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Spectral CT

Mustafa Dogan, Bunyamin Kutluksaman, Ibrahim Keles, Mustafa Karalar, Ahmet Omer Halat
PURPOSE: To compare the effects of alfuzosin hydrochloride and tamsulosin hydrochloride on choroidal thickness (CT) and pupil diameter (PD) sizes in patients with benign prostatic hyperplasia. SUBJECTS AND METHODS: Sixty-three men patients with newly diagnosis of benign prostatic hyperplasia were randomly assigned to either alfuzosin hydrochloride or to tamsulosin hydrochloride groups in this prospective, randomized, parallel-group clinical trial. Enhanced depth imaging spectral-domain optical coherence tomography, pupillography were obtained at baseline, 1st and 3rd month, and choroidal thicknesses and pupil diameter sizes were compared between the two groups...
September 22, 2017: Current Eye Research
Solmaz Abdolrahimzadeh, Francesco Parisi, Andrea Maria Plateroti, Federica Evangelista, Vito Fenicia, Gianluca Scuderi, Santi Maria Recupero
PURPOSE: To investigate best corrected visual acuity (BCVA), and choroidal and retinal thickness values between high myopes without myopic maculopathy and emmetropes. MATERIALS AND METHODS: Case control study where 53 myopes with axial length (AL) above 26 mm without myopic maculopathy and 53 age-matched emmetropes with AL between 21.50 and 24.50 were included as controls. Complete ophthalmological examination and biometry were performed. Choroidal and individual retinal layer thickness maps using spectral domain optical coherence tomography were obtained in the macular and peripapillary area with enhanced depth imaging...
September 21, 2017: Current Eye Research
Nils Große Hokamp, V Neuhaus, N Abdullayev, K Laukamp, S Lennartz, A Mpotsaris, J Borggrefe
OBJECTIVE: Aim of this study was to assess the artifact reduction in patients with orthopedic hardware in the spine as provided by (1) metal-artifact-reduction algorithms (O-MAR) and (2) virtual monoenergetic images (MonoE) as provided by spectral detector CT (SDCT) compared to conventional iterative reconstruction (CI). METHODS: In all, 28 consecutive patients with orthopedic hardware in the spine who underwent SDCT-examinations were included. CI, O-MAR and MonoE (40-200 keV) images were reconstructed...
September 21, 2017: Skeletal Radiology
Rolf Symons, Daniel S Reich, Mohammadhadi Bagheri, Tyler E Cork, Bernhard Krauss, Stefan Ulzheimer, Steffen Kappler, David A Bluemke, Amir Pourmorteza
PURPOSE: The purpose of this study was to evaluate image quality of a spectral photon-counting detector (PCD) computed tomography (CT) system for evaluation of major arteries of the head and neck compared with conventional single-energy CT scans using energy-integrating detectors (EIDs). METHODS: In this institutional review board-approved study, 16 asymptomatic subjects (7 men) provided informed consent and received both PCD and EID contrast-enhanced CT scans of the head and neck (mean age, 58 years; range, 46-75 years)...
September 18, 2017: Investigative Radiology
Peter Trueb, Pietro Zambon, Christian Broennimann
PURPOSE: Hybrid Photon Counting (HPC) detectors profoundly improved x-ray diffraction experiments at third generation synchrotron facilities. Enabling the simultaneous measurement of x-ray intensities in multiple energy bins, they also have many potential applications in the field of medical imaging. A prerequisite for this is a clean spectral response. To quantify how efficiently HPC detectors are able to assign photons to the correct energy bin, a quantity called Spectral Efficiency (SE) is introduced...
September 2017: Medical Physics
Nicolas Ducros, Juan Felipe Perez-Juste Abascal, Bruno Sixou, Simon Rit, Françoise Peyrin
PURPOSE: Exploiting the x-ray measurements obtained in different energy bins, spectral computed tomography (CT) has the ability to recover the 3-D description of a patient in a material basis. This may be achieved solving two subproblems, namely the material decomposition and the tomographic reconstruction problems. In this work, we address the material decomposition of spectral x-ray projection images, which is a nonlinear ill-posed problem. METHODS: Our main contribution is to introduce a material-dependent spatial regularization in the projection domain...
September 2017: Medical Physics
Mats Persson, Fredrik Grönberg
PURPOSE: In spectral CT, basis material decomposition is commonly used to generate a set of basis images showing the material composition at each point in the field of view. The noise in these images typically contains anticorrelations between the different basis images, which leads to increased noise in each basis image. These anticorrelations can be removed by changing the basis functions used in the material decomposition, but the resulting basis images can then no longer be used for quantitative measurements...
September 2017: Medical Physics
Dong Yue, Cheng Fan Rong, Cai Ning, Hu Liang, Liu Ai Lian, Wang Ru Xin, Luo Ya Hong
Background The evaluation of hip arthroplasty is a challenge in computed tomography (CT). The virtual monochromatic spectral (VMS) images with metal artifact reduction software (MARs) in spectral CT can reduce the artifacts and improve the image quality. Purpose To evaluate the effects of VMS images and MARs for metal artifact reduction in patients with unilateral hip arthroplasty. Material and Methods Thirty-five patients underwent dual-energy CT. Four sets of VMS images without MARs and four sets of VMS images with MARs were obtained...
January 1, 2017: Acta Radiologica
Manikanta Murahari, Karanam Vanitha Prakash, Godefridus J Peters, Y C Mayur
Hybrid systems of acridones with substituted pyrimidines were designed with an objective of discovering next generation anticancer agents targeting multiple mechanisms in the cancer cell. Hybrid compounds were synthesized by simple and convenient methods in the lab, characterized by NMR and Mass spectral methods and screened for cytotoxicity against A549 (lung), Hela (cervical), MCF7 (breast) and MDA-MB-231 (breast) cancer cell lines respectively. Evaluation of compounds for cell proliferation identified active compounds 11b, 11d and 11h against MCF7, MDA-MB-231 and A549 cell lines...
August 12, 2017: European Journal of Medicinal Chemistry
Pan Liang, Xiu-Chun Ren, Jian-Bo Gao, Kui-Sheng Chen, Xiao Xu
OBJECTIVE: The purpose of this study was to use virtual monochromatic spectral CT to investigate the usefulness of iodine concentration (IC) and its correlation with clinicopathologically determined prognostic factors in gastric adenocarcinoma. SUBJECTS AND METHODS: From June 2012 to March 2015, 34 patients with gastric adenocarcinoma underwent arterial and portal venous phase spectral CT. The ICs in the arterial and portal venous phases were calculated and then normalized with the aorta as normalized IC (NIC)...
September 5, 2017: AJR. American Journal of Roentgenology
Okkyun Lee, Steffen Kappler, Christoph Polster, Katsuyuki Taguchi
Photon counting detectors (PCD) provide multiple energy-dependent measurements for estimating basis lineintegrals. However, the measured spectrum is distorted from the spectral response effect (SRE) via charge sharing, K-fluorescence emission, etc. Thus, in order to avoid bias and artifacts in images, the SRE needs to be compensated. For this purpose, we recently developed a computationally efficient three-step algorithm for PCD-CT without contrast agents by approximating smooth x-ray transmittance using low-order polynomial bases...
August 29, 2017: IEEE Transactions on Medical Imaging
Xiaomei Wu, Qian Wang, Jinlei Ma, Wei Zhang, Po Li, Zheng Fang
X-ray computed tomography (CT) can distinguish different materials according to their absorption characteristics. The hyperspectral X-ray CT (HXCT) system proposed in the present work reconstructs each voxel according to its X-ray absorption spectral characteristics. In contrast to a dual-energy or multi-energy CT system, HXCT employs cadmium telluride (CdTe) as the x-ray detector, which provides higher spectral resolution and separate spectral lines according to the material's photon-counter working principle...
August 2017: Review of Scientific Instruments
Bilgehan Sezgin Asena, Eyyup Karahan, Mahmut Kaskaloglu
PURPOSE: The purpose of this study was to compare the short-term changes in retina and choroidal tissue after femtosecond laser-assisted cataract surgery (FLACS) and standard phacoemulsification (PE) surgery. METHODS: In all, 25 eyes undergoing FLACS and 27 eyes undergoing PE surgery were included in this nonrandomized, retrospective, cross-sectional study. Central retinal thickness (CRT) and choroidal thickness (CT) were measured pre- and postoperatively (at day 1, 1 week later, and after 1 month) with spectral domain optical coherence tomography (OCT) in all patients and were compared...
2017: Clinical Ophthalmology
Mario Buty, Ziyue Xu, Aaron Wu, Mingchen Gao, Chelyse Nelson, Georgios Z Papadakis, Uygar Teomete, Haydar Celik, Baris Turkbey, Peter Choyke, Daniel J Mollura, Ulas Bagci, Les R Folio
We present a new image quality assessment method for determining whether reducing radiation dose impairs the image quality of computed tomography (CT) in qualitative and quantitative clinical analyses tasks. In this Institutional Review Board-exempt study, we conducted a review of 50 patients (male, 22; female, 28) who underwent reduced-dose CT scanning on the first follow-up after standard-dose multiphase CT scanning. Scans were for surveillance of von Hippel-Lindau disease (N = 26) and renal cell carcinoma (N = 10)...
June 2017: Tomography: a Journal for Imaging Research
Jonas Doerner, Christian Wybranski, Jonathan Byrtus, Christian Houbois, Myriam Hauger, Carola Heneweer, Florian Siedek, Tilman Hickethier, Nils Große Hokamp, David Maintz, Stefan Haneder
OBJECTIVES: To quantitatively and qualitatively assess abdominal arterial and venous phase contrast-enhanced spectral detector computed tomography (SDCT) virtual mono-energetic (MonoE) datasets in comparison to conventional CT reconstructions provided by the same system. MATERIALS AND METHODS: Conventional and MonoE images at 40-120 kilo-electron volt (keV) levels with a 10 keV increment as well as 160 and 200 keV were reconstructed in abdominal SDCT datasets of 55 patients...
2017: PloS One
Tracy E Kirkbride, Aamir Y Raja, Kristin Müller, Christopher J Bateman, Fabio Becce, Nigel G Anderson
OBJECTIVE: We aimed to determine whether multienergy spectral photon-counting CT could distinguish between clinically relevant calcium crystals at clinical x-ray energy ranges. Energy thresholds of 15, 22, 29, and 36 keV and tube voltages of 50, 80, and 110 kVp were selected. Images were analyzed to assess differences in linear attenuation coefficients between various concentrations of calcium hydroxyapatite (54.3, 211.7, 808.5, and 1169.3 mg/cm(3)) and calcium oxalate (2000 mg/cm(3))...
August 23, 2017: AJR. American Journal of Roentgenology
Akinori Shimizu, Keisuke Nagasaki, Yoshihisa Inoue, Tadashi Mori
Circular dichroisms (CDs) of neutral and protonated [3.3]anthracenopyridinophane (1 and 1-H(+) ) were investigated experimentally and theoretically. Introducing an anthracene moiety with extended conjugation affected the cyclophane structure with the bent angles being appreciably  reduced from those of parent [3.3]pyridinophane. The Cotton effects (CEs) observed at the (1) Bb band for both 1 and 1-H(+) were fairly strong and apparently bisignate, which, however, turned out not to be a simple exciton couplet but to be composed of multiple transitions...
August 18, 2017: Chirality
Dean G Assimos
No abstract text is available yet for this article.
September 2017: Journal of Urology
Bhavik N Patel, Alex Bibbey, Kingshuk R Choudhury, Richard A Leder, Rendon C Nelson, Daniele Marin
OBJECTIVE: The purpose of this study is to determine whether single-phase contrast-enhanced dual-energy quantitative spectral analysis improves the accuracy of diagnosis of small (< 4.0 cm) renal lesions, compared with conventional single-energy attenuation measurements. MATERIALS AND METHODS: In this retrospective study, 136 consecutive patients (95 men and 41 women; mean age, 54 years) with 144 renal lesions (111 benign and 33 malignant) underwent single-energy unenhanced and dual-energy contrast-enhanced CT of the abdomen...
August 16, 2017: AJR. American Journal of Roentgenology
Jianli Liu, Junlin Zhou, Jie Li, Lingyan Zhang, Peili Zhang, Bin Liu
To investigate the use of multi-parameter spectral computed tomography (CT) for the evaluation of rat C6 glioma, 15 male Wistar rats were seeded with C6 glioma cells into the right basal ganglia and scanned 12 days later using spectral CT. Brain sections corresponding to scanned regions were immunostained for proliferation marker protein Ki67 (Ki67). Pearson's correlation coefficients between spectral CT parameters and Ki67 expression were determined. Thirteen rats survived 12 days and developed tumors. Optimal contrast-to-noise ratio achieved was 65 keV...
August 2017: Experimental and Therapeutic Medicine
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