scholarly journals Investigation of imaging properties of novel contrast agents based on gold, silver and bismuth nanoparticles in spectral computed tomography using Monte Carlo simulation

2020 ◽  
Vol 26 (1) ◽  
pp. 21-29
Author(s):  
Maryam Sadeghian ◽  
Parisa Akhlaghi ◽  
Asghar Mesbahi
Keyword(s):  
Computed Tomography ◽  
Gold Nanoparticles ◽  
Monte Carlo ◽  
Contrast Agents ◽  
Ct Number ◽  
Bismuth Nanoparticles ◽  
Iodinated Contrast ◽  
Spectral Computed Tomography ◽  
Iodinated Contrast Agent ◽  
Imaging Properties

AbstractIn the present paper, some imaging properties of nanoparticles-based contrast agents including gold, bismuth, and silver were assessed and compared with conventional (iodinated) contrast agent in spectral computed tomography (CT). A spectral CT scanner with photon-counting detectors (PCD) and 6 energy bins was simulated using the Monte Carlo (MC) simulation method. The nanoparticles were designed with a diameter of 50 nm at concentrations of 2, 4, and 8 mg/ml. Water-filled cylindrical phantom was modeled with a diameter of 10 cm containing a hole with a diameter of 5 cm in its center, where was filled with contrast agents. The MC results were used to reconstruct images. Image reconstruction was accomplished with the filtered back-projection (FBP) method with hamming filter and linear interpolation method. CT number and contrast-to-noise ratio (CNR) of all studied contrast materials were calculated in spectral images. The simulations indicated that nanoparticle-based contrast agents have a higher CT number and CNR than the iodinated contrast agent at the same concentration and for all energy bins. In general, gold nanoparticles produced the highest CT number and CNR compared to silver and bismuth nanoparticles at the same concentration. However, at low energies (below 80 keV), silver nanoparticles performed similarly to gold nanoparticles and at high energies (120 keV), bismuth nanoparticles can be a good substitute for gold nanoparticles.

Nonionic Low-Osmolar Monomeric Iodinated Contrast Material: Some Aspects of use for Computed Tomography in Children

2017 ◽  
pp. 118-129
Author(s):  
I. A. Kondrashov ◽  
V. Mandal
Keyword(s):  
Computed Tomography ◽  
Contrast Agents ◽  
Adverse Reactions ◽  
Contrast Material ◽  
Iodine Content ◽  
Diagnostic Procedures ◽  
Diagnostic Efficacy ◽  
Minimum Risk ◽  
Electrical Neutrality ◽  
Iodinated Contrast

Iodine containing contrast media are used much frequently now-a-days for computed tomography examinations in children. The group of non-ionic monomers occupies a special place among modern contrast agents. Low osmolarity and viscosity, electrical neutrality and the highest iodine content of these contrast materials provide the best diagnostic efficacy with minimum risk of adverse reactions. However, characteristic anatomic and physiological aspects of a growing child’s body require additional attention and care during diagnostic procedures with use of such contrast agents. This article presents concise literature review of recent years highlighting practical aspects of nonionic lowosmolar iodinated contrast material use for computed tomography assisted diagnostic examinations in child population.

scholarly journals Tunable, biodegradable gold nanoparticles as contrast agents for computed tomography and photoacoustic imaging

Biomaterials ◽  
2016 ◽  
Vol 102 ◽  
pp. 87-97 ◽  
Author(s):  
Rabee Cheheltani ◽  
Rami M. Ezzibdeh ◽  
Peter Chhour ◽  
Kumidini Pulaparthi ◽  
Johoon Kim ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Gold Nanoparticles ◽  
Contrast Agents ◽  
Photoacoustic Imaging

X-ray computed tomography contrast agents prepared by seeded growth of gold nanoparticles in PEGylated dendrimer

2010 ◽  
Vol 21 (24) ◽  
pp. 245104 ◽  
Author(s):  
Chie Kojima ◽  
Yasuhito Umeda ◽  
Mikako Ogawa ◽  
Atsushi Harada ◽  
Yasuhiro Magata ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Gold Nanoparticles ◽  
Contrast Agents ◽  
Seeded Growth ◽  
X Ray ◽  
X Ray Computed

scholarly journals Design of a Monte Carlo model based on dual-source computed tomography (DSCT) scanners for dose and image quality assessment using the Monte Carlo N-Particle (MCNP5) code

2020 ◽  
Vol 26 (1) ◽  
pp. 11-20
Author(s):  
Stefania Chantzi ◽  
Emmanouil Papanastasiou ◽  
Christina Athanasopoulou ◽  
Elisavet Molyvda-Athanasopoulou ◽  
Panagiotis Bamidis ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Monte Carlo ◽  
Monte Carlo Model ◽  
Dose Assessment ◽  
Projection Algorithm ◽  
Projection Data ◽  
Ct Number ◽  
Low Contrast ◽  
Dual Source ◽  
Dual Source Computed Tomography

AbstractThe purpose of this work was to develop and validate a Monte Carlo model for a Dual Source Computed Tomography (DSCT) scanner based on the Monte Carlo N-particle radiation transport computer code (MCNP5). The geometry of the Siemens Somatom Definition CT scanner was modeled, taking into consideration the x-ray spectrum, bowtie filter, collimator, and detector system. The accuracy of the simulation from the dosimetry point of view was tested by calculating the Computed Tomography Dose Index (CTDI) values. Furthermore, typical quality assurance phantoms were modeled in order to assess the imaging aspects of the simulation. Simulated projection data were processed, using the MATLAB software, in order to reconstruct slices, using a Filtered Back Projection algorithm. CTDI, image noise, CT-number linearity, spatial and low contrast resolution were calculated using the simulated test phantoms. The results were compared using several published values including IMPACT, NIST and actual measurements. Bowtie filter shapes are in agreement with those theoretically expected. Results show that low contrast and spatial resolution are comparable with expected ones, taking into consideration the relatively limited number of events used for the simulation. The differences between simulated and nominal CT-number values were small. The present attempt to simulate a DSCT scanner could provide a powerful tool for dose assessment and support the training of clinical scientists in the imaging performance characteristics of Computed Tomography scanners.

Gold Nanoparticle-Optimized Computed Tomography Imaging Combined with Transcranial Magnetic Stimulation on Rehabilitation Training of Children with Cerebral Palsy

2021 ◽  
Vol 13 (9) ◽  
pp. 1674-1684
Author(s):  
Yangfan Zhang ◽  
Yuanyuan Luo ◽  
Xinglei Wu ◽  
Liuqiong Yang ◽  
Dandan Cui ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Gold Nanoparticles ◽  
Transcranial Magnetic Stimulation ◽  
Contrast Agents ◽  
Magnetic Stimulation ◽  
Ct Imaging ◽  
Nude Mouse Model ◽  
Children With Cerebral Palsy ◽  
Movement Function ◽  
Ct Contrast

Traditional computed tomography (CT) contrast agents, such as iodine-containing small molecules (omnipaque), have limitations in some applications. The development of nanotechnology has made it possible to develop CT contrast agents based on this technology. In this study, a large number of surface functional groups of the fifth-generation polyamide-amine dendrimer (P5-NH2) were applied to functionally modify polyethylene glycol (PEG), targeting molecules, or drugs, which were used as the carrier of CT contrast agents. With the help of sodium borohydride (NaBH4), there was a rapid reduction. The fluorescein thiocyanate (FT) and PEG modified with lactobionic acid (PEG-LA) weres connected before gold coating to obtain gold nanoparticles coated with targeted dendrimer (Au(P5-LA)DENPs). In the experiment, the gold nanoparticles were characterized, and the liver cancer nude mouse model was established, so as to analyze the CT imaging performance of the material. Besides, the above was applied in the motor function of children with cerebral palsy, and the improvement effect of CT imaging combined with transcranial magnetic stimulation based on the preparation of nanomaterials on the movement function of children was analyzed and demonstrated with the help of graph theory. The results showed that the average particle size of gold nanoparticles was 1.88 nm. Within the range of 5 °C–50 °C and pH = 4–7, the physical properties of the aqueous solution of this material were stable. What’s more, the cell activity still exceeded 80% when the material concentration reached 2000 nm. The nude mouse model of liver cancer indicated that the CT imaging based on this material enhanced the image contrast effect of the tumor part, and the material had no obvious toxic and side effects. CT imaging based on the preparation of nanomaterials can promote transcranial magnetic stimulation to accelerate the efficiency of brain movement, accelerate the global and local information exchange and integration speed of brain network, thereby improving the movement function of children.

CMR 2007: 8.03: Gold nanoparticles as contrast agents for MRI and X-ray computed tomography imaging

2007 ◽  
Vol 2 (6) ◽  
pp. 292-293
Author(s):  
S. Roux ◽  
C. Alric ◽  
J. Taleb ◽  
C. Mandon ◽  
C. Billotey ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Gold Nanoparticles ◽  
Contrast Agents ◽  
Computed Tomography Imaging ◽  
X Ray ◽  
Tomography Imaging ◽  
X Ray Computed

scholarly journals The comparison of bolus tracking and test bolus techniques for computed tomography thoracic angiography in healthy beagles

2013 ◽  
Vol 84 (1) ◽  
Author(s):  
Nicolette Cassel ◽  
Ann Carstens ◽  
Pieter Becker
Keyword(s):  
Computed Tomography ◽  
Contrast Agent ◽  
Test Dose ◽  
Dose Length Product ◽  
Bolus Tracking ◽  
Iodinated Contrast ◽  
Iodinated Contrast Agent ◽  
Test Bolus ◽  
The Mean ◽  
Computed Tomography Dose Index

Computed tomography thoracic angiography studies were performed on five adult beagles using the bolus tracking (BT) technique and the test bolus (TB) technique, which were performed at least two weeks apart. For the BT technique, 2 mL/kg of 300 mgI/mL iodinated contrast agent was injected intravenously. Scans were initiated when the contrast in the aorta reached 150 Hounsfield units (HU). For the TB technique, the dogs received a test dose of 15% of 2 mL/kg of 300 mgI/mL iodinated contrast agent, followed by a series of low dose sequential scans. The full dose of the contrast agent was then administered and the scans were conducted at optimal times as identified from time attenuation curves. Mean attenuation in HU was measured in the aorta (Ao) and right caudal pulmonary artery (rCPA). Additional observations included the study duration, milliAmpere (mA), computed tomography dose index volume (CTDI[vol]) and dose length product (DLP). The attenuation in the Ao (BT = 660 52 HU ± 138 49 HU, TB = 469 82 HU ± 199 52 HU, p = 0.13) and in the rCPA (BT = 606 34 HU ± 143 37 HU, TB = 413 72 HU ± 174.99 HU, p = 0.28) did not differ significantly between the two techniques. The BT technique was conducted in a significantly shorter time period than the TB technique (p = 0.03). The mean mA for the BT technique was significantly lower than the TB technique (p = 0.03), as was the mean CTDI(vol) (p = 0.001). The mean DLP did not differ significantly between the two techniques (p = 0.17). No preference was given to either technique when evaluating the Ao or rCPA but the BT technique was shown to be shorter in duration and resulted in less DLP than the TB technique.

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