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https://www.readbyqxmd.com/read/28540184/detection-of-intramyocardially-injected-dir-labeled-mesenchymal-stem-cells-by-optical-and-optoacoustic-tomography
#1
Markus T Berninger, Pouyan Mohajerani, Moritz Wildgruber, Nicolas Beziere, Melanie A Kimm, Xiaopeng Ma, Bernhard Haller, Megan J Fleming, Stephan Vogt, Martina Anton, Andreas B Imhoff, Vasilis Ntziachristos, Reinhard Meier, Tobias D Henning
The distribution of intramyocardially injected rabbit MSCs, labeled with the near-infrared dye 1,1'-dioctadecyl-3,3,3',3'-tetramethylindotricarbo-cyanine-iodide (DiR) using hybrid Fluorescence Molecular Tomography-X-ray Computed Tomography (FMT-XCT) and Multispectral Optoacoustic Tomography (MSOT) imaging technologies, was investigated. Viability and induction of apoptosis of DiR labeled MSCs were assessed by XTT- and Caspase-3/-7-testing in vitro. 2 × 10(6), 2 × 10(5) and 2 × 10(4) MSCs labeled with 5 and 10 μg DiR/ml were injected into fresh frozen rabbit hearts...
June 2017: Photoacoustics
https://www.readbyqxmd.com/read/28535910/dose-warping-performance-in-deformable-image-registration-in-lung
#2
Shunsuke Moriya, Hidenobu Tachibana, Nozomi Kitamura, Amit Sawant, Masanori Sato
PURPOSE: It is unclear that spatial accuracy can reflect the impact of deformed dose distribution. In this study, we used dosimetric parameters to compare an in-house deformable image registration (DIR) system using NiftyReg, with two commercially available systems, MIM Maestro (MIM) and Velocity AI (Velocity). METHODS: For 19 non-small-cell lung cancer patients, the peak inspiration (0%)-4DCT images were deformed to the peak expiration (50%)-4DCT images using each of the three DIR systems, which included computation of the deformation vector fields (DVF)...
May 2017: Physica Medica: PM
https://www.readbyqxmd.com/read/28529253/relationship-between-blurring-and-refocus-flip-angle-in-3d-double-inversion-recovery-mri
#3
Tomoyuki Wada, Norio Hayashi, Shunichi Motegi, Hiroyuki Nagase, Kouichi Ujita, Akio Ogura, Toshihiro Ogura, Takehiro Shimada, Yoshito Tsushima
It is important to optimize imaging parameters in 3D-double inversion recovery (DIR) magnetic resonance imaging (MRI) for detecting cortical micro lesions. However, inadequate parameters markedly raise blurring in 3DDIR MRI. The purpose of this study was to evaluate the relationship between the blurring and refocus flip angle (RFA) in 3D-DIR MRI. White matter attenuated inversion recovery (WAIR) images as a test sample were obtained by 1.5T MRI with various RFA settings (30°, 40°, 60°, 100°, 140°, 180°, and variable refocus flip angle (VRFA))...
2017: Nihon Hoshasen Gijutsu Gakkai Zasshi
https://www.readbyqxmd.com/read/28506023/optimization-method-of-mri-scan-parameters-of-a-double-inversion-recovery-sequence-using-a-t1-map-and-a-developed-analysis-algorithm
#4
Norio Hayashi, Kazuma Yarita, Kozue Sakata, Shunichi Motegi, Hiroyuki Nagase, Kouichi Ujita, Akio Ogura, Toshihiro Ogura, Takehiro Shimada, Yoshito Tsushima
BACKGROUND: Optimizing scan parameters for double inversion recovery (DIR) sequences remains difficult. OBJECTIVE: To evaluate a new method for optimizing DIR sequence scan parameters using T1 mapping and a newly developed analysis algorithm. METHODS: Twelve healthy volunteers underwent T1 mapping and DIR magnetic resonance imaging. The following steps were used for image optimization including: 1) measurement of gray matter (GM), white matter (WM), and cerebrospinal fluid (CSF) T1 values to create a T1 map; 2) calculation of optimized scan parameters by using a developed analysis algorithm; 3) performance assessment of DIR magnetic resonance imaging by using the calculated optimized imaging parameters...
May 6, 2017: Journal of X-ray Science and Technology
https://www.readbyqxmd.com/read/28494089/evaluation-of-the-tumor-registration-error-in-biopsy-procedures-performed-under-real-time-pet-ct-guidance
#5
Louise M Fanchon, Adytia Apte, C Ross Schmidtlein, Ellen Yorke, Yu-Chi Hu, Snjezana Dogan, Mathieu Hatt, Dimitris Visvikis, John L Humm, Stephen B Solomon, Assen S Kirov
PURPOSE: The purpose of this study is to quantify tumor displacement during real-time PET/CT guided biopsy and to investigate correlations between tumor displacement and false-negative results. METHODS: 19 patients who underwent real-time (18) F-FDG PET-guided biopsy and were found positive for malignancy were included in this study under IRB approval. PET/CT images were acquired for all patients within minute prior biopsy to visualize the FDG-avid region and plan the needle insertion...
May 11, 2017: Medical Physics
https://www.readbyqxmd.com/read/28490254/validating-dose-uncertainty-estimates-produced-by-autodirect-an-automated-program-to-evaluate-deformable-image-registration-accuracy
#6
Hojin Kim, Josephine Chen, Justin Phillips, Jason Pukala, Sue S Yom, Neil Kirby
Deformable image registration is a powerful tool for mapping information, such as radiation therapy dose calculations, from one computed tomography image to another. However, deformable image registration is susceptible to mapping errors. Recently, an automated deformable image registration evaluation of confidence tool was proposed to predict voxel-specific deformable image registration dose mapping errors on a patient-by-patient basis. The purpose of this work is to conduct an extensive analysis of automated deformable image registration evaluation of confidence tool to show its effectiveness in estimating dose mapping errors...
January 1, 2017: Technology in Cancer Research & Treatment
https://www.readbyqxmd.com/read/28477378/evaluating-the-accuracy-of-4d-ct-ventilation-imaging-first-comparison-with-technegas-spect-ventilation
#7
Fiona Hegi-Johnson, Paul Keall, Jeff Barber, Chuong Bui, John Kipritidis
INTRODUCTION: Computed tomography ventilation imaging (CTVI) is a highly accessible functional lung imaging modality that can unlock the potential for functional avoidance in lung cancer radiation therapy. Previous attempts to validate CTVI against clinical ventilation single-photon emission computed tomography (V-SPECT) have been hindered by radioaerosol clumping artifacts. This work builds on those studies by performing the first comparison of CTVI with (99m) Tc-carbon ('Technegas'), a clinical V-SPECT modality featuring smaller radioaerosol particles with less clumping...
May 5, 2017: Medical Physics
https://www.readbyqxmd.com/read/28477340/a-neural-network-approach-for-fast-automated-quantification-of-dir-performance
#8
John Neylon, Yugang Min, Daniel A Low, Anand Santhanam
PURPOSE: A critical step in adaptive radiotherapy (ART) workflow is deformably registering the simulation CT with the daily or weekly volumetric imaging. Quantifying the deformable image registration accuracy under these circumstances is a complex task due to the lack of known ground-truth landmark correspondences between the source data and target data. Generating landmarks manually (using experts) is time-consuming, and limited by image quality and observer variability. While image similarity metrics (ISM) may be used as an alternative approach to quantify the registration error, there is a need to characterize the ISM values by developing a non-linear cost function and translate them to physical distance measures in order to enable fast, quantitative comparison of registration performance...
May 5, 2017: Medical Physics
https://www.readbyqxmd.com/read/28475493/adaptive-radiotherapy-for-nsclc-patients-utilizing-the-principle-of-energy-conservation-to-evaluate-dose-mapping-operations
#9
Hualiang Zhong, Indrin J Chetty
Tumor regression during the course of fractionated radiotherapy confounds the ability to accurately estimate the total dose delivered to tumor targets. Here we present a new criterion to improve the accuracy of image intensity-based dose mapping operations for adaptive radiotherapy for patients with non-small cell lung cancer (NSCLC). Six NSCLC patients were retrospectively investigated in this study. An image intensity-based B-spline registration algorithm was used for deformable image registration (DIR) of weekly CBCT images to a reference image...
May 5, 2017: Physics in Medicine and Biology
https://www.readbyqxmd.com/read/28472925/registration-error-of-the-liver-ct-using-deformable-image-registration-of-mim-maestro-and-velocity-ai
#10
Nobuyoshi Fukumitsu, Kazunori Nitta, Toshiyuki Terunuma, Toshiyuki Okumura, Haruko Numajiri, Yoshiko Oshiro, Kayoko Ohnishi, Masashi Mizumoto, Teruhito Aihara, Hitoshi Ishikawa, Koji Tsuboi, Hideyuki Sakurai
BACKGROUND: Understanding the irradiated area and dose correctly is important for the reirradiation of organs that deform after irradiation, such as the liver. We investigated the spatial registration error using the deformable image registration (DIR) software products MIM Maestro (MIM) and Velocity AI (Velocity). METHODS: Image registration of pretreatment computed tomography (CT) and posttreatment CT was performed in 24 patients with liver tumors. All the patients received proton beam therapy, and the follow-up period was 4-14 (median: 10) months...
May 4, 2017: BMC Medical Imaging
https://www.readbyqxmd.com/read/28472349/dirigent-proteins-in-plants-modulating-cell-wall-metabolism-during-abiotic-and-biotic-stress-exposure
#11
Candelas Paniagua, Anna Bilkova, Phil Jackson, Siarhei Dabravolski, Willi Riber, Vojtech Didi, Josef Houser, Nora Gigli-Bisceglia, Michaela Wimmerova, Eva Budinska, Thorsten Hamann, Jan Hejatko
Dirigent (DIR) proteins were found to mediate regio- and stereoselectivity of bimolecular phenoxy radical coupling during lignan biosynthesis. Here we summarize the current knowledge of the importance of DIR proteins in lignan and lignin biosynthesis and highlight their possible importance in plant development. We focus on the still rather enigmatic Arabidopsis DIR gene family, discussing the few members with known functional importance. We comment on recent discoveries describing the detailed structure of two DIR proteins with implications in the mechanism of DIR-mediated catalysis...
May 3, 2017: Journal of Experimental Botany
https://www.readbyqxmd.com/read/28426189/issues-confronting-rural-pharmacies-after-a-decade-of-medicare-part-d
#12
Fred Ullrich, Abiodun Salako, Keith Mueller
Purpose. The RUPRI Center for Rural Health Policy Analysis has been monitoring the status of rural independent pharmacies since the implementation of Medicare Part D in 2005. After a decade of Part D, we reassess in this brief the issues that concern rural pharmacies and may ultimately challenge their provision of services. This reassessment is based on survey responses from rural pharmacists. Key Findings: (1) Rural pharmacists indicated that two challenges--direct and indirect remuneration (DIR) fees, and delayed maximum allowable cost (MAC) adjustment--ranked highest on scales of both magnitude and immediacy...
April 2017: Rural Policy Brief
https://www.readbyqxmd.com/read/28421669/misfortune-may-be-a-blessing-in-disguise-fairness-perception-and-emotion-modulate-decision-making
#13
Hong-Hsiang Liu, Yin-Dir Hwang, Ming H Hsieh, Yung-Fong Hsu, Wen-Sung Lai
Fairness perception and equality during social interactions frequently elicit affective arousal and affect decision making. By integrating the dictator game and a probabilistic gambling task, this study aimed to investigate the effects of a negative experience induced by perceived unfairness on decision making using behavioral, model fitting, and electrophysiological approaches. Participants were randomly assigned to the neutral, harsh, or kind groups, which consisted of various asset allocation scenarios to induce different levels of perceived unfairness...
April 19, 2017: Psychophysiology
https://www.readbyqxmd.com/read/28419602/physics-for-clinicians-fluid-attenuated-inversion-recovery-flair-and-double-inversion-recovery-dir-imaging
#14
REVIEW
Manojkumar Saranathan, Pauline W Worters, Dan W Rettmann, Blair Winegar, Jennifer Becker
A pedagogical review of fluid-attenuated inversion recovery (FLAIR) and double inversion recovery (DIR) imaging is conducted in this article. The basics of the two pulse sequences are first described, including the details of the inversion preparation and imaging sequences with accompanying mathematical formulae for choosing the inversion time in a variety of scenarios for use on clinical MRI scanners. Magnetization preparation (or T2prep), a strategy for improving image signal-to-noise ratio and contrast and reducing T1 weighting at high field strengths, is also described...
April 17, 2017: Journal of Magnetic Resonance Imaging: JMRI
https://www.readbyqxmd.com/read/28414799/comprehensive-evaluation-of-ten-deformable-image-registration-algorithms-for-contour-propagation-between-ct-and-cone-beam-ct-images-in-adaptive-head-neck-radiotherapy
#15
Xin Li, Yuyu Zhang, Yinghua Shi, Shuyu Wu, Yang Xiao, Xuejun Gu, Xin Zhen, Linghong Zhou
Deformable image registration (DIR) is a critical technic in adaptive radiotherapy (ART) for propagating contours between planning computerized tomography (CT) images and treatment CT/cone-beam CT (CBCT) images to account for organ deformation for treatment re-planning. To validate the ability and accuracy of DIR algorithms in organ at risk (OAR) contour mapping, ten intensity-based DIR strategies, which were classified into four categories-optical flow-based, demons-based, level-set-based and spline-based-were tested on planning CT and fractional CBCT images acquired from twenty-one head & neck (H&N) cancer patients who underwent 6~7-week intensity-modulated radiation therapy (IMRT)...
2017: PloS One
https://www.readbyqxmd.com/read/28398630/mitigating-differential-baseline-shifts-in-locally-advanced-lung-cancer-patients-using-an-average-anatomy-model
#16
Mehrsima Abdoli, Simon R van Kranen, Uros Stankovic, Maddalena M G Rossi, Jose S A Belderbos, Jan-Jakob Sonke
BACKGROUND AND PURPOSE: Differential baseline shifts between primary tumor and involved lymph nodes in locally advanced lung cancer patients compromise the accuracy of radiotherapy. The purpose of this study was to evaluate the performance of an average anatomy model (AAM) derived from repeat imaging and deformable registration to reduce these geometrical uncertainties. METHODS AND MATERIALS: An in-house implementation of a B-Spline deformable image registration (DIR) algorithm was first validated using three different validation approaches: 1) a circle method to test the consistency of the DIR, 2) fiducial marker target registration error, and 3) the recovery of a known deformation vector field (DVF)...
April 11, 2017: Medical Physics
https://www.readbyqxmd.com/read/28395561/acoustic-and-perceptual-effects-of-magnifying-interaural-difference-cues-in-a-simulated-binaural-hearing-aid
#17
Tobias de Taillez, Giso Grimm, Birger Kollmeier, Tobias Neher
OBJECTIVE: To investigate the influence of an algorithm designed to enhance or magnify interaural difference cues on speech signals in noisy, spatially complex conditions using both technical and perceptual measurements. To also investigate the combination of interaural magnification (IM), monaural microphone directionality (DIR), and binaural coherence-based noise reduction (BC). DESIGN: Speech-in-noise stimuli were generated using virtual acoustics. A computational model of binaural hearing was used to analyse the spatial effects of IM...
April 10, 2017: International Journal of Audiology
https://www.readbyqxmd.com/read/28393298/double-inversion-recovery-imaging-of-the-brain-deriving-the-most-relevant-sequence-through-real-images
#18
Shunichi Motegi, Takehiro Shimada, Norio Hayashi, Hiroyuki Nagase, Ayako Taketomi-Takahashi, Yoshito Tsushima
We propose a practical method for setting the optimal inversion times (TI) for double inversion recovery (DIR) sequences. Our method used the measurement of signal intensity (SI) from real images to set the optimal TI for white-matter (WM) and gray-matter (GM)-attenuated inversion recovery (WAIR and GAIR, respectively) images. 3D-DIR images of healthy volunteers were obtained on 1.5- and 3.0-T magnetic resonance (MR) scanners and the SIs of GM, WM, and cerebrospinal fluid (CSF) were evaluated on real images...
April 9, 2017: Radiological Physics and Technology
https://www.readbyqxmd.com/read/28391845/selection-and-characterization-of-dimethylindole-red-dna-aptamers-for-the-development-of-light-up-fluorescent-probes
#19
Hongyan Wang, Jine Wang, Qinglin Wang, Xing Chen, Min Liu, Hongxia Chen, Renjun Pei
To develop novel label-free light-up probes with improved performance characteristics and low background, we selected DNA aptamers for dimethylindole red (DIR) by a modified affinity chromatography based SELEX method. DIR is an anionic propylsulfonate substituted red-emitting dye derivative of thiazole orange and exhibited weak fluorescence in fluid solution and in the presence of dsDNA. After 14 rounds of selection, a shortened 42-mer DNA aptamer with sub-micromolar dissociation constant (Kd=0.65±0.17μM) was selected...
June 1, 2017: Talanta
https://www.readbyqxmd.com/read/28391192/estimation-of-large-motion-in-lung-ct-by-integrating-regularized-keypoint-correspondences-into-dense-deformable-registration
#20
Jan Ruhaak, Thomas Polzin, Stefan Heldmann, Ivor Simpson, Heinz Handels, Jan Modersitzki, Mattias Paul Heinrich
We present a novel algorithm for the registration of pulmonary CT scans. Our method is designed for large respiratory motion by integrating sparse keypoint correspondences into a dense continuous optimization framework. The detection of keypoint correspondences enables robustness against large deformations by jointly optimizing over a large number of potential discrete displacements, whereas the dense continuous registration achieves sub-voxel alignment with smooth transformations. Both steps are driven by the same normalized gradient fields data term...
April 5, 2017: IEEE Transactions on Medical Imaging
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