed to obtain specimens for the pathological evaluation of patients with GI and pancreaticobiliary masses as well as lymphadenopathies of unknown origin. Photodynamic diagnosis by using 5-aminolebulinic acid (ALA) has been reported to be useful for enabling the visual differentiation between malignant and normal tissue in various cancers. To evaluate the diagnostic accuracy of fluorescence cytology with ALA in EUS-FNA. A prospective study. A single center. A total of 28 consecutive patients who underwent EUS-FNA for the pathological diagnosis of a pancreaticobiliary mass lesion or intra-abdominal lymphadenopathy of unknown origin. Patients were orally administered ALA 3 to 6 hours before EUS-FNA. The sample was obtained via EUS-FNA for fluorescence cytology and conventional cytology. A single gastroenterologist performed the fluorescence cytology by using fluorescence microscopy after the procedure, independently of the conventional cytology by pathologists. The accuracy of fluorescence cytology with ALA in the differentiation between benign and malignant lesions by comparing the results of fluorescence cytology with the final diagnosis. Of the 28 patients included in the study, 22 were considered as having malignant lesions and 6 patients as having benign lesions. Fluorescence cytology could correctly discriminate between benign and malignant lesions in all patients. Therefore, both the sensitivity and specificity of fluorescence cytology were 100% in our study. Fluorescence cytology was performed by only 1 gastroenterologist with a small number of patients. Fluorescence cytology with ALA in EUS-FNA may be an effective and simple method for differentiating between benign and malignant lesions. Copyright © 2015 American Society for Gastrointestinal Endoscopy. Published by Elsevier Inc. All rights reserved.

  2. Three-dimensional computed tomography-guided monotherapeutic pararectal brachytherapy of prostate cancer with seminal vesicle invasion

    International Nuclear Information System (INIS)

    Koutrouvelis, Panos; Lailas, Niko; Hendricks, Fred; Gil-Montero, Guillermo; Sehn, James; Katz, Stuart

    2001-01-01

    Purpose: To treat patients with prostate cancer and seminal vesicle invasion with monotherapeutic three dimensional computed tomography (3-DCT)-guided posterior pararectal brachytherapy. Methods and materials: Three hundred and sixty two patients with clinical stage T1 a,b or T2 a,b of prostate cancer were referred for 3-DCT-guided brachytherapy. Each underwent further staging with 3-D CT-guided pararectal biopsy of the seminal vesicles under local anesthesia during the pre-treatment CT-planning. Forty-three patients (12%) were upstaged to T3 cNoMo disease. In the set of 43 patients, Eight had Gleason's score≤6, 24 Gleason's score=7, and 11 patients ≥8. Initial PSA was 20 in 18 patients. Of the 43 patients, 37 patients were treated monotherapeutically with 3-D CT-guided brachytherapy. No patients received hormone therapy after the implant. The prescribed dosage to the seminal vesicles and prostate is 120 Gy with Pd-103 seeds and 144 Gy with 1-125 seeds. Results: The prescribed dosage was achieved in all 37 patient's throughout the seminal vesicles whose range of target radiation extended 5-10 mm outside the target in the adjacent fat as calculated with post-implant CT-dosimetry with Varian Brachy Vision or MMS software. Prostate Specific Antigen (PSA) outcome data were available in 34 patients treated with monotherapy and follow up ranged from 12-56 months (median, 24 months). Decreased PSA levels were stratified into six groups based on the presenting Gleason's score and initial PSA. In the first group (with Gleason's score≤6 and initial PSA 20 ng/ml), PSA decreased to less than 0.5 ng/ml in four out of eight patients (50%). All of the patients in the fourth group (with Gleason's score≥8 and initial PSA 20 ng/ml). There were no patients with Gleason's score of 1-6 and greater than 20 ng/ml initial PSA. Patients, irrespective of the Gleason's score and PSA, had an overall response of decreased PSA (less than 1 ng/ml) of 79%. Conclusion: 3-D CT-guided

  3. Highly Specific and Sensitive Fluorescent Nanoprobes for Image-Guided Resection of Sub-Millimeter Peritoneal Tumors.

    Science.gov (United States)

    Colby, Aaron H; Berry, Samantha M; Moran, Ann M; Pasion, Kristine Amber; Liu, Rong; Colson, Yolonda L; Ruiz-Opazo, Nelson; Grinstaff, Mark W; Herrera, Victoria L M

    2017-02-28

    A current challenge in the treatment of peritoneal carcinomatosis is the inability to detect, visualize, and resect small or microscopic tumors of pancreatic, ovarian, or mesothelial origin. In these diseases, the completeness of primary tumor resection is directly correlated with patient survival, and hence, identifying small sub-millimeter tumors (i.e., disseminated disease) is critical. Thus, new imaging techniques and probes are needed to improve cytoreductive surgery and patient outcomes. Highly fluorescent rhodamine-labeled expansile nanoparticles (HFR-eNPs) are described for use as a visual aid during cytoreductive surgery of pancreatic carcinomatosis. The covalent incorporation of rhodamine into ∼30 nm eNPs increases the fluorescent signal compared to free rhodamine, thereby affording a brighter and more effective probe than would be achieved by a single rhodamine molecule. Using the intraperitoneal route of administration, HFR-eNPs localize to regions of large (∼1 cm), sub-centimeter, and sub-millimeter intraperitoneal tumor in three different animal models, including pancreatic, mesothelioma, and ovarian carcinoma. Tumoral localization of the HFR-eNPs depends on both the material property (i.e., eNP polymer) as well as the surface chemistry (anionic surfactant vs PEGylated noncharged surfactant). In a rat model of pancreatic carcinomatosis, HFR-eNP identification of tumor is validated against gold-standard histopathological analysis to reveal that HFR-eNPs possess high specificity (99%) and sensitivity (92%) for tumors, in particular, sub-centimeter and microscopic sub-millimeter tumors, with an overall accuracy of 95%. Finally, as a proof-of-concept, HFR-eNPs are used to guide the resection of pancreatic tumors in a rat model of peritoneal carcinomatosis.

  4. Handheld single photon emission computed tomography (handheld SPECT) navigated video-assisted thoracoscopic surgery of computer tomography-guided radioactively marked pulmonary lesions.

    Science.gov (United States)

    Müller, Joachim; Putora, Paul Martin; Schneider, Tino; Zeisel, Christoph; Brutsche, Martin; Baty, Florent; Markus, Alexander; Kick, Jochen

    2016-09-01

    Radioactive marking can be a valuable extension to minimally invasive surgery. The technique has been clinically applied in procedures involving sentinel lymph nodes, parathyroidectomy as well as interventions in thoracic surgery. Improvements in equipment and techniques allow one to improve the limits. Pulmonary nodules are frequently surgically removed for diagnostic or therapeutic reasons; here video-assisted thoracoscopic surgery (VATS) is the preferred technique. VATS might be impossible with nodules that are small or located deep in the lung. In this study, we examined the clinical application and safety of employing the newly developed handheld single photon emission tomography (handheld SPECT) device in combination with CT-guided radioactive marking of pulmonary nodules. In this pilot study, 10 subjects requiring surgical resection of a pulmonary nodule were included. The technique involved CT-guided marking of the target nodule with a 20-G needle, with subsequent injection of 25-30 MBq (effective: 7-14 MBq) Tc-99m MAA (Macro Albumin Aggregate). Quality control was made with conventional SPECT-CT to confirm the correct localization and exclude possible complications related to the puncture procedure. VATS was subsequently carried out using the handheld SPECT to localize the radioactivity intraoperatively and therefore the target nodule. A 3D virtual image was superimposed on the intraoperative visual image for surgical guidance. In 9 of the 10 subjects, the radioactive application was successfully placed directly in or in the immediate vicinity of the target nodule. The average size of the involved nodules was 9 mm (range 4-15). All successfully marked nodules were subsequently completely excised (R0) using VATS. The procedure was well tolerated. An asymptomatic clinically insignificant pneumothorax occurred in 5 subjects. Two subjects were found to have non-significant discrete haemorrhage in the infiltration canal of the needle. In a single subject, the

  5. Fluorescent angiography and optical coherence tomography with angiography of the ocular fundus in patients with "the wet" form of an age-related macular degeneration.

    Directory of Open Access Journals (Sweden)

    Virsta A.M.

    2017-06-01

    Full Text Available Purpose: to investigate the informative value of fluorescent angiography (FA and optical coherence tomography with fundus angiography (angio-OCT in the diagnosis of "wet" form of age-related macular degeneration (AMD. Material and methods. The present study included 20 patients (20 eyes diagnosed with degeneration of macula and posterior pole of the eye, the "wet" form (late stage age-related macular degeneration, AREDS category 4. The study used machines: optical coherence tomography, Spectralis HRA+OCT (Heidelberg Engeneering, Germany, optical со- herence tomography-angiography CIRRUS HD-OCT MODEL 5000 (Carl Zeiss, Germany. Results. When conducting the FA, in 11 patients found the ill-defined zone of small leakage of dye in 7 patients revealed a clearly defined area of hyperfluorescence in the early phase, and marked leakage of dye in the late phase, 2 patients — uncertain indices. In connection with the received data questionable PHAGE in 11 patients, all were held angio-OCT, to clarify the localization of choroidal neovascularization (CNV. When performing angio-OCT in 11 patients revealed that "wet" form of AMD with occult choroidal neovascularization. In 7 patients there had been discovered classic CNV in 2 patients combined. Conclusion. Angio-OCT gives a clearer picture about the presence of a choroidal neovascular membrane that plays a significant role in determining the course of treatment of patients with wet age-related macular degeneration.

  6. Magnetic resonance imaging-guided attenuation correction of positron emission tomography data in PET/MRI

    Science.gov (United States)

    Izquierdo-Garcia, David; Catana, Ciprian

    2018-01-01

    Synopsis Attenuation correction (AC) is one of the most important challenges in the recently introduced combined positron emission tomography/magnetic resonance imaging (PET/MR) scanners. PET/MR AC (MR-AC) approaches aim to develop methods that allow accurate estimation of the linear attenuation coefficients (LACs) of the tissues and other components located in the PET field of view (FoV). MR-AC methods can be divided into three main categories: segmentation-, atlas- and PET-based. This review aims to provide a comprehensive list of the state of the art MR-AC approaches as well as their pros and cons. The main sources of artifacts such as body-truncation, metallic implants and hardware correction will be presented. Finally, this review will discuss the current status of MR-AC approaches for clinical applications. PMID:26952727

  7. Computed tomography-guided cryoablation of local recurrence after primary resection of pancreatic adenocarcinoma

    Directory of Open Access Journals (Sweden)

    Claudio Pusceddu

    2015-06-01

    Full Text Available The optimal management of local recurrences after primary resection of pancreatic cancer still remains to be clarified. A 58-yearold woman developed an isolated recurrence of pancreatic cancer six year after distal pancreatectomy. Re-resection was attempted but the lesion was deemed unresectable at surgery. Then chemotherapy was administrated without obtaining a reduction of the tumor size nor an improvement of the patient’s symptoms. Thus the patient underwent percutaneous cryoablation under computed tomography (CT-guidance obtaining tumor necrosis and a significant improvement in the quality of life. A CT scan one month later showed a stable lesion with no contrast enhancement. While the use of percutaneous cryoblation has widened its applications in patients with unresectable pancreatic cancer, it has never been described for the treatment of local pancreatic cancer recurrence after primary resection. Percutaneous cryoablation deserves further studies in the multimodality treatment of local recurrence after primary pancreatic surgery.

  8. High frame-rate MR-guided near-infrared tomography system to monitor breast hemodynamics

    Science.gov (United States)

    Li, Zhiqiu; Jiang, Shudong; Krishnaswamy, Venkataramanan; Davis, Scott C.; Srinivasan, Subhadra; Paulsen, Keith D.; Pogue, Brian W.

    2011-02-01

    A near-infrared (NIR) tomography system with spectral-encoded sources at two wavelength bands was built to quantify the temporal contrast at 20 Hz bandwidth, while imaging breast tissue. The NIR system was integrated with a magnetic resonance (MR) machine through a custom breast coil interface, and both NIR data and MR images were acquired simultaneously. MR images provided breast tissue structural information for NIR reconstruction. Acquisition of finger pulse oximeter (PO) plethysmogram was synchronized with the NIR system in the experiment to offer a frequency-locked reference. The recovered absorption coefficients of the breast at two wavelengths showed identical temporal frequency as the PO output, proving this multi-modality design can recover the small pulsatile variation of absorption property in breast tissue related to the heartbeat. And it also showed the system's ability on novel contrast imaging of fast flow signals in deep tissue.

  9. Three dimensional subsurface elemental identification of minerals using confocal micro-X-ray fluorescence and micro-X-ray computed tomography

    International Nuclear Information System (INIS)

    Cordes, Nikolaus L.; Seshadri, Srivatsan; Havrilla, George J.; Yuan, Xiaoli; Feser, Michael; Patterson, Brian M.

    2015-01-01

    Current non-destructive elemental characterization methods, such as scanning electron microscopy-based energy dispersive spectroscopy (SEM–EDS) and micro-X-ray fluorescence spectroscopy (MXRF), are limited to either elemental identification at the surface (SEM–EDS) or suffer from an inability to discriminate between surface or depth information (MXRF). Thus, a non-destructive elemental characterization of individual embedded particles beneath the surface is impossible with either of these techniques. This limitation can be overcome by using laboratory-based 3D confocal micro-X-ray fluorescence spectroscopy (confocal MXRF). This technique utilizes focusing optics on the X-ray source and detector which allows for spatial discrimination in all three dimensions. However, the voxel-by-voxel serial acquisition of a 3D elemental scan can be very time-intensive (~ 1 to 4 weeks) if it is necessary to locate individual embedded particles of interest. As an example, if each point takes a 5 s measurement time, a small volume of 50 × 50 × 50 pixels leads to an acquisition time of approximately 174 h, not including sample stage movement time. Initially screening the samples for particles of interest using micro-X-ray computed tomography (micro-CT) can significantly reduce the time required to spatially locate these particles. Once located, these individual particles can be elementally characterized with confocal MXRF. Herein, we report the elemental identification of high atomic number surface and subsurface particles embedded in a mineralogical matrix by coupling micro-CT and confocal MXRF. Synergistically, these two X-ray based techniques first rapidly locate and then elementally identify individual subsurface particles. - Highlights: • Coupling of confocal X-ray fluorescence spectroscopy and X-ray computed tomography • Qualitative elemental identification of surface and subsurface mineral particles • Non-destructive particle size measurements • Utilization of

  10. Three dimensional subsurface elemental identification of minerals using confocal micro-X-ray fluorescence and micro-X-ray computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Cordes, Nikolaus L., E-mail: ncordes@lanl.gov [Polymers and Coatings Group, Material Science and Technology Division, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Seshadri, Srivatsan, E-mail: srivatsan.seshadri@zeiss.com [Carl Zeiss X-ray Microscopy, Inc., Pleasanton, CA 94588 (United States); Havrilla, George J. [Chemical Diagnostics and Engineering, Chemistry Division, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Yuan, Xiaoli [Julius Kruttschnitt Mineral Research Centre, University of Queensland, Indooroopilly, Brisbane, QLD 4068 (Australia); Feser, Michael [Carl Zeiss X-ray Microscopy, Inc., Pleasanton, CA 94588 (United States); Patterson, Brian M. [Polymers and Coatings Group, Material Science and Technology Division, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States)

    2015-01-01

    Current non-destructive elemental characterization methods, such as scanning electron microscopy-based energy dispersive spectroscopy (SEM–EDS) and micro-X-ray fluorescence spectroscopy (MXRF), are limited to either elemental identification at the surface (SEM–EDS) or suffer from an inability to discriminate between surface or depth information (MXRF). Thus, a non-destructive elemental characterization of individual embedded particles beneath the surface is impossible with either of these techniques. This limitation can be overcome by using laboratory-based 3D confocal micro-X-ray fluorescence spectroscopy (confocal MXRF). This technique utilizes focusing optics on the X-ray source and detector which allows for spatial discrimination in all three dimensions. However, the voxel-by-voxel serial acquisition of a 3D elemental scan can be very time-intensive (~ 1 to 4 weeks) if it is necessary to locate individual embedded particles of interest. As an example, if each point takes a 5 s measurement time, a small volume of 50 × 50 × 50 pixels leads to an acquisition time of approximately 174 h, not including sample stage movement time. Initially screening the samples for particles of interest using micro-X-ray computed tomography (micro-CT) can significantly reduce the time required to spatially locate these particles. Once located, these individual particles can be elementally characterized with confocal MXRF. Herein, we report the elemental identification of high atomic number surface and subsurface particles embedded in a mineralogical matrix by coupling micro-CT and confocal MXRF. Synergistically, these two X-ray based techniques first rapidly locate and then elementally identify individual subsurface particles. - Highlights: • Coupling of confocal X-ray fluorescence spectroscopy and X-ray computed tomography • Qualitative elemental identification of surface and subsurface mineral particles • Non-destructive particle size measurements • Utilization of

  11. Fatal paradoxical pulmonary air embolism complicating percutaneous computed tomography-guided needle biopsy of the lung

    International Nuclear Information System (INIS)

    Chakravarti, Rajesh; Singh, Virendra; Isaac, Rethish; John, Joseph

    2004-01-01

    A 63-year-old man with left upper zone haziness on chest X-ray and an infiltrative lesion with a pleural mass in the left upper lobe on CT scan was scheduled for CT-guided percutaneous trans-thoracic needle biopsy. During the procedure, the patient had massive haemoptysis and cardiorespiratory arrest and could not be revived. Post-mortem CT showed air in the right atrium, right ventricle, pulmonary artery and also in the left atrium and aorta. A discussion on paradoxical air embolism following percutaneous trans-thoracic needle biopsy is presented Copyright (2004) Blackwell Publishing Asia Pty Ltd

  12. Multimodal Imaging of Integrin Receptor-Positive Tumors by Bioluminescence, Fluorescence, Gamma Scintigraphy, and Single-Photon Emission Computed Tomography Using a Cyclic RGD Peptide Labeled with a Near-Infrared Fluorescent Dye and a Radionuclide

    Directory of Open Access Journals (Sweden)

    W. Barry Edwards

    2009-03-01

    Full Text Available Integrins, particularly the αvβ3 heterodimers, play important roles in tumor-induced angiogenesis and invasiveness. To image the expression pattern of the αvβ3 integrin in tumors through a multimodality imaging paradigm, we prepared a cyclic RGDyK peptide analogue (LS308 bearing a tetraazamacrocycle 1,4,7,10-tetraazacyclododecane-N, N′, N″, N‴-tetraacetic acid (DOTA and a lipophilic near-infrared (NIR fluorescent dye cypate. The αvβ3 integrin binding affinity and the internalization properties of LS308 mediated by the αvβ3 integrin in 4t1luc cells were investigated by receptor binding assay and fluorescence microscopy, respectively. The in vivo distribution of 111In-labeled LS308 in a 4t1luc tumor-bearing mouse model was studied by fluorescence, bioluminescence, planar gamma, and single-photon emission computed tomography (SPECT. The results show that LS308 has high affinity for αvβ3 integrin and internalized preferentially via the αvβ3 integrin-mediated endocytosis in 4t1luc cells. We also found that LS308 selectively accumulated in αvβ3-positve tumors in a receptor-specific manner and was visualized by the four imaging methods. Whereas the endogenous bioluminescence imaging identified the ensemble of the tumor tissue, the fluorescence and SPECT methods with the exogenous contrast agent LS308 reported the local expression of αvβ3 integrin. Thus, the multimodal imaging approach could provide important complementary diagnostic information for monitoring the efficacy of new antiangiogenic drugs.

  13. Optical coherence tomography-guided laser microsurgery for blood coagulation with continuous-wave laser diode.

    Science.gov (United States)

    Chang, Feng-Yu; Tsai, Meng-Tsan; Wang, Zu-Yi; Chi, Chun-Kai; Lee, Cheng-Kuang; Yang, Chih-Hsun; Chan, Ming-Che; Lee, Ya-Ju

    2015-11-16

    Blood coagulation is the clotting and subsequent dissolution of the clot following repair to the damaged tissue. However, inducing blood coagulation is difficult for some patients with homeostasis dysfunction or during surgery. In this study, we proposed a method to develop an integrated system that combines optical coherence tomography (OCT) and laser microsurgery for blood coagulation. Also, an algorithm for positioning of the treatment location from OCT images was developed. With OCT scanning, 2D/3D OCT images and angiography of tissue can be obtained simultaneously, enabling to noninvasively reconstruct the morphological and microvascular structures for real-time monitoring of changes in biological tissues during laser microsurgery. Instead of high-cost pulsed lasers, continuous-wave laser diodes (CW-LDs) with the central wavelengths of 450 nm and 532 nm are used for blood coagulation, corresponding to higher absorption coefficients of oxyhemoglobin and deoxyhemoglobin. Experimental results showed that the location of laser exposure can be accurately controlled with the proposed approach of imaging-based feedback positioning. Moreover, blood coagulation can be efficiently induced by CW-LDs and the coagulation process can be monitored in real-time with OCT. This technology enables to potentially provide accurate positioning for laser microsurgery and control the laser exposure to avoid extra damage by real-time OCT imaging.

  14. Diagnostic yield and complications of transthoracic computed tomography-guided biopsies

    DEFF Research Database (Denmark)

    Vagn-Hansen, Chris Aksel; Pedersen, Malene Roland Vils; Rafaelsen, Søren Rafael

    2016-01-01

    , the tissue material was found to be sufficient. In 32% of the biopsies, a complication arose, mostly pneumothorax (30%), but chest drainage was needed in only 15% of the 520 cases. Patients with more than ten cigarette pack-years had a complication risk that was twice as high at that of patients with fewer...... packyears. We found that the risk of pneumothorax increased the further the lesion was from the skin surface, the smaller the lesions were and when the patient was biopsied in a lateral position. We also found a higher risk of complications in females than in males. CONCLUSIONS: CT-guided biopsy...... is an excellent tool for analysing pulmonary lesions. The present study clearly shows that the risk of developing a pneumothorax is significantly increased among smokers and former smokers with more than ten pack-years....

  15. Positron emission tomography radiopharmaceutical studies in humans: a guide to regulations for academic researchers.

    Science.gov (United States)

    Fleming, Ian N; Whelan, Mark; Baxendale, Roy; Gilbert, Fiona J; Matthews, Paul P; Aigbirhio, Franklin I

    2012-09-01

    All clinical trials are covered by a series of regulations that seek to protect the rights, safety and welfare of participating patients. The regulations covering PET studies are especially complex to interpret because of the specialized nature of the language of the regulations and of PET studies themselves. It is often unclear whether the application demands that the radiotracer used be treated as an investigational medical product. This paper is intended to act as a general guide for UK researchers planning to perform PET research in humans by clarifying key aspects of the regulations that may affect the study and/or the radiopharmaceutical manufacturing process, providing links to useful information sources, introducing the concept of a UK Medicines and Healthcare products Regulatory Agency (MHRA) PET expert panel and outlining the value of sharing investigational medical product dossiers.

  16. Evaluation of intraoperative fluorescence imaging-guided surgery in cancer-bearing dogs: a prospective proof-of-concept phase II study in 9 cases.

    Science.gov (United States)

    Cabon, Quentin; Sayag, David; Texier, Isabelle; Navarro, Fabrice; Boisgard, Raphaël; Virieux-Watrelot, Dorothée; Ponce, Frédérique; Carozzo, Claude

    2016-04-01

    The objective was to prospectively evaluate the application of intraoperative fluorescence imaging (IOFI) in the surgical excision of malignant masses in dogs, using a novel lipid nanoparticle contrast agent. Dogs presenting with spontaneous soft-tissue sarcoma or subcutaneous tumors were prospectively enrolled. Clinical staging and whole-body computed tomography (CT) were performed. All the dogs received an intravenous injection of dye-loaded lipid nanoparticles, LipImage 815. Wide or radical resection was realized after CT examination. Real-time IOFI was performed before skin incision and after tumor excision. In cases of radical resection, the lymph nodes (LNs) were imaged. The margin/healthy tissues fluorescence ratio or LN/healthy tissues fluorescence ratio was measured and compared with the histologic margins or LN status. Nine dogs were included. Limb amputation was performed in 3 dogs, and wide resection in 6. No adverse effect was noted. Fluorescence was observed in all 9 of the tumors. The margins were clean in 5 of 6 dogs after wide surgical resection, and the margin/healthy tissues fluorescence ratio was close to 1.0 in all these dogs. Infiltrated margins were observed in 1 case, with a margin/healthy tissues fluorescence ratio of 3.2. Metastasis was confirmed in 2 of 3 LNs, associated with LN/healthy tissues fluorescence ratios of 2.1 and 4.2, whereas nonmetastatic LN was associated with a ratio of 1.0. LipImage 815 used as a contrast agent during IOFI seemed to allow for good discrimination between tumoral and healthy tissues. Future studies are scheduled to evaluate the sensitivity and specificity of IOFI using LipImage 815 as a tracer. Copyright © 2016 Elsevier Inc. All rights reserved.

  17. Concomitant radio- and fluorescence-guided sentinel lymph node biopsy in squamous cell carcinoma of the oral cavity using ICG-{sup 99m}Tc-nanocolloid

    Energy Technology Data Exchange (ETDEWEB)

    Berg, Nynke S. van den; Leeuwen, Fijs W.B. van [Netherlands Cancer Institute-Antoni van Leeuwenhoek Hospital, Department of Nuclear Medicine, Amsterdam (Netherlands); Leiden University Medical Center, Department of Radiology, Interventional Molecular Imaging Section, Albinusdreef 2 (C2-S zone), P.O. Box 9600, Leiden (Netherlands); Brouwer, Oscar R.; Valdes Olmos, Renato A. [Netherlands Cancer Institute-Antoni van Leeuwenhoek Hospital, Department of Nuclear Medicine, Amsterdam (Netherlands); Klop, W.M.C.; Karakullukcu, Baris; Zuur, Charlotte L.; Tan, I.B.; Balm, Alfons J.M.; Brekel, Michiel W.M. van den [Netherlands Cancer Institute-Antoni van Leeuwenhoek Hospital, Department of Head and Neck Surgery and Oncology, Amsterdam (Netherlands)

    2012-07-15

    For oral cavity malignancies, sentinel lymph node (SLN) mapping is performed by injecting a radiocolloid around the primary tumour followed by lymphoscintigraphy. Surgically, SLNs can then be localized using a handheld gamma ray detection probe. The aim of this study was to evaluate the added value of intraoperative fluorescence imaging to the conventional radioguided procedure. For this we used indocyanine green (ICG)-{sup 99m}Tc-nanocolloid, a hybrid tracer that is both radioactive and fluorescent. Fourteen patients with oral cavity squamous cell carcinoma were peritumourally injected with ICG-{sup 99m}Tc-nanocolloid. SLNs were preoperatively identified with lymphoscintigraphy followed by single photon emission computed tomography (SPECT)/CT for anatomical localization. During surgery, SLNs were detected with a handheld gamma ray detection probe and a handheld near-infrared fluorescence camera. Pre-incision and post-excision imaging with a portable gamma camera was performed to confirm complete removal of all SLNs. SLNs were preoperatively identified using the radioactive signature of ICG-{sup 99m}Tc-nanocolloid. Intraoperatively, 43 SLNs could be localized and excised with combined radio- and fluorescence guidance. Additionally, in four patients, an SLN located close to the primary injection site (in three patients this SLN was located in level I) could only be intraoperatively localized using fluorescence imaging. Pathological analysis of the SLNs revealed a metastasis in one patient. Combined preoperative SLN identification and intraoperative radio- and fluorescence guidance during SLN biopsies for oral cavity cancer proved feasible using ICG-{sup 99m}Tc-nanocolloid. The addition of fluorescence imaging was shown to be of particular value when SLNs were located in close proximity to the primary tumour. (orig.)

  18. Computed-tomography-guided high-dose-rate brachytherapy (CT-HDRBT) ablation of metastases adjacent to the liver hilum

    Energy Technology Data Exchange (ETDEWEB)

    Collettini, Federico, E-mail: federico.collettini@charite.de [Department of Radiology, Charité Universitätsmedizin Berlin, Charitéplatz 1, 10117 Berlin (Germany); Department of Radiation Oncology, Charité – Universitätsmedizin Berlin, Campus Virchow-Klinikum, Augustenburger Platz 1, 13353 Berlin (Germany); Singh, Anju [Department of Medical Oncology, Charité – Universitätsmedizin Berlin, Campus Virchow-Klinikum, Augustenburger Platz 1, 13353 Berlin (Germany); Schnapauff, Dirk [Department of Radiology, Charité – Universitätsmedizin Berlin, Campus Virchow-Klinikum, Augustenburger Platz 1, 13353 Berlin (Germany); Department of Radiation Oncology, Charité – Universitätsmedizin Berlin, Campus Virchow-Klinikum, Augustenburger Platz 1, 13353 Berlin (Germany); Powerski, Maciej Janusz [Charité – Universitätsmedizin Berlin, Campus Benjamin Franklin, Hindenburgdamm 30, 12203 Berlin (Germany); Department of Radiation Oncology, Charité – Universitätsmedizin Berlin, Campus Virchow-Klinikum, Augustenburger Platz 1, 13353 Berlin (Germany); and others

    2013-10-01

    Purpose: To evaluate technical feasibility and clinical outcome of computed tomography-guided high-dose-rate-brachytherapy (CT-HDRBT) ablation of metastases adjacent to the liver hilum. Materials and methods: Between November 2007 and May 2012, 32 consecutive patients with 34 metastases adjacent to the liver hilum (common bile duct or hepatic bifurcation ≤5 mm distance) were treated with CT-HDRBT. Treatment was performed by CT-guided applicator placement and high-dose-rate brachytherapy with an iridium-192 source. MRI follow-up was performed 6 weeks and every 3 months post intervention. The primary endpoint was local tumor control (LTC); secondary endpoints included time to progression (TTP) and overall survival (OS). Results: Patients were available for MRI evaluation for a mean follow-up time of 18.75 months (range: 3–56 months). Mean tumor diameter was 4.3 cm (range: 1.3–10.7 cm). One major complication was observed. Four (11.8%) local recurrences were observed after a local tumor control of 5, 8, 9 and 10 months, respectively. Twenty-two patients (68.75%) experienced a systemic tumor progression during the follow up period. Mean TTP was 12.9 months (range: 2–56 months). Nine patients died during the follow-up period. Median OS was 20.24 months. Conclusion: Minimally invasive CT-HDRBT is a safe and effective option also for unresectable liver metastases adjacent to the liver hilum that would have been untreatable by thermal ablation.

  19. Individualized treatment of craniovertebral junction malformation guided by intraoperative computed tomography.

    Science.gov (United States)

    Li, Lianfeng; Wang, Peng; Chen, LiFeng; Ma, Xiaodong; Bu, Bo; Yu, Xinguang

    2012-04-01

    This study was designed to report our preliminary experience of intraoperative computed tomography (iCT) using a mobile scanner with integrated neuronavigation system (NNS). The objective of this study was to assess the feasibility and potential utility of iCT with integrated NNS in individualized treatment of craniovertebral junction malformation (CVJM). The surgical management of congenital craniovertebral anomalies is complex due to the relative difficulty in accessing the region, critical relationships of neurovascular structures, and the intricate biomechanical issues involved. We reported our first 19 complex CVJM cases including 11 male and 8 female patients from January, 2009 to June, 2009 (mean age, 33.9 y; age range, 13 to 58 y). A sliding gantry 40-slice CT scanner was installed in a preexisting operating room. Image data was transferred directly from the scanner into the NNS using an automated registration system. We applied this technology to transoral odontoidectomy in 17 patients. Moreover, with the extra help of iCT integrated with NNS, odontoidectomy through posterior midline approach, and transoral atlantal lateral mass resection were, for the first time, performed for treatment of complex CVJM. NNS was found to correlate well with the intraoperative findings, and the recalibration was uneven in all cases with an accuracy of 1.6 mm (1.6: 1.2 to 2.0). All patients were clinically evaluated by Nurick grade criteria, and neurological deficits were monitored after 3 months of surgery. Fifteen patients (79%) were improved by at least 1 Nurick grade, whereas the grade did not change in 4 patients (21%). iCT scanning with integrated NNS was both feasible and beneficial for the surgical management of complex CVJM. In this unusual patient population, the technique seemed to be valuable in negotiating complex anatomy and achieving a safe and predictable decompression.

  20. Dynamic Assessment of the Endothelialization of Tissue-Engineered Blood Vessels Using an Optical Coherence Tomography Catheter-Based Fluorescence Imaging System.

    Science.gov (United States)

    Gurjarpadhye, Abhijit Achyut; DeWitt, Matthew R; Xu, Yong; Wang, Ge; Rylander, Marissa Nichole; Rylander, Christopher G

    2015-07-01

    Lumen endothelialization of bioengineered vascular scaffolds is essential to maintain small-diameter graft patency and prevent thrombosis postimplantation. Unfortunately, nondestructive imaging methods to visualize this dynamic process are lacking, thus slowing development and clinical translation of these potential tissue-engineering approaches. To meet this need, a fluorescence imaging system utilizing a commercial optical coherence tomography (OCT) catheter was designed to visualize graft endothelialization. C7 DragonFly™ intravascular OCT catheter was used as a channel for delivery and collection of excitation and emission spectra. Poly-dl-lactide (PDLLA) electrospun scaffolds were seeded with endothelial cells (ECs). Seeded cells were exposed to Calcein AM before imaging, causing the living cells to emit green fluorescence in response to blue laser. By positioning the catheter tip precisely over a specimen using high-fidelity electromechanical components, small regions of the specimen were excited selectively. The resulting fluorescence intensities were mapped on a two-dimensional digital grid to generate spatial distribution of fluorophores at single-cell-level resolution. Fluorescence imaging of endothelialization on glass and PDLLA scaffolds was performed using the OCT catheter-based imaging system as well as with a commercial fluorescence microscope. Cell coverage area was calculated for both image sets for quantitative comparison of imaging techniques. Tubular PDLLA scaffolds were maintained in a bioreactor on seeding with ECs, and endothelialization was monitored over 5 days using the OCT catheter-based imaging system. No significant difference was observed in images obtained using our imaging system to those acquired with the fluorescence microscope. Cell area coverage calculated using the images yielded similar values. Nondestructive imaging of endothelialization on tubular scaffolds showed cell proliferation with cell coverage area increasing from

  1. Prosthesis-guided implant restoration of an auricular defect using computed tomography and 3-dimensional photographic imaging technologies: a clinical report.

    Science.gov (United States)

    Wang, Shuming; Leng, Xu; Zheng, Yaqi; Zhang, Dapeng; Wu, Guofeng

    2015-02-01

    The concept of prosthesis-guided implantation has been widely accepted for intraoral implant placement, although clinicians do not fully appreciate its use for facial defect restoration. In this clinical report, multiple digital technologies were used to restore a facial defect with prosthesis-guided implantation. A simulation surgery was performed to remove the residual auricular tissue and to ensure the correct position of the mirrored contralateral ear model. The combined application of computed tomography and 3-dimensional photography preserved the position of the mirrored model and facilitated the definitive implant-retained auricular prosthesis. Copyright © 2015 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

  2. Optical Coherence Tomography for Retinal Surgery: Perioperative Analysis to Real-Time Four-Dimensional Image-Guided Surgery.

    Science.gov (United States)

    Carrasco-Zevallos, Oscar M; Keller, Brenton; Viehland, Christian; Shen, Liangbo; Seider, Michael I; Izatt, Joseph A; Toth, Cynthia A

    2016-07-01

    Magnification of the surgical field using the operating microscope facilitated profound innovations in retinal surgery in the 1970s, such as pars plana vitrectomy. Although surgical instrumentation and illumination techniques are continually developing, the operating microscope for vitreoretinal procedures has remained essentially unchanged and currently limits the surgeon's depth perception and assessment of subtle microanatomy. Optical coherence tomography (OCT) has revolutionized clinical management of retinal pathology, and its introduction into the operating suite may have a similar impact on surgical visualization and treatment. In this article, we review the evolution of OCT for retinal surgery, from perioperative analysis to live volumetric (four-dimensional, 4D) image-guided surgery. We begin by briefly addressing the benefits and limitations of the operating microscope, the progression of OCT technology, and OCT applications in clinical/perioperative retinal imaging. Next, we review intraoperative OCT (iOCT) applications using handheld probes during surgical pauses, two-dimensional (2D) microscope-integrated OCT (MIOCT) of live surgery, and volumetric MIOCT of live surgery. The iOCT discussion focuses on technological advancements, applications during human retinal surgery, translational difficulties and limitations, and future directions.

  3. Image Guided Virtual Autopsy: An Adjunct with Radiographic and Computed Tomography Modalities - An Important Tool in Forensic Identification

    Directory of Open Access Journals (Sweden)

    Shalu Rai

    2017-01-01

    Full Text Available The forensic examination of dead bodies is very helpful in order to identify the person, cause of death, gender, and solving the mysterious cases. It includes a number of techniques, out of which autopsy is the primary investigation that is performed in every medicolegal case. Because of mutilation technologies, traditional autopsy technique is most disturbing in terms of emotions and rituals of relatives. The use of radiology in forensic science comprises performance, interpretation, and reporting of radiographs that is helpful in detecting those changes that are not clinically visible. Forensic radiology plays an important role for identification of humans in mass disasters, criminal investigations, and evaluation of cause of death. The introduction of radiological modalities in autopsy techniques is a complementary tool for forensic identification and is known as virtual autopsy. The advance imaging techniques such as computed tomography (CT and magnetic resonance imaging (MRI is used in virtual autopsy in order to visualize and reconstruct the internal organs to know the site, type, and depth of injury. This review elaborates the role of maxillofacial imaging in image-guided virtual autopsy.

  4. Two-step reconstruction method using global optimization and conjugate gradient for ultrasound-guided diffuse optical tomography.

    Science.gov (United States)

    Tavakoli, Behnoosh; Zhu, Quing

    2013-01-01

    Ultrasound-guided diffuse optical tomography (DOT) is a promising method for characterizing malignant and benign lesions in the female breast. We introduce a new two-step algorithm for DOT inversion in which the optical parameters are estimated with the global optimization method, genetic algorithm. The estimation result is applied as an initial guess to the conjugate gradient (CG) optimization method to obtain the absorption and scattering distributions simultaneously. Simulations and phantom experiments have shown that the maximum absorption and reduced scattering coefficients are reconstructed with less than 10% and 25% errors, respectively. This is in contrast with the CG method alone, which generates about 20% error for the absorption coefficient and does not accurately recover the scattering distribution. A new measure of scattering contrast has been introduced to characterize benign and malignant breast lesions. The results of 16 clinical cases reconstructed with the two-step method demonstrates that, on average, the absorption coefficient and scattering contrast of malignant lesions are about 1.8 and 3.32 times higher than the benign cases, respectively.

  5. The use of computerised tomography guided percutaneous fine needle aspiration in the evaluation of solitary pulmonary nodules.

    LENUS (Irish Health Repository)

    Khan, K A

    2012-02-01

    The evaluation of a solitary pulmonary nodule (SPN) has changed over the years with increased access to percutaneous computerised tomography (CT) guided fine needle aspiration (FNA), where bronchoscopy is unhelpful. The aim of our study was to evaluate the sample adequacy, diagnostic and complication rate of CT-FNA of a SPN at our academic teaching hospital over an 18 month period. CT-FNA was performed by a radiologist, with a cytopathologist in attendance to confirm the adequacy of the sample obtained. The size of the nodule, sample material and adequacy, diagnosis and complications were recorded. A total of 101 patients were included, 54 male and the mean age was 68 +\\/- 11 years. The mean size of the SPN was 2.3 cm (range 1-11 cm). 56 (56%) patients had a right SPN, 45 (45%) had a left SPN. CT-FNA was diagnostic in 80 (80%) patients and non-diagnostic in 21 (20%) patients. The sample was insufficient for immunocytochemistry, although the morphological appearance was diagnostic in 20 (25%) of the 80 patients. Pneumothorax occurred in 26\\/101 (26%) patients post CT-FNA, of these 7 (27%) required chest drain insertion, while 19 (73%) were managed conservatively. CT FNA is a useful tool for the diagnosis of a SPN, with our diagnostic accuracy comparable to that reported in the literature. However, CT-FNA may not provide adequate sample volume to perform ancillary testing and has a moderate complication rate.

  6. Computed tomography-guided needle aspiration and biopsy of pulmonary lesions - A single-center experience in 1000 patients

    Energy Technology Data Exchange (ETDEWEB)

    Poulou, Loukia S.; Tsagouli, Paraskevi; Thanos, Loukas [Dept. of Medical Imaging and Interventional Radiology, General Hospital of Chest Diseases ' Sotiria' , Athens (Greece)], e-mail: ploukia@hotmail.com; Ziakas, Panayiotis D. [Program of Outcomes Research, Div. of Infectious Diseases, Warren Alpert Medical School, Brown Univ., RI, and Div. of Infectious Diseases, Rhode Island Hospital, Rhode Island (United States); Politi, Dimitra [Dept. of Cythopathology, General Hospital of Chest Diseases ' Sotiria' Athens (Greece); Trigidou, Rodoula [Dept. of Pathology, General Hospital of Chest Diseases ' Sotiria' Athens (Greece)

    2013-07-15

    Background: Computed tomography (CT)-guided fine needle aspiration (FNA) and biopsies are well-established, minimally invasive diagnostic tools for pulmonary lesions. Purpose: To analyze retrospectively the results of 1000 consecutive lung CT-guided FNA and/or core needle biopsies (CNB), the main outcome measures being diagnostic yield, and complication rates. Material and Methods: Patients considered eligible were those referred to our department for lung lesions. The choice of FNA, CNB, or both was based upon the radiologist's judgment. Diagnostic yield was defined as the probability of having a definite result by cytology/histology. Results: The study included 733 male patients and 267 female patients, with a mean (SD) age of 66.4 (11.4) years. The mean (SD) lesion size was 3.7 (2.4) cm in maximal diameter. Six hundred and forty-one (64%) patients underwent an FNA procedure, 245 (25%) a CNB, and 114 (11%) had been subjected to both. The diagnostic yield was 960/994 (96.6%); this decreased significantly with the use of CNB only (odds ratio [OR] 0.32; 95% CI 0.12 - 0.88; P = 0.03), while it increased with lesion size (OR 1.35; 95% CI 1.03 - 1.79; P = 0.03 per cm increase). In 506 patients (52.7%), a malignant process was diagnosed by cytopathology/histology. The complication rate reached 97/1000 (9.7%); complications included: hemorrhage, 62 (6.2%); pneumothorax, 28 (2.8%); hemorrhage and pneumothorax, 5 (0.5%); and hemoptysis, 2 (0.2%). It was not significantly affected by the type of procedure or localization of the lesion. The overall risk for complications was three times higher for lesions <4 cm (OR 3.26; 95% CI 1.96 - 5.42; P < 0.001). Conclusion: CT-guided lung biopsy has a high diagnostic yield using FNA, CNB, or both. The CNB procedure alone will not suffice. Complication rates were acceptable and correlated inversely with lesion size, not localization or type of procedure.

  7. The Use of Cone Beam Computed Tomography for Image Guided Gamma Knife Stereotactic Radiosurgery: Initial Clinical Evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Li, Winnie; Cho, Young-Bin [Radiation Medicine Program, Princess Margaret Cancer Centre, Toronto, Ontario (Canada); Department of Radiation Oncology, University of Toronto, Toronto, Ontario (Canada); Ansell, Steve [Radiation Medicine Program, Princess Margaret Cancer Centre, Toronto, Ontario (Canada); Laperriere, Normand; Ménard, Cynthia; Millar, Barbara-Ann [Radiation Medicine Program, Princess Margaret Cancer Centre, Toronto, Ontario (Canada); Department of Radiation Oncology, University of Toronto, Toronto, Ontario (Canada); Zadeh, Gelareh [Division of Neurosurgery, University of Toronto University Health Network, Toronto Western Hospital, Toronto, Ontario (Canada); Macfeeters-Hamilton Centre for Neuro-oncology, Ontario Cancer Institute, Toronto, Ontario (Canada); Kongkham, Paul; Bernstein, Mark [Division of Neurosurgery, University of Toronto University Health Network, Toronto Western Hospital, Toronto, Ontario (Canada); Jaffray, David A. [Radiation Medicine Program, Princess Margaret Cancer Centre, Toronto, Ontario (Canada); Department of Radiation Oncology, University of Toronto, Toronto, Ontario (Canada); Department of Medical Biophysics, University of Toronto, Toronto, Ontario (Canada); Chung, Caroline, E-mail: caroline.chung.md@gmail.com [Radiation Medicine Program, Princess Margaret Cancer Centre, Toronto, Ontario (Canada); Department of Radiation Oncology, University of Toronto, Toronto, Ontario (Canada)

    2016-09-01

    Purpose: The present study used cone beam computed tomography (CBCT) to measure the inter- and intrafraction uncertainties for intracranial stereotactic radiosurgery (SRS) using the Leksell Gamma Knife (GK). Methods and Materials: Using a novel CBCT system adapted to the GK radiosurgery treatment unit, CBCT images were acquired immediately before and after treatment for each treatment session within the context of a research ethics board–approved prospective clinical trial. Patients were immobilized in the Leksell coordinate frame (LCF) for both volumetric CBCT imaging and GK-SRS delivery. The relative displacement of the patient's skull to the stereotactic reference (interfraction motion) was measured for each CBCT scan. Differences between the pre- and post-treatment CBCT scans were used to determine the intrafraction motion. Results: We analyzed 20 pre- and 17 post-treatment CBCT scans in 20 LCF patients treated with SRS. The mean translational pretreatment setup error ± standard deviation in the left-right, anteroposterior, and craniocaudal directions was −0.19 ± 0.32, 0.06 ± 0.27, and −0.23 ± 0.2 mm, with a maximum of −0.74, −0.53, and −0.68 mm, respectively. After an average time between the pre- and post-treatment CBCT scans of 82 minutes (range 27-170), the mean intrafraction error ± standard deviation for the LCF was −0.03 ± 0.05, −0.03 ± 0.18, and −0.03 ± 0.12 mm in the left-right, anteroposterior, and craniocaudual direction, respectively. Conclusions: Using CBCT on a prototype image guided GK Perfexion unit, we were able to measure the inter- and intrafraction positional changes for GK-SRS using the invasive frame. In the era of image guided radiation therapy, the use of CBCT image guidance for both frame- and non–frame-based immobilization systems could serve as a useful quality assurance tool. Our preliminary measurements can guide the application of achievable thresholds for inter- and intrafraction

  8. The Use of Cone Beam Computed Tomography for Image Guided Gamma Knife Stereotactic Radiosurgery: Initial Clinical Evaluation

    International Nuclear Information System (INIS)

    Li, Winnie; Cho, Young-Bin; Ansell, Steve; Laperriere, Normand; Ménard, Cynthia; Millar, Barbara-Ann; Zadeh, Gelareh; Kongkham, Paul; Bernstein, Mark; Jaffray, David A.; Chung, Caroline

    2016-01-01

    Purpose: The present study used cone beam computed tomography (CBCT) to measure the inter- and intrafraction uncertainties for intracranial stereotactic radiosurgery (SRS) using the Leksell Gamma Knife (GK). Methods and Materials: Using a novel CBCT system adapted to the GK radiosurgery treatment unit, CBCT images were acquired immediately before and after treatment for each treatment session within the context of a research ethics board–approved prospective clinical trial. Patients were immobilized in the Leksell coordinate frame (LCF) for both volumetric CBCT imaging and GK-SRS delivery. The relative displacement of the patient's skull to the stereotactic reference (interfraction motion) was measured for each CBCT scan. Differences between the pre- and post-treatment CBCT scans were used to determine the intrafraction motion. Results: We analyzed 20 pre- and 17 post-treatment CBCT scans in 20 LCF patients treated with SRS. The mean translational pretreatment setup error ± standard deviation in the left-right, anteroposterior, and craniocaudal directions was −0.19 ± 0.32, 0.06 ± 0.27, and −0.23 ± 0.2 mm, with a maximum of −0.74, −0.53, and −0.68 mm, respectively. After an average time between the pre- and post-treatment CBCT scans of 82 minutes (range 27-170), the mean intrafraction error ± standard deviation for the LCF was −0.03 ± 0.05, −0.03 ± 0.18, and −0.03 ± 0.12 mm in the left-right, anteroposterior, and craniocaudual direction, respectively. Conclusions: Using CBCT on a prototype image guided GK Perfexion unit, we were able to measure the inter- and intrafraction positional changes for GK-SRS using the invasive frame. In the era of image guided radiation therapy, the use of CBCT image guidance for both frame- and non–frame-based immobilization systems could serve as a useful quality assurance tool. Our preliminary measurements can guide the application of achievable thresholds for inter- and intrafraction

  9. WE-FG-BRA-06: Systematic Study of Target Localization for Bioluminescence Tomography Guided Radiation Therapy for Preclinical Research

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, B; Reyes, J; Wong, J; Wang, K [Department of Radiation Oncology and Molecular Radiation Sciences, Johns Hopkins University, Baltimore, MD (United States); Yu, J [Department of Radiation Oncology and Molecular Radiation Sciences, Johns Hopkins University, Baltimore, MD (United States); School of Physics and Information Technology, Shaanxi Normal University, Shaanxi (China); Iordachita, I [Laboratory for Computational Sensing and Robotics, Johns Hopkins University, Baltimore, MD (United States); Liu, Z [Department of Oncology, Department of Surgery, Johns Hopkins University, Baltimore, MD (United States); Department of GI Oncology, Peking University School of Oncology, Beijing Cancer Hospital & Institute, Beijing (China); Brock, M [Department of Oncology, Department of Surgery, Johns Hopkins University, Baltimore, MD (United States); Patterson, M [McMaster University, Hamilton, Ontario, CA (Canada)

    2016-06-15

    Purpose: To overcome the limitation of CT/CBCT in guiding radiation for soft tissue targets, we developed a bioluminescence tomography(BLT) system for preclinical radiation research. We systematically assessed the system performance in target localization and the ability of resolving two sources in simulations, phantom and in vivo environments. Methods: Multispectral images acquired in single projection were used for the BLT reconstruction. Simulation studies were conducted for single spherical source radius from 0.5 to 3 mm at depth of 3 to 12 mm. The same configuration was also applied for the double sources simulation with source separations varying from 3 to 9 mm. Experiments were performed in a standalone BLT/CBCT system. Two sources with 3 and 4.7 mm separations placed inside a tissue-mimicking phantom were chosen as the test cases. Live mice implanted with single source at 6 and 9 mm depth, 2 sources with 3 and 5 mm separation at depth of 5 mm or 3 sources in the abdomen were also used to illustrate the in vivo localization capability of the BLT system. Results: Simulation and phantom results illustrate that our BLT can provide 3D source localization with approximately 1 mm accuracy. The in vivo results are encouraging that 1 and 1.7 mm accuracy can be attained for the single source case at 6 and 9 mm depth, respectively. For the 2 sources study, both sources can be distinguished at 3 and 5 mm separations at approximately 1 mm accuracy using 3D BLT but not 2D bioluminescence image. Conclusion: Our BLT/CBCT system can be potentially applied to localize and resolve targets at a wide range of target sizes, depths and separations. The information provided in this study can be instructive to devise margins for BLT-guided irradiation and suggests that the BLT could guide radiation for multiple targets, such as metastasis. Drs. John W. Wong and Iulian I. Iordachita receive royalty payment from a licensing agreement between Xstrahl Ltd and Johns Hopkins University.

  10. Optical coherence tomography image-guided smart laser knife for surgery.

    Science.gov (United States)

    Katta, Nitesh; McElroy, Austin B; Estrada, Arnold D; Milner, Thomas E

    2018-03-01

    Surgical oncology can benefit from specialized tools that enhance imaging and enable precise cutting and removal of tissue without damage to adjacent structures. The combination of high-resolution, fast optical coherence tomography (OCT) co-aligned with a nanosecond pulsed thulium (Tm) laser offers advantages over conventional surgical laser systems. Tm lasers provide superior beam quality, high volumetric tissue removal rates with minimal residual thermal footprint in tissue, enabling a reduction in unwanted damage to delicate adjacent sub-surface structures such as nerves or micro-vessels. We investigated such a combined Tm/OCT system with co-aligned imaging and cutting beams-a configuration we call a "smart laser knife." A blow-off model that considers absorption coefficients and beam delivery systems was utilized to predict Tm cut depth, tissue removal rate and spatial distribution of residual thermal injury. Experiments were performed to verify the volumetric removal rate predicted by the model as a function of average power. A bench-top, combined Tm/OCT system was constructed using a 15W 1940 nm nanosecond pulsed Tm fiber laser (500 μJ pulse energy, 100 ns pulse duration, 30 kHz repetition rate) for removing tissue and a swept source laser (1310 ± 70 nm, 100 kHz sweep rate) for OCT imaging. Tissue phantoms were used to demonstrate precise surgery with blood vessel avoidance. Depth imaging informed cutting/removal of targeted tissue structures by the Tm laser was performed. Laser cutting was accomplished around and above phantom blood vessels while avoiding damage to vessel walls. A tissue removal rate of 5.5 mm 3 /sec was achieved experimentally, in comparison to the model prediction of approximately 6 mm 3 /sec. We describe a system that combines OCT and laser tissue modification with a Tm laser. Simulation results of the tissue removal rate using a simple model, as a function of average power, are in good agreement with experimental

  11. Macular laser photocoagulation guided by spectral-domain optical coherence tomography versus fluorescein angiography for diabetic macular edema

    Directory of Open Access Journals (Sweden)

    Gallego-Pinazo R

    2011-05-01

    Full Text Available Roberto Gallego-Pinazo1,2, Ana Marina Suelves-Cogollos1, Rosa Dolz-Marco1, J Fernando Arevalo3, Salvador García-Delpech1, J Luis Mullor4, Manuel Díaz-Llopis1,2,51Department of Ophthalmology, Hospital Universitario La Fe, Valencia, Spain; 2Centro de Investigación Biomédica en Red de Enfermedades Raras, Valencia, Spain; 3Retina and Vitreous Service, Clinical Ophthalmology Center, Caracas, Venezuela; 4Unit of Experimental Ophthalmology, Hospital Universitario La Fe, Valencia, Spain; 5University of Valencia, Faculty of Medicine, Valencia, SpainBackground: The aim of this study was to compare the efficacy of spectral-domain optical coherence tomography (SD-OCT and fluorescein angiography (FA in the guidance of macular laser photocoagulation for diabetic macular edema.Methods: This was a prospective interventional clinical comparative pilot study. Forty eyes from 24 consecutive patients with diabetic macular edema were allocated to receive laser photocoagulation guided by SD-OCT or FA. Best-corrected visual acuity (BCVA, central macular thickness, and retinal volume were assessed at baseline and two months after treatment.Results: Subjects treated using FA-guided laser improved BCVA from the logarithm of the minimum angle of resolution (logMAR 0.52 ± 0.2 to 0.37 ± 0.2 (P < 0.001, and decreased mean central macular thickness from 397.25 ± 139.1 to 333.50 ± 105.7 µm (P < 0.001 and retinal volume from 12.61 ± 1.6 to 10.94 ± 1.4 mm3 (P < 0.001. Subjects treated using SD-OCT guided laser had improved BCVA from 0.48 ± 0.2 to 0.33 ± 0.2 logMAR (P < 0.001, and decreased mean central macular thickness from 425.90 ± 149.6 to 353.4 ± 140 µm (P < 0.001 and retinal volume from 12.38 ± 2.1 to 11.53 ± 1.1 mm3 (P < 0.001. No significant differences between the groups were found in two-month BCVA (P = 0.505, two-month central macular thickness (P = 0.660, or two-month retinal volume (P = 0.582.Conclusion: The short-term results of this pilot study

  12. Incoherent-scatter computed tomography with monochromatic synchrotron x ray: feasibility of multi-CT imaging system for simultaneous measurement-of fluorescent and incoherent scatter x rays

    Science.gov (United States)

    Yuasa, T.; Akiba, M.; Takeda, T.; Kazama, M.; Hoshino, A.; Watanabe, Y.; Hyodo, K.; Dilmanian, F. A.; Akatsuka, T.; Itai, Y.

    1997-10-01

    We describe a new system of incoherent scatter computed tomography (ISCT) using monochromatic synchrotron X rays, and we discuss its potential to be used in in vivo imaging for medical use. The system operates on the basis of computed tomography (CT) of the first generation. The reconstruction method for ISCT uses the least squares method with singular value decomposition. The research was carried out at the BLNE-5A bending magnet beam line of the Tristan Accumulation Ring in KEK, Japan. An acrylic cylindrical phantom of 20-mm diameter containing a cross-shaped channel was imaged. The channel was filled with a diluted iodine solution with a concentration of 200 /spl mu/gI/ml. Spectra obtained with the system's high purity germanium (HPGe) detector separated the incoherent X-ray line from the other notable peaks, i.e., the iK/sub /spl alpha// and K/sub /spl beta/1/ X-ray fluorescent lines and the coherent scattering peak. CT images were reconstructed from projections generated by integrating the counts In the energy window centering around the incoherent scattering peak and whose width was approximately 2 keV. The reconstruction routine employed an X-ray attenuation correction algorithm. The resulting image showed more homogeneity than one without the attenuation correction.

  13. The Value of 5-Aminolevulinic Acid in Low-grade Gliomas and High-grade Gliomas Lacking Glioblastoma Imaging Features: An Analysis Based on Fluorescence, Magnetic Resonance Imaging, 18F-Fluoroethyl Tyrosine Positron Emission Tomography, and Tumor Molecular Factors.

    Science.gov (United States)

    Jaber, Mohammed; Wölfer, Johannes; Ewelt, Christian; Holling, Markus; Hasselblatt, Martin; Niederstadt, Thomas; Zoubi, Tarek; Weckesser, Matthias; Stummer, Walter

    2016-03-01

    Approximately 20% of grade II and most grade III gliomas fluoresce after 5-aminolevulinic acid (5-ALA) application. Conversely, approximately 30% of nonenhancing gliomas are actually high grade. The aim of this study was to identify preoperative factors (ie, age, enhancement, 18F-fluoroethyl tyrosine positron emission tomography [F-FET PET] uptake ratios) for predicting fluorescence in gliomas without typical glioblastomas imaging features and to determine whether fluorescence will allow prediction of tumor grade or molecular characteristics. Patients harboring gliomas without typical glioblastoma imaging features were given 5-ALA. Fluorescence was recorded intraoperatively, and biopsy specimens collected from fluorescing tissue. World Health Organization (WHO) grade, Ki-67/MIB-1 index, IDH1 (R132H) mutation status, O-methylguanine DNA methyltransferase (MGMT) promoter methylation status, and 1p/19q co-deletion status were assessed. Predictive factors for fluorescence were derived from preoperative magnetic resonance imaging and F-FET PET. Classification and regression tree analysis and receiver-operating-characteristic curves were generated for defining predictors. Of 166 tumors, 82 were diagnosed as WHO grade II, 76 as grade III, and 8 as glioblastomas grade IV. Contrast enhancement, tumor volume, and F-FET PET uptake ratio >1.85 predicted fluorescence. Fluorescence correlated with WHO grade (P fluorescing grade III gliomas was higher than in nonfluorescing tumors, whereas in fluorescing and nonfluorescing grade II tumors, no differences were noted. Age, tumor volume, and F-FET PET uptake are factors predicting 5-ALA-induced fluorescence in gliomas without typical glioblastoma imaging features. Fluorescence was associated with an increased Ki-67/MIB-1 index and high-grade pathology. Whether fluorescence in grade II gliomas identifies a subtype with worse prognosis remains to be determined.

  14. Fluorescence and Magnetic Resonance Dual-Modality Imaging-Guided Photothermal and Photodynamic Dual-Therapy with Magnetic Porphyrin-Metal Organic Framework Nanocomposites

    Science.gov (United States)

    Zhang, Hui; Li, Yu-Hao; Chen, Yang; Wang, Man-Man; Wang, Xue-Sheng; Yin, Xue-Bo

    2017-03-01

    Phototherapy shows some unique advantages in clinical application, such as remote controllability, improved selectivity, and low bio-toxicity, than chemotherapy. In order to improve the safety and therapeutic efficacy, imaging-guided therapy seems particularly important because it integrates visible information to speculate the distribution and metabolism of the probe. Here we prepare biocompatible core-shell nanocomposites for dual-modality imaging-guided photothermal and photodynamic dual-therapy by the in situ growth of porphyrin-metal organic framework (PMOF) on Fe3O4@C core. Fe3O4@C core was used as T2-weighted magnetic resonance (MR) imaging and photothermal therapy (PTT) agent. The optical properties of porphyrin were well remained in PMOF, and PMOF was therefore selected for photodynamic therapy (PDT) and fluorescence imaging. Fluorescence and MR dual-modality imaging-guided PTT and PDT dual-therapy was confirmed with tumour-bearing mice as model. The high tumour accumulation of Fe3O4@C@PMOF and controllable light excitation at the tumour site achieved efficient cancer therapy, but low toxicity was observed to the normal tissues. The results demonstrated that Fe3O4@C@PMOF was a promising dual-imaging guided PTT and PDT dual-therapy platform for tumour diagnosis and treatment with low cytotoxicity and negligible in vivo toxicity.

  15. Preliminary study on X-ray fluorescence computed tomography imaging of gold nanoparticles: Acceleration of data acquisition by multiple pinholes scheme

    Science.gov (United States)

    Sasaya, Tenta; Sunaguchi, Naoki; Seo, Seung-Jum; Hyodo, Kazuyuki; Zeniya, Tsutomu; Kim, Jong-Ki; Yuasa, Tetsuya

    2018-04-01

    Gold nanoparticles (GNPs) have recently attracted attention in nanomedicine as novel contrast agents for cancer imaging. A decisive tomographic imaging technique has not yet been established to depict the 3-D distribution of GNPs in an object. An imaging technique known as pinhole-based X-ray fluorescence computed tomography (XFCT) is a promising method that can be used to reconstruct the distribution of GNPs from the X-ray fluorescence emitted by GNPs. We address the acceleration of data acquisition in pinhole-based XFCT for preclinical use using a multiple pinhole scheme. In this scheme, multiple projections are simultaneously acquired through a multi-pinhole collimator with a 2-D detector and full-field volumetric beam to enhance the signal-to-noise ratio of the projections; this enables fast data acquisition. To demonstrate the efficacy of this method, we performed an imaging experiment using a physical phantom with an actual multi-pinhole XFCT system that was constructed using the beamline AR-NE7A at KEK. The preliminary study showed that the multi-pinhole XFCT achieved a data acquisition time of 20 min at a theoretical detection limit of approximately 0.1 Au mg/ml and at a spatial resolution of 0.4 mm.

  16. 3D characterisation of the gaseous and liquid phase using laser-induced exciplex fluorescence (LIEF) tomography; Dreidimensionale Charakterisierung der Gas- und Fluessigphase mittels laserinduzierter Exciplexfluoreszenz (LIEF) Tomografie

    Energy Technology Data Exchange (ETDEWEB)

    Rogler, P.; Grzeszik, R.; Arndt, S. [Robert Bosch GmbH, Stuttgart (Germany); Waidmann, C. [Fachhochschule Aalen (Germany); Aigner, M. [DLR, Stuttgart (Germany). Inst. fuer Verbrennungstechnik

    2007-07-01

    The quality of mixture formation in gasoline engines has a significant influence on combustion, emissions and mileage. The measurement technique used for mixture formation analysis of both liquid and vapor phase is laser induced exciplex fluorescence (LIEF), where the aromatics TMPD and naphthalene are added to a non-fluorescing model fuel free of aromatic compounds. For spatially high-resolved measurements of liquid and vapor phase this technique was extended from planar to volume information via tomography. This new approach requires fundamental studies of tracer behavior and new evaluation algorithms for reliable signal interpretation of fluid dynamics in sprays. Using this measurement technique GDI sprays are investigated at a typical stratified engine operation point at part load. For the different injector types, e.g. multi hole and annular orifice injector, an optimal illumination is crucial. With the collected data the spray volume can be calculated, mixture homogeneity can be evaluated and, using a few assumptions, the air/fuel ratio {lambda} can be computed. (orig.)

  17. Positron emission tomography-guided magnetic resonance spectroscopy in Alzheimer disease.

    Science.gov (United States)

    Sheikh-Bahaei, Nasim; Sajjadi, S Ahmad; Manavaki, Roido; McLean, Mary; O'Brien, John T; Gillard, Jonathan H

    2018-04-01

    To determine whether the level of metabolites in magnetic resonance spectroscopy (MRS) is a representative marker of underlying pathological changes identified in positron emission tomographic (PET) images in Alzheimer disease (AD). We performed PET-guided MRS in cases of probable AD, mild cognitive impairment (MCI), and healthy controls (HC). All participants were imaged by 11 C-Pittsburgh compound B ( 11 C-PiB) and 18 F-fluorodeoxyglucose ( 18 F-FDG) PET followed by 3T MRS. PET images were assessed both visually and using standardized uptake value ratios (SUVRs). MRS voxels were placed in regions with maximum abnormality on amyloid (Aβ+) and FDG (hypometabolic) areas on PET scans. Corresponding normal areas were selected in controls. The ratios of total N-acetyl (tNA) group, myoinositol (mI), choline, and glutamate + glutamine over creatine (Cr) were compared between these regions. Aβ + regions had significantly higher (p = 0.02) mI/Cr and lower tNA/Cr (p = 0.02), whereas in hypometabolic areas only tNA/Cr was reduced (p = 0.003). Multiple regression analysis adjusting for sex, age, and education showed mI/Cr was only associated with 11 C-PiB SUVR (p < 0.0001). tNA/Cr, however, was associated with both PiB (p = 0.0003) and 18 F-FDG SUVR (p = 0.006). The level of mI/Cr was not significantly different between MCI and AD (p = 0.28), but tNA/Cr showed significant decline from HC to MCI to AD (p = 0.001, p = 0.04). mI/Cr has significant temporal and spatial associations with Aβ and could potentially be considered as a disease state biomarker. tNA is an indicator of early neurodegenerative changes and might have a role as disease stage biomarker and also as a valuable surrogate marker for treatment response. Ann Neurol 2018;83:771-778. © 2018 American Neurological Association.

  18. Multimodal nanoparticles as alignment and correlation markers in fluorescence/soft X-ray cryo-microscopy/tomography of nucleoplasmic reticulum and apoptosis in mammalian cells

    International Nuclear Information System (INIS)

    Hagen, Christoph; Werner, Stephan; Carregal-Romero, Susana; Malhas, Ashraf N.; Klupp, Barbara G.; Guttmann, Peter; Rehbein, Stefan; Henzler, Katja; Mettenleiter, Thomas C.

    2014-01-01

    Correlative fluorescence and soft X-ray cryo-microscopy/tomography on flat sample holders is perfectly suited to study the uncompromised physiological status of adherent cells at its best possible preservation by imaging after fast cryo-immobilization. To understand the mechanism by which herpesviruses induce nucleoplasmic reticulum, i.e. invaginations of the nuclear envelope, during their egress from the host cell nucleus, morphologically similar structures found in laminopathies and after chemical induction were investigated as a potentially more easily accessible model system. For example, anti-retroviral protease inhibitors like Saquinavir also induce invaginations of the nuclear membranes. With the help of newly designed multimodal nanoparticles as alignment and correlation markers, and by optimizing fluorescence cryo-microscopy data acquisition, an elaborate three-dimensional network of nucleoplasmic reticulum was demonstrated in nuclei of Saquinavir-treated rabbit kidney cells expressing a fluorescently labeled inner nuclear membrane protein. In part of the protease inhibitor-treated samples, nuclei exhibited dramatic ultrastructural changes indicative of programmed cell death/apoptosis. This unexpected observation highlights another unique feature of soft X-ray microscopy, i.e. high absorption contrast information not relying on labeled cellular components, at a 3D resolution of approximately 40 nm (half-pitch) and through a sample thickness of several micrometers. These properties make it a valuable part of the cell biology imaging toolbox to visualize the cellular ultrastructure in its completeness. - Highlights: • Nucleoplasmic reticulum was demonstrated in nuclei of Saquinavir-treated cells. • New polyelectrolyte-Qdot ® 605 coated gold beads were employed as fiducials. • Saquinavir can induce a strong apoptotic phenotype in the nucleus. • CryoXT is an auspicious imaging technique in apoptosis research

  19. The feasibility of polychromatic cone-beam x-ray fluorescence computed tomography (XFCT) imaging of gold nanoparticle-loaded objects: a Monte Carlo study.

    Science.gov (United States)

    Jones, Bernard L; Cho, Sang Hyun

    2011-06-21

    A recent study investigated the feasibility to develop a bench-top x-ray fluorescence computed tomography (XFCT) system capable of determining the spatial distribution and concentration of gold nanoparticles (GNPs) in vivo using a diagnostic energy range polychromatic (i.e. 110 kVp) pencil-beam source. In this follow-up study, we examined the feasibility of a polychromatic cone-beam implementation of XFCT by Monte Carlo (MC) simulations using the MCNP5 code. In the current MC model, cylindrical columns with various sizes (5-10 mm in diameter) containing water loaded with GNPs (0.1-2% gold by weight) were inserted into a 5 cm diameter cylindrical polymethyl methacrylate phantom. The phantom was then irradiated by a lead-filtered 110 kVp x-ray source, and the resulting gold fluorescence and Compton-scattered photons were collected by a series of energy-sensitive tallies after passing through lead parallel-hole collimators. A maximum-likelihood iterative reconstruction algorithm was implemented to reconstruct the image of GNP-loaded objects within the phantom. The effects of attenuation of both the primary beam through the phantom and the gold fluorescence photons en route to the detector were corrected during the image reconstruction. Accurate images of the GNP-containing phantom were successfully reconstructed for three different phantom configurations, with both spatial distribution and relative concentration of GNPs well identified. The pixel intensity of regions containing GNPs was linearly proportional to the gold concentration. The current MC study strongly suggests the possibility of developing a bench-top, polychromatic, cone-beam XFCT system for in vivo imaging.

  20. Endobronchial ultrasound-guided transbronchial needle aspiration for systematic nodal staging of lung cancer in patients with N0 disease by computed tomography and integrated positron emission tomography-computed tomography.

    Science.gov (United States)

    Ong, Philip; Grosu, Horiana; Eapen, George A; Rodriguez, Macarena; Lazarus, Donald; Ost, David; Jimenez, Carlos A; Morice, Rodolfo; Bandi, Venkata; Tamara, Luis; Cornwell, Lorraine; Green, Linda; Zhu, Angela; Casal, Roberto F

    2015-03-01

    Data regarding the sensitivity of endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) for staging of lung cancer in patients with radiographic N0 disease is scant and inconsistent. With increasing use of nonoperative ablative therapies, studies focusing on the performance characteristics of EBUS-TBNA in this population are important. To evaluate the sensitivity and negative predictive value (NPV) of EBUS-TBNA in patients with non-small cell lung cancer and radiographic N0 disease both by computed tomography (CT) and positron emission tomography (PET)-CT. This was a retrospective review of EBUS-TBNA performed for lung cancer staging at two major academic centers from 2009 to 2014. Patients with radiographic N0 disease (lymph nodes [LN]≤1 cm in the short axis and maximum standardized uptake value≤2.5 by PET-CT) were included. Primary outcome was sensitivity and NPV of EBUS-TBNA. Two hundred twenty patients with radiographic N0 disease underwent EBUS-TBNA, and 734 LN were sampled (median 3, range 1-6). Median LN diameter was 0.72 cm. One hundred patients (45.5%) underwent surgery, and 120 patients (54.5%) had nonsurgical therapy. N status was up-staged in 49 patients (22.3%): 18 by EBUS-TBNA (N1=11, N2=6, N3=1), 27 by surgery (N1 intralobar=16, N1 extralobar=3, N2=8 [5 LN in stations 4 and 7, and 3 LN in stations 5-6), and 4 by imaging follow-up (N1=2, N2=2). Overall false-negative rate of EBUS was 14.1% (sensitivity, 36.7%; specificity, 100%; and NPV, 84.7%). False-negative rate was 27 and 3.3% in surgical and nonsurgical populations, respectively. Excluding patients with occult disease "outside" the reach of EBUS, the overall false-negative rate of EBUS-TBNA was 5.5% (sensitivity, 60%; specificity, 100%; and NPV, 93.4%). This is the largest report of EBUS-TBNA in patients with N0 disease by "integrated" PET-CT. The majority of false-negative EBUS results were in LN stations outside its reach. In our study, both sensitivity and NPV of

  1. Dosimetric consequences of the shift towards computed tomography guided target definition and planning for breast conserving radiotherapy

    Directory of Open Access Journals (Sweden)

    Korevaar Erik W

    2008-01-01

    Full Text Available Abstract Background The shift from conventional two-dimensional (2D to three-dimensional (3D-conformal target definition and dose-planning seems to have introduced volumetric as well as geometric changes. The purpose of this study was to compare coverage of computed tomography (CT-based breast and boost planning target volumes (PTV, absolute volumes irradiated, and dose delivered to the organs at risk with conventional 2D and 3D-conformal breast conserving radiotherapy. Methods Twenty-five patients with left-sided breast cancer were subject of CT-guided target definition and 3D-conformal dose-planning, and conventionally defined target volumes and treatment plans were reconstructed on the planning CT. Accumulated dose-distributions were calculated for the conventional and 3D-conformal dose-plans, taking into account a prescribed dose of 50 Gy for the breast plans and 16 Gy for the boost plans. Results With conventional treatment plans, CT-based breast and boost PTVs received the intended dose in 78% and 32% of the patients, respectively, and smaller volumes received the prescribed breast and boost doses compared with 3D-conformal dose-planning. The mean lung dose, the volume of the lungs receiving > 20 Gy, the mean heart dose, and volume of the heart receiving > 30 Gy were significantly less with conventional treatment plans. Specific areas within the breast and boost PTVs systematically received a lower than intended dose with conventional treatment plans. Conclusion The shift towards CT-guided target definition and planning as the golden standard for breast conserving radiotherapy has resulted in improved target coverage at the cost of larger irradiated volumes and an increased dose delivered to organs at risk. Tissue is now included into the breast and boost target volumes that was never explicitly defined or included with conventional treatment. Therefore, a coherent definition of the breast and boost target volumes is needed, based on

  2. Four-dimensional volume-of-interest reconstruction for cone-beam computed tomography-guided radiation therapy.

    Science.gov (United States)

    Ahmad, Moiz; Balter, Peter; Pan, Tinsu

    2011-10-01

    Data sufficiency are a major problem in four-dimensional cone-beam computed tomography (4D-CBCT) on linear accelerator-integrated scanners for image-guided radiotherapy. Scan times must be in the range of 4-6 min to avoid undersampling artifacts. Various image reconstruction algorithms have been proposed to accommodate undersampled data acquisitions, but these algorithms are computationally expensive, may require long reconstruction times, and may require algorithm parameters to be optimized. The authors present a novel reconstruction method, 4D volume-of-interest (4D-VOI) reconstruction which suppresses undersampling artifacts and resolves lung tumor motion for undersampled 1-min scans. The 4D-VOI reconstruction is much less computationally expensive than other 4D-CBCT algorithms. The 4D-VOI method uses respiration-correlated projection data to reconstruct a four-dimensional (4D) image inside a VOI containing the moving tumor, and uncorrelated projection data to reconstruct a three-dimensional (3D) image outside the VOI. Anatomical motion is resolved inside the VOI and blurred outside the VOI. The authors acquired a 1-min. scan of an anthropomorphic chest phantom containing a moving water-filled sphere. The authors also used previously acquired 1-min scans for two lung cancer patients who had received CBCT-guided radiation therapy. The same raw data were used to test and compare the 4D-VOI reconstruction with the standard 4D reconstruction and the McKinnon-Bates (MB) reconstruction algorithms. Both the 4D-VOI and the MB reconstructions suppress nearly all the streak artifacts compared with the standard 4D reconstruction, but the 4D-VOI has 3-8 times greater contrast-to-noise ratio than the MB reconstruction. In the dynamic chest phantom study, the 4D-VOI and the standard 4D reconstructions both resolved a moving sphere with an 18 mm displacement. The 4D-VOI reconstruction shows a motion blur of only 3 mm, whereas the MB reconstruction shows a motion blur of 13 mm

  3. Computed Tomography Number Changes Observed During Computed Tomography–Guided Radiation Therapy for Head and Neck Cancer

    International Nuclear Information System (INIS)

    Feng, Mei; Yang, Cungeng; Chen, Xiaojian; Xu, Shouping; Moraru, Ion; Lang, Jinyi; Schultz, Christopher; Li, X. Allen

    2015-01-01

    Purpose: To investigate CT number (CTN) changes in gross tumor volume (GTV) and organ at risk (OAR) according to daily diagnostic-quality CT acquired during CT-guided intensity modulated radiation therapy for head and neck cancer (HNC) patients. Methods and Materials: Computed tomography scans acquired using a CT-on-rails during daily CT-guided intensity modulated radiation therapy for 15 patients with stage II to IVa squamous cell carcinoma of the head and neck were analyzed. The GTV, parotid glands, spinal cord, and nonspecified tissue were generated on each selected daily CT. The changes in CTN distributions and the mean and mode values were collected. Pearson analysis was used to assess the correlation between the CTN change, organ volume reduction, and delivered radiation dose. Results: Volume and CTN changes for GTV and parotid glands can be observed during radiation therapy delivery for HNC. The mean (±SD) CTNs in GTV and ipsi- and contralateral parotid glands were reduced by 6 ± 10, 8 ± 7, and 11 ± 10 Hounsfield units, respectively, for all patients studied. The mean CTN changes in both spinal cord and nonspecified tissue were almost invisible (<2 Hounsfield units). For 2 patients studied, the absolute mean CTN changes in GTV and parotid glands were strongly correlated with the dose delivered (P<.001 and P<.05, respectively). For the correlation between CTN reductions and delivered isodose bins for parotid glands, the Pearson coefficient varied from −0.98 (P<.001) in regions with low-dose bins to 0.96 (P<.001) in high-dose bins and were patient specific. Conclusions: The CTN can be reduced in tumor and parotid glands during the course of radiation therapy for HNC. There was a fair correlation between CTN reduction and radiation doses for a subset of patients, whereas the correlation between CTN reductions and volume reductions in GTV and parotid glands were weak. More studies are needed to understand the mechanism for the radiation-induced CTN changes

  4. Substantial dose reduction in modern multi-slice spiral computed tomography (MSCT)-guided craniofacial and skull base surgery

    International Nuclear Information System (INIS)

    Widmann, G.; Fasser, M.; Jaschke, W.; Bale, R.; Schullian, P.; Zangerl, A.; Puelacher, W.; Kral, F.; Riechelmann, H.

    2012-01-01

    Purpose: Reduction of the radiation exposure involved in image-guided craniofacial and skull base surgery is an important goal. The purpose was to evaluate the influence of low-dose protocols in modern multi-slice spiral computed tomography (MSCT) on target registration errors (TREs). Materials and Methods: An anthropomorphic skull phantom with target markers at the craniofacial bone and the anterior skull base was scanned in Sensation Open (40-slice), LightSpeed VCT (64-slice) and Definition Flash (128-slice). Identical baseline protocols (BP) at 120 kV/100 mAs were compared to the following low-dose protocols (LD) in care dose/dose modulation: (LD-I) 100 kV/35ref. mAs, (LD-II) 80 kV/40 - 41ref. mAs, and (LD-III) 80 kV/15 - 17ref. mAs. CTDIvol and DLP were obtained. TREs using an optical navigation system were calculated for all scanners and protocols. Results were statistically analyzed in SPSS and compared for significant differences (p ≤ 0.05). Results: CTDIvol for the Sensation Open/LightSpeed VCT/Definition Flash showed: (BP) 22.24 /32.48 /14.32 mGy; (LD-I) 4.61 /3.52 /1,62 mGy; (LD-II) 3.15 /2.01 /0.87 mGy; and (LD-III) na/0.76 /0.76 mGy. Differences between the BfS (Bundesamt fuer Strahlenschutz) reference CTDIvol of 9 mGy and the lowest CTDIvol were approximately 3-fold for Sensation Open, and 12-fold for the LightSpeed VCT and Definition Flash. A total of 33 registrations and 297 TRE measurements were performed. In all MSCT scanners, the TREs did not significantly differ between the low-dose and the baseline protocols. Conclusion: Low-dose protocols in modern MSCT provided substantial dose reductions without significant influence on TRE and should be strongly considered in image-guided surgery. (orig.)

  5. Dosimetric consequences of the shift towards computed tomography guided target definition and planning for breast conserving radiotherapy

    International Nuclear Information System (INIS)

    Laan, Hans Paul van der; Dolsma, Wil V; Maduro, John H; Korevaar, Erik W; Langendijk, Johannes A

    2008-01-01

    The shift from conventional two-dimensional (2D) to three-dimensional (3D)-conformal target definition and dose-planning seems to have introduced volumetric as well as geometric changes. The purpose of this study was to compare coverage of computed tomography (CT)-based breast and boost planning target volumes (PTV), absolute volumes irradiated, and dose delivered to the organs at risk with conventional 2D and 3D-conformal breast conserving radiotherapy. Twenty-five patients with left-sided breast cancer were subject of CT-guided target definition and 3D-conformal dose-planning, and conventionally defined target volumes and treatment plans were reconstructed on the planning CT. Accumulated dose-distributions were calculated for the conventional and 3D-conformal dose-plans, taking into account a prescribed dose of 50 Gy for the breast plans and 16 Gy for the boost plans. With conventional treatment plans, CT-based breast and boost PTVs received the intended dose in 78% and 32% of the patients, respectively, and smaller volumes received the prescribed breast and boost doses compared with 3D-conformal dose-planning. The mean lung dose, the volume of the lungs receiving > 20 Gy, the mean heart dose, and volume of the heart receiving > 30 Gy were significantly less with conventional treatment plans. Specific areas within the breast and boost PTVs systematically received a lower than intended dose with conventional treatment plans. The shift towards CT-guided target definition and planning as the golden standard for breast conserving radiotherapy has resulted in improved target coverage at the cost of larger irradiated volumes and an increased dose delivered to organs at risk. Tissue is now included into the breast and boost target volumes that was never explicitly defined or included with conventional treatment. Therefore, a coherent definition of the breast and boost target volumes is needed, based on clinical data confirming tumour control probability and normal

  6. Proposal of a technical guide for the evaluation and management of the solitary pulmonary nodule in function of the radiological characteristics obtained by computed tomography

    International Nuclear Information System (INIS)

    Clinton Hidalgo, Carolina

    2015-01-01

    A guide is proposed to guide clinical personnel in early diagnosis, assessment and management of the solitary pulmonary nodule, with high potential of to develop lung cancer, in function of the radiological characteristics obtained by computed tomography. The management of patients with diagnosis of solitary pulmonary nodule is standardized with the purpose of to unify diagnostic criteria in a multidisciplinary and institutional environment. Tomographic radiological characteristics are described to allow the suspicion of the solitary pulmonary nodule benignity or malignity. A flow diagram is developed to guide the physician to an adequate monitoring, control and eventual therapeutic treatment. A clear and structured perspective of the diagnostic and therapeutic process is provided to the treating physician and patient [es

  7. Computed tomography-guided percutaneous trephine removal of the nidus in osteoid osteoma patients: experience of a single center in Brazil

    Energy Technology Data Exchange (ETDEWEB)

    Petrilli, Marcelo; Senerchia, Andreza Almeida; Petrilli, Antonio Sergio; Lederman, Henrique Manoel; Garcia Filho, Reynaldo Jesus, E-mail: andrezasenerchia@hotmail.com [Universidade Federal de Sao Paulo (UNIFESP), Sao Paulo, SP (Brazil). Instituto de Oncologia Pediatrica

    2015-07-15

    Objective: to report the results of computed tomography (CT)-guided percutaneous resection of the nidus in 18 cases of osteoid osteoma. Materials and methods: the medical records of 18 cases of osteoid osteoma in children, adolescents and young adults, who underwent CT-guided removal of the nidus between November, 2004 and March, 2009 were reviewed retrospectively for demographic data, lesion site, clinical outcome and complications after procedure. Results: clinical follow-up was available for all cases at a median of 29 months (range 6-60 months). No persistence of pre-procedural pain was noted on 17 patients. Only one patient experienced recurrence of symptoms 12 months after percutaneous resection, and was successfully retreated by the same technique, resulting in a secondary success rate of 18/18 (100%). Conclusion: CT-guided removal or destruction of the nidus is a safe and effective alternative to surgical resection of the osteoid osteoma nidus. (author)

  8. Frequency and Risk Factors of Various Complications After Computed Tomography-Guided Radiofrequency Ablation of Lung Tumors

    International Nuclear Information System (INIS)

    Okuma, Tomohisa; Matsuoka, Toshiyuki; Yamamoto, Akira; Oyama, Yoshimasa; Toyoshima, Masami; Nakamura, Kenji; Inoue, Yuichi

    2008-01-01

    Objective. To retrospectively determine the frequency and risk factors of various side effects and complications after percutaneous computed tomography-guided radiofrequency (RF) ablation of lung tumors. Methods. We reviewed and analyzed records of 112 treatment sessions in 57 of our patients (45 men and 12 women) with unresectable lung tumors treated by ablation. Risk factors, including sex, age, tumor diameter, tumor location, history of surgery, presence of pulmonary emphysema, electrode gauge, array diameter, patient position, maximum power output, ablation time, and minimum impedance during ablation, were analyzed using univariate and multivariate analyses. Results. Total rates of side effects and minor and major complications occurred in 17%, 50%, and 8% of treatment sessions, respectively. Side effects, including pain during ablation (46% of sessions) and pleural effusion (13% of sessions), occurred with RF ablation. Minor complications, including pneumothorax not requiring chest tube drainage (30% of sessions), subcutaneous emphysema (16% of sessions), and hemoptysis (9% of sessions) also occurred after the procedure. Regarding major complications, three patients developed fever >38.5 deg. C; three patients developed abscesses; two patients developed pneumothorax requiring chest tube insertion; and one patient had air embolism and was discharged without neurologic deficit. Univariate and multivariate analyses suggested that a lesion located ≤1 cm of the chest wall was significantly related to pain (p < 0.01, hazard index 5.76). Risk factors for pneumothorax increased significantly with previous pulmonary surgery (p < 0.05, hazard index 6.1) and presence of emphysema (p <0.01, hazard index 13.6). Conclusion. The total complication rate for all treatment sessions was 58%, and 25% of patients did not have any complications after RF ablation. Although major complications can occur, RF ablation of lung tumors can be considered a safe and minimally invasive

  9. Impact of Computed Tomography Image Quality on Image-Guided Radiation Therapy Based on Soft Tissue Registration

    International Nuclear Information System (INIS)

    Morrow, Natalya V.; Lawton, Colleen A.; Qi, X. Sharon; Li, X. Allen

    2012-01-01

    Purpose: In image-guided radiation therapy (IGRT), different computed tomography (CT) modalities with varying image quality are being used to correct for interfractional variations in patient set-up and anatomy changes, thereby reducing clinical target volume to the planning target volume (CTV-to-PTV) margins. We explore how CT image quality affects patient repositioning and CTV-to-PTV margins in soft tissue registration-based IGRT for prostate cancer patients. Methods and Materials: Four CT-based IGRT modalities used for prostate RT were considered in this study: MV fan beam CT (MVFBCT) (Tomotherapy), MV cone beam CT (MVCBCT) (MVision; Siemens), kV fan beam CT (kVFBCT) (CTVision, Siemens), and kV cone beam CT (kVCBCT) (Synergy; Elekta). Daily shifts were determined by manual registration to achieve the best soft tissue agreement. Effect of image quality on patient repositioning was determined by statistical analysis of daily shifts for 136 patients (34 per modality). Inter- and intraobserver variability of soft tissue registration was evaluated based on the registration of a representative scan for each CT modality with its corresponding planning scan. Results: Superior image quality with the kVFBCT resulted in reduced uncertainty in soft tissue registration during IGRT compared with other image modalities for IGRT. The largest interobserver variations of soft tissue registration were 1.1 mm, 2.5 mm, 2.6 mm, and 3.2 mm for kVFBCT, kVCBCT, MVFBCT, and MVCBCT, respectively. Conclusions: Image quality adversely affects the reproducibility of soft tissue-based registration for IGRT and necessitates a careful consideration of residual uncertainties in determining different CTV-to-PTV margins for IGRT using different image modalities.

  10. Prognostic Factors Influencing the Development of an Iatrogenic Pneumothorax for Computed Tomography-Guided Radiofrequency Ablation of Upper Renal Tumor

    International Nuclear Information System (INIS)

    Park, B.K.; Kim, C.K.

    2008-01-01

    Background: Percutaneous radiofrequency (RF) ablation of upper renal tumors is considered a minimally invasive treatment, but this technique may cause pneumothorax. Purpose: To assess retrospectively the prognostic factors influencing the development of iatrogenic pneumothorax for RF ablation of upper renal tumors. Material and Methods: Computed tomography (CT)-guided RF ablation was performed in 24 patients (21 men, three women; age range 31-77 years, mean age 53.3 years) with 28 upper renal tumors. Various factors for pneumothorax-complicated (PC) upper renal tumors and non-pneumothoracic (NP) upper renal tumors were compared during RF ablation to determine which of the factors were involved in the development of pneumothorax. Results: Among 28 upper renal tumors in 24 patients, a pneumothorax occurred accidentally in six patients with eight tumors and intentionally in two patients with two tumors. This complication was treated with conservative management, instead of tube drainage. PC upper renal tumors had shorter distance from the lung or from the costophrenic line to the tumor, a larger angle between the costophrenic line and the tumor, and a higher incidence of intervening lung tissue than NP upper renal tumors (P<0.01). Intervening lung tissue was more frequently detected on CT images obtained with the patient in the prone position than on CT images obtained with the patient in the supine position. Conclusion: The presence of intervening lung tissue and the close proximity between an upper renal tumor and the lung are high risk factors for developing an iatrogenic pneumothorax. Pre-ablation CT scan should be performed in the prone position to exactly evaluate intervening lung tissue

  11. Impact of Computed Tomography Image Quality on Image-Guided Radiation Therapy Based on Soft Tissue Registration

    Energy Technology Data Exchange (ETDEWEB)

    Morrow, Natalya V.; Lawton, Colleen A. [Department of Radiation Oncology, Medical College of Wisconsin, Milwaukee, Wisconsin (United States); Qi, X. Sharon [Department of Radiation Oncology, University of Colorado Denver, Denver, Colorado (United States); Li, X. Allen, E-mail: ali@mcw.edu [Department of Radiation Oncology, Medical College of Wisconsin, Milwaukee, Wisconsin (United States)

    2012-04-01

    Purpose: In image-guided radiation therapy (IGRT), different computed tomography (CT) modalities with varying image quality are being used to correct for interfractional variations in patient set-up and anatomy changes, thereby reducing clinical target volume to the planning target volume (CTV-to-PTV) margins. We explore how CT image quality affects patient repositioning and CTV-to-PTV margins in soft tissue registration-based IGRT for prostate cancer patients. Methods and Materials: Four CT-based IGRT modalities used for prostate RT were considered in this study: MV fan beam CT (MVFBCT) (Tomotherapy), MV cone beam CT (MVCBCT) (MVision; Siemens), kV fan beam CT (kVFBCT) (CTVision, Siemens), and kV cone beam CT (kVCBCT) (Synergy; Elekta). Daily shifts were determined by manual registration to achieve the best soft tissue agreement. Effect of image quality on patient repositioning was determined by statistical analysis of daily shifts for 136 patients (34 per modality). Inter- and intraobserver variability of soft tissue registration was evaluated based on the registration of a representative scan for each CT modality with its corresponding planning scan. Results: Superior image quality with the kVFBCT resulted in reduced uncertainty in soft tissue registration during IGRT compared with other image modalities for IGRT. The largest interobserver variations of soft tissue registration were 1.1 mm, 2.5 mm, 2.6 mm, and 3.2 mm for kVFBCT, kVCBCT, MVFBCT, and MVCBCT, respectively. Conclusions: Image quality adversely affects the reproducibility of soft tissue-based registration for IGRT and necessitates a careful consideration of residual uncertainties in determining different CTV-to-PTV margins for IGRT using different image modalities.

  12. Distributed Kalman filtering compared to Fourier domain preconditioned conjugate gradient for laser guide star tomography on extremely large telescopes.

    Science.gov (United States)

    Gilles, Luc; Massioni, Paolo; Kulcsár, Caroline; Raynaud, Henri-François; Ellerbroek, Brent

    2013-05-01

    This paper discusses the performance and cost of two computationally efficient Fourier-based tomographic wavefront reconstruction algorithms for wide-field laser guide star (LGS) adaptive optics (AO). The first algorithm is the iterative Fourier domain preconditioned conjugate gradient (FDPCG) algorithm developed by Yang et al. [Appl. Opt.45, 5281 (2006)], combined with pseudo-open-loop control (POLC). FDPCG's computational cost is proportional to N log(N), where N denotes the dimensionality of the tomography problem. The second algorithm is the distributed Kalman filter (DKF) developed by Massioni et al. [J. Opt. Soc. Am. A28, 2298 (2011)], which is a noniterative spatially invariant controller. When implemented in the Fourier domain, DKF's cost is also proportional to N log(N). Both algorithms are capable of estimating spatial frequency components of the residual phase beyond the wavefront sensor (WFS) cutoff frequency thanks to regularization, thereby reducing WFS spatial aliasing at the expense of more computations. We present performance and cost analyses for the LGS multiconjugate AO system under design for the Thirty Meter Telescope, as well as DKF's sensitivity to uncertainties in wind profile prior information. We found that, provided the wind profile is known to better than 10% wind speed accuracy and 20 deg wind direction accuracy, DKF, despite its spatial invariance assumptions, delivers a significantly reduced wavefront error compared to the static FDPCG minimum variance estimator combined with POLC. Due to its nonsequential nature and high degree of parallelism, DKF is particularly well suited for real-time implementation on inexpensive off-the-shelf graphics processing units.

  13. Improved resection and prolonged overall survival with PD-1-IRDye800CW fluorescence probe-guided surgery and PD-1 adjuvant immunotherapy in 4T1 mouse model

    Directory of Open Access Journals (Sweden)

    Du Y

    2017-11-01

    Full Text Available Yang Du,1,2,* Ting Sun,3,* Xiaolong Liang,4,* Yuan Li,3 Zhengyu Jin,3 Huadan Xue,3 Yihong Wan,5 Jie Tian1,2 1CAS Key Laboratory of Molecular Imaging, 2The State Key Laboratory of Management and Control for Complex Systems, Institute of Automation, Chinese Academy of Sciences, 3Department of Radiology, Peking Union Medical College Hospital, 4Department of Ultrasound, Peking University Third Hospital, Beijing, China; 5Department of Pharmacology, University of Texas Southwestern Medical Center, Dallas, TX, USA *These authors contributed equally to this work Abstract: An intraoperative technique to accurately identify microscopic tumor residuals could decrease the risk of positive surgical margins. Several lines of evidence support the expression and immunotherapeutic effect of PD-1 in breast cancer. Here, we sought to develop a fluorescence-labeled PD-1 probe for in vivo breast tumor imaging and image-guided surgery. The efficacy of PD-1 monoclonal antibody (PD-1 mAb as adjuvant immunotherapy after surgery was also assessed. PD-1-IRDye800CW was developed and examined for its application in tumor imaging and image-guided tumor resection in an immunocompetent 4T1 mouse tumor model. Fluorescence molecular imaging was performed to monitor probe biodistribution and intraoperative imaging. Bioluminescence imaging was performed to monitor tumor growth and evaluate postsurgical tumor residuals, recurrences, and metastases. The PD-1-IRDye800CW exhibited a specific signal at the tumor region compared with the IgG control. Furthermore, PD-1-IRDye800CW-guided surgery combined with PD-1 adjuvant immunotherapy inhibited tumor regrowth and microtumor metastases and thus improved survival rate. Our study demonstrates the feasibility of using PD-1-IRDye800CW for breast tumor imaging and image-guided tumor resection. Moreover, PD-1 mAb adjuvant immunotherapy reduces cancer recurrences and metastases emanating from tumor residuals. Keywords: PD-1, programmed cell

  14. TU-A-9A-05: First Experimental Demonstration of the Anisotropic Detection Principle in X-Ray Fluorescence Computed Tomography

    International Nuclear Information System (INIS)

    Ahmad, M; Bazalova, M; Fahrig, R; Xing, L

    2014-01-01

    Purpose: To improve the sensitivity of X-ray fluorescence computed tomography (XFCT) for in vivo molecular imaging. Is the maximum sensitivity achieved with an isotropic (4π) detector configuration? We prove that this is not necessarily true, and that a greater sensitivity is possible with anisotropic detector configuration. Methods: An XFCT imaging system was constructed consisting of 1) a collimated pencil beam x-ray source using a fluoroscopy grade x-ray tube; 2) a CdTe x-ray photon counting detector to detect fluorescent x-rays; and 3) a rotation/translation stage for tomographic imaging. We created a 6.5-cm diameter water phantom with 2-cm inserts of low gold concentration (0.25%–1%) to simulate tumors targeted by gold nano-particles. The placement of x-ray fluorescence detector were chosen to minimize scatter x-rays. XFCT imaging was performed at three different detector positions (60°, 90°, 145°) to determine the impact of forward-scatter, side-scatter, and back-scatter on imaging performance. The three data sets were also combined to estimate the imaging performance with an isotropic detector. Results: The highest imaging performance was achieved when the XF detector was in the backscatter 145° configuration. The signal-to-noise ratio (SNR) was 5.5 for the 0.25% gold concentration compared to SNRs of 1.4, 0, and 2.4 for 60°, 90°, and combined (60°+90°+145°) datasets. Only the 145° detector arrangement alone could detect the 0.25% concentration. The imaging dose was 14 mGy for each detector arrangement experiment. Conclusion: This study experimentally proves, for the fist time, the Anisotropic Detection Principle in XF imaging, which holds that optimized anisotropic x-ray fluorescence detection provides greater sensitivity than isotropic detection. The optimized detection arrangement was used to improve the sensitivity of the XFCT experiment. The achieved XFCT sensitivity is the highest ever for a phantom at least this large using a benchtop x

  15. An analysis of brachytherapy with computed tomography-guided permanent implantation of Iodine-125 seeds for recurrent nonkeratin nasopharyngeal carcinoma

    Directory of Open Access Journals (Sweden)

    Shen X

    2015-05-01

    Full Text Available Xinying Shen,1,2 Yong Li,2 Yanfang Zhang,2 Jian Kong,2 Yanhao Li1 1Department of Interventional Radiology, Nanfang Hospital, Southern Medical University, Guangzhou, 2Department of Interventional Radiology, Shenzhen People’s Hospital, The Second Clinical Medical College of Jinan University, Shenzhen, People’s Republic of China Background: 125I seed implantation is a new method in treatment of nasopharyngeal carcinoma (NPC, and it is worthwhile to evaluate its feasibility. In this study, we performed brachytherapy with computed tomography (CT-guided permanent implantation of 125I seeds in the treatment of patients with the recurrence of NPC.Methods: A total 30 patients (20 male and ten female at the median age of 55 (range 25–80 years were diagnosed with recurrent nonkeratin NPC, with a total 38 lesions and a short disease-free interval (median ~11 months after primary radiotherapy alone or combined with chemotherapy. Patients received CT scan, starting from 2 months after the treatment. Follow-up was conducted for ~2–38 months to observe the local control rate and overall survival rate. We also analyzed the possible correlation between survival periods and the status of recurrent tumors.Results: The local control rates at 6, 12, 24, 30, and 36 months after the procedure of 125I seed implantation were 86.8%, 73.7%, 26.3%, 15.8%, and 5.3%, respectively. The overall 1-, 2-, and 3-year survival rates were 80.0% (24/30, 30.0% (9/30, and 6.7% (2/30, respectively, with a median survival period of 18 months (17.6±8.6 months. Interestingly, the survival periods of the patients who had primary radiotherapy with or without chemotherapy were 15.8±7.9 and 24.3±7.9 months, respectively. Kaplan–Meier survival analysis demonstrated that χ2 (log rank was 7.555, with very significant difference (P<0.01. The survival periods of patients in tumor stages I, II, III, and IV were 25.4±8.7, 19.8±9.4, 16.1±4.5, and 12.8±7.8 months, respectively, with

  16. Preoperative Computed Tomography-Guided Percutaneous Hookwire Localization of Metallic Marker Clips in the Breast with a Radial Approach: Initial Experience

    Energy Technology Data Exchange (ETDEWEB)

    Uematsu, T.; Kasami, M.; Uchida, Y.; Sanuki, J.; Kimura, K.; Tanaka, K.; Takahashi, K. [Dept. of Diagnostic Radiology, Dept. of Pathology, and Dept. of Breast Surgery, Shizuoka Cancer Center Hospital, Naga-izumi, Shizuoka (Japan)

    2007-07-15

    Background: Hookwire localization is the current standard technique for radiological marking of nonpalpable breast lesions. Stereotactic directional vacuum-assisted breast biopsy (SVAB) is of sufficient sensitivity and specificity to replace surgical biopsy. Wire localization for metallic marker clips placed after SVAB is needed. Purpose: To describe a method for performing computed tomography (CT)-guided hookwire localization using a radial approach for metallic marker clips placed percutaneously after SVAB. Material and Methods: Nineteen women scheduled for SVAB with marker-clip placement, CT-guided wire localization of marker clips, and, eventually, surgical excision were prospectively entered into the study. CT-guided wire localization was performed with a radial approach, followed by placement of a localizing marker-clip surgical excision. Feasibility and reliability of the procedure and the incidence of complications were examined. Results: CT-guided wire localization surgical excision was successfully performed in all 19 women without any complications. The mean total procedure time was 15 min. The median distance on CT image from marker clip to hookwire was 2 mm (range 0-3 mm). Conclusion: CT-guided preoperative hookwire localization with a radial approach for marker clips after SVAB is technically feasible.

  17. Preoperative computed tomography-guided percutaneous hookwire localization of metallic marker clips in the breast with a radial approach: initial experience.

    Science.gov (United States)

    Uematsu, T; Kasami, M; Uchida, Y; Sanuki, J; Kimura, K; Tanaka, K; Takahashi, K

    2007-06-01

    Hookwire localization is the current standard technique for radiological marking of nonpalpable breast lesions. Stereotactic directional vacuum-assisted breast biopsy (SVAB) is of sufficient sensitivity and specificity to replace surgical biopsy. Wire localization for metallic marker clips placed after SVAB is needed. To describe a method for performing computed tomography (CT)-guided hookwire localization using a radial approach for metallic marker clips placed percutaneously after SVAB. Nineteen women scheduled for SVAB with marker-clip placement, CT-guided wire localization of marker clips, and, eventually, surgical excision were prospectively entered into the study. CT-guided wire localization was performed with a radial approach, followed by placement of a localizing marker-clip surgical excision. Feasibility and reliability of the procedure and the incidence of complications were examined. CT-guided wire localization surgical excision was successfully performed in all 19 women without any complications. The mean total procedure time was 15 min. The median distance on CT image from marker clip to hookwire was 2 mm (range 0-3 mm). CT-guided preoperative hookwire localization with a radial approach for marker clips after SVAB is technically feasible.

  18. Positron Emission Tomography/Computed Tomography-Guided Intensity-Modulated Radiotherapy for Limited-Stage Small-Cell Lung Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Shirvani, Shervin M.; Komaki, Ritsuko [Department of Radiation Oncology, University of Texas M.D. Anderson Cancer Center, Houston, TX (United States); Heymach, John V.; Fossella, Frank V. [Department of Thoracic/Head and Neck Medical Oncology, University of Texas M.D. Anderson Cancer Center, Houston, TX (United States); Chang, Joe Y., E-mail: jychang@mdanderson.org [Department of Radiation Oncology, University of Texas M.D. Anderson Cancer Center, Houston, TX (United States)

    2012-01-01

    Purpose: Omitting elective nodal irradiation from planning target volumes does not compromise outcomes in patients with non-small-cell lung cancer, but whether the same is true for those with limited-stage small-cell lung cancer (LS-SCLC) is unknown. Therefore, in the present study, we sought to determine the clinical outcomes and the frequency of elective nodal failure in patients with LS-SCLC staged using positron emission tomography/computed tomography and treated with involved-field intensity-modulated radiotherapy. Methods and Materials: Between 2005 and 2008, 60 patients with LS-SCLC at our institution underwent disease staging using positron emission tomography/computed tomography before treatment using an intensity-modulated radiotherapy plan in which elective nodal irradiation was intentionally omitted from the planning target volume (mode and median dose, 45 Gy in 30 fractions; range, 40.5 Gy in 27 fractions to 63.8 Gy in 35 fractions). In most cases, concurrent platinum-based chemotherapy was administered. We retrospectively reviewed the clinical outcomes to determine the overall survival, relapse-free survival, and failure patterns. Elective nodal failure was defined as recurrence in initially uninvolved hilar, mediastinal, or supraclavicular nodes. Survival was assessed using the Kaplan-Meier method. Results: The median age of the study patients at diagnosis was 63 years (range, 39-86). The median follow-up duration was 21 months (range, 4-58) in all patients and 26 months (range, 4-58) in the survivors. The 2-year actuarial overall survival and relapse-free survival rate were 58% and 43%, respectively. Of the 30 patients with recurrence, 23 had metastatic disease and 7 had locoregional failure. We observed only one isolated elective nodal failure. Conclusions: To our knowledge, this is the first study to examine the outcomes in patients with LS-SCLC staged with positron emission tomography/computed tomography and treated with definitive intensity

  19. Positron Emission Tomography/Computed Tomography-Guided Intensity-Modulated Radiotherapy for Limited-Stage Small-Cell Lung Cancer

    International Nuclear Information System (INIS)

    Shirvani, Shervin M.; Komaki, Ritsuko; Heymach, John V.; Fossella, Frank V.; Chang, Joe Y.

    2012-01-01

    Purpose: Omitting elective nodal irradiation from planning target volumes does not compromise outcomes in patients with non–small-cell lung cancer, but whether the same is true for those with limited-stage small-cell lung cancer (LS-SCLC) is unknown. Therefore, in the present study, we sought to determine the clinical outcomes and the frequency of elective nodal failure in patients with LS-SCLC staged using positron emission tomography/computed tomography and treated with involved-field intensity-modulated radiotherapy. Methods and Materials: Between 2005 and 2008, 60 patients with LS-SCLC at our institution underwent disease staging using positron emission tomography/computed tomography before treatment using an intensity-modulated radiotherapy plan in which elective nodal irradiation was intentionally omitted from the planning target volume (mode and median dose, 45 Gy in 30 fractions; range, 40.5 Gy in 27 fractions to 63.8 Gy in 35 fractions). In most cases, concurrent platinum-based chemotherapy was administered. We retrospectively reviewed the clinical outcomes to determine the overall survival, relapse-free survival, and failure patterns. Elective nodal failure was defined as recurrence in initially uninvolved hilar, mediastinal, or supraclavicular nodes. Survival was assessed using the Kaplan-Meier method. Results: The median age of the study patients at diagnosis was 63 years (range, 39–86). The median follow-up duration was 21 months (range, 4–58) in all patients and 26 months (range, 4–58) in the survivors. The 2-year actuarial overall survival and relapse-free survival rate were 58% and 43%, respectively. Of the 30 patients with recurrence, 23 had metastatic disease and 7 had locoregional failure. We observed only one isolated elective nodal failure. Conclusions: To our knowledge, this is the first study to examine the outcomes in patients with LS-SCLC staged with positron emission tomography/computed tomography and treated with definitive

  20. Improving x-ray fluorescence signal for benchtop polychromatic cone-beam x-ray fluorescence computed tomography by incident x-ray spectrum optimization: a Monte Carlo study.

    Science.gov (United States)

    Manohar, Nivedh; Jones, Bernard L; Cho, Sang Hyun

    2014-10-01

    To develop an accurate and comprehensive Monte Carlo (MC) model of an experimental benchtop polychromatic cone-beam x-ray fluorescence computed tomography (XFCT) setup and apply this MC model to optimize incident x-ray spectrum for improving production/detection of x-ray fluorescence photons from gold nanoparticles (GNPs). A detailed MC model, based on an experimental XFCT system, was created using the Monte Carlo N-Particle (MCNP) transport code. The model was validated by comparing MC results including x-ray fluorescence (XRF) and scatter photon spectra with measured data obtained under identical conditions using 105 kVp cone-beam x-rays filtered by either 1 mm of lead (Pb) or 0.9 mm of tin (Sn). After validation, the model was used to investigate the effects of additional filtration of the incident beam with Pb and Sn. Supplementary incident x-ray spectra, representing heavier filtration (Pb: 2 and 3 mm; Sn: 1, 2, and 3 mm) were computationally generated and used with the model to obtain XRF/scatter spectra. Quasimonochromatic incident x-ray spectra (81, 85, 90, 95, and 100 keV with 10 keV full width at half maximum) were also investigated to determine the ideal energy for distinguishing gold XRF signal from the scatter background. Fluorescence signal-to-dose ratio (FSDR) and fluorescence-normalized scan time (FNST) were used as metrics to assess results. Calculated XRF/scatter spectra for 1-mm Pb and 0.9-mm Sn filters matched (r ≥ 0.996) experimental measurements. Calculated spectra representing additional filtration for both filter materials showed that the spectral hardening improved the FSDR at the expense of requiring a much longer FNST. In general, using Sn instead of Pb, at a given filter thickness, allowed an increase of up to 20% in FSDR, more prominent gold XRF peaks, and up to an order of magnitude decrease in FNST. Simulations using quasimonochromatic spectra suggested that increasing source x-ray energy, in the investigated range of 81-100 ke

  1. Evaluation of every other day-cone beam computed tomography in image guided radiation therapy for prostate cancer

    International Nuclear Information System (INIS)

    Park, Byoung Suk; Ahn, Jong Ho; Kim, Jong Sik; Song, Ki Won

    2014-01-01

    Cone Beam Computed Tomography(CBCT) in Image Guided Radiation Therapy(IGRT), Set-up error can be reduced but exposure dose of the patient due to CBCT will increase. Through this study, we are to evaluate by making a scenario with the implementation period of CBCT as every other day. Of prostate cancer patients, 9 patients who got a Intensity Modulated Radiation Therapy(IMRT) with CBCT in IGRT were analyzed. Based on values corrected by analyzing set-up error by using CBCT every day during actual treatment, we created a scenario that conducts CBCT every other day. After applying set-up error values of the day not performing CBCT in the scenario to the treatment planning system(Pinnacle 9.2, Philips, USA) by moving them from the treatment iso-center during actual treatment, we established re-treatment plan under the same conditions as actual treatment. Based on this, the dose distribution of normal organs and Planning Target Volume(PTV) was compared and analyzed. In the scenario that performs CBCT every other day based on set-up error values when conducting CBCT every day, average X-axis : 0.2±0.73 mm , Y-axis : 0.1±0.58 mm , Z-axis : -1.3±1.17 mm difference was shown. This was applied to the treatment planning to establish re-treatment plan and dose distribution was evaluated and as a result, Dmean : -0.17 Gy, D99% : -0.71 Gy of PTV difference was shown in comparison with the result obtained when carrying out CBCT every day. As for normal organs, V66 : 1.55% of rectal wall, V66 : -0.76% of bladder difference was shown. In case of a CBCT perform every other day could reduce exposure dose and additional treatment time. And it is thought to be able to consider the application depending on the condition of the patient because the difference in the dose distribution of normal organs, PTV is not large

  2. The clinical feasibility and effect of online cone beam computer tomography-guided intensity-modulated radiotherapy for nasopharyngeal cancer

    International Nuclear Information System (INIS)

    Wang Jin; Bai Sen; Chen Nianyong; Xu Feng; Jiang Xiaoqin; Li Yan; Xu Qingfeng; Shen Yali; Zhang Hong; Gong Youling; Zhong Renming; Jiang Qingfeng

    2009-01-01

    Background and purpose: Online adaptive correction in image-guided intensity-modulated radiotherapy appeared to be a promising approach for precision radiation treatment in head and neck tumors. This protocol was designed to evaluate the clinical feasibility and effect of online cone beam computed tomography (CBCT) guidance in IMRT of nasopharyngeal cancer (NPC). Methods and materials: The Elekta Synergy system, which integrates an X-ray volumetric imager (XVI), was used to deliver radiation treatment for 22 cases of NPC. The acquired CBCT was registered to the planning CT for online and offline analysis. The systematic and random setup errors, as well as planning target volume (PTV) margin, were calculated at different correction threshold levels. The impact of online setup correction on dosimetry was evaluated by simulation of pre-correction errors. Results: The correction-of-setup-errors frequencies for 1, 2 and 3 mm thresholds were 41.3-53.9%, 12.7-21.2% and 6.3-10.3%, respectively. Online correction was effective at the 2 mm threshold level for all three axes. The pre-correction systematic errors for the whole group ranged 1.1-1.3 mm, and the random errors were also 1.1-1.3 mm. After online correction, the systematic and random errors ranged 0.4-0.5 mm and 0.7-0.8 mm, respectively, in the three directions. The PTV margins for the pre-correction, pretreatment and post-treatment positions were 3.5-4.2 mm, 1.6-1.8 mm and 2.5-3.2 mm, respectively, in three directions. Analysis of hypothetical dosimetric change due to a translational isocenter shift of 3 mm showed that if no correction was applied, the mean maximum dose to both the brain stem and spinal cord would be increased by 10 Gy, the mean dose to the left and right parotids would be increased by 7.8 and 8.5 Gy, respectively, and the dose to target volumes would be decreased: 4 Gy for 95% GTV and 5.6 Gy for 95% CTV 60. Conclusions: CBCT-based online correction increased the accuracy of IMRT for NPC and

  3. Priori mask guided image reconstruction (p-MGIR) for ultra-low dose cone-beam computed tomography

    Science.gov (United States)

    Park, Justin C.; Zhang, Hao; Chen, Yunmei; Fan, Qiyong; Kahler, Darren L.; Liu, Chihray; Lu, Bo

    2015-11-01

    Recently, the compressed sensing (CS) based iterative reconstruction method has received attention because of its ability to reconstruct cone beam computed tomography (CBCT) images with good quality using sparsely sampled or noisy projections, thus enabling dose reduction. However, some challenges remain. In particular, there is always a tradeoff between image resolution and noise/streak artifact reduction based on the amount of regularization weighting that is applied uniformly across the CBCT volume. The purpose of this study is to develop a novel low-dose CBCT reconstruction algorithm framework called priori mask guided image reconstruction (p-MGIR) that allows reconstruction of high-quality low-dose CBCT images while preserving the image resolution. In p-MGIR, the unknown CBCT volume was mathematically modeled as a combination of two regions: (1) where anatomical structures are complex, and (2) where intensities are relatively uniform. The priori mask, which is the key concept of the p-MGIR algorithm, was defined as the matrix that distinguishes between the two separate CBCT regions where the resolution needs to be preserved and where streak or noise needs to be suppressed. We then alternately updated each part of image by solving two sub-minimization problems iteratively, where one minimization was focused on preserving the edge information of the first part while the other concentrated on the removal of noise/artifacts from the latter part. To evaluate the performance of the p-MGIR algorithm, a numerical head-and-neck phantom, a Catphan 600 physical phantom, and a clinical head-and-neck cancer case were used for analysis. The results were compared with the standard Feldkamp-Davis-Kress as well as conventional CS-based algorithms. Examination of the p-MGIR algorithm showed that high-quality low-dose CBCT images can be reconstructed without compromising the image resolution. For both phantom and the patient cases, the p-MGIR is able to achieve a clinically

  4. Computed tomography-guided percutaneous ozone injection of the Gasserian ganglion for the treatment of trigeminal neuralgia

    Directory of Open Access Journals (Sweden)

    An JX

    2018-01-01

    Full Text Available Jian-Xiong An,1,2 Hui Liu,1 Ruo-Wen Chen,1,2 Yong Wang,1 Wen-Xing Zhao,1 Derek Eastwood,3 John P Williams4 1Department of Anesthesiology, Pain Medicine & Critical Care Medicine, Aviation General Hospital of China Medical University & Beijing Institute of Translational Medicine, Chinese Academy of Sciences, 2Department of Anesthesiology, Weifang Medical University, Beijing, People’s Republic of China; 3Department of Pain Services, Wirral University Teaching Hospital, Wirral, Merseyside, UK; 4Department of Anesthesiology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA Objective: The aim of this study was to evaluate the therapeutic effect of computed tomography (CT-guided percutaneous ozone injection for refractory trigeminal neuralgia. Design: A retrospective evaluation was performed in the study. Setting: The study was conducted at a university hospital pain center. Patients and methods: A total of 29 patients with a clinical diagnosis of refractory trigeminal neuralgia were enrolled. All patients were treated with a percutaneous ozone injection and one patient was excluded. There were 21 patients with classical trigeminal neuralgia (group A and seven patients with painful trigeminal neuropathy caused by post-herpetic neuralgia (group B. The percutaneous injection was an oxygen–ozone mixture at an ozone concentration of 30 mg/­mL into the Gasserian ganglion performed under CT guidance. The number of ­procedures performed varied from one to as many as 16. Outcomes were evaluated using visual analog scale (VAS pain scores. Results: The combined VAS scores were 7.11 ± 1.23 pretreatment, 2.86 ± 1.69 posttreatment (P < 0.05 and 3.25 ± 2.01 after 6-month follow-up (P < 0.05. In group A, the VAS scores were 7.10 ± 1.04 pretreatment and 2.90 ± 1.84 posttreatment (P < 0.05. In group B, the VAS scores were 7.14 ± 1.77 pretreatment and 2.71 ± 1.25 posttreatment (P < 0.05. After 6-months follow-up, the VAS score was 3.38

  5. Personalized Assessment of kV Cone Beam Computed Tomography Doses in Image-guided Radiotherapy of Pediatric Cancer Patients

    Energy Technology Data Exchange (ETDEWEB)

    Zhang Yibao [Beijing Key Lab of Medical Physics and Engineering, Peking University, Beijing (China); Yan Yulong [Department of Radiation Oncology, University of Arkansas for Medical Sciences, Little Rock, Arkansas (United States); Nath, Ravinder [Department of Therapeutic Radiology, Yale University, New Haven, Connecticut (United States); Bao Shanglian [Beijing Key Lab of Medical Physics and Engineering, Peking University, Beijing (China); Deng Jun, E-mail: jun.deng@yale.edu [Department of Therapeutic Radiology, Yale University, New Haven, Connecticut (United States)

    2012-08-01

    Purpose: To develop a quantitative method for the estimation of kV cone beam computed tomography (kVCBCT) doses in pediatric patients undergoing image-guided radiotherapy. Methods and Materials: Forty-two children were retrospectively analyzed in subgroups of different scanned regions: one group in the head-and-neck and the other group in the pelvis. Critical structures in planning CT images were delineated on an Eclipse treatment planning system before being converted into CT phantoms for Monte Carlo simulations. A benchmarked EGS4 Monte Carlo code was used to calculate three-dimensional dose distributions of kVCBCT scans with full-fan high-quality head or half-fan pelvis protocols predefined by the manufacturer. Based on planning CT images and structures exported in DICOM RT format, occipital-frontal circumferences (OFC) were calculated for head-and-neck patients using DICOMan software. Similarly, hip circumferences (HIP) were acquired for the pelvic group. Correlations between mean organ doses and age, weight, OFC, and HIP values were analyzed with SigmaPlot software suite, where regression performances were analyzed with relative dose differences (RDD) and coefficients of determination (R{sup 2}). Results: kVCBCT-contributed mean doses to all critical structures decreased monotonically with studied parameters, with a steeper decrease in the pelvis than in the head. Empirical functions have been developed for a dose estimation of the major organs at risk in the head and pelvis, respectively. If evaluated with physical parameters other than age, a mean RDD of up to 7.9% was observed for all the structures in our population of 42 patients. Conclusions: kVCBCT doses are highly correlated with patient size. According to this study, weight can be used as a primary index for dose assessment in both head and pelvis scans, while OFC and HIP may serve as secondary indices for dose estimation in corresponding regions. With the proposed empirical functions, it is possible

  6. Dimensional metrology of lab-on-a-chip internal structures: a comparison of optical coherence tomography with confocal fluorescence microscopy.

    Science.gov (United States)

    Reyes, D R; Halter, M; Hwang, J

    2015-07-01

    The characterization of internal structures in a polymeric microfluidic device, especially of a final product, will require a different set of optical metrology tools than those traditionally used for microelectronic devices. We demonstrate that optical coherence tomography (OCT) imaging is a promising technique to characterize the internal structures of poly(methyl methacrylate) devices where the subsurface structures often cannot be imaged by conventional wide field optical microscopy. The structural details of channels in the devices were imaged with OCT and analyzed with an in-house written ImageJ macro in an effort to identify the structural details of the channel. The dimensional values obtained with OCT were compared with laser-scanning confocal microscopy images of channels filled with a fluorophore solution. Attempts were also made using confocal reflectance and interferometry microscopy to measure the channel dimensions, but artefacts present in the images precluded quantitative analysis. OCT provided the most accurate estimates for the channel height based on an analysis of optical micrographs obtained after destructively slicing the channel with a microtome. OCT may be a promising technique for the future of three-dimensional metrology of critical internal structures in lab-on-a-chip devices because scans can be performed rapidly and noninvasively prior to their use. © 2015 The Authors Journal of Microscopy © 2015 Royal Microscopical Society.

  7. Concept of a selective tumour therapy and its evaluation by near-infrared fluorescence imaging and flat-panel volume computed tomography in mice.

    Science.gov (United States)

    Alves, Frauke; Dullin, Christian; Napp, Joanna; Missbach-Guentner, Jeannine; Jannasch, Katharina; Mathejczyk, Julia; Pardo, Luis A; Stühmer, Walter; Tietze, Lutz-F

    2009-05-01

    Conventional chemotherapy of cancer has its limitations, especially in advanced and disseminated disease and suffers from lack of specificity. This results in a poor therapeutic index and considerable toxicity to normal organs. Therefore, many efforts are made to develop novel therapeutic tools against cancer with the aim of selectively targeting the drug to the tumour site. Drug delivery strategies fundamentally rely on the identification of good-quality biomarkers, allowing unequivocal discrimination between cancer and healthy tissue. At present, antibodies or antibody fragments have clearly proven their value as carrier molecules specific for a tumour-associated molecular marker. This present review draws attention to the use of near-infrared fluorescence (NIRF) imaging to investigate binding specificity and kinetics of carrier molecules such as monoclonal antibodies. In addition, flat-panel volume computed tomography (fpVCT) will be presented to monitor anatomical structures in tumour mouse models over time in a non-invasive manner. Each imaging device sheds light on a different aspect; functional imaging is applied to optimise the dose schedule and the concept of selective tumour therapies, whereas anatomical imaging assesses preclinically the efficacy of novel tumour therapies. Both imaging techniques in combination allow the visualisation of functional information obtained by NIRF imaging within an adequate anatomic framework.

  8. Computed tomography guided navigation assisted percutaneous ablation of osteoid osteoma in a 7-year-old patient: the low dose approach

    Energy Technology Data Exchange (ETDEWEB)

    Krokidis, Miltiadis; Tappero, Carlo; Bogdanovic, Daniel; Stamm, Anna-Christina [Inselspital, Bern University Hospital, Department of Diagnostic, Interventional and Pediatric Radiology, Bern (Switzerland); Ziebarth, Kai [Inselspital, Bern University Hospital, Department of Pediatric Surgery, Bern (Switzerland)

    2017-07-15

    Osteoid osteoma (OO) is a benign tumour that can cause severe pain and functional limitation to children and young adults; the treatment of choice is image-guided ablation. Due to the very small size of the lesion, detection and accurate needle placement may be challenging. Computed tomography (CT) offers very detailed imaging of the skeleton and is the modality of choice for the detection of small OO and for ablation guidance. Nevertheless, CT-guided positioning of the ablation applicator is linked to significant radiation exposure, particularly for the paediatric population. This case describes the successful use of a novel CT-based navigation system that offers the possibility of accurate ablation with only minimal radiation exposure in a paediatric patient. (orig.)

  9. First-in-Man Computed Tomography-Guided Percutaneous Revascularization of Coronary Chronic Total Occlusion Using a Wearable Computer: Proof of Concept.

    Science.gov (United States)

    Opolski, Maksymilian P; Debski, Artur; Borucki, Bartosz A; Szpak, Marcin; Staruch, Adam D; Kepka, Cezary; Witkowski, Adam

    2016-06-01

    We report a case of successful computed tomography-guided percutaneous revascularization of a chronically occluded right coronary artery using a wearable, hands-free computer with a head-mounted display worn by interventional cardiologists in the catheterization laboratory. The projection of 3-dimensional computed tomographic reconstructions onto the screen of virtual reality glass allowed the operators to clearly visualize the distal coronary vessel, and verify the direction of the guide wire advancement relative to the course of the occluded vessel segment. This case provides proof of concept that wearable computers can improve operator comfort and procedure efficiency in interventional cardiology. Copyright © 2016 Canadian Cardiovascular Society. Published by Elsevier Inc. All rights reserved.

  10. Multimodality optical coherence tomography and fluorescence confocal scanning laser ophthalmoscopy in a zebrafish model of retinal vascular occlusion and remodeling

    Science.gov (United States)

    Li, Xiaoyue; Spitz, Kathleen; Bozic, Ivan; Tao, Yuankai K.

    2018-02-01

    Neovascularization in diabetic retinopathy (DR) and age-related macular degeneration (AMD) result in severe vision-loss and are two of the leading causes of blindness. The structural, metabolic, and vascular changes underlying retinal neovascularization are unknown and, thus, there is an unmet need to identify mechanisms of pathogenesis and novel anti-angiogenic therapies. Zebrafish is a robust ophthalmological model because its retina has comparable structure to the human retina and its fecundity and life-cycle enable development of mutant phenotypes of human pathologies. Here, we perform multimodal imaging with OCT and fluorescence confocal scanning laser ophthalmoscopy (cSLO) to identify changes in retinal structure and function in a zebrafish model of vascular leakage. Transgenic zebrafish with EGFP tagged plasma protein were imaged longitudinally at six time points over two weeks to visualize vascular perfusion changes from diethylaminobenzaldehyde (DEAB) treatment. Complementary contrast from OCT-A perfusion maps and cSLO imaging of plasma protein EGFP shows vascular occlusions posttreatment. cSLO images confirm presence of vessels despite loss of OCT-A signal. Plasma protein EGFP contrast also shows significant changes in vessel structure as compared to baseline images. OCT structural volumes show empty vessel cross-sections confirming non-perfusion. In addition, we present algorithms for automated biometric identification of OCT datasets using OCT-A vascular patterns in the presence of significant vascular perfusion changes. These results establish a framework for large-scale in vivo assays to identify novel anti-angiogenic compounds and understand the mechanisms ofneovascularization associated with retinal ocular pathologies.

  11. Role of [18F]fluorodeoxyglucose positron emission tomography-computed tomography, sonography, and sonographically guided fine-needle aspiration biopsy in the diagnosis of axillary lymph nodes in patients with breast cancer: comparison of diagnostic performance.

    Science.gov (United States)

    Sohn, Yu-Mee; Hong, Il Ki; Han, Kyunghwa

    2014-06-01

    The aim of this study was to compare the diagnostic performance of [(18)F]fluorodeoxyglucose (FDG) positron emission tomography-computed tomography (PET-CT) with that of sonography and sonographically guided fine-needle aspiration (FNA) for determining the preoperative axillary lymph node (ALN) status and to evaluate the factors related to false-negative PET-CT, sonographic, and FNA results in ALN staging of invasive ductal carcinoma. From March 2009 to July 2012, 226 patients had a diagnosis of primary breast cancer. Among these patients, 107 constituted the study population after exclusion of transferred patients and patients with breast cancer other than invasive ductal carcinoma. The diagnostic performance of the modalities was compared with pathologic reports. Univariate and multivariate analyses were used to evaluate the relationship between clinicopathologic factors (symptoms, T stage, hormone receptors, and histologic grade), false-negative results, and true-negative results on PET-CT, sonography, and FNA. Of the 107 patients, 45 (42.1%) had positive results on final pathologic analysis of ALNs. Sonographically guided FNA had a significantly higher specificity, positive predictive value, accuracy, and area under the receiver operating characteristic curve than sonography and PET-CT (P < .01). When sonography and PET-CT were combined, the sensitivity was significantly improved (P = .019) compared with sonography alone. When FNA and PET-CT were combined, the sensitivity and negative predictive value were significantly increased compared with each modality (P < .01). Sonographically guided FNA was found to be an excellent diagnostic tool for preoperative evaluation of the ALN status. To obviate the step of sentinel lymph node biopsy for determining the ALN status, combined evaluation of ALNs by these modalities may be more complementary than the use of a single modality. © 2014 by the American Institute of Ultrasound in Medicine.

  12. Evaluation of optical coherence tomography in the diagnosis of age related macula degeneration compared with fluorescence angiography

    Directory of Open Access Journals (Sweden)

    Fröschl, Barbara

    2007-02-01

    Full Text Available Background: In industrialised nations age-related macular degeneration (AMD is the most common cause of blindness and severe visual impairment. AMD is a disease of the retina characterized by the accumulation of metabolic products in the macula. In early stages drusen and pigment disorders occur, in late stages a dry form is distinguished from the exsudative form with choroidal neovascularisation. AMD causes vision disorders such as blurred vision of the central part of the visual field, leading finally to a dark spot. Several therapies are available for the exsudative form, however an exact diagnosis is partially essential. The gold standard for the diagnosis of AMD is fluorescein angiography (FA, an invasive investigation with intravenous application of a dye. Optical coherence tomography (OCT is a more recent non-invasive procedure. Objectives: The aim of this HTA report is to investigate the efficacy and efficiency of OCT compared to FA. Ethical, societal and legal aspects are also considered. Methods: A systematic literature search was performed in 34 international databases which yielded 2324 articles. Eight publications were included for assessment, according to predefined selection criteria. Results: The number of studies investigating OCT compared to FA in patients with AMD is presently very limited and the quality of the studies is generally low. The number of investigated patients is below 35 in four publications and in only one publication it is above 100. Moreover in most of the articles very selected patient groups are studied. Economic studies concerning the efficiency of OCT compared to FA cannot be identified. DiscussionEven though the patient groups investigated and the objectives of the studies are very heterogenous, all publications uniformly show that OCT cannot replace FA. However, OCT yields additional diagnostic findings and may verify unclear findings of FA. Therefore the application of OCT in addition to FA is useful in

  13. Accurate pre-surgical determination for self-drilling miniscrew implant placement using surgical guides and cone-beam computed tomography.

    Science.gov (United States)

    Miyazawa, Ken; Kawaguchi, Misuzu; Tabuchi, Masako; Goto, Shigemi

    2010-12-01

    Miniscrew implants have proven to be effective in providing absolute orthodontic anchorage. However, as self-drilling miniscrew implants have become more popular, a problem has emerged, i.e. root contact, which can lead to perforation and other root injuries. To avoid possible root damage, a surgical guide was fabricated and cone-beam computed tomography (CBCT) was used to incorporate guide tubes drilled in accordance with the planned direction of the implants. Eighteen patients (5 males and 13 females; mean age 23.8 years; minimum 10.7, maximum 45.5) were included in the study. Forty-four self-drilling miniscrew implants (diameter 1.6, and length 8 mm) were placed in interradicular bone using a surgical guide procedure, the majority in the maxillary molar area. To determine the success rates, statistical analysis was undertaken using Fisher's exact probability test. CBCT images of post-surgical self-drilling miniscrew implant placement showed no root contact (0/44). However, based on CBCT evaluation, it was necessary to change the location or angle of 52.3 per cent (23/44) of the guide tubes prior to surgery in order to obtain optimal placement. If orthodontic force could be applied to the screw until completion of orthodontic treatment, screw anchorage was recorded as successful. The total success rate of all miniscrews was 90.9 per cent (40/44). Orthodontic self-drilling miniscrew implants must be inserted carefully, particularly in the case of blind placement, since even guide tubes made on casts frequently require repositioning to avoid the roots of the teeth. The use of surgical guides, fabricated using CBCT images, appears to be a promising technique for placement of orthodontic self-drilling miniscrew implants adjacent to the dental roots and maxillary sinuses.

  14. Common-mask guided image reconstruction (c-MGIR) for enhanced 4D cone-beam computed tomography

    International Nuclear Information System (INIS)

    Park, Justin C; Li, Jonathan G; Liu, Chihray; Lu, Bo; Zhang, Hao; Chen, Yunmei; Fan, Qiyong

    2015-01-01

    Compared to 3D cone beam computed tomography (3D CBCT), the image quality of commercially available four-dimensional (4D) CBCT is severely impaired due to the insufficient amount of projection data available for each phase. Since the traditional Feldkamp-Davis-Kress (FDK)-based algorithm is infeasible for reconstructing high quality 4D CBCT images with limited projections, investigators had developed several compress-sensing (CS) based algorithms to improve image quality. The aim of this study is to develop a novel algorithm which can provide better image quality than the FDK and other CS based algorithms with limited projections. We named this algorithm ‘the common mask guided image reconstruction’ (c-MGIR).In c-MGIR, the unknown CBCT volume is mathematically modeled as a combination of phase-specific motion vectors and phase-independent static vectors. The common-mask matrix, which is the key concept behind the c-MGIR algorithm, separates the common static part across all phase images from the possible moving part in each phase image. The moving part and the static part of the volumes were then alternatively updated by solving two sub-minimization problems iteratively. As the novel mathematical transformation allows the static volume and moving volumes to be updated (during each iteration) with global projections and ‘well’ solved static volume respectively, the algorithm was able to reduce the noise and under-sampling artifact (an issue faced by other algorithms) to the maximum extent. To evaluate the performance of our proposed c-MGIR, we utilized imaging data from both numerical phantoms and a lung cancer patient. The qualities of the images reconstructed with c-MGIR were compared with (1) standard FDK algorithm, (2) conventional total variation (CTV) based algorithm, (3) prior image constrained compressed sensing (PICCS) algorithm, and (4) motion-map constrained image reconstruction (MCIR) algorithm, respectively. To improve the efficiency of the

  15. Common-mask guided image reconstruction (c-MGIR) for enhanced 4D cone-beam computed tomography.

    Science.gov (United States)

    Park, Justin C; Zhang, Hao; Chen, Yunmei; Fan, Qiyong; Li, Jonathan G; Liu, Chihray; Lu, Bo

    2015-12-07

    Compared to 3D cone beam computed tomography (3D CBCT), the image quality of commercially available four-dimensional (4D) CBCT is severely impaired due to the insufficient amount of projection data available for each phase. Since the traditional Feldkamp-Davis-Kress (FDK)-based algorithm is infeasible for reconstructing high quality 4D CBCT images with limited projections, investigators had developed several compress-sensing (CS) based algorithms to improve image quality. The aim of this study is to develop a novel algorithm which can provide better image quality than the FDK and other CS based algorithms with limited projections. We named this algorithm 'the common mask guided image reconstruction' (c-MGIR).In c-MGIR, the unknown CBCT volume is mathematically modeled as a combination of phase-specific motion vectors and phase-independent static vectors. The common-mask matrix, which is the key concept behind the c-MGIR algorithm, separates the common static part across all phase images from the possible moving part in each phase image. The moving part and the static part of the volumes were then alternatively updated by solving two sub-minimization problems iteratively. As the novel mathematical transformation allows the static volume and moving volumes to be updated (during each iteration) with global projections and 'well' solved static volume respectively, the algorithm was able to reduce the noise and under-sampling artifact (an issue faced by other algorithms) to the maximum extent. To evaluate the performance of our proposed c-MGIR, we utilized imaging data from both numerical phantoms and a lung cancer patient. The qualities of the images reconstructed with c-MGIR were compared with (1) standard FDK algorithm, (2) conventional total variation (CTV) based algorithm, (3) prior image constrained compressed sensing (PICCS) algorithm, and (4) motion-map constrained image reconstruction (MCIR) algorithm, respectively. To improve the efficiency of the algorithm

  16. High-resolution and high sensitivity mesoscopic fluorescence tomography based on de-scanning EMCCD: System design and thick tissue imaging applications

    Science.gov (United States)

    Ozturk, Mehmet Saadeddin

    Optical microscopy has been one of the essential tools for biological studies for decades, however, its application areas was limited to superficial investigation due to strong scattering in live tissues. Even though advanced techniques such as confocal or multiphoton methods have been recently developed to penetrate beyond a few hundreds of microns deep in tissues, they still cannot perform in the mesoscopic regime (millimeter scale) without using destructive sample preparation protocols such as clearing techniques. They provide rich cellular information; however, they cannot be readily employed to investigate the biological processes at larger scales. Herein, we will present our effort to establish a novel imaging approach that can quantify molecular expression in intact tissues, well beyond the current microscopy depth limits. Mesoscopic Fluorescence Molecular Tomography (MFMT) is an emerging imaging modality that offers unique potential for the non-invasive molecular assessment of thick in-vitro and in-vivo live tissues. This novel imaging modality is based on an optical inverse problem that allows for retrieval of the quantitative spatial distribution of fluorescent tagged bio-markers at millimeter depth. MFMT is well-suited for in-vivo subsurface tissue imaging and thick bio-printed specimens due to its high sensitivity and fast acquisition times, as well as relatively large fields of view. Herein, we will first demonstrate the potential of this technique using our first generation MFMT system applied to multiplexed reporter gene imaging (in-vitro) and determination of Photodynamic Therapy (PDT) agent bio-distribution in a mouse model (in-vivo). Second, we will present the design rationale, in silico benchmarking, and experimental validation of a second generation MFMT (2GMFMT) system. We will demonstrate the gain in resolution and sensitivity achieved due to the de-scanned dense detector configuration implemented. The potential of this novel platform will be

  17. Visibility of solid and liquid fiducial markers used for image-guided radiation therapy on optical coherence tomography: an esophageal phantom study (Conference Presentation)

    Science.gov (United States)

    Jelvehgaran, Pouya; Alderliesten, Tanja; Weda, Jelmer J. A.; de Bruin, Daniel M.; Faber, Dirk J.; Hulshof, Maarten C. C. M.; van Leeuwen, Ton G.; van Herk, Marcel B.; de Boer, Johannes F.

    2017-03-01

    Radiation therapy (RT) is used in operable and inoperable esophageal cancer patients. Endoscopic ultrasound-guided fiducial marker placement allows improved translation of the disease extent on endoscopy to computed tomography (CT) images used for RT planning and enables image-guided RT. However, microscopic tumor extent at the time of RT planning is unknown. Endoscopic optical coherence tomography (OCT) is a high-resolution (10-30µm) imaging modality with the potential for accurately determining the longitudinal disease extent. Visibility of fiducial markers on OCT is crucial for integrating OCT findings with the RT planning CT. We investigated the visibility on OCT (NinePoint Medical, Inc.) of 13 commercially available solid (Visicoil, Gold Anchor, Flexicoil, Polymark, and QLRAD) and liquid (BioXmark, Lipiodol, and Hydrogel) fiducial markers of different diameter. We designed and manufactured a set of dedicated Silicone-based esophageal phantoms to perform imaging in a controlled environment. The esophageal phantoms consist of several layers with different TiO2 concentrations to simulate the scattering properties of a typical healthy human esophagus. Markers were placed at various depths (0.5, 1.1, 2.0, and 3.0mm). OCT imaging allowed detection of all fiducial markers and phantom layers. The signal to background ratio was 6-fold higher for the solid fiducial markers than the liquid fiducial markers, yet OCT was capable of visualizing all 13 fiducial markers at all investigated depths. We conclude that RT fiducial markers can be visualized with OCT. This allows integration of OCT findings with CT for image-guided RT.

  18. Evaluation of a novel Seldinger-needle for computed tomography guided interventions: initial experiences; Evaluierung einer neuen Seldinger-Nadel fuer computertomografisch gesteuerte Interventionen: Erste Erfahrungen

    Energy Technology Data Exchange (ETDEWEB)

    Plumhans, C.; Mahnken, A.; Iwa, R.; Behrendt, F.F.; Sebastian, K.; Guenther, R.W.; Honnef, D. [Universitaetsklinikum RWTH Aachen (Germany). Klinik fuer Radiologische Diagnostik

    2009-02-15

    To evaluate a new Seldinger puncture device for computed tomography-guided interventions under difficult conditions, to analyze applicability, and to investigate assets and drawbacks. From November 2007 to March 2008, we performed CT-guided interventions in 16 patients (7 women, 9 men; mean age 62 years old) using a new 20G-Seldinger needle (Sika-Med, Wiehl, Germany). This novel needle serves as a guide for many different interventional devices due to a guide wire welded on the proximal needle end. It allows continuous application of anesthesia via four tiny holes at the distal needle end until the region of interest is reached. Each intervention was subject to difficult interventional conditions. The indications for intervention were drainage (n = 7), Trucut biopsy of tumor (n = 8) and radiofrequency ablation (n = 1). Handling, success, advantages, drawbacks, complications and patient tolerance were noted after each procedure. A pain scale from 1 - 10 was used to grade the pain level during the intervention. All interventions were performed successfully and no severe complications were observed. Patient tolerance was very good resulting in a mean pain score of 2 {+-} 1. Regions with dangerous and difficult access were successfully reached with the new Seldinger needle in 15 of 16 cases by dilatation of the puncture tract and continuous administration of local anesthesia via the system. Furthermore, different devices such as Trucut systems and a drainage catheter were able to be inserted without complication via the needle. With a proximal removable luer-lock connection, liquid material was able to be aspirated in six cases. Under difficult interventional conditions, the use of a Seldinger needle as a reliable technique for CT-guided interventions can provide a safe and successful procedure. (orig.)

  19. Computed Tomography-Guided Core-Needle Biopsy Specimens Demonstrate Epidermal Growth Factor Receptor Mutations in Patients with Non-Small-Cell Lung Cancer

    International Nuclear Information System (INIS)

    Chen, C.M.; Chang, J.W.C.; Cheung, Y.C.; Lin, G.; Hsieh, J.J.; Hsu, T.; Huang, S.F.

    2008-01-01

    Background: Target therapy with a new class of epidermal growth factor receptor (EGFR) inhibitors shows improved clinical response in EGFR gene-mutated lung cancers. Purpose: To evaluate the use of computed tomography (CT)-guided core-needle biopsy specimens for the assessment of EGFR gene mutation in non-small-cell lung cancer (NSCLC). Material and Methods: Seventeen (nine males, eight females) patients with advanced NSCLC were enrolled in this study. All patients underwent CT-guided core-needle biopsy of the lung tumor prior to treatment with the EGFR inhibitor gefitinib. There were no life-threatening complications of biopsy. The specimens were sent fresh-frozen for EGFR mutation analysis and histopathological study. Results: There were 12 (70.6%) EGFR gene mutants and five (29.4%) nonmutants. The objective response rate to gefitinib therapy was 73.3% (11 of 15 patients), with 91.7% (11 of 12 mutants) for the mutant group and 0% for the nonmutant group. Conclusion: CT-guided core-needle biopsy of advanced NSCLC enables the acquisition of sufficient tissue for EGFR gene mutation analysis

  20. Short-term outcomes and safety of computed tomography-guided percutaneous microwave ablation of solitary adrenal metastasis from lung cancer: A multi-center retrospective study

    Energy Technology Data Exchange (ETDEWEB)

    Men, Min; Ye, Xin; Yang, Xia; Zheng, Aimin; Huang, Guang Hui; Wei, Zhigang [Dept. of Oncology, Shandong Provincial Hospital Affiliated with Shandong University, Jinan (China); Fan, Wei Jun [Imaging and Interventional Center, Sun Yat-sen University Cancer Center, Guangzhou (China); Zhang, Kaixian [Dept. of Oncology, Teng Zhou Central People' s Hospital Affiliated with Jining Medical College, Tengzhou (China); Bi, Jing Wang [Dept. of Oncology, Jinan Military General Hospital of Chinese People' s Liberation Army, Jinan (China)

    2016-11-15

    To retrospectively evaluate the short-term outcomes and safety of computed tomography (CT)-guided percutaneous microwave ablation (MWA) of solitary adrenal metastasis from lung cancer. From May 2010 to April 2014, 31 patients with unilateral adrenal metastasis from lung cancer who were treated with CT-guided percutaneous MWA were enrolled. This study was conducted with approval from local Institutional Review Board. Clinical outcomes and complications of MWA were assessed. Their tumors ranged from 1.5 to 5.4 cm in diameter. After a median follow-up period of 11.1 months, primary efficacy rate was 90.3% (28/31). Local tumor progression was detected in 7 (22.6%) of 31 cases. Their median overall survival time was 12 months. The 1-year overall survival rate was 44.3%. Median local tumor progression-free survival time was 9 months. Local tumor progression-free survival rate was 77.4%. Of 36 MWA sessions, two (5.6%) had major complications (hypertensive crisis). CT-guided percutaneous MWA may be fairly safe and effective for treating solitary adrenal metastasis from lung cancer.

  1. Conventional multi-slice computed tomography (CT) and cone-beam CT (CBCT) for computer-aided implant placement. Part II: reliability of mucosa-supported stereolithographic guides.

    Science.gov (United States)

    Arisan, Volkan; Karabuda, Zihni Cüneyt; Pişkin, Bülent; Özdemir, Tayfun

    2013-12-01

    Deviations of implants that were placed by conventional computed tomography (CT)- or cone beam CT (CBCT)-derived mucosa-supported stereolithographic (SLA) surgical guides were analyzed in this study. Eleven patients were randomly scanned by a multi-slice CT (CT group) or a CBCT scanner (CBCT group). A total of 108 implants were planned on the software and placed using SLA guides. A new CT or CBCT scan was obtained and merged with the planning data to identify the deviations between the planned and placed implants. Results were analyzed by Mann-Whitney U test and multiple regressions (p < .05). Mean angular and linear deviations in the CT group were 3.30° (SD 0.36), and 0.75 (SD 0.32) and 0.80 mm (SD 0.35) at the implant shoulder and tip, respectively. In the CBCT group, mean angular and linear deviations were 3.47° (SD 0.37), and 0.81 (SD 0.32) and 0.87 mm (SD 0.32) at the implant shoulder and tip, respectively. No statistically significant differences were detected between the CT and CBCT groups (p = .169 and p = .551, p = .113 for angular and linear deviations, respectively). Implant placement via CT- or CBCT-derived mucosa-supported SLA guides yielded similar deviation values. Results should be confirmed on alternative CBCT scanners. © 2012 Wiley Periodicals, Inc.

  2. Outcomes of microscope-integrated intraoperative optical coherence tomography-guided center-sparing internal limiting membrane peeling for myopic traction maculopathy: a novel technique.

    Science.gov (United States)

    Kumar, Atul; Ravani, Raghav; Mehta, Aditi; Simakurthy, Sriram; Dhull, Chirakshi

    2017-07-04

    To evaluate the outcomes of pars plana vitrectomy (PPV) with microscope-integrated intraoperative optical coherence tomography (I-OCT)-guided traction removal and center-sparing internal limiting membrane (cs-ILM) peeling. Nine eyes with myopic traction maculopathy as diagnosed on SD-OCT underwent PPV with I-OCT-guided cs-ILM peeling and were evaluated prospectively for resolution of central macular thickness (CMT) and improvement in best-corrected visual acuity (BCVA), and complications, if any, were noted. All patients were followed up for more than 9 months. Resolution of the macular retinoschisis was seen in all nine eyes on SD-OCT. At 36 weeks, there was a significant improvement in mean BCVA from the preoperative BCVA (P = 0.0089) along with a reduction in the CMT from 569.77 ± 263.19 to 166.0 ± 43.91 um (P = 0.0039). None of the eyes showed worsening of BCVA or development of full-thickness macular hole in the intraoperative or follow-up period. PPV with I-OCT-guided cs-ILM peeling helps in complete removal of traction, resolution of retinoschisis and good functional recovery with low intraoperative and postoperative complications.

  3. Cervical Gross Tumor Volume Dose Predicts Local Control Using Magnetic Resonance Imaging/Diffusion-Weighted Imaging—Guided High-Dose-Rate and Positron Emission Tomography/Computed Tomography—Guided Intensity Modulated Radiation Therapy

    Energy Technology Data Exchange (ETDEWEB)

    Dyk, Pawel; Jiang, Naomi; Sun, Baozhou; DeWees, Todd A. [Department of Radiation Oncology, Washington University School of Medicine, St Louis, Missouri (United States); Fowler, Kathryn J.; Narra, Vamsi [Department of Diagnostic Radiology, Mallinckrodt Institute of Radiology, Washington University School of Medicine, St Louis, Missouri (United States); Garcia-Ramirez, Jose L.; Schwarz, Julie K. [Department of Radiation Oncology, Washington University School of Medicine, St Louis, Missouri (United States); Grigsby, Perry W., E-mail: pgrigsby@wustl.edu [Department of Radiation Oncology, Washington University School of Medicine, St Louis, Missouri (United States); Division of Nuclear Medicine, Mallinckrodt Institute of Radiology, Washington University School of Medicine, St Louis, Missouri (United States); Division of Gynecologic Oncology, Mallinckrodt Institute of Radiology, Washington University School of Medicine, St Louis, Missouri (United States); Alvin J. Siteman Cancer Center, Washington University School of Medicine, St Louis, Missouri (United States)

    2014-11-15

    Purpose: Magnetic resonance imaging/diffusion weighted-imaging (MRI/DWI)-guided high-dose-rate (HDR) brachytherapy and {sup 18}F-fluorodeoxyglucose (FDG) — positron emission tomography/computed tomography (PET/CT)-guided intensity modulated radiation therapy (IMRT) for the definitive treatment of cervical cancer is a novel treatment technique. The purpose of this study was to report our analysis of dose-volume parameters predicting gross tumor volume (GTV) control. Methods and Materials: We analyzed the records of 134 patients with International Federation of Gynecology and Obstetrics stages IB1-IVB cervical cancer treated with combined MRI-guided HDR and IMRT from July 2009 to July 2011. IMRT was targeted to the metabolic tumor volume and lymph nodes by use of FDG-PET/CT simulation. The GTV for each HDR fraction was delineated by use of T2-weighted or apparent diffusion coefficient maps from diffusion-weighted sequences. The D100, D90, and Dmean delivered to the GTV from HDR and IMRT were summed to EQD2. Results: One hundred twenty-five patients received all irradiation treatment as planned, and 9 did not complete treatment. All 134 patients are included in this analysis. Treatment failure in the cervix occurred in 24 patients (18.0%). Patients with cervix failures had a lower D100, D90, and Dmean than those who did not experience failure in the cervix. The respective doses to the GTV were 41, 58, and 136 Gy for failures compared with 67, 99, and 236 Gy for those who did not experience failure (P<.001). Probit analysis estimated the minimum D100, D90, and Dmean doses required for ≥90% local control to be 69, 98, and 260 Gy (P<.001). Conclusions: Total dose delivered to the GTV from combined MRI-guided HDR and PET/CT-guided IMRT is highly correlated with local tumor control. The findings can be directly applied in the clinic for dose adaptation to maximize local control.

  4. Fluorescence-guided surgery of a highly-metastatic variant of human triple-negative breast cancer targeted with a cancer-specific GFP adenovirus prevents recurrence

    Science.gov (United States)

    Yano, Shuya; Takehara, Kiyoto; Miwa, Shinji; Kishimoto, Hiroyuki; Tazawa, Hiroshi; Urata, Yasuo; Kagawa, Shunsuke; Bouvet, Michael; Fujiwara, Toshiyoshi; Hoffman, Robert M.

    2016-01-01

    We have previously developed a genetically-engineered GFP-expressing telomerase-dependent adenovirus, OBP-401, which can selectively illuminate cancer cells. In the present report, we demonstrate that targeting a triple-negative high-invasive human breast cancer, orthotopically-growing in nude mice, with OBP-401 enables curative fluorescence-guided surgery (FGS). OBP-401 enabled complete resection and prevented local recurrence and greatly inhibited lymph-node metastasis due to the ability of the virus to selectively label and subsequently kill cancer cells. In contrast, residual breast cancer cells become more aggressive after bright (white)-light surgery (BLS). OBP-401-based FGS also improved the overall survival compared with conventional BLS. Thus, metastasis from a highly-aggressive triple-negative breast cancer can be prevented by FGS in a clinically-relevant mouse model. PMID:27689331

  5. Development of a novel combined fluorescence and reflectance spectroscopy system for guiding high-grade glioma resections: confirmation of capability in lab experiments

    Science.gov (United States)

    Mousavi, Monirehalsadat; Xie, Haiyan; Xie, Zhiyuan; Brydegaard, Mikkel; Axelsson, Johan; Andersson-Engels, Stefan

    2013-11-01

    Total resection of glioblastoma multiform (GBM), the most common and aggressive malignant brain tumor, is challenging among other things due to difficulty in intraoperative discrimination between normal and residual tumor cells. This project demonstrates the potential of a system based on a combination of autofluorescence and diffuse reflectance spectroscopy to be useful as an intraoperative guiding tool. In this context, a system based on 5 LEDs coupled to optical fibers was employed to deliver UV/visible light to the sample sequentially. Remitted light from the tissue; including diffuse reflected and fluorescence of endogenous and exogenous fluorophores, as well as its photobleaching product, is transmitted to one photodiode and four avalanche photodiodes. This instrument has been evaluated with very promising results by performing various tissue-equivalent phantom laboratory and clinical studies on skin lesions.

  6. Single-molecule fluorescence measurements reveal the reaction mechanisms of the core RISC, composed of human Argonaute 2 and a guide RNA.

    Science.gov (United States)

    Jo, Myung Hyun; Song, Ji-Joon; Hohng, Sungchul

    2015-12-01

    In eukaryotes, small RNAs play important roles in both gene regulation and resistance to viral infection. Argonaute proteins have been identified as a key component of the effector complexes of various RNA-silencing pathways, but the mechanistic roles of Argonaute proteins in these pathways are not clearly understood. To address this question, we performed single-molecule fluorescence experiments using an RNA-induced silencing complex (core-RISC) composed of a small RNA and human Argonaute 2. We found that target binding of core-RISC starts at the seed region of the guide RNA. After target binding, four distinct reactions followed: target cleavage, transient binding, stable binding, and Argonaute unloading. Target cleavage required extensive sequence complementarity and accelerated core-RISC dissociation for recycling. In contrast, the stable binding of core-RISC to target RNAs required seed-match only, suggesting a potential explanation for the seed-match rule of microRNA (miRNA) target selection.

  7. Combine TV-L1 model with guided image filtering for wide and faint ring artifacts correction of in-line x-ray phase contrast computed tomography.

    Science.gov (United States)

    Ji, Dongjiang; Qu, Gangrong; Hu, Chunhong; Zhao, Yuqing; Chen, Xiaodong

    2018-01-01

    In practice, mis-calibrated detector pixels give rise to wide and faint ring artifacts in the reconstruction image of the In-line phase-contrast computed tomography (IL-PC-CT). Ring artifacts correction is essential in IL-PC-CT. In this study, a novel method of wide and faint ring artifacts correction was presented based on combining TV-L1 model with guided image filtering (GIF) in the reconstruction image domain. The new correction method includes two main steps namely, the GIF step and the TV-L1 step. To validate the performance of this method, simulation data and real experimental synchrotron data are provided. The results demonstrate that TV-L1 model with GIF step can effectively correct the wide and faint ring artifacts for IL-PC-CT.

  8. Comparisons of Positron Emission Tomography/Computed Tomography and Ultrasound Imaging for Detection of Internal Mammary Lymph Node Metastases in Patients With Breast Cancer and Pathologic Correlation by Ultrasound-Guided Biopsy Procedures.

    Science.gov (United States)

    An, Yeong Yi; Kim, Sung Hun; Kang, Bong Joo; Lee, Ah Won

    2015-08-01

    To compare the diagnostic performance of [(18)F]fluorodeoxyglucose positron emission tomography/computed tomography (PET/CT) and ultrasound imaging (US) with pathologic results obtained by US-guided biopsy and to evaluate the role of US in detecting internal mammary lymph node (LN) metastases in patients with breast cancer. Between January 2008 and December 2012, 37 patients with breast cancer (median age, 51.4 years; range, 40-79 years) underwent US-guided biopsy for suspected internal mammary LN metastases. Medical records, radiologic images, and reports were reviewed and correlated with pathologic results. The positive internal mammary LN metastasis rate was 78.4%. All biopsies were performed safely without major complications. Only 8.1% of obtained samples were unsatisfactory. There were statistically significant differences in lesion size (P = .0002), standardized uptake value on PET/CT (P = .0015), biopsy methods (P = .002), and specimen adequacy (P = .007) between metastatic and benign groups. Of the clinical factorsreviewed, only concurrent distant metastasis was correlated with internal mammary LN metastasis (P< .0001). Sensitivities for detecting internal mammary LN metastases were 76.7%, 96.7%, and 92.9% for initial US examinations, initial US combined with second-look US for initially missed cases, and PET/CT, respectively (P= .017). In a subgroup analysis, the only significant difference found was in sensitivities between initial and combined US (P = .019). In a receiver operating characteristic curve analysis, the area under the curve for PET/CT using standardized uptake criteria (0.87) was higher than that for US using size criteria (0.83); however, this difference was not significant. Although PET/CT is the best noninvasive method for evaluating internal mammary LN metastases, US is also useful if internal mammary LN evaluation is routine during standard US surveillance of patients with breast cancer. Additionally, US-guided biopsies could be

  9. Cone beam computed tomography guided treatment delivery and planning verification for magnetic resonance imaging only radiotherapy of the brain

    DEFF Research Database (Denmark)

    Edmund, Jens M.; Andreasen, Daniel; Mahmood, Faisal

    2015-01-01

    CT (CBCT) can be used for MRI-only image-guided radiotherapy (IGRT) and for verifying the correctness of the corresponding pCT. Material and methods. Six patients receiving palliative cranial RT were included in the study. Each patient had three-dimensional (3D) T1W MRI, a CBCT and a CT for reference...

  10. Possible Radiation-Induced Damage to the Molecular Structure of Wooden Artifacts Due to Micro-Computed Tomography, Handheld X-Ray Fluorescence, and X-Ray Photoelectron Spectroscopic Techniques

    Directory of Open Access Journals (Sweden)

    Madalena Kozachuk

    2016-05-01

    Full Text Available This study was undertaken to ascertain whether radiation produced by X-ray photoelectron spectroscopy (XPS, micro-computed tomography (μCT and/or portable handheld X-ray fluorescence (XRF equipment might damage wood artifacts during analysis. Changes at the molecular level were monitored by Fourier transform infrared (FTIR analysis. No significant changes in FTIR spectra were observed as a result of μCT or handheld XRF analysis. No substantial changes in the collected FTIR spectra were observed when XPS analytical times on the order of minutes were used. However, XPS analysis collected over tens of hours did produce significant changes in the FTIR spectra.

  11. Computed-Tomography-Guided Percutaneous Core Needle Biopsies of Suspected Malignant Lymphomas: Impact of Biopsy, Lesion, and Patient Parameters on Diagnostic Yield

    International Nuclear Information System (INIS)

    Hesselmann, V.; Zaehringer, M.; Krug, B.; Wesselmann, C.; Haferkamp, K.; Wickenhauser, C.; Lackner, K.

    2004-01-01

    Purpose: To investigate the diagnostic yield of core needle biopsy in patients with malignant lymphoma. Material and Methods: Computed-tomography-guided core needle biopsies in patients with malignant lymphoma performed in the period 1996 to 2001 were evaluated retrospectively. A biopsy was considered as 'fully diagnostic' if a histological diagnosis, including the histologic subtype in the event of malignant lymphoma, was achieved and the clinical course and CT follow-up of at least 6 months confirmed the biopsy results. A biopsy was regarded as 'partly diagnostic' if histological work-up defined malignant lymphoma but not the histological subtype, and if histological diagnosis bore therapeutic relevance. Diagnostic yield was correlated with features such as size of specimen, location and depth of the target lesion, and experience of the investigator. Results: 45 biopsies were performed in 40 patients. With respect to definite histopathological diagnosis, 31 biopsies (68.9%) were diagnostic and 14 (31.1%) non-diagnostic. In 4 cases (8.8%), biopsies yielded partly diagnostic results, since therapy could be scheduled after biopsy without final sub-classification. Statistical analysis of biopsy parameters revealed that sample sizes were significantly larger in the diagnostic group. Conclusion: CT-guided biopsy can be considered as an alternative for lymphoma diagnosis and should be the first interventional procedure. The most important parameter for diagnostic success is the size of the specimen

  12. Initial Experience with Computed Tomography and Fluoroscopically Guided Placement of Push-Type Gastrostomy Tubes Using a Rupture-Free Balloon Catheter

    International Nuclear Information System (INIS)

    Fujita, Takeshi; Tanabe, Masahiro; Yamatogi, Shigenari; Shimizu, Kensaku; Matsunaga, Naofumi

    2011-01-01

    The purpose of this study was to evaluate the safety and feasibility of percutaneous radiologic gastrostomy placement of push-type gastrostomy tubes using a rupture-free balloon (RFB) catheter under computed tomography (CT) and fluoroscopic guidance. A total of 35 patients (23 men and 12 women; age range 57–93 years [mean 71.7]) underwent percutaneous CT and fluoroscopically guided gastrostomy placement of a push-type gastrostomy tube using an RFB catheter between April 2005 and July 2008. Technical success, procedure duration, and complications were analyzed. Percutaneous radiologic gastrostomy placement was considered technically successful in all patients. The median procedure time was 39 ± 13 (SD) min (range 24–78). The average follow-up time interval was 103 days (range 7–812). No major complications related to the procedure were encountered. No tubes failed because of blockage, and neither tube dislodgement nor intraperitoneal leakage occurred during the follow-up period. The investigators conclude that percutaneous CT and fluoroscopically guided gastrostomy placement with push-type tubes using an RFB catheter is a safe and effective means of gastric feeding when performed by radiologists.

  13. Radiation Exposure of Interventional Radiologists During Computed Tomography Fluoroscopy-Guided Renal Cryoablation and Lung Radiofrequency Ablation: Direct Measurement in a Clinical Setting

    Energy Technology Data Exchange (ETDEWEB)

    Matsui, Yusuke, E-mail: wckyh140@yahoo.co.jp; Hiraki, Takao, E-mail: takaoh@tc4.so-net.ne.jp; Gobara, Hideo, E-mail: gobara@cc.okayama-u.ac.jp; Iguchi, Toshihiro, E-mail: i10476@yahoo.co.jp; Fujiwara, Hiroyasu, E-mail: hirofujiwar@gmail.com; Kawabata, Takahiro, E-mail: tkhr-kwbt@yahoo.co.jp [Okayama University Medical School, Department of Radiology (Japan); Yamauchi, Takatsugu, E-mail: me9248@hp.okayama-u.ac.jp; Yamaguchi, Takuya, E-mail: me8738@hp.okayama-u.ac.jp [Okayama University Hospital, Central Division of Radiology (Japan); Kanazawa, Susumu, E-mail: susumu@cc.okayama-u.ac.jp [Okayama University Medical School, Department of Radiology (Japan)

    2016-06-15

    IntroductionComputed tomography (CT) fluoroscopy-guided renal cryoablation and lung radiofrequency ablation (RFA) have received increasing attention as promising cancer therapies. Although radiation exposure of interventional radiologists during these procedures is an important concern, data on operator exposure are lacking.Materials and MethodsRadiation dose to interventional radiologists during CT fluoroscopy-guided renal cryoablation (n = 20) and lung RFA (n = 20) was measured prospectively in a clinical setting. Effective dose to the operator was calculated from the 1-cm dose equivalent measured on the neck outside the lead apron, and on the left chest inside the lead apron, using electronic dosimeters. Equivalent dose to the operator’s finger skin was measured using thermoluminescent dosimeter rings.ResultsThe mean (median) effective dose to the operator per procedure was 6.05 (4.52) μSv during renal cryoablation and 0.74 (0.55) μSv during lung RFA. The mean (median) equivalent dose to the operator’s finger skin per procedure was 2.1 (2.1) mSv during renal cryoablation, and 0.3 (0.3) mSv during lung RFA.ConclusionRadiation dose to interventional radiologists during renal cryoablation and lung RFA were at an acceptable level, and in line with recommended dose limits for occupational radiation exposure.

  14. Radiation Exposure of Interventional Radiologists During Computed Tomography Fluoroscopy-Guided Renal Cryoablation and Lung Radiofrequency Ablation: Direct Measurement in a Clinical Setting.

    Science.gov (United States)

    Matsui, Yusuke; Hiraki, Takao; Gobara, Hideo; Iguchi, Toshihiro; Fujiwara, Hiroyasu; Kawabata, Takahiro; Yamauchi, Takatsugu; Yamaguchi, Takuya; Kanazawa, Susumu

    2016-06-01

    Computed tomography (CT) fluoroscopy-guided renal cryoablation and lung radiofrequency ablation (RFA) have received increasing attention as promising cancer therapies. Although radiation exposure of interventional radiologists during these procedures is an important concern, data on operator exposure are lacking. Radiation dose to interventional radiologists during CT fluoroscopy-guided renal cryoablation (n = 20) and lung RFA (n = 20) was measured prospectively in a clinical setting. Effective dose to the operator was calculated from the 1-cm dose equivalent measured on the neck outside the lead apron, and on the left chest inside the lead apron, using electronic dosimeters. Equivalent dose to the operator's finger skin was measured using thermoluminescent dosimeter rings. The mean (median) effective dose to the operator per procedure was 6.05 (4.52) μSv during renal cryoablation and 0.74 (0.55) μSv during lung RFA. The mean (median) equivalent dose to the operator's finger skin per procedure was 2.1 (2.1) mSv during renal cryoablation, and 0.3 (0.3) mSv during lung RFA. Radiation dose to interventional radiologists during renal cryoablation and lung RFA were at an acceptable level, and in line with recommended dose limits for occupational radiation exposure.

  15. ULTRASONOGRAPHY AND COMPUTED TOMOGRAPHY GUIDED FINE NEEDLE ASPIRATION CYTOLOGY IN DIAGNOSING INTRA-ABDOMINAL LESIONS- A 6-YEAR RETROSPECTIVE STUDY IN A TERTIARY CARE HOSPITAL IN MANIPUR

    Directory of Open Access Journals (Sweden)

    Ratan Konjengbam

    2017-07-01

    Full Text Available BACKGROUND Fine-Needle Aspiration Cytology (FNAC is a widely used method, which is accurate and safe in a readily palpable masses. But, in those inaccessible lesions and deeper organs are safely aspirated using fine needle radiological procedure like ultrasound or computed tomography guided. The aim of the study is to assess the utility of FNAC in the diagnosis of intra-abdominal lesions and different pattern of lesions in particular to the sites. MATERIALS AND METHODS This retrospective study was done in the Department of Pathology, Regional Institute of Medical Sciences (RIMS, Imphal, between June 2010 and June 2016. The study included 128 intra-abdominal masses. Giemsa and Papanicolaou’s stains were used. The cytological diagnosis was correlated with clinical and radiological data to arrive at a final diagnosis. RESULTS Reports on FNAC smears were retrospectively analysed, which had been done in various anatomic sites- liver (70 cases, colon (19 cases, gallbladder (17 cases, mesenteric lymph nodes (12 cases, ovary (3 cases, adrenals (2 cases and 1 case each of pancreas, peritoneal wall, pelvic, suprapubic and flank masses. The mean age was 42.16 years with M:F of 1.3:1. The diagnostic yield was 85.2% in combination for Ultrasound Guided (USG and Computed Tomography (CT guided aspiration. The smears were classified as benign neoplastic, malignant neoplastic, non-neoplastic, inconclusive and unsatisfactory for interpretation. There were 79 (61.7% malignant neoplastic lesion, 5 (3.9% benign neoplastic lesion, 25 (19.5% non-neoplastic lesion, one (0.7% inconclusive lesions and 18 (14.1% unsatisfactory smears. The liver and the colon were the most common sites. Adenocarcinomas and Hepatocellular Carcinoma (HCC were the most common malignant lesions comprising of 35 (44.3% and 25 (31.6% of the total malignant lesions diagnosed. CONCLUSION Intra-abdominal FNA is a simple, economical and a safe procedure with high sensitivity, specificity and

  16. Prostate contouring uncertainty in megavoltage computed tomography images acquired with a helical tomotherapy unit during image-guided radiation therapy

    International Nuclear Information System (INIS)

    Song, William Y.; Chiu, Bernard; Bauman, Glenn S.; Lock, Michael; Rodrigues, George; Ash, Robert; Lewis, Craig; Fenster, Aaron; Battista, Jerry J.; Van Dyk, Jake

    2006-01-01

    Purpose: To evaluate the image-guidance capabilities of megavoltage computed tomography (MVCT), this article compares the interobserver and intraobserver contouring uncertainty in kilovoltage computed tomography (KVCT) used for radiotherapy planning with MVCT acquired with helical tomotherapy. Methods and Materials: Five prostate-cancer patients were evaluated. Each patient underwent a KVCT and an MVCT study, a total of 10 CT studies. For interobserver variability analysis, four radiation oncologists, one physicist, and two radiation therapists (seven observers in total) contoured the prostate and seminal vesicles (SV) in the 10 studies. The intraobserver variability was assessed by asking all observers to repeat the contouring of 1 patient's KVCT and MVCT studies. Quantitative analysis of contour variations was performed by use of volumes and radial distances. Results: The interobserver and intraobserver contouring uncertainty was larger in MVCT compared with KVCT. Observers consistently segmented larger volumes on MVCT where the ratio of average prostate and SV volumes was 1.1 and 1.2, respectively. On average (interobserver and intraobserver), the local delineation variability, in terms of standard deviations [Δσ = √(σ 2 MVCT - σ 2 KVCT )], increased by 0.32 cm from KVCT to MVCT. Conclusions: Although MVCT was inferior to KVCT for prostate delineation, the application of MVCT in prostate radiotherapy remains useful

  17. Immediate and intermediate-term results of optical coherence tomography guided atherectomy in the treatment of peripheral arterial disease: Initial results from the VISION trial

    International Nuclear Information System (INIS)

    Cawich, Ian; Paixao, Andre R.M.; Marmagkiolis, Konstantinos; Lendel, Vasili; Rodriguez-Araujo, Gerardo; Rollefson, William A.; Mego, David M.; Cilingiroglu, Mehmet

    2016-01-01

    Background: Long-term patency rates for percutaneous peripheral arterial interventions are suboptimal. Optical coherence tomography (OCT) guided atherectomy may yield superior patency by optimizing plaque removal while preserving the tunica media and adventitia. Methods: The VISION study is a multicenter prospective study of patients with peripheral arterial disease undergoing OCT guided atherectomy with the Pantheris™ device. In 11 patients enrolled in a single center, we report procedural and clinical outcomes, at 30 days and 6 months. Results: The mean age was 63 ± 11 years and 73% (n = 8) were men. The target lesion was in the superficial femoral artery in 82% (n = 9) of the patients. Mean stenosis severity was 87% ± 10% and mean lesion length was 39 ± 31 mm. Procedural success was observed in all patients with no device related complications. Mean post-atherectomy stenosis was 18% ± 15%. Almost all excised tissue consisted of intimal plaque (94%). At 30 days, significant improvements in Rutherford class, VascuQoL scores and ABI were observed, 0.9 ± 0.8 vs. 3.1 ± 0.7 (p = 0.01), 4.9 ± 1.9 vs. 3.6 ± 1.5 (p = 0.03) and 1.04 ± 0.19 vs. 0.80 ± 0.19 (p < 0.01) respectively. At 6 months, there were significant improvements in Rutherford class (1.0 ± 1.0 vs. 3.1 ± 0.7, p = 0.01) and ABI (0.93 ± 0.19 versus 0.80 ± 0.19, p = 0.02) but not in VascuQoL scores (3.7 ± 1.4 versus 3.6 ± 1.5, p = 0.48). Target lesion revascularization occurred in 18% (n = 2) of the patients. Conclusion: OCT guided atherectomy resulted in high procedural success, no device related complications and encouraging results up to 6 months. Histological analysis suggested little injury to the media and adventitia. Larger studies are needed to confirm the efficacy of this approach. - Highlights: • OCT- guided atherectomy may yield superior patency by optimizing plaque removal and preserving the tunica media and adventitia. • OCT guided atherectomy resulted in high procedural

  18. Immediate and intermediate-term results of optical coherence tomography guided atherectomy in the treatment of peripheral arterial disease: Initial results from the VISION trial

    Energy Technology Data Exchange (ETDEWEB)

    Cawich, Ian; Paixao, Andre R.M. [Arkansas Heart Hospital, Peripheral Vascular Institute, Little Rock, AR (United States); Marmagkiolis, Konstantinos [Citizens Memorial Heart and Vascular Institute, Bolivar, MO (United States); University of Missouri, Columbia, MO (United States); Lendel, Vasili; Rodriguez-Araujo, Gerardo; Rollefson, William A.; Mego, David M. [Arkansas Heart Hospital, Peripheral Vascular Institute, Little Rock, AR (United States); Cilingiroglu, Mehmet, E-mail: Cilingiroglumehmet@gmail.com [Arkansas Heart Hospital, Peripheral Vascular Institute, Little Rock, AR (United States); Koc University, School of Medicine, Istanbul (Turkey)

    2016-10-15

    Background: Long-term patency rates for percutaneous peripheral arterial interventions are suboptimal. Optical coherence tomography (OCT) guided atherectomy may yield superior patency by optimizing plaque removal while preserving the tunica media and adventitia. Methods: The VISION study is a multicenter prospective study of patients with peripheral arterial disease undergoing OCT guided atherectomy with the Pantheris™ device. In 11 patients enrolled in a single center, we report procedural and clinical outcomes, at 30 days and 6 months. Results: The mean age was 63 ± 11 years and 73% (n = 8) were men. The target lesion was in the superficial femoral artery in 82% (n = 9) of the patients. Mean stenosis severity was 87% ± 10% and mean lesion length was 39 ± 31 mm. Procedural success was observed in all patients with no device related complications. Mean post-atherectomy stenosis was 18% ± 15%. Almost all excised tissue consisted of intimal plaque (94%). At 30 days, significant improvements in Rutherford class, VascuQoL scores and ABI were observed, 0.9 ± 0.8 vs. 3.1 ± 0.7 (p = 0.01), 4.9 ± 1.9 vs. 3.6 ± 1.5 (p = 0.03) and 1.04 ± 0.19 vs. 0.80 ± 0.19 (p < 0.01) respectively. At 6 months, there were significant improvements in Rutherford class (1.0 ± 1.0 vs. 3.1 ± 0.7, p = 0.01) and ABI (0.93 ± 0.19 versus 0.80 ± 0.19, p = 0.02) but not in VascuQoL scores (3.7 ± 1.4 versus 3.6 ± 1.5, p = 0.48). Target lesion revascularization occurred in 18% (n = 2) of the patients. Conclusion: OCT guided atherectomy resulted in high procedural success, no device related complications and encouraging results up to 6 months. Histological analysis suggested little injury to the media and adventitia. Larger studies are needed to confirm the efficacy of this approach. - Highlights: • OCT- guided atherectomy may yield superior patency by optimizing plaque removal and preserving the tunica media and adventitia. • OCT guided atherectomy resulted in high procedural

  19. Developing an automated database for monitoring ultrasound- and computed tomography-guided procedure complications and diagnostic yield.

    Science.gov (United States)

    Itri, Jason N; Jones, Lisa P; Kim, Woojin; Boonn, William W; Kolansky, Ana S; Hilton, Susan; Zafar, Hanna M

    2014-04-01

    Monitoring complications and diagnostic yield for image-guided procedures is an important component of maintaining high quality patient care promoted by professional societies in radiology and accreditation organizations such as the American College of Radiology (ACR) and Joint Commission. These outcome metrics can be used as part of a comprehensive quality assurance/quality improvement program to reduce variation in clinical practice, provide opportunities to engage in practice quality improvement, and contribute to developing national benchmarks and standards. The purpose of this article is to describe the development and successful implementation of an automated web-based software application to monitor procedural outcomes for US- and CT-guided procedures in an academic radiology department. The open source tools PHP: Hypertext Preprocessor (PHP) and MySQL were used to extract relevant procedural information from the Radiology Information System (RIS), auto-populate the procedure log database, and develop a user interface that generates real-time reports of complication rates and diagnostic yield by site and by operator. Utilizing structured radiology report templates resulted in significantly improved accuracy of information auto-populated from radiology reports, as well as greater compliance with manual data entry. An automated web-based procedure log database is an effective tool to reliably track complication rates and diagnostic yield for US- and CT-guided procedures performed in a radiology department.

  20. A new optical method improves fluorescence guided diagnosis of bladder tumor in the outpatient department and reveals significant photo bleaching problems in established inpatients PDD techniques

    DEFF Research Database (Denmark)

    Lindvold, Lars René; Hermann, Gregers G.

    2013-01-01

    the fluorescence during PDD used in the OPD. Urine contains fluorescent metabolites that are excited by blue light giving an opaque green fluorescence confounding the desired red fluorescence (PDD) from the tumour tissue. Measurements from the clinical situation has shown that some systems for PPD based on blue...

  1. α-Lipoic acid stabilized DTX/IR780 micelles for photoacoustic/fluorescence imaging guided photothermal therapy/chemotherapy of breast cancer.

    Science.gov (United States)

    Li, WenTing; Peng, JinRong; Yang, Qian; Chen, LiJuan; Zhang, Lan; Chen, XiaoXin; Qian, ZhiYong

    2018-05-01

    Micellar nanoparticles have unique advantages as carriers for therapeutic or imaging agents, owing to their smaller size and better penetration of tumors. However, some agents, due to their physical or chemical properties, are difficult to load into micelles. IR780 is one of these agents, and is also a promising near-infrared dye for fluorescence imaging (FI)/photoacoustic imaging (PAI) and cancer photothermal therapy (PTT). Its hydrophobic and high crystallization structure results in limited bioavailability in vivo. It is difficult to load into micelles constructed from an amphiphilic block polymer with relatively low molecular weight. In this study, we use computer simulation and introduce another small biomolecule, α-lipoic acid, into the micelles constructed from a mPEG-PCL copolymer, to lower the energy of molecular interaction between MPEG-PCL and IR780, and expect to enhance the loading capacity of the micelles to IR780. The introduction of α-lipoic acid decreases the energy of molecular interaction between MEPG-PCL and IR780 from -46.18 kJ mol-1 to -196.52 kJ mol-1 and increases the loading capacity and stability of the mPEG-PCL micelles to IR780, which also maintains the loading capacity to DTX. We further construct DTX/IR780 co-loaded mPEG-PCL micelles for FI/PAI dual modal imaging guided PTT/chemotherapy of cancer. By FI and PAI evaluation in vitro and in vivo, we demonstrate that the DTX/IR780 co-loaded micelles can be used as FI and PAI probes. By further evaluating the therapeutic outcome of PTT/chemotherapy co-therapy of breast cancer, we demonstrate that the DTX/IR780 co-loaded mPEG-PCL micelles can serve as promising candidates for FI and PAI guided PTT/chemotherapy of breast cancer.

  2. In Vivo Dual-Modality Fluorescence and Magnetic Resonance Imaging-Guided Lymph Node Mapping with Good Biocompatibility Manganese Oxide Nanoparticles

    Directory of Open Access Journals (Sweden)

    Yonghua Zhan

    2017-12-01

    Full Text Available Multifunctional manganese oxide nanoparticles (NPs with impressive enhanced T1 contrast ability show great promise in biomedical diagnosis. Herein, we developed a dual-modality imaging agent system based on polyethylene glycol (PEG-coated manganese oxide NPs conjugated with organic dye (Cy7.5, which functions as a fluorescence imaging (FI agent as well as a magnetic resonance imaging (MRI imaging agent. The formed Mn3O4@PEG-Cy7.5 NPs with the size of ~10 nm exhibit good colloidal stability in different physiological media. Serial FI and MRI studies that non-invasively assessed the bio-distribution pattern and the feasibility for in vivo dual-modality imaging-guided lymph node mapping have been investigated. In addition, histological and biochemical analyses exhibited low toxicity even at a dose of 20 mg/kg in vivo. Since Mn3O4@PEG-Cy7.5 NPs exhibited desirable properties as imaging agents and good biocompatibility, this work offers a robust, safe, and accurate diagnostic platform based on manganese oxide NPs for tumor metastasis diagnosis.

  3. Setting ventilation parameters guided by electrical impedance tomography in an animal trial of acute respiratory distress syndrome

    Science.gov (United States)

    Czaplik, Michael; Biener, Ingeborg; Leonhardt, Steffen; Rossaint, Rolf

    2014-03-01

    Since mechanical ventilation can cause harm to lung tissue it should be as protective as possible. Whereas numerous options exist to set ventilator parameters, an adequate monitoring is lacking up to date. The Electrical Impedance Tomography (EIT) provides a non-invasive visualization of ventilation which is relatively easy to apply and commercially available. Although there are a number of published measures and parameters derived from EIT, it is not clear how to use EIT to improve clinical outcome of e.g. patients suffering from acute respiratory distress syndrome (ARDS), a severe disease with a high mortality rate. On the one hand, parameters should be easy to obtain, on the other hand clinical algorithms should consider them to optimize ventilator settings. The so called Global inhomogeneity (GI) index bases on the fact that ARDS is characterized by an inhomogeneous injury pattern. By applying positive endexpiratory pressures (PEEP), homogeneity should be attained. In this study, ARDS was induced by a double hit procedure in six pigs. They were randomly assigned to either the EIT or the control group. Whereas in the control group the ARDS network table was used to set the PEEP according to the current inspiratory oxygen fraction, in the EIT group the GI index was calculated during a decremental PEEP trial. PEEP was kept when GI index was lowest. Interestingly, PEEP was significantly higher in the EIT group. Additionally, two of these animals died ahead of the schedule. Obviously, not only homogeneity of ventilation distribution matters but also limitation of over-distension.

  4. Absolute electrical impedance tomography (aEIT) guided ventilation therapy in critical care patients: simulations and future trends.

    Science.gov (United States)

    Denaï, Mouloud A; Mahfouf, Mahdi; Mohamad-Samuri, Suzani; Panoutsos, George; Brown, Brian H; Mills, Gary H

    2010-05-01

    Thoracic electrical impedance tomography (EIT) is a noninvasive, radiation-free monitoring technique whose aim is to reconstruct a cross-sectional image of the internal spatial distribution of conductivity from electrical measurements made by injecting small alternating currents via an electrode array placed on the surface of the thorax. The purpose of this paper is to discuss the fundamentals of EIT and demonstrate the principles of mechanical ventilation, lung recruitment, and EIT imaging on a comprehensive physiological model, which combines a model of respiratory mechanics, a model of the human lung absolute resistivity as a function of air content, and a 2-D finite-element mesh of the thorax to simulate EIT image reconstruction during mechanical ventilation. The overall model gives a good understanding of respiratory physiology and EIT monitoring techniques in mechanically ventilated patients. The model proposed here was able to reproduce consistent images of ventilation distribution in simulated acutely injured and collapsed lung conditions. A new advisory system architecture integrating a previously developed data-driven physiological model for continuous and noninvasive predictions of blood gas parameters with the regional lung function data/information generated from absolute EIT (aEIT) is proposed for monitoring and ventilator therapy management of critical care patients.

  5. Compression-recovery model of absorptive glass mat (AGM) separator guided by X-ray micro-computed tomography analysis

    Science.gov (United States)

    Kameswara Rao, P. V.; Rawal, Amit; Kumar, Vijay; Rajput, Krishn Gopal

    2017-10-01

    Absorptive glass mat (AGM) separators play a key role in enhancing the cycle life of the valve regulated lead acid (VRLA) batteries by maintaining the elastic characteristics under a defined level of compression force with the plates of the electrodes. Inevitably, there are inherent challenges to maintain the required level of compression characteristics of AGM separators during the charge and discharge of the battery. Herein, we report a three-dimensional (3D) analytical model for predicting the compression-recovery behavior of AGM separators by formulating a direct relationship with the constituent fiber and structural parameters. The analytical model of compression-recovery behavior of AGM separators has successfully included the fiber slippage criterion and internal friction losses. The presented work uses, for the first time, 3D data of fiber orientation from X-ray micro-computed tomography, for predicting the compression-recovery behavior of AGM separators. A comparison has been made between the theoretical and experimental results of compression-recovery behavior of AGM samples with defined fiber orientation characteristics. In general, the theory agreed reasonably well with the experimental results of AGM samples in both dry and wet states. Through theoretical modeling, fiber volume fraction was established as one of the key structural parameters that modulates the compression hysteresis of an AGM separator.

  6. Non-real-time computed tomography-guided percutaneous ethanol injection therapy for heapocellular carcinoma undetectable by ultrasonography

    International Nuclear Information System (INIS)

    Ueda, Kazushige; Ohkawara, Tohru; Minami, Masahito; Sawa, Yoshihiko; Morinaga, Osamu; Kohli, Yoshihiro; Ohkawara, Yasuo

    1998-01-01

    The purpose of this study was to evaluate the feasibility of non-real-time CT-guided percutaneous ethanol injection therapy (PEIT) for hepatocellular carcinoma (HCC, 37 lesions) untreatable by ultrasonography-guided (US)-PEIT. The HCC lesion was localized on the lipiodol CT image with a graduated grid system. We advanced a 21 G or 22 G needle in a stepwise fashion with intermittent localization scans using a tandem method to position the tip of the needle in the lesion. Ethanol containing contrast medium was injected with monitoring scans obtained after incremental volumes of injection, until perfusion of the lesion was judged to be complete. A total of 44 CT-PEIT procedures were performed. The average number of needle passes from the skin to the liver in each CT-PEIT procedure was 2.3, the average amount of ethanol injected was 14.4 ml, and the average time required was 49.3 minutes. Complete perfusion of the lesion by ethanol on monitoring CT images was achieved in all lesions with only a single or double CT-PEIT procedure without severe complication. Local recurrence was detected only in 5 lesions. At present, it is more time-consuming to perform CT-PEIT than US-PEIT because conventional CT guidance is not real-time imaging. However, it is expected that this limitation of CT-PEIT will be overcome in the near future with the introduction of CT fluoroscopy. In conclusion, CT-PEIT should prove to be a feasible, acceptable treatment for challenging cases of HCC undetectable by US. (author)

  7. In vivo assessment of the gastric mucosal tolerance dose after single fraction, small volume irradiation of liver malignancies by computed tomography-guided, high-dose-rate brachytherapy

    International Nuclear Information System (INIS)

    Streitparth, Florian; Pech, Maciej; Boehmig, Michael; Ruehl, Ricarda; Peters, Nils; Wieners, Gero; Steinberg, Johannes; Lopez-Haenninen, Enrique; Felix, Roland; Wust, Peter; Ricke, Jens

    2006-01-01

    Purpose: The aim of this study was to assess the tolerance dose of gastric mucosa for single-fraction computed tomography (CT)-guided, high-dose-rate (HDR) brachytherapy of liver malignancies. Methods and Materials: A total of 33 patients treated by CT-guided HDR brachytherapy of liver malignancies in segments II and/or III were included. Dose planning was performed upon a three-dimensional CT data set acquired after percutaneous applicator positioning. All patients received gastric protection post-treatment. For further analysis, the contours of the gastric wall were defined in every CT slice using Brachyvision Software. Dose-volume histograms were calculated for each treatment and correlated with clinical data derived from questionnaires assessing Common Toxicity Criteria (CTC). All patients presenting symptoms of upper GI toxicity were examined endoscopically. Results: Summarizing all patients the minimum dose applied to 1 ml of the gastric wall (D 1ml ) ranged from 6.3 to 34.2 Gy; median, 14.3 Gy. Toxicity was present in 18 patients (55%). We found nausea in 16 (69%), emesis in 9 (27%), cramping in 13 (39%), weight loss in 12 (36%), gastritis in 4 (12%), and ulceration in 5 patients (15%). We found a threshold dose D 1ml of 11 Gy for general gastric toxicity and 15.5 Gy for gastric ulceration verified by an univariate analysis (p = 0.01). Conclusions: For a single fraction, small volume irradiation we found in the upper abdomen a threshold dose D 1ml of 15.5 Gy for the clinical endpoint ulceration of the gastric mucosa. This in vivo assessment is in accordance with previously published tolerance data

  8. Determinants of Local Progression After Computed Tomography-Guided Percutaneous Radiofrequency Ablation for Unresectable Lung Tumors: 9-Year Experience in a Single Institution

    International Nuclear Information System (INIS)

    Okuma, Tomohisa; Matsuoka, Toshiyuki; Yamamoto, Akira; Oyama, Yoshimasa; Hamamoto, Shinichi; Toyoshima, Masami; Nakamura, Kenji; Miki, Yukio

    2010-01-01

    The purpose of this study was to retrospectively determine the local control rate and contributing factors to local progression after computed tomography (CT)-guided radiofrequency ablation (RFA) for unresectable lung tumor. This study included 138 lung tumors in 72 patients (56 men and 16 women; age 70.0 ± 11.6 years (range 31-94); mean tumor size 2.1 ± 1.2 cm [range 0.2-9]) who underwent lung RFA between June 2000 and May 2009. Mean follow-up periods for patients and tumors were 14 and 12 months, respectively. The local progression-free rate and survival rate were calculated to determine the contributing factors to local progression. During follow-up, 44 of 138 (32%) lung tumors showed local progression. The 1-, 2-, 3-, and 5-year overall local control rates were 61, 57, 57, and 38%, respectively. The risk factors for local progression were age (≥70 years), tumor size (≥2 cm), sex (male), and no achievement of roll-off during RFA (P < 0.05). Multivariate analysis identified tumor size ≥2 cm as the only independent factor for local progression (P = 0.003). For tumors <2 cm, 17 of 68 (25%) showed local progression, and the 1-, 2-, and 3-year overall local control rates were 77, 73, and 73%, respectively. Multivariate analysis identified that age ≥70 years was an independent determinant of local progression for tumors <2 cm in diameter (P = 0.011). The present study showed that 32% of lung tumors developed local progression after CT-guided RFA. The significant risk factor for local progression after RFA for lung tumors was tumor size ≥2 cm.

  9. Imaging regional variation of cellular proliferation in gliomas using 3'-deoxy-3'-[18F]fluorothymidine positron-emission tomography: an image-guided biopsy study

    International Nuclear Information System (INIS)

    Price, S.J.; Fryer, T.D.; Cleij, M.C.; Dean, A.F.; Joseph, J.; Salvador, R.; Wang, D.D.; Hutchinson, P.J.; Clark, J.C.; Burnet, N.G.; Pickard, J.D.; Aigbirhio, F.I.

    2009-01-01

    Aim: To compare regional variations in uptake of 3'-deoxy-3'- [ 18 F]-fluorothymidine (FLT) images using positron-emission tomography (PET) with measures of cellular proliferation from biopsy specimens obtained by image-guided brain biopsies. Materials and methods: Fourteen patients with a supratentorial glioma that required an image-guided brain biopsy were imaged preoperatively with dynamic PET after the administration of FLT. Maps of FLT irreversible uptake rate (K i ) and standardized uptake value (SUV) were calculated. These maps were co-registered to a gadolinium-enhanced T1-weighted spoiled gradient echo (SPGR) sequence that was used for biopsy guidance, and the mean and maximum K i and SUV determined for each biopsy site. These values were correlated with the MIB-1 labelling index (a tissue marker of proliferation) from these biopsy sites. Results: A total of 57 biopsy sites were studied. Although all measures correlated with MIB-1 labelling index, K i max provided the best correlation (Pearson coefficient, r = 0.68; p i mean (±SD) was significantly higher than in normal tissue (3.3 ± 1.7 x 10 -3 ml plasma /min/ml tissue versus 1.2 ± 0.7 x 10 -3 ml plasma /min/ml tissue ; p = 0.001). High-grade gliomas showed heterogeneous uptake with a mean K i of 7.7 ± 4 x 10 -3 ml plasma /min/ml tissue . A threshold K i mean of 1.8 x 10 -3 differentiates between normal tissue and tumour (sensitivity 84%, specificity 88%); however, the latter threshold underestimated the extent of tumour in half the cases. SUV closely agreed with K i measurements. Conclusion: FLT PET is a useful marker of cellular proliferation that correlates with regional variation in cellular proliferation; however, it is unable to identify the margin of gliomas

  10. Immediate and intermediate-term results of optical coherence tomography guided atherectomy in the treatment of peripheral arterial disease: Initial results from the VISION trial.

    Science.gov (United States)

    Cawich, Ian; Paixao, Andre R M; Marmagkiolis, Konstantinos; Lendel, Vasili; Rodriguez-Araujo, Gerardo; Rollefson, William A; Mego, David M; Cilingiroglu, Mehmet

    Long-term patency rates for percutaneous peripheral arterial interventions are suboptimal. Optical coherence tomography (OCT) guided atherectomy may yield superior patency by optimizing plaque removal while preserving the tunica media and adventitia. The VISION study is a multicenter prospective study of patients with peripheral arterial disease undergoing OCT guided atherectomy with the Pantheris™ device. In 11 patients enrolled in a single center, we report procedural and clinical outcomes, at 30days and 6months. The mean age was 63±11years and 73% (n=8) were men. The target lesion was in the superficial femoral artery in 82% (n=9) of the patients. Mean stenosis severity was 87%±10% and mean lesion length was 39±31mm. Procedural success was observed in all patients with no device related complications. Mean post-atherectomy stenosis was 18%±15%. Almost all excised tissue consisted of intimal plaque (94%). At 30days, significant improvements in Rutherford class, VascuQoL scores and ABI were observed, 0.9±0.8 vs. 3.1±0.7 (p=0.01), 4.9±1.9 vs. 3.6±1.5 (p=0.03) and 1.04±0.19 vs. 0.80±0.19 (patherectomy resulted in high procedural success, no device related complications and encouraging results up to 6months. Histological analysis suggested little injury to the media and adventitia. Larger studies are needed to confirm the efficacy of this approach. Copyright © 2016 Elsevier Inc. All rights reserved.

  11. The value of ultrasound with ultrasound-guided fine-needle aspiration biopsy compared to computed tomography in the detection of regional metastases in the clinically negative neck

    International Nuclear Information System (INIS)

    Takes, Robert P.; Righi, Paul; Meeuwis, Cees A.; Manni, Johannes J.; Knegt, Paul; Marres, Henri A.M.; Spoelstra, Hubert A.A.; Boer, Maarten F. de; Mey, Andel G.L. van der; Bruaset, I.; Ball, Valerie; Weisberger, Edward; Radpour, Shokri; Kruyt, Rene H.; Joosten, Frank B.M.; Lameris, Johan S.; Oostayen, Jacques A. van; Kopecky, Kenyon; Caldemeyer, Karen; Henzen-Logmans, Sonja C.; Wiersma-van Tilburg, J.M.; Bosman, Fred T.; Krieken, J. Han J.M. van; Hermans, Jo; Baatenburg de Jong, Robert J.

    1998-01-01

    Purpose: Head and neck oncologists have not reached consensus regarding the role of contemporary imaging techniques in the evaluation of the clinically negative neck in patients with head and neck squamous cell carcinoma (HNSCC). The purpose of the present study was to compare the accuracy of ultrasound with guided fine-needle aspiration biopsy (UGFNAB) and computed tomography (CT) in detecting lymph node metastasis in the clinically negative neck. Methods and Materials: Sixty-four neck sides of patients with HNSCC were examined preoperatively by ultrasound/UGFNAB and CT at one of five participating tertiary care medical centers. The findings were correlated with the results of histopathologic examination of the neck specimen. Results: Ultrasound with guided fine-needle aspiration biopsy was characterized by a sensitivity of 48%, specificity of 100%, and overall accuracy of 79%. Three cases had nondiagnostic aspirations using UGFNAB and were excluded. CT demonstrated a sensitivity of 54%, specificity of 92%, and overall accuracy of 77%. UGFNAB detected two additional metastases not visualized on CT, whereas CT detected no metastases not seen on UGFNAB. The results of UGFNAB were similar between the participating centers. Conclusions: Approximately one half of the clinically occult nodal metastases in our patient group were identified by both CT and UGFNAB. Overall, UGFNAB and CT demonstrated comparable accuracy. The sensitivity of CT was slightly better than UGFNAB, but the latter remained characterized by a superior specificity. The results of CT and UGFNAB did not appear to be supplementary. The choice of imaging modality for staging of the clinically negative neck depends on tumor site, T-stage, and experience and preference of the head and neck oncologist. If CT is required for staging of the primary tumor, additional staging of the neck by UGFNAB does not provide significant additional value

  12. Feasibility of computed tomography-guided core needle biopsy in producing state-of-the-art clinical management in Chinese lung cancer.

    Science.gov (United States)

    Chen, Hua-Jun; Yang, Jin-Ji; Fang, Liang-Yi; Huang, Min-Min; Yan, Hong-Hong; Zhang, Xu-Chao; Xu, Chong-Rui; Wu, Yi-Long

    2014-03-01

    A satisfactory biopsy determines the state-of-the-art management of lung cancer in this era of personalized medicine. This study aimed to investigate the suitability and efficacy of computed tomography (CT)-guided core needle biopsy in clinical management. A cohort of 353 patients with clinically suspected lung cancer was enrolled in the study. Patient factors and biopsy variables were recorded. Epidermal growth factor receptor (EGFR) gene mutations and echinoderm microtubule-associated protein-like 4 (EML4)-anaplastic lymphoma kinase (ALK) rearrangement were detected in tumor specimens. Adequacy of biopsic obtainment for clinical trial screening and tissue bank establishment were reviewed. Overall diagnostic accuracy of malignancy achieved 98.5%. The median biopsy time of the cohort was 20 minutes. In patients with non-small cell lung cancer (NSCLC), 99.3% (287/289) were diagnosed as specific histologic subtypes, and two patients (0.7%) were determined as NSCLC not otherwise specified (NOS). EGFR mutations were analyzed in 81.7% (236/289) of patients with NSCLC, and 98.7% (233/236) showed conclusive results. EML4-ALK gene fusion was tested in 43.9% (127/289) of NSCLC patients, and 98.4% (125/127) showed conclusive results: 6.4% (8/125) of those had gene fusion. Ninety-six NSCLC patients participated in clinical trial screening and provided mandatory tumor slides for molecular profiling. Pathological evaluation was fulfilled in 90 patients (93.8%); 99.4% (320/322) of patients with malignancy provided extra tissue for the establishment of a tumor bank. CT-guided core needle biopsy provided optimal clinical management in this era of translational medicine. The biopsic modality should be prioritized in selected lung cancer patients.

  13. Early Chest Computed Tomography Scan to Assist Diagnosis and Guide Treatment Decision for Suspected Community-acquired Pneumonia.

    Science.gov (United States)

    Claessens, Yann-Erick; Debray, Marie-Pierre; Tubach, Florence; Brun, Anne-Laure; Rammaert, Blandine; Hausfater, Pierre; Naccache, Jean-Marc; Ray, Patrick; Choquet, Christophe; Carette, Marie-France; Mayaud, Charles; Leport, Catherine; Duval, Xavier

    2015-10-15

    Clinical decision making relative to community-acquired pneumonia (CAP) diagnosis is difficult. Chest radiograph is key in establishing parenchymal lung involvement. However, radiologic performance may lead to misdiagnosis, rendering questionable the use of chest computed tomography (CT) scan in patients with clinically suspected CAP. To assess whether early multidetector chest CT scan affects diagnosis and management of patients visiting the emergency department with suspected CAP. A total of 319 prospectively enrolled patients with clinically suspected CAP underwent multidetector chest CT scan within 4 hours. CAP diagnosis probability (definite, probable, possible, or excluded) and therapeutic plans (antibiotic initiation/discontinuation, hospitalization/discharge) were established by emergency physicians before and after CT scan results. The adjudication committee established the final CAP classification on Day 28. Chest radiograph revealed a parenchymal infiltrate in 188 patients. CAP was initially classified as definite in 143 patients (44.8%), probable or possible in 172 (53.8%), and excluded in 4 (1.2%). CT scan revealed a parenchymal infiltrate in 40 (33%) of the patients without infiltrate on chest radiograph and excluded CAP in 56 (29.8%) of the 188 with parenchymal infiltrate on radiograph. CT scan modified classification in 187 (58.6%; 95% confidence interval, 53.2-64.0), leading to 50.8% definite CAP and 28.8% excluded CAP, and 80% of modifications were in accordance with adjudication committee classification. Because of CT scan, antibiotics were initiated in 51 (16%) and discontinued in 29 (9%), and hospitalization was decided in 22 and discharge in 23. In CAP-suspected patients visiting the emergency unit, early CT scan findings complementary to chest radiograph markedly affect both diagnosis and clinical management. Clinical trial registered with www.clinicaltrials.gov (NCT 01574066).

  14. Ultrasound-guided diffuse optical tomography (DOT) of invasive breast carcinoma: Does tumour total haemoglobin concentration contribute to the prediction of axillary lymph node status?

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, Qingli, E-mail: qinglizhu@gmail.com [Department of Diagnostic Ultrasound, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Shuaifuyuan 1, Dongcheng District, Beijing 100730 (China); Xiao, Mengsu, E-mail: xiaomengsu_2000@sina.com [Department of Diagnostic Ultrasound, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Shuaifuyuan 1, Dongcheng District, Beijing 100730 (China); You, Shanshan, E-mail: shanshan_0531@sina.com [Department of Diagnostic Ultrasound, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Shuaifuyuan 1, Dongcheng District, Beijing 100730 (China); Zhang, Jing, E-mail: zhang.jing1029@163.com [Department of Diagnostic Ultrasound, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Shuaifuyuan 1, Dongcheng District, Beijing 100730 (China); Jiang, Yuxin, E-mail: yuxinjiangxh@yahoo.com.cn [Department of Diagnostic Ultrasound, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Shuaifuyuan 1, Dongcheng District, Beijing 100730 (China); Lai, Xingjian, E-mail: lxjpumch@yahoo.com.cn [Department of Diagnostic Ultrasound, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Shuaifuyuan 1, Dongcheng District, Beijing 100730 (China); Dai, Qing, E-mail: qingdai_2000@yahoo.com [Department of Diagnostic Ultrasound, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Shuaifuyuan 1, Dongcheng District, Beijing 100730 (China)

    2012-11-15

    Objectives: To prospectively study the ultrasound-guided near-infrared diffuse optical tomography (DOT) findings of the total haemoglobin concentration (THC) detected in invasive breast carcinomas and its contribution to the prediction of axillary lymph node (LN) status. Methods: A total of 195 invasive breast carcinomas were prospectively studied with DOT before surgery. Lumpectomy or mastectomy with full axillary nodal dissection was performed. Tumour size and THC level were correlated with LN status by a logistic regression analysis. Results: One hundred twenty-four patients (63.59%) was LN(-) and 71 (36.41%) was LN(+). The average THC was significantly higher in the LN(+) group than in the LN(-) group (252.94 {+-} 69.19 {mu}mol/L versus 203.86 {+-} 83.13 {mu}mol/L, P = 0.01). A multivariate analysis showed an independent relationship between the probability of axillary metastasis, elevated THC level (P = 0.01), and tumour size (P = 0.001). The odds ratio with THC {>=} 140 {mu}mol/L was 13.651 (1.781-104.560), whereas that of tumour size with a 1 cm increment was only 1.777 (1.283-2.246). Conclusions: The THC level and the tumour size are independent and preoperative predictors of axillary nodal status; these variables may improve the diagnosis of patients with lymph node metastasis.

  15. Comparative Investigation of Guided Fuzzy Clustering and Mean Shift Clustering for Edge Detection in Electrical Resistivity Tomography Images of Mineral Deposits

    Science.gov (United States)

    Ward, Wil; Wilkinson, Paul; Chambers, Jon; Bai, Li

    2014-05-01

    Geophysical surveying using electrical resistivity tomography (ERT) can be used as a rapid non-intrusive method to investigate mineral deposits [1]. One of the key challenges with this approach is to find a robust automated method to assess and characterise deposits on the basis of an ERT image. Recent research applying edge detection techniques has yielded a framework that can successfully locate geological interfaces in ERT images using a minimal assumption data clustering technique, the guided fuzzy clustering method (gfcm) [2]. Non-parametric clustering techniques are statistically grounded methods of image segmentation that do not require any assumptions about the distribution of data under investigation. This study is a comparison of two such methods to assess geological structure based on the resistivity images. In addition to gfcm, a method called mean-shift clustering [3] is investigated with comparisons directed at accuracy, computational expense, and degree of user interaction. Neither approach requires the number of clusters as input (a common parameter and often impractical), rather they are based on a similar theory that data can be clustered based on peaks in the probability density function (pdf) of the data. Each local maximum in these functions represents the modal value of a particular population corresponding to a cluster and as such the data are assigned based on their relationships to these model values. The two methods differ in that gfcm approximates the pdf using kernel density estimation and identifies population means, assigning cluster membership probabilities to each resistivity value in the model based on its distance from the distribution averages. Whereas, in mean-shift clustering, the density function is not calculated, but a gradient ascent method creates a vector that leads each datum towards high density distributions iteratively using weighted kernels to calculate locally dense regions. The only parameter needed in both methods

  16. Optical coherence tomography compared with intravascular ultrasound and with angiography to guide coronary stent implantation (ILUMIEN III: OPTIMIZE PCI): a randomised controlled trial.

    Science.gov (United States)

    Ali, Ziad A; Maehara, Akiko; Généreux, Philippe; Shlofmitz, Richard A; Fabbiocchi, Franco; Nazif, Tamim M; Guagliumi, Giulio; Meraj, Perwaiz M; Alfonso, Fernando; Samady, Habib; Akasaka, Takashi; Carlson, Eric B; Leesar, Massoud A; Matsumura, Mitsuaki; Ozan, Melek Ozgu; Mintz, Gary S; Ben-Yehuda, Ori; Stone, Gregg W

    2016-11-26

    Percutaneous coronary intervention (PCI) is most commonly guided by angiography alone. Intravascular ultrasound (IVUS) guidance has been shown to reduce major adverse cardiovascular events (MACE) after PCI, principally by resulting in a larger postprocedure lumen than with angiographic guidance. Optical coherence tomography (OCT) provides higher resolution imaging than does IVUS, although findings from some studies suggest that it might lead to smaller luminal diameters after stent implantation. We sought to establish whether or not a novel OCT-based stent sizing strategy would result in a minimum stent area similar to or better than that achieved with IVUS guidance and better than that achieved with angiography guidance alone. In this randomised controlled trial, we recruited patients aged 18 years or older undergoing PCI from 29 hospitals in eight countries. Eligible patients had one or more target lesions located in a native coronary artery with a visually estimated reference vessel diameter of 2·25-3·50 mm and a length of less than 40 mm. We excluded patients with left main or ostial right coronary artery stenoses, bypass graft stenoses, chronic total occlusions, planned two-stent bifurcations, and in-stent restenosis. Participants were randomly assigned (1:1:1; with use of an interactive web-based system in block sizes of three, stratified by site) to OCT guidance, IVUS guidance, or angiography-guided stent implantation. We did OCT-guided PCI using a specific protocol to establish stent length, diameter, and expansion according to reference segment external elastic lamina measurements. All patients underwent final OCT imaging (operators in the IVUS and angiography groups were masked to the OCT images). The primary efficacy endpoint was post-PCI minimum stent area, measured by OCT at a masked independent core laboratory at completion of enrolment, in all randomly allocated participants who had primary outcome data. The primary safety endpoint was procedural

  17. PEG-phospholipid-encapsulated bismuth sulfide and CdSe/ZnS quantum dot core–shell nanoparticle and its computed tomography/fluorescence performance

    International Nuclear Information System (INIS)

    Chen, Jun; Yang, Xiao-Quan; Qin, Meng-Yao; Zhang, Xiao-Shuai; Xuan, Yang; Zhao, Yuan-Di

    2015-01-01

    In this paper, polyethylene glycol-phospholipid structure is used to synthesize hybrid cluster of 40–50 nm diameter that contains hydrophobic bismuth sulfide nanoparticles and CdSe/ZnS quantum dots. The composite probe’s toxicity, CT imaging, and fluorescence imaging performance are also studied. Experimental results show that the nanocomposite hybrid cluster has obvious CT contrast enhancement and fluorescence imaging capability in vitro even after cellular uptake. It gives a CT number of 700 (Hounsfield units) at 15 mg/mL, higher than that of the current iobitridol CT contrast agent. 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide experiment reveals that it has low cytotoxicity at concentration up to of 3.14 mg/mL of Bi, indicating the composite probe has potential ability for CT and fluorescence bimodal imaging

  18. Bioresponsive and fluorescent hyaluronic acid-iodixanol nanogels for targeted X-ray computed tomography imaging and chemotherapy of breast tumors

    NARCIS (Netherlands)

    Zhu, Yaqin; Wang, Xinhui; Wang, X.; Chen, J.; Meng, Fenghua; Deng, D.; Cheng, R.; Feijen, Jan; Zhong, Zhiyuan

    2016-01-01

    Nanotheranostics is a rapidly growing field combining disease diagnosis and therapy, which ultimately may add in the development of ‘personalized medicine’. Here, we designed and developed bioresponsive and fluorescent hyaluronic acid-iodixanol nanogels (HAI-NGs) for targeted X-ray computed

  19. High and intermediate risk prostate cancer treated with three-dimensional computed tomography-guided brachytherapy: 2-8-year follow-up

    International Nuclear Information System (INIS)

    Koutrouvelis, Panos G.; Gillenwater, Jay; Lailas, Niko; Hendricks, Fred; Katz, Stuart; Sehn, James; Gil-Montero, Guillermo; Khawand, Nabil

    2003-01-01

    Purpose: To report post-brachytherapy results in high and intermediate risk patients of prostatic adenocarcinoma. Methods and materials: From June 1994 to June 2000, 356 consecutive high and intermediate risk patients were treated with three-dimensional computed tomography-guided stereotactic pararectal brachytherapy. The age was 42-90 years (median, 68 years), the initial prostate volume was 14-180 cm 3 (median, 59 cm 3 ), and initial PSA was 1.7-143 ng/ml (median, 10.5 ng/ml). Three hundred forty-eight patients were available for follow-up for 2 - 8 years (median, 4.5 years). Two hundred eighty patients had one or more high risk factors (PSA >20 ng/ml, Gleason>7, Stage T2b, T3a, or T3b). Sixty-eight patients had only one intermediate risk factor (PSA 10-20 ng/ml or Gleason=7). Patients with both intermediate risks were considered high risk. The high-risk group was further stratified into subgroups with similar risk profile. A dose of 144 Gy with 125 I or 120 Gy with 103 Pd was achieved in 90-100% of the target. Thirty (30) patients (9%) had prior transurethral resection and 229 (64%) were treated with 3 months neoadjuvant androgen ablation. Results: Biochemical disease-free survival was 92% of 280 high risk patients and 96% of 68 intermediate risk patients. Seven patients (2%) required catheterization during the first year for urinary retention, nine patients (3%) required TUR 1-3 years post-implant, three patients (1%) developed grade 1 or 2 incontinence after a second TUR, and four patients (1%) developed grade 3 rectal complications. Conclusion: This method produces a high level of biochemical control 2-8 years (median 4.5 years). Morbidity is acceptable regardless of risk profile or initial prostate volume

  20. Dosimetric Advantages of Four-Dimensional Adaptive Image-Guided Radiotherapy for Lung Tumors Using Online Cone-Beam Computed Tomography

    International Nuclear Information System (INIS)

    Harsolia, Asif; Hugo, Geoffrey D.; Kestin, Larry L.; Grills, Inga S.; Yan Di

    2008-01-01

    Purpose: This study compares multiple planning techniques designed to improve accuracy while allowing reduced planning target volume (PTV) margins though image-guided radiotherapy (IGRT) with four-dimensional (4D) cone-beam computed tomography (CBCT). Methods and Materials: Free-breathing planning and 4D-CBCT scans were obtained in 8 patients with lung tumors. Four plans were generated for each patient: 3D-conformal, 4D-union, 4D-offline adaptive with a single correction (offline ART), and 4D-online adaptive with daily correction (online ART). For the 4D-union plan, the union of gross tumor volumes from all phases of the 4D-CBCT was created with a 5-mm expansion applied for setup uncertainty. For offline and online ART, the gross tumor volume was delineated at the mean position of tumor motion from the 4D-CBCT. The PTV margins were calculated from the random components of tumor motion and setup uncertainty. Results: Adaptive IGRT techniques provided better PTV coverage with less irradiated normal tissues. Compared with 3D plans, mean relative decreases in PTV volumes were 15%, 39%, and 44% using 4D-union, offline ART, and online ART planning techniques, respectively. This resulted in mean lung volume receiving ≥ 20Gy (V20) relative decreases of 21%, 23%, and 31% and mean lung dose relative decreases of 16%, 26%, and 31% for the 4D-union, 4D-offline ART, and 4D-online ART, respectively. Conclusions: Adaptive IGRT using CBCT is feasible for the treatment of patients with lung tumors and significantly decreases PTV volume and dose to normal tissues, allowing for the possibility of dose escalation. All analyzed 4D planning strategies resulted in improvements over 3D plans, with 4D-online ART appearing optimal

  1. Improved Resection and Outcome of Colon-Cancer Liver Metastasis with Fluorescence-Guided Surgery Using In Situ GFP Labeling with a Telomerase-Dependent Adenovirus in an Orthotopic Mouse Model.

    Directory of Open Access Journals (Sweden)

    Shuya Yano

    Full Text Available Fluorescence-guided surgery (FGS of cancer is an area of intense development. In the present report, we demonstrate that the telomerase-dependent green fluorescent protein (GFP-containing adenovirus OBP-401 could label colon-cancer liver metastasis in situ in an orthotopic mouse model enabling successful FGS. OBP-401-GFP-labeled liver metastasis resulted in complete resection with FGS, in contrast, conventional bright-light surgery (BLS did not result in complete resection of the metastasis. OBP-401-FGS reduced the recurrence rate and prolonged over-all survival compared with BLS. In conclusion, adenovirus OBP-401 is a powerful tool to label liver metastasis in situ with GFP which enables its complete resection, not possible with conventional BLS.

  2. Lung tumor reproducibility with active breath control (ABC) in image-guided radiotherapy based on cone-beam computed tomography with two registration methods

    International Nuclear Information System (INIS)

    Wang Xin; Zhong Renming; Bai Sen; Xu Qingfeng; Zhao Yaqin; Wang Jin; Jiang Xiaoqin; Shen Yali; Xu Feng; Wei Yuquan

    2011-01-01

    Purpose: To study the inter- and intrafraction tumor reproducibility with active breath control (ABC) utilizing cone-beam computed tomography (CBCT), and compare validity of registration with two different regions of interest (ROI). Methods and materials: Thirty-one lung tumors in 19 patients received conventional or stereotactic body radiotherapy with ABC. During each treatment, patients had three CBCT scanned before and after online position correction and after treatment. These CBCT images were aligned to the planning CT using the gray scale registration of tumor and bony registration of the thorax, and tumor position uncertainties were then determined. Results: The interfraction systematic and random translation errors in the left-right (LR), superior-inferior (SI) and anterior-posterior (AP) directions were 3.6, 4.8, and 2.9 mm; 2.5, 4.5, and 3.5 mm, respectively, with gray scale alignment; 1.9, 4.3, 2.0 mm and 2.5, 4.4, 2.9 mm, respectively, with bony alignment. The interfraction systematic and random rotation errors with gray scale and bony alignment groups ranged from 1.4 o to 3.0 o and 0.8 o to 2.3 o , respectively. The intrafraction systematic and random errors with gray scale registration in LR, SI, AP directions were 0.9, 2.0, 1.8 mm and 1.5, 1.7, 2.9 mm, respectively, for translation; 1.5 o , 0.9 o , 1.0 o and 1.2 o , 2.2 o , 1.8 o , respectively, for rotation. The translational errors in SI direction with bony alignment were significantly larger than that of gray scale (p < 0.05). Conclusions: With CBCT guided online correction the interfraction positioning errors can be markedly reduced. The intrafraction errors were not diminished by the use of ABC. Rotation errors were not very remarkable both inter- and intrafraction. Gray scale alignment of tumor may provide a better registration in SI direction.

  3. Perfusion computed tomography-guided intravenous thrombolysis for acute ischemic stroke beyond 4.5 hours: a case-control study.

    Science.gov (United States)

    García-Bermejo, Pablo; Calleja, Ana I; Pérez-Fernández, Santiago; Cortijo, Elisa; del Monte, José M; García-Porrero, Miguel; Fe Muñoz, M; Fernández-Herranz, Rosario; Arenillas, Juan F

    2012-01-01

    Extending the therapeutic window of intravenous thrombolysis for acute ischemic stroke beyond the established 4.5-hour limit is of critical importance in order to increase the proportion of thrombolysed stroke patients. In this setting, the capacity of MRI to select acute stroke patients for reperfusion therapies in delayed time windows has been and is being tested in clinical trials. However, whether the more available and cost-effective perfusion computed tomography (PCT) may be useful to select candidates for delayed intravenous thrombolysis remains largely unexplored. We aimed to evaluate the safety and efficacy of PCT-guided intravenous thrombolysis beyond 4.5 h after stroke onset. We prospectively studied all consecutive acute ischemic stroke patients treated with intravenous tissue plasminogen activator (tPA) in our stroke unit between January 2008 and December 2010. Patients treated within 0- 4.5 h were treated according to non-contrast CT (NCCT) criteria. Beyond 4.5 h, patients received intravenous tPA according to PCT criteria, i.e. an infarct core on cerebral blood volume (CBV) maps not exceeding one third of the middle cerebral artery (MCA) territory and tissue at risk as defined by mean transit time-CBV mismatch greater than 20%. Predetermined primary endpoints were symptomatic hemorrhagic transformation and favorable long-term outcome, while early neurological improvement and MCA recanalization were considered secondary endpoints. Statistical analysis included bivariate comparisons between the two groups for each endpoint and logistic regression models when significance was found in bivariate analyses. This study was approved by our local ethics committee. A total of 245 patients received intravenous thrombolysis. After the groups were matched by baseline National Institutes of Health Stroke Scale score, 172 patients treated at 4.5 h were finally included. Early and late groups were comparable regarding baseline variables; only cardioembolic etiology

  4. Clinical use of organic near-infrared fluorescent contrast agents in image-guided oncologic procedures and its potential in veterinary oncology.

    Science.gov (United States)

    Favril, Sophie; Abma, Eline; Blasi, Francesco; Stock, Emmelie; Devriendt, Nausikaa; Vanderperren, Katrien; de Rooster, Hilde

    2018-04-28

    One of the major challenges in surgical oncology is the intraoperative discrimination of tumoural versus healthy tissue. Until today, surgeons rely on visual inspection and palpation to define the tumoural margins during surgery and, unfortunately, for various cancer types, the local recurrence rate thus remains unacceptably high. Near-infrared (NIR) fluorescence imaging is an optical imaging technique that can provide real-time preoperative and intraoperative information after administration of a fluorescent probe that emits NIR light once exposed to a NIR light source. This technique is safe, cost-effective and technically easy. Several NIR fluorescent probes are currently studied for their ability to highlight neoplastic cells. In addition, NIR fluorescence imaging holds great promise for sentinel lymph node mapping. The aim of this manuscript is to provide a literature review of the current organic NIR fluorescent probes tested in the light of human oncology and to introduce fluorescence imaging as a valuable asset in veterinary oncology. © British Veterinary Association (unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

  5. A feasibility study of NIR fluorescent image-guided surgery in head and neck cancer based on the assessment of optimum surgical time as revealed through dynamic imaging

    Directory of Open Access Journals (Sweden)

    Yokoyama J

    2013-04-01

    Full Text Available Junkichi Yokoyama,* Mitsuhisa Fujimaki,* Shinichi Ohba, Takashi Anzai, Ryota Yoshii, Shin Ito, Masataka Kojima, Katsuhisa IkedaDepartment of Otolaryngology-Head and Neck Surgery, Juntendo University School of Medicine, Tokyo, Japan *These authors contributed equally to this study Background: In order to minimize surgical stress and preserve organs, endoscopic or robotic surgery is often performed when conducting head and neck surgery. However, it is impossible to physically touch tumors or to observe diffusely invaded deep organs through the procedure of endoscopic or robotic surgery. In order to visualize and safely resect tumors even in these cases, we propose using an indocyanine green (ICG fluorescence method for navigation surgery in head and neck cancer. Objective: To determine the optimum surgical time for tumor resection after the administration of ICG based on the investigation of dynamic ICG fluorescence imaging. Methods: Nine patients underwent dynamic ICG fluorescence imaging for 360 minutes, assessing tumor visibility at 10, 30, 60, 120, 180, and 360 minutes. All cases were scored according to near-infrared (NIR fluorescence imaging visibility scored from 0 to 5. Results: Dynamic NIR fluorescence imaging under the HyperEye Medical System indicated that the greatest contrast in fluorescent images between tumor and normal tissue could be observed from 30 minutes to 1 hour after the administration of ICG. The optimum surgical time was determined to be between 30 minutes to 2 hours after ICG injection. These findings are particularly useful for detection and safe resection of tumors invading the parapharyngeal space. Conclusion: ICG fluorescence imaging is effective for the detection of head and neck cancer. Preliminary findings suggest that the optimum timing for surgery is from 30 minutes to 2 hours after the ICG injection. Keywords: indocyanine green (ICG, navigation surgery, robotic surgery, endoscopic surgery, minimally invasive

  6. Superselective intra-arterial hepatic injection of indocyanine green (ICG) for fluorescence image-guided segmental positive staining: experimental proof of the concept.

    Science.gov (United States)

    Diana, Michele; Liu, Yu-Yin; Pop, Raoul; Kong, Seong-Ho; Legnèr, Andras; Beaujeux, Remy; Pessaux, Patrick; Soler, Luc; Mutter, Didier; Dallemagne, Bernard; Marescaux, Jacques

    2017-03-01

    Intraoperative liver segmentation can be obtained by means of percutaneous intra-portal injection of a fluorophore and illumination with a near-infrared light source. However, the percutaneous approach is challenging in the minimally invasive setting. We aimed to evaluate the feasibility of fluorescence liver segmentation by superselective intra-hepatic arterial injection of indocyanine green (ICG). Eight pigs (mean weight: 26.01 ± 5.21 kg) were involved. Procedures were performed in a hybrid experimental operative suite equipped with the Artis Zeego ® , multiaxis robotic angiography system. A pneumoperitoneum was established and four laparoscopic ports were introduced. The celiac trunk was catheterized, and a microcatheter was advanced into different segmental hepatic artery branches. A near-infrared laparoscope (D-Light P, Karl Storz) was used to detect the fluorescent signal. To assess the correspondence between arterial-based fluorescence demarcation and liver volume, metallic markers were placed along the fluorescent border, followed by a 3D CT-scanning, after injecting intra-arterial radiological contrast (n = 3). To assess the correspondence between arterial and portal supplies, percutaneous intra-portal angiography and intra-arterial angiography were performed simultaneously (n = 1). Bright fluorescence signal enhancing the demarcation of target segments was obtained from 0.1 mg/mL, in matter of seconds. Correspondence between the volume of hepatic segments and arterial territories was confirmed by CT angiography. Higher background fluorescence noise was found after positive staining by intra-portal ICG injection, due to parenchymal accumulation and porto-systemic shunting. Intra-hepatic arterial ICG injection, rapidly highlights hepatic target segment borders, with a better signal-to-background ratio as compared to portal vein injection, in the experimental setting.

  7. uPAR-targeted optical near-infrared (NIR) fluorescence imaging and PET for image-guided surgery in head and neck cancer

    DEFF Research Database (Denmark)

    Christensen, Anders; Juhl, Karina; Persson, Morten

    2017-01-01

    . Histological analysis showed co-localization of the fluorescent signal, uPAR expression and tumor deposits. In addition, the feasibility of uPARguided robotic cancer surgery was demonstrated. Also, uPAR-PET imaging showed a clear and localized signal in the tongue tumors. Conclusions: This study demonstrated...

  8. A new optical method improves fluorescence guided diagnosis of bladder tumor in the outpatient department and reveals significant photo bleaching problems in established inpatients PDD techniques

    Science.gov (United States)

    Lindvold, Lars R.; Hermann, Gregers G.

    2013-03-01

    Photo dynamic diagnosis (PDD) is a convenient and well-documented procedure for diagnosis of bladder cancer and tumours using endoscopic techniques. At present, this procedure is available only for routine use in an operating room (OR) and often with substantial photobleaching effects of the photosensitizer. We present a novel optical design of the endoscopic PDD procedure that allows the procedure to be performed in the outpatient department (OPD) and not only in the OR. Thereby, inpatient procedures lasting 1-2 days may be replaced by a few hours lasting procedure in the OPD. Urine blurs the fluorescence during PDD used in the OPD. Urine contains fluorescent metabolites that are excited by blue light giving an opaque green fluorescence confounding the desired red fluorescence (PDD) from the tumour tissue. Measurements from the clinical situation has shown that some systems for PPD based on blue light illumination (PDD mode) and white light illumination used for bladder tumour diagnosis and surgery suffers some inherent disadvantages, i.e., photo bleaching in white light that impairs the possibility for PDD as white light usually is used before the blue light for PDD. Based on spectroscopic observations of urine and the photoactive dye Protoporphyrin IX used in PDD a novel optical system for use with the cystoscope has been devised that solves the problem of green fluorescence from urine. This and the knowledge of photo-bleaching pitfalls in established systems make it possible to perform PDD of bladder tumours in the OPD and to improve PDD in the OR.

  9. The efficacy of the use of IR laser phototherapy associated to biphasic ceramic graft and guided bone regeneration on surgical fractures treated with wire osteosynthesis: a comparative laser fluorescence and Raman spectral study on rabbits.

    Science.gov (United States)

    Pinheiro, Antônio Luiz Barbosa; Santos, Nicole Ribeiro Silva; Oliveira, Priscila Chagas; Aciole, Gilberth Tadeu Santos; Ramos, Thais Andrade; Gonzalez, Tayná Assunção; da Silva, Laís Nogueira; Barbosa, Artur Felipe Santos; Silveira, Landulfo

    2013-05-01

    The aim of the present study was to assess, by Raman spectroscopy and laser fluorescence, the repair of surgical fractures fixed with wire osteosynthesis treated or not with infrared laser (λ780 nm, 50 mW, 4 × 4 J/cm(2) =16 J/cm(2), ϕ=0.5 cm(2), CW) associated or not to the use of hydroxyapatite and guided bone regeneration. Surgical tibial fractures were created under general anesthesia on 15 rabbits that were divided into five groups, maintained on individual cages, at day/night cycle, fed with solid laboratory pelted diet, and had water ad libitum. The fractures in groups II, III, IV, and V were fixed with wires. Animals in groups III and V were grafted with hydroxyapatite (HA) and guided bone regeneration (GBR) technique used. Animals in groups IV and V were irradiated at every other day during 2 weeks (4 × 4 J/cm(2), 16 J/cm(2) =112 J/cm(2)). Observation time was that of 30 days. After animal death, specimens were taken and kept in liquid nitrogen and used for Raman spectroscopy. The Raman results showed basal readings of 1,234.38 ± 220. Groups WO+B+L showed higher readings (1,680.22 ± 822) and group WO+B the lowest (501.425 ± 328). Fluorescence data showed basal readings of 5.83333 ± 0.7. Groups WO showed higher readings (6.91667 ± 0.9) and group WO+B+L the lowest (1.66667 ± 0.5). There were significant differences between groups on both cases (pRaman peaks of calcium hydroxyapatite (CHA) are increased, the level of fluorescence is reduced. It is concluded that the use of near-infrared lasertherapy associated to HA graft and GBR was effective in improving bone healing on fractured bones as a result of the increasing deposition of CHA measured by Raman spectroscopy and decrease of the organic components as shown by the fluorescence readings.

  10. Fluorescence spectroscopy

    DEFF Research Database (Denmark)

    Bagatolli, Luis

    2016-01-01

    Fluorescence spectroscopy is a powerful experimental tool used by scientists from many disciplines. During the last decades there have been important developments on distinct fluorescence methods, particularly those related to the study of biological phenomena. This chapter discusses the foundati......Fluorescence spectroscopy is a powerful experimental tool used by scientists from many disciplines. During the last decades there have been important developments on distinct fluorescence methods, particularly those related to the study of biological phenomena. This chapter discusses...

  11. TH-AB-209-01: Making Benchtop X-Ray Fluorescence Computed Tomography (XFCT) Practical for in Vivo Imaging by Integration of a Dedicated High-Performance X-Ray Source in Conjunction with Micro-CT Functionality

    International Nuclear Information System (INIS)

    Manohar, N; Cho, S; Reynoso, F

    2016-01-01

    Purpose: To make benchtop x-ray fluorescence computed tomography (XFCT) practical for routine preclinical imaging tasks with gold nanoparticles (GNPs) by deploying, integrating, and characterizing a dedicated high-performance x-ray source and addition of simultaneous micro-CT functionality. Methods: Considerable research effort is currently under way to develop a polychromatic benchtop cone-beam XFCT system capable of imaging GNPs by stimulation and detection of gold K-shell x-ray fluorescence (XRF) photons. Recently, an ad hoc high-power x-ray source was incorporated and used to image the biodistribution of GNPs within a mouse, postmortem. In the current work, a dedicated x-ray source system featuring a liquid-cooled tungsten-target x-ray tube (max 160 kVp, ∼3 kW power) was deployed. The source was operated at 125 kVp, 24 mA. The tube’s compact dimensions allowed greater flexibility for optimizing both the irradiation and detection geometries. Incident x-rays were shaped by a conical collimator and filtered by 2 mm of tin. A compact “OEM” cadmium-telluride x-ray detector was implemented for detecting XRF/scatter spectra. Additionally, a flat panel detector was installed to allow simultaneous transmission CT imaging. The performance of the system was characterized by determining the detection limit (10-second acquisition time) for inserts filled with water/GNPs at various concentrations (0 and 0.010–1.0 wt%) and embedded in a small-animal-sized phantom. The phantom was loaded with 0.5, 0.3, and 0.1 wt% inserts and imaged using XFCT and simultaneous micro-CT. Results: An unprecedented detection limit of 0.030 wt% was experimentally demonstrated, with a 33% reduction in acquisition time. The reconstructed XFCT image accurately localized the imaging inserts. Micro-CT imaging did not provide enough contrast to distinguish imaging inserts from the phantom under the current conditions. Conclusion: The system is immediately capable of in vivo preclinical XFCT

  12. TH-AB-209-01: Making Benchtop X-Ray Fluorescence Computed Tomography (XFCT) Practical for in Vivo Imaging by Integration of a Dedicated High-Performance X-Ray Source in Conjunction with Micro-CT Functionality

    Energy Technology Data Exchange (ETDEWEB)

    Manohar, N; Cho, S [UT MD Anderson Cancer Center, Houston, TX (United States); Reynoso, F [UT MD Anderson Cancer Center, Houston, TX (United States); Washington University School of Medicine, St. Louis, MO (United States)

    2016-06-15

    Purpose: To make benchtop x-ray fluorescence computed tomography (XFCT) practical for routine preclinical imaging tasks with gold nanoparticles (GNPs) by deploying, integrating, and characterizing a dedicated high-performance x-ray source and addition of simultaneous micro-CT functionality. Methods: Considerable research effort is currently under way to develop a polychromatic benchtop cone-beam XFCT system capable of imaging GNPs by stimulation and detection of gold K-shell x-ray fluorescence (XRF) photons. Recently, an ad hoc high-power x-ray source was incorporated and used to image the biodistribution of GNPs within a mouse, postmortem. In the current work, a dedicated x-ray source system featuring a liquid-cooled tungsten-target x-ray tube (max 160 kVp, ∼3 kW power) was deployed. The source was operated at 125 kVp, 24 mA. The tube’s compact dimensions allowed greater flexibility for optimizing both the irradiation and detection geometries. Incident x-rays were shaped by a conical collimator and filtered by 2 mm of tin. A compact “OEM” cadmium-telluride x-ray detector was implemented for detecting XRF/scatter spectra. Additionally, a flat panel detector was installed to allow simultaneous transmission CT imaging. The performance of the system was characterized by determining the detection limit (10-second acquisition time) for inserts filled with water/GNPs at various concentrations (0 and 0.010–1.0 wt%) and embedded in a small-animal-sized phantom. The phantom was loaded with 0.5, 0.3, and 0.1 wt% inserts and imaged using XFCT and simultaneous micro-CT. Results: An unprecedented detection limit of 0.030 wt% was experimentally demonstrated, with a 33% reduction in acquisition time. The reconstructed XFCT image accurately localized the imaging inserts. Micro-CT imaging did not provide enough contrast to distinguish imaging inserts from the phantom under the current conditions. Conclusion: The system is immediately capable of in vivo preclinical XFCT

  13. Optical Coherence Tomography Guided Percutaneous Coronary Intervention With Nobori Stent Implantation in Patients With Non-ST-Segment-Elevation Myocardial Infarction (OCTACS) Trial

    DEFF Research Database (Denmark)

    Antonsen, Lisbeth; Thayssen, Per; Maehara, Akiko

    2015-01-01

    (s). A final OCT was performed in case of reintervention. Six-month OCT follow-up was available in 85 patients. Twenty-three (46%) OCT-guided patients had additional postdilation or stenting. The percentage of acutely malapposed struts was substantially lower in the OCT-guided group (3.4% [interquartile range......, 0.3-7.6] versus 7.8% [interquartile range, 2.3-19.4]; Pinterquartile range, 1.2-9.8] versus 9.0% [interquartile range, 5.5-14.5], P

  14. Computerized tomography

    International Nuclear Information System (INIS)

    Rubashov, I.B.

    1985-01-01

    Operating principle is described for the devices of computerized tomography used in medicine for diagnosis of brain diseases. Computerized tomography is considered as a part of computerized diagnosis, as a part of information science. It is shown that computerized tomography is a real existed field of investigations in medicine and industrial production

  15. Magnetic resonance tomography-guided interventional procedure for diagnosis of prostate cancer; MRT-gezielte interventionelle Verfahren zur Abklaerung des Prostatakarzinoms

    Energy Technology Data Exchange (ETDEWEB)

    Schernthaner, M.; Helbich, T.H.; Fueger, B.J.; Memarsadeghi, M.; Stiglbauer, A.; Linhart, H.G.; Doan, A.; Pinker, K.; Brader, P. [Medizinische Universitaet Wien, Univ.-Klinik fuer Radiodiagnostik, Division fuer Molekulare und Gender-Bildgebung, Wien (Austria); Margreiter, M. [Medizinische Universitaet Wien, Univ.-Klinik fuer Urologie, Wien (Austria)

    2011-11-15

    In recent years magnetic resonance imaging (MRI) has been increasingly established in the diagnosis of prostate cancer in addition to transrectal ultrasonography (TRUS). The use of T2-weighted imaging allows an exact delineation of the zonal anatomy of the prostate and its surrounding structures. Other MR imaging tools, such as dynamic contrast-enhanced T1-weighted imaging or diffusion-weighted imaging allow an inference of the biochemical characteristics (multiparametric MRI). Prostate cancer, which could only be diagnosed using MR imaging or lesions suspected as being prostate cancer, which are localized in the anterior aspect of the prostate and were missed with repetitive TRUS biopsy, need to undergo MR guided biopsy. Recent studies have shown a good correlation between MR imaging and histopathology of specimens collected by MR-guided biopsy. Improved lesion targeting is therefore possible with MR-guided biopsy. So far data suggest that MR-guided biopsy of the prostate is a promising alternative diagnostic tool to TRUS-guided biopsy. (orig.) [German] Neben dem transrektalen Ultraschall (TRUS) hat sich in den letzten Jahren die MRT als nichtinvasive Methode zur Bildgebung von Prostatatumoren etabliert. Mittels T2-gewichteter Sequenzen ist eine exakte anatomische Darstellung der Prostata und ihrer umliegenden Strukturen moeglich. Andere MRT-Techniken ermoeglichen Rueckschluesse auf das biologische Verhalten des Tumors: dynamische kontrastmittelverstaerkte T1-gewichtete Sequenzen zur Darstellung der Angiogenese, diffusionsgewichtete Aufnahmen zur Beurteilung der Zelldichte und die Spektroskopie zur Bestimmung von Gewebemetaboliten wie Cholin und Kreatin (multiparametrische Bildgebung). Prostatatumoren, die nur mittels MRT nachweisbar sind oder verdaechtige Tumoren, die hauptsaechlich anterior in der Prostata lokalisiert sind und in wiederholten TRUS-gezielten Biopsien verfehlt wurden, benoetigen eine MRT-gezielte Biopsie zur Diagnosesicherung. Die bisherigen

  16. Direct detection of fungal siderophores on bats with white-nose syndrome via fluorescence microscopy-guided ambient ionization mass spectrometry.

    Science.gov (United States)

    Mascuch, Samantha J; Moree, Wilna J; Hsu, Cheng-Chih; Turner, Gregory G; Cheng, Tina L; Blehert, David S; Kilpatrick, A Marm; Frick, Winifred F; Meehan, Michael J; Dorrestein, Pieter C; Gerwick, Lena

    2015-01-01

    White-nose syndrome (WNS) caused by the pathogenic fungus Pseudogymnoascus destructans is decimating the populations of several hibernating North American bat species. Little is known about the molecular interplay between pathogen and host in this disease. Fluorescence microscopy ambient ionization mass spectrometry was used to generate metabolic profiles from the wings of both healthy and diseased bats of the genus Myotis. Fungal siderophores, molecules that scavenge iron from the environment, were detected on the wings of bats with WNS, but not on healthy bats. This work is among the first examples in which microbial molecules are directly detected from an infected host and highlights the ability of atmospheric ionization methodologies to provide direct molecular insight into infection.

  17. Direct detection of fungal siderophores on bats with white-nose syndrome via fluorescence microscopy-guided ambient ionization mass spectrometry

    Science.gov (United States)

    Mascuch, Samantha J.; Moree, Wilna J.; Cheng-Chih Hsu, Cheng-Chih; Turner, Gregory G.; Cheng, Tina L.; Blehert, David S.; Kilpatrick, A. Marm; Frick, Winifred F.; Meehan, Michael J.; Dorrestein, Pieter C.; Gerwick, Lena

    2015-01-01

    White-nose syndrome (WNS) caused by the pathogenic fungus Pseudogymnoascus destructans is decimating the populations of several hibernating North American bat species. Little is known about the molecular interplay between pathogen and host in this disease. Fluorescence microscopy ambient ionization mass spectrometry was used to generate metabolic profiles from the wings of both healthy and diseased bats of the genus Myotis. Fungal siderophores, molecules that scavenge iron from the environment, were detected on the wings of bats with WNS, but not on healthy bats. This work is among the first examples in which microbial molecules are directly detected from an infected host and highlights the ability of atmospheric ionization methodologies to provide direct molecular insight into infection.

  18. Direct detection of fungal siderophores on bats with white-nose syndrome via fluorescence microscopy-guided ambient ionization mass spectrometry.

    Directory of Open Access Journals (Sweden)

    Samantha J Mascuch

    Full Text Available White-nose syndrome (WNS caused by the pathogenic fungus Pseudogymnoascus destructans is decimating the populations of several hibernating North American bat species. Little is known about the molecular interplay between pathogen and host in this disease. Fluorescence microscopy ambient ionization mass spectrometry was used to generate metabolic profiles from the wings of both healthy and diseased bats of the genus Myotis. Fungal siderophores, molecules that scavenge iron from the environment, were detected on the wings of bats with WNS, but not on healthy bats. This work is among the first examples in which microbial molecules are directly detected from an infected host and highlights the ability of atmospheric ionization methodologies to provide direct molecular insight into infection.

  19. Ultrasound-guided image fusion with computed tomography and magnetic resonance imaging. Clinical utility for imaging and interventional diagnostics of hepatic lesions

    International Nuclear Information System (INIS)

    Clevert, D.A.; Helck, A.; Paprottka, P.M.; Trumm, C.; Reiser, M.F.; Zengel, P.

    2012-01-01

    Abdominal ultrasound is often the first-line imaging modality for assessing focal liver lesions. Due to various new ultrasound techniques, such as image fusion, global positioning system (GPS) tracking and needle tracking guided biopsy, abdominal ultrasound now has great potential regarding detection, characterization and treatment of focal liver lesions. Furthermore, these new techniques will help to improve the clinical management of patients before and during interventional procedures. This article presents the principle and clinical impact of recently developed techniques in the field of ultrasound, e.g. image fusion, GPS tracking and needle tracking guided biopsy and discusses the results based on a feasibility study on 20 patients with focal hepatic lesions. (orig.) [de

  20. WE-G-BRF-06: Positron Emission Tomography (PET)-Guided Dynamic Lung Tumor Tracking for Cancer Radiotherapy: First Patient Simulations

    International Nuclear Information System (INIS)

    Yang, J; Loo, B; Graves, E; Yamamoto, T; Keall, P

    2014-01-01

    Purpose: PET-guided dynamic tumor tracking is a novel concept of biologically targeted image guidance for radiotherapy. A dynamic tumor tracking algorithm based on list-mode PET data has been developed and previously tested on dynamic phantom data. In this study, we investigate if dynamic tumor tracking is clinically feasible by applying the method to lung cancer patient PET data. Methods: PET-guided tumor tracking estimates the target position of a segmented volume in PET images reconstructed continuously from accumulated coincidence events correlated with external respiratory motion, simulating real-time applications, i.e., only data up to the current time point is used to estimate the target position. A target volume is segmented with a 50% threshold, consistently, of the maximum intensity in the predetermined volume of interest. Through this algorithm, the PET-estimated trajectories are quantified from four lung cancer patients who have distinct tumor location and size. The accuracy of the PET-estimated trajectories is evaluated by comparing to external respiratory motion because the ground-truth of tumor motion is not known in patients; however, previous phantom studies demonstrated sub-2mm accuracy using clinically derived 3D tumor motion. Results: The overall similarity of motion patterns between the PET-estimated trajectories and the external respiratory traces implies that the PET-guided tracking algorithm can provide an acceptable level of targeting accuracy. However, there are variations in the tracking accuracy between tumors due to the quality of the segmentation which depends on target-to-background ratio, tumor location and size. Conclusion: For the first time, a dynamic tumor tracking algorithm has been applied to lung cancer patient PET data, demonstrating clinical feasibility of real-time tumor tracking for integrated PET-linacs. The target-to-background ratio is a significant factor determining accuracy: screening during treatment planning would

  1. Fully integrated high-speed intravascular optical coherence tomography/near-infrared fluorescence structural/molecular imaging in vivo using a clinically available near-infrared fluorescence-emitting indocyanine green to detect inflamed lipid-rich atheromata in coronary-sized vessels.

    Science.gov (United States)

    Lee, Sunki; Lee, Min Woo; Cho, Han Saem; Song, Joon Woo; Nam, Hyeong Soo; Oh, Dong Joo; Park, Kyeongsoon; Oh, Wang-Yuhl; Yoo, Hongki; Kim, Jin Won

    2014-08-01

    Lipid-rich inflamed coronary plaques are prone to rupture. The purpose of this study was to assess lipid-rich inflamed plaques in vivo using fully integrated high-speed optical coherence tomography (OCT)/near-infrared fluorescence (NIRF) molecular imaging with a Food and Drug Administration-approved indocyanine green (ICG). An integrated high-speed intravascular OCT/NIRF imaging catheter and a dual-modal OCT/NIRF system were constructed based on a clinical OCT platform. For imaging lipid-rich inflamed plaques, the Food and Drug Administration-approved NIRF-emitting ICG (2.25 mg/kg) or saline was injected intravenously into rabbit models with experimental atheromata induced by balloon injury and 12- to 14-week high-cholesterol diets. Twenty minutes after injection, in vivo OCT/NIRF imaging of the infrarenal aorta and iliac arteries was acquired only under contrast flushing through catheter (pullback speed up to ≤20 mm/s). NIRF signals were strongly detected in the OCT-visualized atheromata of the ICG-injected rabbits. The in vivo NIRF target-to-background ratio was significantly larger in the ICG-injected rabbits than in the saline-injected controls (Pfluorescence reflectance imaging, which correlated well with the in vivo target-to-background ratios (Pfluorescence microscopy, and histopathology also corroborated the in vivo imaging findings. Integrated OCT/NIRF structural/molecular imaging with a Food and Drug Administration -approved ICG accurately identified lipid-rich inflamed atheromata in coronary-sized vessels. This highly translatable dual-modal imaging approach could enhance our capabilities to detect high-risk coronary plaques. © 2014 American Heart Association, Inc.

  2. Computed tomography of the pancreas

    International Nuclear Information System (INIS)

    Kolmannskog, F.; Kolbenstvedt, A.; Aakhus, T.; Bergan, A.; Fausa, O.; Elgjo, K.

    1980-01-01

    The findings by computed tomography in 203 cases of suspected pancreatic tumours, pancreatitis or peripancreatic abnormalities were evaluated. The appearances of the normal and the diseased pancreas are described. Computed tomography is highly accurate in detecting pancreatic masses, but can not differentiate neoplastic from inflammatory disease. The only reliable signs of pancreatic carcinoma are a focal mass in the pancreas, together with liver metastasis. When a pancreatic mass is revealed by computed tomography, CT-guided fine-needle aspiration biopsy of the pancreas is recommended. Thus the need for more invasive diagnostic procedures and explorative laparotomy may be avoided in some patients. (Auth.)

  3. Recent developments in multimodality fluorescence imaging probes

    Directory of Open Access Journals (Sweden)

    Jianhong Zhao

    2018-05-01

    Full Text Available Multimodality optical imaging probes have emerged as powerful tools that improve detection sensitivity and accuracy, important in disease diagnosis and treatment. In this review, we focus on recent developments of optical fluorescence imaging (OFI probe integration with other imaging modalities such as X-ray computed tomography (CT, magnetic resonance imaging (MRI, positron emission tomography (PET, single-photon emission computed tomography (SPECT, and photoacoustic imaging (PAI. The imaging technologies are briefly described in order to introduce the strengths and limitations of each techniques and the need for further multimodality optical imaging probe development. The emphasis of this account is placed on how design strategies are currently implemented to afford physicochemically and biologically compatible multimodality optical fluorescence imaging probes. We also present studies that overcame intrinsic disadvantages of each imaging technique by multimodality approach with improved detection sensitivity and accuracy. KEY WORDS: Optical imaging, Fluorescence, Multimodality, Near-infrared fluorescence, Nanoprobe, Computed tomography, Magnetic resonance imaging, Positron emission tomography, Single-photon emission computed tomography, Photoacoustic imaging

  4. Guided Endodontic Access in Maxillary Molars Using Cone-beam Computed Tomography and Computer-aided Design/Computer-aided Manufacturing System: A Case Report.

    Science.gov (United States)

    Lara-Mendes, Sônia T de O; Barbosa, Camila de Freitas M; Santa-Rosa, Caroline C; Machado, Vinícius C

    2018-05-01

    The aim of this study was to describe a guided endodontic technique that facilitates access to root canals of molars presenting with pulp calcifications. A 61-year-old woman presented to our service with pain in the upper left molar region. The second and third left molars showed signs of apical periodontitis confirmed by the cone-beam computed tomographic (CBCT) scans brought to us by the patient at the initial appointment. Conventional endodontic treatment was discontinued given the difficulty in locating the root canals. Intraoral scanning and the CBCT scans were used to plan the access to the calcified canals by means of implant planning software. Guides were fabricated through rapid prototyping and allowed for the correct orientation of a cylindrical drill used to provide access through the calcifications. Second to that, the root canals were prepared with reciprocating endodontic instruments and rested for 2 weeks with intracanal medication. Subsequently, canals were packed with gutta-percha cones using the hydraulic compression technique. Permanent restorations of the access cavities were performed. By comparing the tomographic images, the authors observed a drastic reduction of the periapical lesions as well as the absence of pain symptoms after 3 months. This condition was maintained at the 1-year follow-up. The guided endodontic technique in maxillary molars was shown to be a fast, safe, and predictable therapy and can be regarded as an excellent option for the location of calcified root canals, avoiding failures in complex cases. Copyright © 2018 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  5. Safety of panitumumab-IRDye800CW and cetuximab-IRDye800CW for fluorescence-guided surgical navigation in head and neck cancers.

    Science.gov (United States)

    Gao, Rebecca W; Teraphongphom, Nutte; de Boer, Esther; van den Berg, Nynke S; Divi, Vasu; Kaplan, Michael J; Oberhelman, Nicholas J; Hong, Steven S; Capes, Elissa; Colevas, A Dimitrios; Warram, Jason M; Rosenthal, Eben L

    2018-01-01

    Purpose: To demonstrate the safety and feasibility of leveraging therapeutic antibodies for surgical imaging. Procedures: We conducted two phase I trials for anti-epidermal growth factor receptor antibodies cetuximab-IRDye800CW (n=12) and panitumumab-IRDye800CW (n=15). Adults with biopsy-confirmed head and neck squamous cell carcinoma scheduled for standard-of-care surgery were eligible. For cetuximab-IRDye800CW, cohort 1 was intravenously infused with 2.5 mg/m 2 , cohort 2 received 25 mg/m 2 , and cohort 3 received 62.5 mg/m 2 . For panitumumab-IRDye800CW, cohorts received 0.06 mg/kg, 0.5 mg/kg, and 1 mg/kg, respectively. Electrocardiograms and blood samples were obtained, and patients were followed for 30 days post-study drug infusion. Results: Both fluorescently labeled antibodies had similar pharmacodynamic properties and minimal toxicities. Two infusion reactions occurred with cetuximab and none with panitumumab. There were no grade 2 or higher toxicities attributable to cetuximab-IRDye800CW or panitumumab-IRDye800CW; fifteen grade 1 adverse events occurred with cetuximab-IRDye800CW, and one grade 1 occurred with panitumumab-IRDye800CW. There were no significant differences in QTc prolongation between the two trials (p=0.8). Conclusions: Panitumumab-IRDye800CW and cetuximab-IRDye800CW have toxicity and pharmacodynamic profiles that match the parent compound, suggesting that other therapeutic antibodies may be repurposed as imaging agents with limited preclinical toxicology data.

  6. Interventional management of intractable sympathetically mediated pain by computed tomography-guided catheter implantation for block and neuroablation of the thoracic sympathetic chain: technical approach and review of 322 procedures.

    Science.gov (United States)

    Agarwal-Kozlowski, K; Lorke, D E; Habermann, C R; Schulte am Esch, J; Beck, H

    2011-08-01

    We retrospectively evaluated the safety and efficacy of computed tomography-guided placement of percutaneous catheters in close proximity to the thoracic sympathetic chain by rating pain intensity and systematically reviewing charts and computed tomography scans. Interventions were performed 322 times in 293 patients of mean (SD) age 59.4 (17.0) years, and male to female ratio 105:188, with postherpetic neuralgia (n = 103, 35.1%), various neuralgias (n = 88, 30.0%), complex regional pain syndrome (n = 69, 23.6%), facial pain (n = 17, 5.8%), ischaemic limb pain (n = 7, 2.4%), phantom limb pain (n = 4, 1.4%), pain following cerebrovascular accident (n = 2, 0.7%), syringomyelia (n = 2, 0.7%) and palmar hyperhidrosis (n = 1, 0.3%). The interventions were associated with a total of 23 adverse events (7.1% of all procedures): catheter dislocation (n = 9, 2.8%); increase in pain intensity (n = 8, 2.5%); pneumothorax (n = 3, 0.9%); local infection (n = 2, 0.6%); and puncture of the spinal cord (n = 1, 0.3%). Continuous infusion of 10 ml.h(-1) ropivacaine 0.2% through the catheters decreased median (IQR [range]) pain scores from 8 (6-9 [2-10]) to 2 (1-3 [0-10]) (p < 0.0001). Chemical neuroablation was necessary in 137 patients (46.8%). We conclude that this procedure leads to a significant reduction of pain intensity in otherwise obstinate burning or stabbing pain and is associated with few hazards. © 2011 The Authors. Anaesthesia © 2011 The Association of Anaesthetists of Great Britain and Ireland.

  7. Optical coherence tomography for the diagnosis, monitoring and guiding of treatment for neovascular age-related macular degeneration: a systematic review and economic evaluation.

    Science.gov (United States)

    Mowatt, Graham; Hernández, Rodolfo; Castillo, Mayret; Lois, Noemi; Elders, Andrew; Fraser, Cynthia; Aremu, Olatunde; Amoaku, Winfried; Burr, Jennifer; Lotery, Andrew; Ramsay, Craig; Azuara-Blanco, Augusto

    2014-12-01

    Age-related macular degeneration is the most common cause of sight impairment in the UK. In neovascular age-related macular degeneration (nAMD), vision worsens rapidly (over weeks) due to abnormal blood vessels developing that leak fluid and blood at the macula. To determine the optimal role of optical coherence tomography (OCT) in diagnosing people newly presenting with suspected nAMD and monitoring those previously diagnosed with the disease. Databases searched: MEDLINE (1946 to March 2013), MEDLINE In-Process & Other Non-Indexed Citations (March 2013), EMBASE (1988 to March 2013), Biosciences Information Service (1995 to March 2013), Science Citation Index (1995 to March 2013), The Cochrane Library (Issue 2 2013), Database of Abstracts of Reviews of Effects (inception to March 2013), Medion (inception to March 2013), Health Technology Assessment database (inception to March 2013). Types of studies: direct/indirect studies reporting diagnostic outcomes. time domain optical coherence tomography (TD-OCT) or spectral domain optical coherence tomography (SD-OCT). clinical evaluation, visual acuity, Amsler grid, colour fundus photographs, infrared reflectance, red-free images/blue reflectance, fundus autofluorescence imaging, indocyanine green angiography, preferential hyperacuity perimetry, microperimetry. Reference standard: fundus fluorescein angiography (FFA). Risk of bias was assessed using quality assessment of diagnostic accuracy studies, version 2. Meta-analysis models were fitted using hierarchical summary receiver operating characteristic curves. A Markov model was developed (65-year-old cohort, nAMD prevalence 70%), with nine strategies for diagnosis and/or monitoring, and cost-utility analysis conducted. NHS and Personal Social Services perspective was adopted. Costs (2011/12 prices) and quality-adjusted life-years (QALYs) were discounted (3.5%). Deterministic and probabilistic sensitivity analyses were performed. In pooled estimates of diagnostic studies

  8. Visibility of fiducial markers used for image-guided radiation therapy on optical coherence tomography for registration with CT: An esophageal phantom study.

    Science.gov (United States)

    Jelvehgaran, Pouya; Alderliesten, Tanja; Weda, Jelmer J A; de Bruin, Martijn; Faber, Dirk J; Hulshof, Maarten C C M; van Leeuwen, Ton G; van Herk, Marcel; de Boer, Johannes F

    2017-12-01

    Optical coherence tomography (OCT) is of interest to visualize microscopic esophageal tumor extensions to improve tumor delineation for radiation therapy (RT) planning. Fiducial marker placement is a common method to ensure target localization during planning and treatment. Visualization of these fiducial markers on OCT permits integrating OCT and computed tomography (CT) images used for RT planning via image registration. We studied the visibility of 13 (eight types) commercially available solid and liquid fiducial markers in OCT images at different depths using dedicated esophageal phantoms and evaluated marker placement depth in clinical practice. We designed and fabricated dedicated esophageal phantoms, in which three layers mimic the anatomical wall structures of a healthy human esophagus. We successfully implanted 13 commercially available fiducial markers that varied in diameter and material property at depths between 0.5 and 3.0 mm. The resulting esophageal phantoms were imaged with OCT, and marker visibility was assessed qualitatively and quantitatively using the contrast-to-background-noise ratio (CNR). The CNR was defined as the difference between the mean intensity of the fiducial markers and the mean intensity of the background divided by the standard deviation of the background intensity. To determine whether, in current clinical practice, the implanted fiducial markers are within the OCT visualization range (up to 3.0 mm depth), we retrospectively measured the distance of 19 fiducial markers to the esophageal lumen on CT scans of 16 esophageal cancer patients. In the esophageal phantoms, all the included fiducial markers were visible on OCT at all investigated depths. Solid fiducial markers were better visible on OCT than liquid fiducial markers with a 1.74-fold higher CNR. Although fiducial marker identification per type and size was slightly easier for superficially implanted fiducial markers, we observed no difference in the ability of OCT to

  9. Quality Assurance of Onboard Megavoltage Computed Tomography Imaging and Target Localization Systems for On- and Off-Line Image-Guided Radiotherapy

    International Nuclear Information System (INIS)

    Langen, Katja M.; Meeks, Sanford L.; Pouliot, Jean

    2008-01-01

    We reviewed the quality assurance procedures that have been used to test fan- and cone-beam megavoltage-based in-room imaging systems. Phantom-based tests have been used to establish the geometric accuracy and precision of megavoltage-based systems. However, the clinical implementation of any system is accompanied by challenges that are best tested in a clinical setting using clinical images. To objectively judge and monitor image quality, a set of standard tests and phantoms can be used. The image noise and spatial and contrast resolution have been assessed using standard computed tomography phantoms. The dose to the patient resulting from the imaging procedure can be determined using calculations or measurements. The off-line use of patient images is of interest for the evaluation of dosimetric changes throughout the treatment course. The accuracy of the dosimetric calculations based on the megavoltage images has been tested for the fan- and cone-beam systems. Some of the described tests are typically performed before the clinical implementation of the imaging system; others are suited to monitor the system's performances

  10. Comparing Effective Doses During Image-Guided Core Needle Biopsies with Computed Tomography Versus C-Arm Cone Beam CT Using Adult and Pediatric Phantoms

    International Nuclear Information System (INIS)

    Ben-Shlomo, A.; Cohen, D.; Bruckheimer, E.; Bachar, G. N.; Konstantinovsky, R.; Birk, E.; Atar, E.

    2016-01-01

    PurposeTo compare the effective doses of needle biopsies based on dose measurements and simulations using adult and pediatric phantoms, between cone beam c-arm CT (CBCT) and CT.MethodEffective doses were calculated and compared based on measurements and Monte Carlo simulations of CT- and CBCT-guided biopsy procedures of the lungs, liver, and kidney using pediatric and adult phantoms.ResultsThe effective doses for pediatric and adult phantoms, using our standard protocols for upper, middle and lower lungs, liver, and kidney biopsies, were significantly lower under CBCT guidance than CT. The average effective dose for a 5-year old for these five biopsies was 0.36 ± 0.05 mSv with the standard CBCT exposure protocols and 2.13 ± 0.26 mSv with CT. The adult average effective dose for the five biopsies was 1.63 ± 0.22 mSv with the standard CBCT protocols and 8.22 ± 1.02 mSv using CT. The CT effective dose was higher than CBCT protocols for child and adult phantoms by 803 and 590 % for upper lung, 639 and 525 % for mid-lung, and 461 and 251 % for lower lung, respectively. Similarly, the effective dose was higher by 691 and 762 % for liver and 513 and 608 % for kidney biopsies.ConclusionsBased on measurements and simulations with pediatric and adult phantoms, radiation effective doses during image-guided needle biopsies of the lung, liver, and kidney are significantly lower with CBCT than with CT.

  11. Comparing Effective Doses During Image-Guided Core Needle Biopsies with Computed Tomography Versus C-Arm Cone Beam CT Using Adult and Pediatric Phantoms

    Energy Technology Data Exchange (ETDEWEB)

    Ben-Shlomo, A. [Soreq NRC, Radiation Protection Domain (Israel); Cohen, D.; Bruckheimer, E. [Schneider Children’s Medical Center, Section of Pediatric Cardiology (Israel); Bachar, G. N.; Konstantinovsky, R. [Rabin Medical Center, Department of Diagnostic Radiology (Israel); Birk, E. [Schneider Children’s Medical Center, Section of Pediatric Cardiology (Israel); Atar, E., E-mail: elia@clalit.org.il [Rabin Medical Center, Department of Diagnostic Radiology (Israel)

    2016-05-15

    PurposeTo compare the effective doses of needle biopsies based on dose measurements and simulations using adult and pediatric phantoms, between cone beam c-arm CT (CBCT) and CT.MethodEffective doses were calculated and compared based on measurements and Monte Carlo simulations of CT- and CBCT-guided biopsy procedures of the lungs, liver, and kidney using pediatric and adult phantoms.ResultsThe effective doses for pediatric and adult phantoms, using our standard protocols for upper, middle and lower lungs, liver, and kidney biopsies, were significantly lower under CBCT guidance than CT. The average effective dose for a 5-year old for these five biopsies was 0.36 ± 0.05 mSv with the standard CBCT exposure protocols and 2.13 ± 0.26 mSv with CT. The adult average effective dose for the five biopsies was 1.63 ± 0.22 mSv with the standard CBCT protocols and 8.22 ± 1.02 mSv using CT. The CT effective dose was higher than CBCT protocols for child and adult phantoms by 803 and 590 % for upper lung, 639 and 525 % for mid-lung, and 461 and 251 % for lower lung, respectively. Similarly, the effective dose was higher by 691 and 762 % for liver and 513 and 608 % for kidney biopsies.ConclusionsBased on measurements and simulations with pediatric and adult phantoms, radiation effective doses during image-guided needle biopsies of the lung, liver, and kidney are significantly lower with CBCT than with CT.

  12. Comparing Effective Doses During Image-Guided Core Needle Biopsies with Computed Tomography Versus C-Arm Cone Beam CT Using Adult and Pediatric Phantoms.

    Science.gov (United States)

    Ben-Shlomo, A; Cohen, D; Bruckheimer, E; Bachar, G N; Konstantinovsky, R; Birk, E; Atar, E

    2016-05-01

    To compare the effective doses of needle biopsies based on dose measurements and simulations using adult and pediatric phantoms, between cone beam c-arm CT (CBCT) and CT. Effective doses were calculated and compared based on measurements and Monte Carlo simulations of CT- and CBCT-guided biopsy procedures of the lungs, liver, and kidney using pediatric and adult phantoms. The effective doses for pediatric and adult phantoms, using our standard protocols for upper, middle and lower lungs, liver, and kidney biopsies, were significantly lower under CBCT guidance than CT. The average effective dose for a 5-year old for these five biopsies was 0.36 ± 0.05 mSv with the standard CBCT exposure protocols and 2.13 ± 0.26 mSv with CT. The adult average effective dose for the five biopsies was 1.63 ± 0.22 mSv with the standard CBCT protocols and 8.22 ± 1.02 mSv using CT. The CT effective dose was higher than CBCT protocols for child and adult phantoms by 803 and 590% for upper lung, 639 and 525% for mid-lung, and 461 and 251% for lower lung, respectively. Similarly, the effective dose was higher by 691 and 762% for liver and 513 and 608% for kidney biopsies. Based on measurements and simulations with pediatric and adult phantoms, radiation effective doses during image-guided needle biopsies of the lung, liver, and kidney are significantly lower with CBCT than with CT.

  13. SU-E-J-243: Possibility of Exposure Dose Reduction of Cone-Beam Computed Tomography in An Image Guided Patient Positioning System by Using Various Noise Suppression Filters

    International Nuclear Information System (INIS)

    Kamezawa, H; Arimura, H; Ohki, M; Shirieda, K; Kameda, N

    2014-01-01

    Purpose: To investigate the possibility of exposure dose reduction of the cone-beam computed tomography (CBCT) in an image guided patient positioning system by using 6 noise suppression filters. Methods: First, a reference dose (RD) and low-dose (LD)-CBCT (X-ray volume imaging system, Elekta Co.) images were acquired with a reference dose of 86.2 mGy (weighted CT dose index: CTDIw) and various low doses of 1.4 to 43.1 mGy, respectively. Second, an automated rigid registration for three axes was performed for estimating setup errors between a planning CT image and the LD-CBCT images, which were processed by 6 noise suppression filters, i.e., averaging filter (AF), median filter (MF), Gaussian filter (GF), bilateral filter (BF), edge preserving smoothing filter (EPF) and adaptive partial median filter (AMF). Third, residual errors representing the patient positioning accuracy were calculated as an Euclidean distance between the setup error vectors estimated using the LD-CBCT image and RD-CBCT image. Finally, the relationships between the residual error and CTDIw were obtained for 6 noise suppression filters, and then the CTDIw for LD-CBCT images processed by the noise suppression filters were measured at the same residual error, which was obtained with the RD-CBCT. This approach was applied to an anthropomorphic pelvic phantom and two cancer patients. Results: For the phantom, the exposure dose could be reduced from 61% (GF) to 78% (AMF) by applying the noise suppression filters to the CBCT images. The exposure dose in a prostate cancer case could be reduced from 8% (AF) to 61% (AMF), and the exposure dose in a lung cancer case could be reduced from 9% (AF) to 37% (AMF). Conclusion: Using noise suppression filters, particularly an adaptive partial median filter, could be feasible to decrease the additional exposure dose to patients in image guided patient positioning systems

  14. SU-E-J-243: Possibility of Exposure Dose Reduction of Cone-Beam Computed Tomography in An Image Guided Patient Positioning System by Using Various Noise Suppression Filters

    Energy Technology Data Exchange (ETDEWEB)

    Kamezawa, H [Graduate School of Medical Sciences, Kyushu University, Higashi-ku, Fukuoka (Japan); Fujimoto General Hospital, Miyakonojo, Miyazaki (Japan); Arimura, H; Ohki, M [Faculty of Medical Sciences, Kyushu University, Higashi-ku, Fukuoka (Japan); Shirieda, K; Kameda, N [Fujimoto General Hospital, Miyakonojo, Miyazaki (Japan)

    2014-06-01

    Purpose: To investigate the possibility of exposure dose reduction of the cone-beam computed tomography (CBCT) in an image guided patient positioning system by using 6 noise suppression filters. Methods: First, a reference dose (RD) and low-dose (LD)-CBCT (X-ray volume imaging system, Elekta Co.) images were acquired with a reference dose of 86.2 mGy (weighted CT dose index: CTDIw) and various low doses of 1.4 to 43.1 mGy, respectively. Second, an automated rigid registration for three axes was performed for estimating setup errors between a planning CT image and the LD-CBCT images, which were processed by 6 noise suppression filters, i.e., averaging filter (AF), median filter (MF), Gaussian filter (GF), bilateral filter (BF), edge preserving smoothing filter (EPF) and adaptive partial median filter (AMF). Third, residual errors representing the patient positioning accuracy were calculated as an Euclidean distance between the setup error vectors estimated using the LD-CBCT image and RD-CBCT image. Finally, the relationships between the residual error and CTDIw were obtained for 6 noise suppression filters, and then the CTDIw for LD-CBCT images processed by the noise suppression filters were measured at the same residual error, which was obtained with the RD-CBCT. This approach was applied to an anthropomorphic pelvic phantom and two cancer patients. Results: For the phantom, the exposure dose could be reduced from 61% (GF) to 78% (AMF) by applying the noise suppression filters to the CBCT images. The exposure dose in a prostate cancer case could be reduced from 8% (AF) to 61% (AMF), and the exposure dose in a lung cancer case could be reduced from 9% (AF) to 37% (AMF). Conclusion: Using noise suppression filters, particularly an adaptive partial median filter, could be feasible to decrease the additional exposure dose to patients in image guided patient positioning systems.

  15. Micro-Computed-Tomography-Guided Analysis of In Vitro Structural Modifications in Two Types of 45S5 Bioactive Glass Based Scaffolds.

    Science.gov (United States)

    Westhauser, Fabian; Ciraldo, Francesca; Balasubramanian, Preethi; Senger, Anne-Sophie; Schmidmaier, Gerhard; Moghaddam, Arash; Boccaccini, Aldo R

    2017-11-23

    Three-dimensional 45S5 bioactive glass (BG)-based scaffolds are being investigated for bone regeneration. Besides structural properties, controlled time-dependent alteration of scaffold morphology is crucial to achieve optimal scaffold characteristics for successful bone repair. There is no in vitro evidence concerning the dependence between structural characteristics and dissolution behavior of 45S5 BG-based scaffolds of different morphology. In this study, the dissolution behavior of scaffolds fabricated by the foam replica method using polyurethane foam (Group A) and maritime sponge Spongia Agaricina (Group B) as sacrificial templates was analyzed by micro-computed-tomography (µCT). The scaffolds were immersed in Dulbecco's Modified Eagle Medium for 56 days under static cell culture conditions and underwent µCT-analysis initially, and after 7, 14, and 56 days. Group A showed high porosity (91%) and trabecular structure formed by macro-pores (average diameter 692 µm ± 72 µm). Group-B-scaffolds were less porous (51%), revealing an optimal pore size distribution within the window of 110-500 µm pore size diameter, combined with superior mechanical stability. Both groups showed similar structural alteration upon immersion. Surface area and scaffold volume increased whilst density decreased, reflecting initial dissolution followed by hydroxycarbonate-apatite-layer-formation on the scaffold surfaces. In vitro- and/or in vivo-testing of cell-seeded BG-scaffolds used in this study should be performed to evaluate the BG-scaffolds' time-dependent osteogenic properties in relation to the measured in vitro structural changes.

  16. Comparison of setup accuracy between exactrac X-ray 6 dimensions and cone-beam computed tomography for intracranial and pelvic image-guided radiotherapy

    International Nuclear Information System (INIS)

    Kudo, Tsuyoshi; Ono, Kaoru; Furukawa, Kengo; Fujimoto, Sachie; Akagi, Yukio; Koyama, Tadashi; Hirokawa, Yutaka

    2012-01-01

    The aim of this study was to compare the setup difference measured with ExacTrac X-ray 6D (ETX6D) and cone-beam computed tomography (CBCT) for non-invasive fractionated radiotherapy. Setup data were collected on a Novalis Tx treatment unit for both a head phantom and patients with intracranial tumors and a pelvic phantom and patients with prostate cancer. Initially, setup was done for a phantom using ETX6D. Secondly, a treatment couch was shifted or rotated by each already known value. Thirdly, ETX6D and CBCT scans were obtained. Finally, setup difference was determined: the registrations of ETX6D images with the corresponding digitally reconstructed radiographs using ETX6D fusion, and registrations of CBCT images with the planning CT using online 6D fusion. The setup difference between ETX6D and CBCT was compared. The impact of shifts and rotations on the difference was evaluated. Patients' setup data was similarly analyzed. In phantom experiments, the root mean square (RMS) of difference of the shift and rotation was less than 0.45 mm for translations, and 0.17 degrees for rotations. In intracranial patients' data, the RMS of that was 0.55 mm and 0.44 degree, respectively. In prostate cancer patients' data, the RMS of that was 0.77 mm and 0.79 degree, respectively. In this study, we observed modest setup differences between ETX6D and CBCT. These differences were generally less than 1.00 mm for translations, and 1.00 degrees for rotations, respectively. (author)

  17. 2D-3D radiograph to cone-beam computed tomography (CBCT) registration for C-arm image-guided robotic surgery.

    Science.gov (United States)

    Liu, Wen Pei; Otake, Yoshito; Azizian, Mahdi; Wagner, Oliver J; Sorger, Jonathan M; Armand, Mehran; Taylor, Russell H

    2015-08-01

    C-arm radiographs are commonly used for intraoperative image guidance in surgical interventions. Fluoroscopy is a cost-effective real-time modality, although image quality can vary greatly depending on the target anatomy. Cone-beam computed tomography (CBCT) scans are sometimes available, so 2D-3D registration is needed for intra-procedural guidance. C-arm radiographs were registered to CBCT scans and used for 3D localization of peritumor fiducials during a minimally invasive thoracic intervention with a da Vinci Si robot. Intensity-based 2D-3D registration of intraoperative radiographs to CBCT was performed. The feasible range of X-ray projections achievable by a C-arm positioned around a da Vinci Si surgical robot, configured for robotic wedge resection, was determined using phantom models. Experiments were conducted on synthetic phantoms and animals imaged with an OEC 9600 and a Siemens Artis zeego, representing the spectrum of different C-arm systems currently available for clinical use. The image guidance workflow was feasible using either an optically tracked OEC 9600 or a Siemens Artis zeego C-arm, resulting in an angular difference of Δθ:∼ 30°. The two C-arm systems provided TRE mean ≤ 2.5 mm and TRE mean ≤ 2.0 mm, respectively (i.e., comparable to standard clinical intraoperative navigation systems). C-arm 3D localization from dual 2D-3D registered radiographs was feasible and applicable for intraoperative image guidance during da Vinci robotic thoracic interventions using the proposed workflow. Tissue deformation and in vivo experiments are required before clinical evaluation of this system.

  18. Implications for high-precision dose radiation therapy planning or limited surgical resection after percutaneous computed tomography-guided lung nodule biopsy using a tract sealant

    Directory of Open Access Journals (Sweden)

    Patricia M. de Groot, MD

    2018-04-01

    Full Text Available Purpose: Precision radiation therapy such as stereotactic body radiation therapy and limited resection are being used more frequently to treat intrathoracic malignancies. Effective local control requires precise radiation target delineation or complete resection. Lung biopsy tracts (LBT on computed tomography (CT scans after the use of tract sealants can mimic malignant tract seeding (MTS and it is unclear whether these LBTs should be included in the calculated tumor volume or resected. This study evaluates the incidence, appearance, evolution, and malignant seeding of LBTs. Methods and materials: A total of 406 lung biopsies were performed in oncology patients using a tract sealant over 19 months. Of these patients, 326 had follow-up CT scans and were included in the study group. Four thoracic radiologists retrospectively analyzed the imaging, and a pathologist examined 10 resected LBTs. Results: A total of 234 of 326 biopsies (72%, including primary lung cancer [n = 98]; metastases [n = 81]; benign [n = 50]; and nondiagnostic [n = 5] showed an LBT on CT. LBTs were identified on imaging 0 to 3 months after biopsy. LBTs were typically straight or serpiginous with a thickness of 2 to 5 mm. Most LBTs were unchanged (92% or decreased (6.3% over time. An increase in LBT thickness/nodularity that was suspicious for MTS occurred in 4 of 234 biopsies (1.7%. MTS only occurred after biopsy of metastases from extrathoracic malignancies, and none occurred in patients with lung cancer. Conclusions: LBTs are common on CT after lung biopsy using a tract sealant. MTS is uncommon and only occurred in patients with extrathoracic malignancies. No MTS was found in patients with primary lung cancer. Accordingly, potential alteration in planned therapy should be considered only in patients with LBTs and extrathoracic malignancies being considered for stereotactic body radiation therapy or wedge resection.

  19. Micro-Computed-Tomography-Guided Analysis of In Vitro Structural Modifications in Two Types of 45S5 Bioactive Glass Based Scaffolds

    Directory of Open Access Journals (Sweden)

    Fabian Westhauser

    2017-11-01

    Full Text Available Three-dimensional 45S5 bioactive glass (BG-based scaffolds are being investigated for bone regeneration. Besides structural properties, controlled time-dependent alteration of scaffold morphology is crucial to achieve optimal scaffold characteristics for successful bone repair. There is no in vitro evidence concerning the dependence between structural characteristics and dissolution behavior of 45S5 BG-based scaffolds of different morphology. In this study, the dissolution behavior of scaffolds fabricated by the foam replica method using polyurethane foam (Group A and maritime sponge Spongia Agaricina (Group B as sacrificial templates was analyzed by micro-computed-tomography (µCT. The scaffolds were immersed in Dulbecco’s Modified Eagle Medium for 56 days under static cell culture conditions and underwent µCT-analysis initially, and after 7, 14, and 56 days. Group A showed high porosity (91% and trabecular structure formed by macro-pores (average diameter 692 µm ± 72 µm. Group-B-scaffolds were less porous (51%, revealing an optimal pore size distribution within the window of 110–500 µm pore size diameter, combined with superior mechanical stability. Both groups showed similar structural alteration upon immersion. Surface area and scaffold volume increased whilst density decreased, reflecting initial dissolution followed by hydroxycarbonate-apatite-layer-formation on the scaffold surfaces. In vitro- and/or in vivo-testing of cell-seeded BG-scaffolds used in this study should be performed to evaluate the BG-scaffolds’ time-dependent osteogenic properties in relation to the measured in vitro structural changes.

  20. Use of positron emission tomography scan response to guide treatment change for locally advanced gastric cancer: the Memorial Sloan Kettering Cancer Center experience.

    Science.gov (United States)

    Won, Elizabeth; Shah, Manish A; Schöder, Heiko; Strong, Vivian E; Coit, Daniel G; Brennan, Murray F; Kelsen, David P; Janjigian, Yelena Y; Tang, Laura H; Capanu, Marinela; Rizk, Nabil P; Allen, Peter J; Bains, Manjit S; Ilson, David H

    2016-08-01

    Early metabolic response on 18-fluorodeoxyglucose-positron emission tomography (FDG-PET) during neoadjuvant chemotherapy is PET non-responders have poor outcomes whether continuing chemotherapy or proceeding directly to surgery. Use of PET may identify early treatment failure, sparing patients from inactive therapy and allowing for crossover to alternative therapies. We examined the effectiveness of PET directed switching to salvage chemotherapy in the PET non-responders. Patients with locally advanced resectable FDG-avid gastric or gastroesophageal junction (GEJ) adenocarcinoma received bevacizumab 15 mg/kg, epirubicin 50 mg/m(2), cisplatin 60 mg/m(2) day 1, and capecitabine 625 mg/m(2) bid (ECX) every 21 days. PET scan was obtained at baseline and after cycle 1. PET responders, (i.e., ≥35% reduction in FDG uptake at the primary tumor) continued ECX + bev. Non-responders switched to docetaxel 30 mg/m(2), irinotecan 50 mg/mg(2) day 1 and 8 plus bevacizumab every 21 days for 2 cycles. Patients then underwent surgery. The primary objective was to improve the 2-year disease free survival (DFS) from 30% (historical control) to 53% in the non-responders. Twenty evaluable patients enrolled before the study closed for poor accrual. Eleven were PET responders and the 9 non-responders switched to the salvage regimen. With a median follow-up of 38.2 months, the 2-year DFS was 55% [95% confidence interval (CI), 30-85%] in responders compared with 56% in the non-responder group (95% CI, 20-80%, P=0.93). The results suggest that changing chemotherapy regimens in PET non-responding patients may improve outcomes. Results from this pilot trial are hypothesis generating and suggest that PET directed neoadjuvant therapy merits evaluation in a larger trial.

  1. Assessment of three-dimensional setup errors in image-guided pelvic radiotherapy for uterine and cervical cancer using kilovoltage cone-beam computed tomography and its effect on planning target volume margins.

    Science.gov (United States)

    Patni, Nidhi; Burela, Nagarjuna; Pasricha, Rajesh; Goyal, Jaishree; Soni, Tej Prakash; Kumar, T Senthil; Natarajan, T

    2017-01-01

    To achieve the best possible therapeutic ratio using high-precision techniques (image-guided radiation therapy/volumetric modulated arc therapy [IGRT/VMAT]) of external beam radiation therapy in cases of carcinoma cervix using kilovoltage cone-beam computed tomography (kV-CBCT). One hundred and five patients of gynecological malignancies who were treated with IGRT (IGRT/VMAT) were included in the study. CBCT was done once a week for intensity-modulated radiation therapy and daily in IGRT/VMAT. These images were registered with the planning CT scan images and translational errors were applied and recorded. In all, 2078 CBCT images were studied. The margins of planning target volume were calculated from the variations in the setup. The setup variation was 5.8, 10.3, and 5.6 mm in anteroposterior, superoinferior, and mediolateral direction. This allowed adequate dose delivery to the clinical target volume and the sparing of organ at risks. Daily kV-CBCT is a satisfactory method of accurate patient positioning in treating gynecological cancers with high-precision techniques. This resulted in avoiding geographic miss.

  2. Target localization of 3D versus 4D cone beam computed tomography in lipiodol-guided stereotactic radiotherapy of hepatocellular carcinomas.

    Science.gov (United States)

    Chan, Mark; Chiang, Chi Leung; Lee, Venus; Cheung, Steven; Leung, Ronnie; Wong, Matthew; Lee, Frankle; Blanck, Oliver

    2017-01-01

    Aim of this study was to comparatively evaluate the accuracy of respiration-correlated (4D) and uncorrelated (3D) cone beam computed tomography (CBCT) in localizing lipiodolized hepatocellular carcinomas during stereotactic body radiotherapy (SBRT). 4D-CBCT scans of eighteen HCCs were acquired during free-breathing SBRT following trans-arterial chemo-embolization (TACE) with lipiodol. Approximately 1320 x-ray projections per 4D-CBCT were collected and phase-sorted into ten bins. A 4D registration workflow was followed to register the reconstructed time-weighted average CBCT with the planning mid-ventilation (MidV) CT by an initial bone registration of the vertebrae and then tissue registration of the lipiodol. For comparison, projections of each 4D-CBCT were combined to synthesize 3D-CBCT without phase-sorting. Using the lipiodolized tumor, uncertainties of the treatment setup estimated from the absolute and relative lipiodol position to bone were analyzed separately for 4D- and 3D-CBCT. Qualitatively, 3D-CBCT showed better lipiodol contrast than 4D-CBCT primarily because of a tenfold increase of projections used for reconstruction. Motion artifact was observed to subside in 4D-CBCT compared to 3D-CBCT. Group mean, systematic and random errors estimated from 4D- and 3D-CBCT agreed to within 1 mm in the cranio-caudal (CC) and 0.5 mm in the anterior-posterior (AP) and left-right (LR) directions. Systematic and random errors are largest in the CC direction, amounting to 4.7 mm and 3.7 mm from 3D-CBCT and 5.6 mm and 3.8 mm from 4D-CBCT, respectively. Safety margin calculated from 3D-CBCT and 4D-CBCT differed by 2.1, 0.1 and 0.0 mm in the CC, AP, and LR directions. 3D-CBCT is an adequate alternative to 4D-CBCT when lipoid is used for localizing HCC during free-breathing SBRT. Similar margins are anticipated with 3D- and 4D-CBCT.

  3. Fluorescence microscopy.

    Science.gov (United States)

    Sanderson, Michael J; Smith, Ian; Parker, Ian; Bootman, Martin D

    2014-10-01

    Fluorescence microscopy is a major tool with which to monitor cell physiology. Although the concepts of fluorescence and its optical separation using filters remain similar, microscope design varies with the aim of increasing image contrast and spatial resolution. The basics of wide-field microscopy are outlined to emphasize the selection, advantages, and correct use of laser scanning confocal microscopy, two-photon microscopy, scanning disk confocal microscopy, total internal reflection, and super-resolution microscopy. In addition, the principles of how these microscopes form images are reviewed to appreciate their capabilities, limitations, and constraints for operation. © 2014 Cold Spring Harbor Laboratory Press.

  4. Fluorescence detection of esophageal neoplasia

    Science.gov (United States)

    Borisova, E.; Vladimirov, B.; Avramov, L.

    2008-06-01

    White-light endoscopy is well-established and wide used modality. However, despite the many technological advances that have been occurred, conventional endoscopy is suboptimal and usually detects advanced stage lesions. The limitations of standard endoscopy initiate development of spectroscopic techniques, additional to standard endoscopic equipment. One of the most sensitive approaches is fluorescence spectroscopy of gastrointestinal mucosa for neoplasia detection. In the recent study delta-aminolevulinic acid/Protoporphyrin IX (5-ALA/PpIX) is used as fluorescent marker for dysplasia and tumor detection in esophagus. The 5-ALA is administered per os six hours before measurements at dose 20 mg/kg weight. Excitation source has max of emission at 405 nm and light is delivered by the standard light guide of the endoscopic equipment. Through endoscopic instrumental channel a fiber is applied to return information about fluorescence to microspectrometer. Spectral features observed during endoscopic investigations could be distinct as the next regions: 450-630 nm region, where tissue autofluorescence is observed; 630-710 nm region, where fluorescence of PpIX is clearly pronounced; 530-580 nm region, where minima in the autofluorescence signal are observed, related to reabsorption of blood. The lack of fluorescence peaks in the red spectral area for normal mucosa is an indication for selective accumulation of 5-ALA/PpIX only in abnormal sites Very good correlation between fluorescence signals and histology examination of the lesions investigated is achieved.

  5. Computed Tomography (CT) -- Sinuses

    Medline Plus

    Full Text Available ... Physician Resources Professions Site Index A-Z Computed Tomography (CT) - Sinuses Computed tomography (CT) of the sinuses ... CT of the Sinuses? What is CT (Computed Tomography) of the Sinuses? Computed tomography, more commonly known ...

  6. Illustrated computer tomography

    International Nuclear Information System (INIS)

    Takahashi, S.

    1983-01-01

    This book provides the following information: basic aspects of computed tomography; atlas of computed tomography of the normal adult; clinical application of computed tomography; and radiotherapy planning and computed tomography

  7. Optical tomography of tissues

    International Nuclear Information System (INIS)

    Zimnyakov, D A; Tuchin, Valerii V

    2002-01-01

    Methods of optical tomography of biological tissues are considered, which include pulse-modulation and frequency-modulation tomography, diffusion tomography with the use of cw radiation sources, optical coherent tomography, speckle-correlation tomography of nonstationary media, and optoacoustic tomography. The method for controlling the optical properties of tissues is studied from the point of view of increasing a probing depth in optical coherent tomography. The modern state and prospects of the development of optical tomography are discussed. (review)

  8. Computed tomography

    International Nuclear Information System (INIS)

    Wells, P.; Davis, J.; Morgan, M.

    1994-01-01

    X-ray or gamma-ray transmission computed tomography (CT) is a powerful non-destructive evaluation (NDE) technique that produces two-dimensional cross-sectional images of an object without the need to physically section it. CT is also known by the acronym CAT, for computerised axial tomography. This review article presents a brief historical perspective on CT, its current status and the underlying physics. The mathematical fundamentals of computed tomography are developed for the simplest transmission CT modality. A description of CT scanner instrumentation is provided with an emphasis on radiation sources and systems. Examples of CT images are shown indicating the range of materials that can be scanned and the spatial and contrast resolutions that may be achieved. Attention is also given to the occurrence, interpretation and minimisation of various image artefacts that may arise. A final brief section is devoted to the principles and potential of a range of more recently developed tomographic modalities including diffraction CT, positron emission CT and seismic tomography. 57 refs., 2 tabs., 14 figs

  9. Doppler Tomography

    Science.gov (United States)

    Marsh, T. R.

    I review the method of Doppler tomography which translates binary-star line profiles taken at a series of orbital phases into a distribution of emission over the binary. I begin with a discussion of the basic principles behind Doppler tomography, including a comparison of the relative merits of maximum entropy regularisation versus filtered back-projection for implementing the inversion. Following this I discuss the issue of noise in Doppler images and possible methods for coping with it. Then I move on to look at the results of Doppler Tomography applied to cataclysmic variable stars. Outstanding successes to date are the discovery of two-arm spiral shocks in cataclysmic variable accretion discs and the probing of the stream/magnetospheric interaction in magnetic cataclysmic variable stars. Doppler tomography has also told us much about the stream/disc interaction in non-magnetic systems and the irradiation of the secondary star in all systems. The latter indirectly reveals such effects as shadowing by the accretion disc or stream. I discuss all of these and finish with some musings on possible future directions for the method. At the end I include a tabulation of Doppler maps published in refereed journals.

  10. Multispectral open-air intraoperative fluorescence imaging.

    Science.gov (United States)

    Behrooz, Ali; Waterman, Peter; Vasquez, Kristine O; Meganck, Jeff; Peterson, Jeffrey D; Faqir, Ilias; Kempner, Joshua

    2017-08-01

    Intraoperative fluorescence imaging informs decisions regarding surgical margins by detecting and localizing signals from fluorescent reporters, labeling targets such as malignant tissues. This guidance reduces the likelihood of undetected malignant tissue remaining after resection, eliminating the need for additional treatment or surgery. The primary challenges in performing open-air intraoperative fluorescence imaging come from the weak intensity of the fluorescence signal in the presence of strong surgical and ambient illumination, and the auto-fluorescence of non-target components, such as tissue, especially in the visible spectral window (400-650 nm). In this work, a multispectral open-air fluorescence imaging system is presented for translational image-guided intraoperative applications, which overcomes these challenges. The system is capable of imaging weak fluorescence signals with nanomolar sensitivity in the presence of surgical illumination. This is done using synchronized fluorescence excitation and image acquisition with real-time background subtraction. Additionally, the system uses a liquid crystal tunable filter for acquisition of multispectral images that are used to spectrally unmix target fluorescence from non-target auto-fluorescence. Results are validated by preclinical studies on murine models and translational canine oncology models.

  11. Problems of fluorescent imaging and its solution using nanofluorophores. Part I: Advantages of fluorescent nanoparticles over conventional organic fluorophores

    International Nuclear Information System (INIS)

    Zhelev, Z.; Hadjidekov, G.; Zlateva, G.; Spasov, L.; Bakalova, R.

    2011-01-01

    The application of fluorescence in deep-tissue imaging is rapidly expanding in fast several years. The progress in fluorescent molecular probes and fluorescent imaging techniques gives an opportunity to detect single cells and even molecules in live organisms. The highly sensitive and high-speed fluorescent molecular sensors and detection devices allow the application of fluorescence in functional imaging. With development of novel bright fluorophores based on nano-technologies and fluorescence scanners with high spatial and temporal resolution, the fluorescent imaging has a potential to become an alternative of the other non-invasive imaging techniques as magnetic resonance imaging, positron-emission tomography, X-ray, computing tomography. This review outlines the current status and future trends of fluorescent nanoparticles - quantum dots (QDs), as a new generation of fluorophores in experimental and pre-clinical fluorescent imaging diagnostic. Part 1 focuses on the advantages of quantum dots over conventional organic fluorophores and defines the major requirements to the 'perfect' fluorophore for fluorescent deep-tissue imaging diagnostic. The analysis is based on the limitations of fluorescent imaging in vivo and overcome by using quantum dots

  12. Lower Extremity Revascularization Using Optical Coherence Tomography-Guided Directional Atherectomy: Final Results of the EValuatIon of the PantheriS OptIcal COherence Tomography ImagiNg Atherectomy System for Use in the Peripheral Vasculature (VISION) Study.

    Science.gov (United States)

    Schwindt, Arne G; Bennett, J Gray; Crowder, William H; Dohad, Suhail; Janzer, Sean F; George, Jon C; Tedder, Barry; Davis, Thomas P; Cawich, Ian M; Gammon, Roger S; Muck, Patrick E; Pigott, John P; Dishmon, Dwight A; Lopez, Lou A; Golzar, Jaafer A; Chamberlin, Jack R; Moulton, Michael J; Zakir, Ramzan M; Kaki, Amir K; Fishbein, Gary J; McDaniel, Huey B; Hezi-Yamit, Ayala; Simpson, John B; Desai, Arjun

    2017-06-01

    To evaluate the safety and efficacy of a novel optical coherence tomography (OCT)-guided atherectomy catheter in treating patients with symptomatic femoropopliteal disease. The VISION trial ( ClinicalTrials.gov identifier NCT01937351) was a single-arm, multicenter, global investigational device exemption study enrolling 158 subjects (mean age 67.2±10.5 years; 87 men) across 20 participating sites. In this cohort, 198 lesions were treated with an average length of 53±40 mm using the Pantheris catheter alone or Pantheris + adjunctive therapy. The primary safety endpoint was the composite of major adverse events (MAEs) through 6 months (objective performance goal 43.2%). Technical success (primary efficacy outcome) was defined as the percent of target lesions with a residual diameter stenosis ≤50% after treatment with the Pantheris device alone (objective performance goal 87.0%). Procedural success was defined as reduction in stenosis to ≤30% after Pantheris ± adjunctive therapy. Tissue specimens retrieved from each treated lesion were histologically analyzed to evaluate the accuracy and precision of OCT image guidance. The primary efficacy outcome was achieved in 192 (97.0%) of the 198 lesions treated with the Pantheris catheter. Across all lesions, mean diameter stenosis was reduced from 78.7%±15.1% at baseline to 30.3%±11.8% after Pantheris alone (patherectomy specimens confirmed atherectomy for femoropopliteal disease is safe and effective. Additionally, the precision afforded by OCT guidance leads to greater removal of plaque during atherectomy while sparing the adventitia.

  13. Nanoparticle-guided radiotherapy

    DEFF Research Database (Denmark)

    2012-01-01

    The present invention relates to a method and nano-sized particles for image guided radiotherapy (IGRT) of a target tissue. More specifically, the invention relates to nano-sized particles comprising X-ray-imaging contrast agents in solid form with the ability to block x-rays, allowing for simult...... for simultaneous or integrated external beam radiotherapy and imaging, e.g., using computed tomography (CT)....

  14. A Guide to Computed Tomography System Specifications

    Science.gov (United States)

    1990-08-01

    particularly where anomalies are not known or expected, where nonimaging measurements of deviations from a norm defy experience or expectation, or...point. 2.9 Archival Requirements Archival requirements usually involve hardcopy, tape, and/or optical disk. These dictate a small subsystem choice, but...some kind of scintillating X-ray crystal, e.g., cadmium tungstate or bismuth germanate that is optically coupled to a photoconversion device like a

  15. Computerized tomography

    International Nuclear Information System (INIS)

    Caille, J.M.; Salamon, G.

    1980-01-01

    As X-ray Ct becomes more commonplace, other techniques of investigation using roughly comparable hardware and software have appeared. Positron-Emission Tomography already provides indispensable physiological and physio-pathological information. Similarly, in the histo-chemical field, Nuclear Magnetic Resonance seems very promising. Some of these new techniques will no doubt shortly be considered as essential as CT in establishing accurate diagnoses non-invasively. (orig./VJ) [de

  16. Computed tomography

    International Nuclear Information System (INIS)

    Andre, M.; Resnick, D.

    1988-01-01

    Computed tomography (CT) has matured into a reliable and prominent tool for study of the muscoloskeletal system. When it was introduced in 1973, it was unique in many ways and posed a challenge to interpretation. It is in these unique features, however, that its advantages lie in comparison with conventional techniques. These advantages will be described in a spectrum of important applications in orthopedics and rheumatology

  17. Multiphoton tomography of astronauts

    Science.gov (United States)

    König, Karsten; Weinigel, Martin; Pietruszka, Anna; Bückle, Rainer; Gerlach, Nicole; Heinrich, Ulrike

    2015-03-01

    Weightlessness may impair the astronaut's health conditions. Skin impairments belong to the most frequent health problems during space missions. Within the Skin B project, skin physiological changes during long duration space flights are currently investigated on three European astronauts that work for nearly half a year at the ISS. Measurements on the hydration, the transepidermal water loss, the surface structure, elasticity and the tissue density by ultrasound are conducted. Furthermore, high-resolution in vivo histology is performed by multiphoton tomography with 300 nm spatial and 200 ps temporal resolution. The mobile certified medical tomograph with a flexible 360° scan head attached to a mechano-optical arm is employed to measure two-photon autofluorescence and SHG in the volar forearm of the astronauts. Modification of the tissue architecture and of the fluorescent biomolecules NAD(P)H, keratin, melanin and elastin are detected as well as of SHG-active collagen. Thinning of the vital epidermis, a decrease of the autofluoresence intensity, an increase in the long fluorescence lifetime, and a reduced skin ageing index SAAID based on an increased collagen level in the upper dermis have been found. Current studies focus on recovery effects.

  18. Fluorescence quantum yield measurements of fluorescent proteins: a laboratory experiment for a biochemistry or molecular biophysics laboratory course.

    Science.gov (United States)

    Wall, Kathryn P; Dillon, Rebecca; Knowles, Michelle K

    2015-01-01

    Fluorescent proteins are commonly used in cell biology to assess where proteins are within a cell as a function of time and provide insight into intracellular protein function. However, the usefulness of a fluorescent protein depends directly on the quantum yield. The quantum yield relates the efficiency at which a fluorescent molecule converts absorbed photons into emitted photons and it is necessary to know for assessing what fluorescent protein is the most appropriate for a particular application. In this work, we have designed an upper-level, biochemistry laboratory experiment where students measure the fluorescence quantum yields of fluorescent proteins relative to a standard organic dye. Four fluorescent protein variants, enhanced cyan fluorescent protein (ECFP), enhanced green fluorescent protein (EGFP), mCitrine, and mCherry, were used, however the methods described are useful for the characterization of any fluorescent protein or could be expanded to fluorescent quantum yield measurements of organic dye molecules. The laboratory is designed as a guided inquiry project and takes two, 4 hr laboratory periods. During the first day students design the experiment by selecting the excitation wavelength, choosing the standard, and determining the concentration needed for the quantum yield experiment that takes place in the second laboratory period. Overall, this laboratory provides students with a guided inquiry learning experience and introduces concepts of fluorescence biophysics into a biochemistry laboratory curriculum. © 2014 The International Union of Biochemistry and Molecular Biology.

  19. PET-NECK: a multicentre randomised Phase III non-inferiority trial comparing a positron emission tomography-computerised tomography-guided watch-and-wait policy with planned neck dissection in the management of locally advanced (N2/N3) nodal metastases in patients with squamous cell head and neck cancer.

    Science.gov (United States)

    Mehanna, Hisham; McConkey, Chris C; Rahman, Joy K; Wong, Wai-Lup; Smith, Alison F; Nutting, Chris; Hartley, Andrew Gj; Hall, Peter; Hulme, Claire; Patel, Dharmesh K; Zeidler, Sandra Ventorin von; Robinson, Max; Sanghera, Bal; Fresco, Lydia; Dunn, Janet A

    2017-04-01

    Planned neck dissection (ND) after radical chemoradiotherapy (CRT) for locally advanced nodal metastases in patients with head and neck squamous cell carcinoma (HNSCC) remains controversial. Thirty per cent of ND specimens show histological evidence of tumour. Consequently, a significant proportion of clinicians still practise planned ND. Fludeoxyglucose positron emission tomography (PET)-computerised tomography (CT) scanning demonstrated high negative predictive values for persistent nodal disease, providing a possible alternative paradigm to ND. Evidence is sparse and drawn mainly from retrospective single-institution studies, illustrating the need for a prospective randomised controlled trial. To determine the efficacy and cost-effectiveness of PET-CT-guided surveillance, compared with planned ND, in a multicentre, prospective, randomised setting. A pragmatic randomised non-inferiority trial comparing PET-CT-guided watch-and-wait policy with the current planned ND policy in HNSCC patients with locally advanced nodal metastases and treated with radical CRT. Patients were randomised in a 1 : 1 ratio. Primary outcomes were overall survival (OS) and cost-effectiveness [incremental cost per incremental quality-adjusted life-year (QALY)]. Cost-effectiveness was assessed over the trial period using individual patient data, and over a lifetime horizon using a decision-analytic model. Secondary outcomes were recurrence in the neck, complication rates and quality of life. The recruitment of 560 patients was planned to detect non-inferior OS in the intervention arm with a 90% power and a type I error of 5%, with non-inferiority defined as having a hazard ratio (HR) of no higher than 1.50. An intention-to-treat analysis was performed by Cox's proportional hazards model. Thirty-seven head and neck cancer-treating centres (43 NHS hospitals) throughout the UK. Patients with locally advanced nodal metastases of oropharynx, hypopharynx, larynx, oral or occult HNSCC receiving

  20. Arrangement for guiding transport cables

    International Nuclear Information System (INIS)

    1981-01-01

    This patent relates especially to x-ray equipment such as that used for computerized tomography, and in particular to an arrangement for guiding and supporting a plurality of power transmission cables and cooling hoses in a flexible manner. (U.K.)

  1. A Practical Guide for the Preparation of Specimens for X-ray Fluorescence and X-ray Diffraction Analysis (by V. E. Buhrke, R. Jenkins, and D. K. Smith)

    Science.gov (United States)

    Rudman, Reuben

    1999-06-01

    Wiley-VCH: New York, 1998. xxiv + 333 pp. ISBN 0-471-19458-1. $79.95. I would have subtitled this book "All You Ever Wanted To Know about ...Sample Preparation". Although its principal thrust is geared towards the analytical chemist in an X-ray diffraction (XRD) or X-ray fluorescence (XRF) service laboratory, this text will be of use primarily as a reference source in all milieus dealing with undergraduate research projects and advanced laboratory courses in physical and analytical chemistry. It contains dozens of suggestions for preparing randomly oriented small samples of nearly anything. For example, rocks and minerals, soft organics and hard ceramics, radioactive and liquid materials, metals and oils are all treated. As the availability of XRD and XRF equipment has increased, so has the use of these techniques in the teaching schedule. Many undergraduate laboratory and research projects utilizing these methods have been described in the literature and are found in laboratory textbooks. Very often, especially with the increasingly common use of automated computer-controlled instrumentation, sample preparation has become the key experimental technique required for successful data collection. However, it is not always easy to prepare the statistically random distribution of small particles (crystallites) that is required by these methods. A multitude of techniques have been developed over the past 70 years, but many of them have been handed down by word of mouth or are scattered throughout the literature. This book represents an attempt to systematically describe the theory and practice of sample preparation. This excellent guide to the intricacies of sample preparation begins with a description of statistical sampling methods and the principles of grinding techniques. After a discussion of XRF specimen preparation, which includes pressing pellets, fusion methods, crucible selection and handling very small samples, detailed descriptions for handling rocks

  2. Intensifying screens in transaxial tomography

    International Nuclear Information System (INIS)

    Debelder, M.H.; Bollen, R.H.

    1981-01-01

    This patent claim by Agfa-Gevaert relates to a method for the production of transaxial tomographs, a combination of materials therefor and X-ray intensifying screens incorporating at least one reflecting element for use in transaxial tomography, wherein the exposure of a photographic silver halide emulsion material proceeds at an angle within the range of 2 0 to 10 0 in conjunction with an X-ray fluorescent intensifying screen including an ultra-violet and/or visible radiation reflective coating or sheet to increase the radiation output of the screen and to reduce the exposure time and radiation dose e.g. in medical X-ray applications. (author)

  3. Instrumentation and Fluorescent Chemistries Used in qPCR

    DEFF Research Database (Denmark)

    Josefsen, Mathilde Hartmann; Löfström, Charlotta; Hansen, Trine

    2012-01-01

    will be discussed from a user perspective leading to an instrument selection guide. Differences between fluorescent DNA binding dyes and target-specific fluorescently labeled primers or probes for detection of amplicon accumulation will be discussed, along with the properties and applications of the most frequently...

  4. Solar tomography adaptive optics.

    Science.gov (United States)

    Ren, Deqing; Zhu, Yongtian; Zhang, Xi; Dou, Jiangpei; Zhao, Gang

    2014-03-10