Read by QxMD icon Read

gamma camera

Tamer M Sakr, M H Sanad, Walaa H Abd-Alla, Dina H Salama, Gehan M Saleh
Challenges facing cardiovascular imaging necessitate innovation of better radiopharmaceuticals to augment or replace the existing ones. This research assesses the ability and competency of radioiodinated esmolol as a potential cardio selective imaging agent. Radioiodinated esmolol was synthesized with 97.3 ± 0.3% radiochemical yield and with high stability up to 48 h at room temperature as well as in rat serum. Molecular modeling study was performed to confirm the binding of iodinated esmolol to β1 -adrenergic receptor...
March 9, 2018: Applied Radiation and Isotopes
Marko Barjaktarović, Milica M Janković, Marija Jeremić, Milovan Matović
Radioiodine therapy in the treatment of differentiated thyroid carcinoma (DTC) is used in clinical practice for the ablation of thyroid residues and/or destruction of tumour tissue. Whole-body scintigraphy for visualization of the spatial 131I distribution performed by a gamma camera (GC) is a standard procedure in DTC patients after application of radioiodine therapy. A common problem is the precise topographic localization of regions where radioiodine is accumulated even in SPECT imaging. SPECT/CT can provide precise topographic localization of regions where radioiodine is accumulated, but it is often unavailable, especially in developing countries because of the high price of the equipment...
March 9, 2018: Computers in Biology and Medicine
Hsuan-Ming Huang, Chih-Chieh Liu, Meei-Ling Jan, Ming-Wei Lee
The Compton camera is an imaging device which has been proposed to detect prompt gammas (PGs) produced by proton-nuclear interactions within tissue during proton beam irradiation. Compton-based PG imaging has been developed to verify proton range because PG rays, particularly characteristic ones, have strong correlations with the distribution of the proton dose. However, accurate image reconstruction from characteristic PGs is challenging because the detector efficiency and resolution are generally low. Our previous study showed that point spread functions can be incorporated into the reconstruction process to improve image resolution...
March 16, 2018: Physics in Medicine and Biology
Larry A Pierce, Stefano Pedemonte, Don DeWitt, Lawrence R MacDonald, William C J Hunter, Koen Van Leemput, Robert Miyaoka
PET detectors use signal multiplexing to reduce the total number of electronics channels needed to cover a given area. Using measured thin-beam calibration data, we tested a principal component based multiplexing scheme for scintillation detectors. The highly-multiplexed detector signal is no longer amenable to standard calibration methodologies. In this study we report results of a prototype multiplexing circuit, and present a new method for calibrating the detector module with multiplexed data. 
 \underline{Methods}: A $50 \times 50 \times 10$ mm$^3$ LYSO scintillation crystal was affixed to a position-sensitive photomultiplier tube with $8 \times 8$ position-outputs and one channel that is the sum of the other 64...
March 2, 2018: Physics in Medicine and Biology
Pavlo Kochkin, A P J van Deursen, M Marisaldi, A Ursi, A I de Boer, M Bardet, C Allasia, J-F Boissin, F Flourens, N Østgaard
An Airbus A340 aircraft flew over Northern Australia with the In-Flight Lightning Damage Assessment System (ILDAS) installed onboard. A long-duration gamma ray emission was detected. The most intense emission was observed at 12 km altitude and lasted for 20 s. Its intensity was 20 times the background counts, and it was abruptly terminated by a distant lightning flash. In this work we reconstruct the aircraft path and event timeline. The glow-terminating flash triggered a discharge from the aircraft wing that was recorded by a video camera operating onboard...
December 16, 2017: Journal of Geophysical Research. Atmospheres: JGR
Najeeb Ahmed, Kashif Niyaz, Aditya Borakati, Fahad Marafi, Rubinder Birk, Sharjeel Usmani
Differentiated thyroid cancer (DTC) has a good prognosis overall; however, lifelong follow-up is required for many cases. Radioiodine planar imaging with iodine-123 (I-123) or radioiodine-131 (I-131) remains the standard in the follow-up after initial surgery and ablation of residual thyroid tissue using I-131 therapy. Radioiodine imaging is also used in risk-stratifying and for staging of thyroid cancer, and in long-term follow-up. Unfortunately, the lack of anatomical detail on planar gamma camera imaging and superimposition of areas presenting with increased radioiodine uptake can make accurate diagnosis and localization of radioiodine-avid metastatic disease challenging, leading to false positive results and potentially to over-treatment of patients...
February 26, 2018: Asian Pacific Journal of Cancer Prevention: APJCP
M A Momin, M N A Abdullah, M S Reza
Renal scintigraphy is an imaging method that uses small amount of radioactive materials called radiotracers, a Gamma camera and a computer to evaluate kidney functions and its anatomy. The present work reports the comparison of the relative renal functions (RRF) calculated with technetium-99m dimercaptosuccinic acid (99m Tc‑DMSA) and technetium-99m diethylenetriaminepentaacetic acid (99m Tc‑DTPA) for kidney patients of ages between 5 months and 71 years. A total of 50 patients including 29 male and 21 female has been selected and studied for renography...
January 2018: Physica Medica: PM
Daria Stypinski, Stephen A McQuarrie, Alexander J B McEwan, Leonard I Wiebe
The objective of this work is to evaluate the potential effect of cardiac stress exercise on the accumulation of [123 I]IAZA, a radiopharmaceutical used to image focal tissue hypoxia, in otherwise normal myocardium in healthy volunteers, and to determine the impact of exercise on [123 I]IAZA pharmacokinetics. The underlying goal is to establish a rational basis and a baseline for studies of focal myocardial hypoxia in cardiac patients using [123 I]IAZA. Three healthy male volunteers ran the 'Bruce' treadmill protocol, a clinically-accepted protocol designed to expose myocardial ischemia in patients...
February 22, 2018: Pharmaceutics
Fiona Helen Barrack, James Scuffham, Sarah McQuaid
Whole body gamma camera images acquired after I-131 treatment for thyroid cancer can suffer from collimator septal penetration artefacts because of the high energy of the gamma photons. This results in the appearance of 'spoke' artefacts, emanating from regions of high activity concentration, caused by the non-isotropic attenuation of the collimator. Deconvolution has the potential to reduce such artefacts, by taking into account the non-Gaussian point-spread-function (PSF) of the system. A Richardson-Lucy deconvolution algorithm, with and without prior scatter-correction was tested as a method of reducing septal penetration in planar gamma camera images...
February 21, 2018: Physics in Medicine and Biology
Seiichi Yamamoto, Kei Kamada, Akira Yoshikawa
High resolution imaging of radiation is required for such radioisotope distribution measurements as alpha particle detection in nuclear facilities or high energy physics experiments. For this purpose, we developed an ultrahigh resolution radiation imaging system using an optical fiber structure scintillator plate. We used a ~1-μm diameter fiber structured GdAlO 3 :Ce (GAP) /α-Al 2 O 3 scintillator plate to reduce the light spread. The fiber structured scintillator plate was optically coupled to a tapered optical fiber plate to magnify the image and combined with a lens-based high sensitivity CCD camera...
February 16, 2018: Scientific Reports
Wilco J C Koppert, Sandra van der Velden, J H Leo Steenbergen, Hugo W A M de Jong
In SPECT/CT systems X-ray and -ray imaging is performed sequentially. Simultaneous acquisition may have advantages, for instance in interventional settings. However, this may expose a gamma camera to relatively high X-ray doses and deteriorate its functioning. We studied the NaI(Tl) response to X-ray pulses with a photodiode, PMT and gamma camera, respectively. Method: First, we exposed a NaI(Tl)-photodiode assembly to X-ray pulses to investigate potential crystal afterglow. Next, we exposed a NaI(Tl)-PMT assembly to 10 ms LED pulses (mimicking X-ray pulses) and measured the response to flashing LED probepulses (mimicking -pulses)...
February 13, 2018: Physics in Medicine and Biology
Congzheng Wang, Song Hu, Chunming Gao, Chang Feng
In this work, we irradiated a high-definition (HD) industrial camera based on a commercial-off-the-shelf (COTS) CMOS image sensor (CIS) with Cobalt-60 gamma-rays. All components of the camera under test were fabricated without radiation hardening, except for the lens. The irradiation experiments of the HD camera under biased conditions were carried out at 1.0, 10.0, 20.0, 50.0 and 100.0 Gy/h. During the experiment, we found that the tested camera showed a remarkable degradation after irradiation and differed in the dose rates...
February 8, 2018: Sensors
Philipp Matthies, Milad Mesri, Francisco Alves Pinto, Jan Wuestemann, Oliver Grosser
INTRODUCTION: Clinical Bremsstrahlung imaging with gamma cameras or SPECT scanners, for example used in selective internal radiation therapy (SIRT) [1], suffers from low contrast due to a continuous spectrum and a high amount of scatter. Information about the scattering of the radionuclide within the patient's body can be obtained from Monte-Carlo simulations and subsequently being used to improve image quality. METHODS: An MAA-acquisition (CT+SPECT) of a HCC patient with a unifocal uptake in the right liver lobe is segmented (lesion) and loaded into the MC simulation framework GATE [2]...
January 2018: Physica Medica: PM
Frank P DiFilippo
PURPOSE: Evaluating gamma camera image quality is a routine task required for annual physics surveys and laboratory accreditation. A common method is visual assessment of a planar view of the American College of Radiology (ACR) phantom, for which a satisfactory result is to resolve 7.9 mm diameter cold rods with high contrast. The objective is to investigate an automated quantitative measure of planar image quality for more precise evaluation of gamma camera performance. METHODS: Planar images were automatically co-registered to a template of the phantom's cold rod pattern...
January 31, 2018: Medical Physics
E Draeger, D Mackin, S Peterson, H Chen, S Avery, S Beddar, J C Polf
We tested the ability of a single Compton camera (CC) to produce 3-dimensional (3D) images of prompt gammas (PGs) emitted during the irradiation of a tissue-equivalent plastic phantom with proton pencil beams for clinical doses delivered at clinical dose rates. PG measurements were made with a small prototype CC placed at three different locations along the proton beam path. We evaluated the ability of the CC to produce images at each location for two clinical scenarios: (1) the delivery of a single 2 Gy pencil beam from a hypo-fractionated treatment (~9  ×  108 protons), and (2) a single pencil beam from a standard treatment (~1  ×  108 protons)...
January 30, 2018: Physics in Medicine and Biology
Hossein Sadeghi, Najmeh Rahmanian, Fereshteh Talebpour Amiri, Hossein Amirfakhrian, Seyed Mohammad Abedi, Seyed Jalal Hosseinimehr
Objectives: The monitoring of cancer treatment response to chemotherapy is considered an essential strategy for follow-up of patients. The aim of this study was to evaluate the use of 99mTc-glucarate as a radiotracer for in vivo quantification and visualization of necrotic area and therapeutic effect of paclitaxel in ovarian cancer xenografted nude mice. Materials and Methods: After implantation of human ovarian cancer (SKOV-3) in nude mice, tumor xenografted mice were enrolled in two groups as control and treatment (paclitaxel) groups...
January 2018: Iranian Journal of Basic Medical Sciences
Helmut J M H Dittmann, Daniel Kopp, Juergen Kupferschlaeger, Diana Feil, Gerd Groezinger, Roland Syha, Matthias Weissinger, Christian La Fougère
Hepatopulmonary shunt fraction (LSF)-estimation using Tc-99m-Macroalbumine (MAA) imaging is performed prior to selective internal radiotherapy (SIRT) of the liver in order to reduce risk of pulmonary irradiation burden. Generally, planar scans are acquired after injection of MAA into the hepatic artery. However, validity of this approach is limited by different attenuation of liver and lung tissue as well as inaccurate segmentation of the organs. Aim of this study was to evaluate quantitative SPECT/CT for LSF-assessment in a prospective clinical cohort...
January 25, 2018: Journal of Nuclear Medicine: Official Publication, Society of Nuclear Medicine
Takuya Yabe, Masataka Komori, Toshiyuki Toshito, Mitsutaka Yamaguchi, Naoki Kawachi, Seiichi Yamamoto
Although the luminescence images of water during proton-beam irradiation using a cooled charge-coupled device (CCD) camera showed almost the same ranges of proton beams as those measured by an ionization chamber, the depth profiles showed lower Bragg peak intensities than those measured by an ionization chamber. In addition, a broad optical baseline signal was observed in depths that exceed the depth of Bragg peak. We hypothesize that this broad baseline signal originates from interaction of proton-induced prompt gamma photons with water...
January 19, 2018: Physics in Medicine and Biology
Rene Nkoulou, Mathias Wolfrum, Aju P Pazhenkottil, Michael Fiechter, Ronny R Buechel, Oliver Gaemperli, Philipp A Kaufmann
BACKGROUND: Left ventricular (LV) ejection fraction (EF) during high dobutamine stress (HD) by real-time gated-SPECT myocardial perfusion imaging (MPI) on a cadmium-zinc-telluride (CZT) gamma camera was validated versus cardiac magnetic resonance imaging (CMR). METHODS AND RESULTS: After injecting 99mTc-tetrofosmin (320 MBq) in 50 patients (mean age 64 +/- 11 years), EF at rest and post-stress as well as relevant changes in EF at HD (ΔEF ≥ 5%) were assessed. CZT and CMR rest EF values yielded an excellent correlation and agreement (r = 0...
January 16, 2018: Journal of Nuclear Cardiology: Official Publication of the American Society of Nuclear Cardiology
Milovan Matovic, Milica Jankovic, Marko Barjaktarovic, Marija Jeremic
OBJECTIVE: After radioiodine therapy of differentiated thyroid cancer (DTC) patients, whole body scintigraphy (WBS) is standard procedure before releasing the patient from the hospital. A common problem is the precise localization of regions where the iod-avide tissue is located. Sometimes is practically impossible to perform precise topographic localization of such regions. METHOD: In order to face this problem, we have developed a low-cost Vision-Fusion system for web-camera image acquisition simultaneously with routine scintigraphic whole body acquisition including the algorithm for fusion of images given from both cameras...
September 2017: Hellenic Journal of Nuclear Medicine
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"