scholarly journals Effect of Gold Nanoparticle Size on Their Properties as Contrast Agents for Computed Tomography

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Yuxi C. Dong ◽  
Maryam Hajfathalian ◽  
Portia S. N. Maidment ◽  
Jessica C. Hsu ◽  
Pratap C. Naha ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Contrast Agents ◽  
Inductively Coupled Plasma ◽  
Ex Vivo ◽  
Photon Counting ◽  
Optical Emission ◽  
X Ray ◽  
Significant Difference ◽  
Ct Contrast

Abstract Computed tomography (CT) is one of the most commonly used clinical imaging modalities. There have recently been many reports of novel contrast agents for CT imaging. In particular, the development of gold nanoparticles (AuNP) as CT contrast agents is a topic of intense interest. AuNP have favorable characteristics for this application such as high payloads of contrast generating material, strong X-ray attenuation, excellent biocompatibility, tailorable surface chemistry, and tunable sizes and shapes. However, there have been conflicting reports on the role of AuNP size on their contrast generation for CT. We therefore sought to extensively investigate the AuNP size-CT contrast relationship. In order to do this, we synthesized AuNP with sizes ranging from 4 to 152 nm and capped them with 5 kDa m-PEG. The contrast generation of AuNP of different sizes was investigated with three clinical CT, a spectral photon counting CT (SPCCT) and two micro CT systems. X-ray attenuation was quantified as attenuation rate in Hounsfield units per unit concentration (HU/mM). No statistically significant difference in CT contrast generation was found among different AuNP sizes via phantom imaging with any of the systems tested. Furthermore, in vivo imaging was performed in mice to provide insight into the effect of AuNP size on animal biodistribution at CT dose levels, which has not previously been explored. Both in vivo imaging and ex vivo analysis with inductively coupled plasma optical emission spectroscopy (ICP-OES) indicated that AuNP that are 15 nm or smaller have long blood circulation times, while larger AuNP accumulated in the liver and spleen more rapidly. Therefore, while we observed no AuNP size effect on CT contrast generation, there is a significant effect of size on AuNP diagnostic utility.

scholarly journals Facile Fabrication of BiF3: Ln (Ln = Gd, Yb, Er)@PVP Nanoparticles for High-Efficiency Computed Tomography Imaging

2021 ◽  
Vol 16 (1) ◽  
Author(s):  
Jun Xie ◽  
Zonglang Zhou ◽  
Sihan Ma ◽  
Xian Luo ◽  
Jiajing Liu ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Oral Administration ◽  
Contrast Agent ◽  
Contrast Agents ◽  
Ct Imaging ◽  
Average Particle ◽  
Gi Tract ◽  
X Ray ◽  
Ct Value ◽  
Ct Contrast

AbstractX-ray computed tomography (CT) has been widely used in clinical practice, and contrast agents such as Iohexol are often used to enhance the contrast of CT imaging between normal and diseased tissue. However, such contrast agents can have some toxicity. Thus, new CT contrast agents are urgently needed. Owing to the high atomic number (Z = 83), low cost, good biological safety, and great X-ray attenuation property (5.74 cm2 kg−1 at 100 keV), bismuth has gained great interest from researchers in the field of nano-sized CT contrast agents. Here, we synthesized BiF3: Ln@PVP nanoparticles (NPs) with an average particle size of about 380 nm. After coating them with polyvinylpyrrolidone (PVP), the BiF3: Ln@PVP NPs possessed good stability and great biocompatibility. Meanwhile, compared with the clinical contrast agent Iohexol, BiF3: Ln@PVP NPs showed superior in vitro CT imaging contrast. Subsequently, after in situ injection with BiF3: Ln@PVP NPs, the CT value of the tumor site after the injection was significantly higher than that before the injection (the CT value of the pre-injection and post-injection was 48.9 HU and 194.58 HU, respectively). The morphology of the gastrointestinal (GI) tract can be clearly observed over time after oral administration of BiF3: Ln@PVP NPs. Finally, the BiF3: Ln@PVP NPs were completely discharged from the GI tract of mice within 48 h of oral administration with no obvious damage to the GI tract. In summary, our easily synthesized BiF3: Ln@PVP NPs can be used as a potential clinical contrast agent and may have broad application prospects in CT imaging.

Mineralization of Sialoliths Investigated by Ex Vivo and In Vivo X-ray Computed Tomography

2019 ◽  
Vol 25 (1) ◽  
pp. 151-163 ◽  
Author(s):  
Pedro Nolasco ◽  
Paulo V. Coelho ◽  
Carla Coelho ◽  
David F. Angelo ◽  
J. R. Dias ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Computed Tomography ◽  
Organic Matter ◽  
Ex Vivo ◽  
Correct Selection ◽  
Quantitative Relation ◽  
Helical Computed Tomography ◽  
X Ray ◽  
X Ray Computed

AbstractThe fraction of organic matter present affects the fragmentation behavior of sialoliths; thus, pretherapeutic information on the degree of mineralization is relevant for a correct selection of lithotripsy procedures. This work proposes a methodology for in vivo characterization of salivary calculi in the pretherapeutic context. Sialoliths were characterized in detail by X-ray computed microtomography (μCT) in combination with atomic emission spectroscopy, Fourier transform infrared spectroscopy, X-ray diffraction, scanning electron microscopy, and transmission electron microscopy. Correlative analysis of the same specimens was performed by in vivo and ex vivo helical computed tomography (HCT) and ex vivo μCT. The mineral matter in the sialoliths consisted essentially of apatite (89 vol%) and whitlockite (11 vol%) with average density of 1.8 g/cm3. In hydrated conditions, the mineral mass prevailed with 53 ± 13 wt%, whereas the organic matter, with a density of 1.2 g/cm3, occupied 65 ± 10% of the sialoliths’ volume. A quantitative relation between sialoliths mineral density and X-ray attenuation is proposed for both HCT and μCT.

Metallic nanoparticles as X-Ray computed tomography (CT) contrast agents: A review

2020 ◽  
Vol 1219 ◽  
pp. 128599 ◽  
Author(s):  
Naim Aslan ◽  
Burhan Ceylan ◽  
Mümin Mehmet Koç ◽  
Fehim Findik
Keyword(s):  
Computed Tomography ◽  
Contrast Agents ◽  
Metallic Nanoparticles ◽  
X Ray ◽  
X Ray Computed ◽  
Ct Contrast

scholarly journals A Review of Ex Vivo X-ray Microfocus Computed Tomography-Based Characterization of the Cardiovascular System

2021 ◽  
Vol 22 (6) ◽  
pp. 3263
Author(s):  
Lisa Leyssens ◽  
Camille Pestiaux ◽  
Greet Kerckhofs
Keyword(s):  
Computed Tomography ◽  
Soft Tissues ◽  
Ex Vivo ◽  
Image Resolution ◽  
Tissue Preparation ◽  
X Ray ◽  
Spatial Image ◽  
Microfocus Computed Tomography

Cardiovascular malformations and diseases are common but complex and often not yet fully understood. To better understand the effects of structural and microstructural changes of the heart and the vasculature on their proper functioning, a detailed characterization of the microstructure is crucial. In vivo imaging approaches are noninvasive and allow visualizing the heart and the vasculature in 3D. However, their spatial image resolution is often too limited for microstructural analyses, and hence, ex vivo imaging is preferred for this purpose. Ex vivo X-ray microfocus computed tomography (microCT) is a rapidly emerging high-resolution 3D structural imaging technique often used for the assessment of calcified tissues. Contrast-enhanced microCT (CE-CT) or phase-contrast microCT (PC-CT) improve this technique by additionally allowing the distinction of different low X-ray-absorbing soft tissues. In this review, we present the strengths of ex vivo microCT, CE-CT and PC-CT for quantitative 3D imaging of the structure and/or microstructure of the heart, the vasculature and their substructures in healthy and diseased state. We also discuss their current limitations, mainly with regard to the contrasting methods and the tissue preparation.

scholarly journals Quantitative Imaging of Gd Nanoparticles in Mice Using Benchtop Cone-Beam X-ray Fluorescence Computed Tomography System

2019 ◽  
Vol 20 (9) ◽  
pp. 2315 ◽  
Author(s):  
Siyuan Zhang ◽  
Liang Li ◽  
Jiayou Chen ◽  
Zhiqiang Chen ◽  
Wenli Zhang ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Spatial Information ◽  
Quantitative Imaging ◽  
Scatter Correction ◽  
Photon Counting ◽  
Correction Method ◽  
Cone Beam ◽  
X Ray ◽  
Photon Counting Detector

Nanoparticles (NPs) are currently under intensive research for their application in tumor diagnosis and therapy. X-ray fluorescence computed tomography (XFCT) is considered a promising non-invasive imaging technique to obtain the bio-distribution of nanoparticles which include high-Z elements (e.g., gadolinium (Gd) or gold (Au)). In the present work, a set of experiments with quantitative imaging of GdNPs in mice were performed using our benchtop XFCT device. GdNPs solution which consists of 20 mg/mL NaGdF4 was injected into a nude mouse and two tumor-bearing mice. Each mouse was then irradiated by a cone-beam X-ray source produced by a conventional X-ray tube and a linear-array photon counting detector with a single pinhole collimator was placed on one side of the beamline to record the intensity and spatial information of the X-ray fluorescent photons. The maximum likelihood iterative algorithm with scatter correction and attenuation correction method was applied for quantitative reconstruction of the XFCT images. The results show that the distribution of GdNPs in each target slice (containing liver, kidney or tumor) was well reconstructed and the concentration of GdNPs deposited in each organ was quantitatively estimated, which indicates that this benchtop XFCT system provides convenient tools for obtaining accurate concentration distribution of NPs injected into animals and has potential for imaging of nanoparticles in vivo.

Contrast enhancement of iohexol-cisplatin-gelatin complex under computed tomography imaging

2014 ◽  
Vol 34 (3) ◽  
pp. 267-271
Author(s):  
Wei-Hung Liu ◽  
Yang-Kao Wang ◽  
Chi-Chang Wu ◽  
Win-Pin Deng ◽  
Kuang-Hsun Lin ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Contrast Agent ◽  
Diagnostic Techniques ◽  
The Body ◽  
X Ray ◽  
Non Invasive ◽  
Ct Contrast Agent ◽  
X Ray Computed ◽  
Ct Contrast

Abstract X-ray computed tomography (CT) is one of the most powerful non-invasive diagnostic techniques nowadays. The iodinated molecules used as CT contrast agents in the clinic have short circulation times in the body, which significantly restrict its applications. Furthermore, some patients are hypersensitive to iodine. So, researchers have made tremendous efforts to improve the property of iodine. Besides, cis-diammineplatinum (II) dichloride (cisplatin), a major chemo agent for cancer treatment, possess higher X-ray attenuation coefficient being a CT contrast agent. The incorporation of cisplatin with an iodinated agent could facilitate the quality of CT images and damage cancer cells simultaneously. To reduce toxicity of a contrast agent, polymer matrix, gelatin, was incorporated for avoiding contact with nontarget cells. In this study, we combined the iodine contrast agent, 1,3-N-bis (2,3-dihydroxypropyl)-5-[N-(2,3-dihydroxypropyl)acetamido]-2,4,6-triiodobenzene-1,3-dicarboxamide (iohexol), with cisplatin, and then examined them in a micro CT with different X-ray tube voltages (50 kV, 80 kV, 100 kV) to find optimal scanning conditions for imaging. As expected, iohexol combined with cisplatin enhanced X-ray attenuation and image contrast. The optimal CT image could be acquired at iohexol and cisplatin concentrations of 50 mg/ml and 3 mg/ml, respectively, under 80 kV irradiation. Finally, the iohexol-cisplatin-gelatin solution was then fabricated into nanoparticles of sizes about 240 nm, which may suitable for in vivo delivery.

scholarly journals Poly(iohexol) Nanoparticles As Contrast Agents for in Vivo X-ray Computed Tomography Imaging

2013 ◽  
Vol 135 (37) ◽  
pp. 13620-13623 ◽  
Author(s):  
Qian Yin ◽  
Felix Y. Yap ◽  
Lichen Yin ◽  
Liang Ma ◽  
Qin Zhou ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Contrast Agents ◽  
Computed Tomography Imaging ◽  
X Ray ◽  
Tomography Imaging ◽  
X Ray Computed
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