Impact on liver position under breath-hold by computed tomography contrast agents in stereotactic body radiotherapy of liver cancer

Introduction: Micro-computed tomography with nanoparticle contrast agents may be a suitable tool for monitoring the time course of the development and progression of tumors. Here, we suggest a practical and convenient experimental method for generating and longitudinally imaging murine liver cancer models. Methods: Liver cancer was induced in 6 experimental mice by injecting clustered regularly interspaced short palindromic repeats/clustered regularly interspaced short palindromic repeats-associated protein 9 plasmids causing mutations in genes expressed by hepatocytes. Nanoparticle agents are captured by Kupffer cells and detected by micro-computed tomography, thereby enabling longitudinal imaging. A total of 9 mice were used for the experiment. Six mice were injected with both plasmids and contrast, 2 injected with contrast alone, and one not injected with either agent. Micro-computed tomography images were acquired every 2- up to 14-weeks after cancer induction. Results: Liver cancer was first detected by micro-computed tomography at 8 weeks. The mean value of hepatic parenchymal attenuation remained almost unchanged over time, although the standard deviation of attenuation, reflecting heterogeneous contrast enhancement of the hepatic parenchyma, increased slowly over time in all mice. Histopathologically, heterogeneous distribution and aggregation of Kupffer cells was more prominent in the experimental group than in the control group. Heterogeneous enhancement of hepatic parenchyma, which could cause image quality deterioration and image misinterpretation, was observed and could be due to variation in Kupffer cells distribution. Conclusion: Micro-computed tomography with nanoparticle contrast is useful in evaluating the induction and characteristics of liver cancer, determining appropriate size of liver cancer for testing, and confirming therapeutic response.

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

Medical Visualization ◽

10.24835/1607-0763-2017-6-118-129 ◽

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.

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Tantalum Oxide Nanoparticles as Versatile Contrast Agents for X-ray Computed Tomography

10.26434/chemrxiv.11845572.v1 ◽

2020 ◽

Author(s):

Shatadru Chakravarty ◽

Jeremy Hix ◽

Kaitlyn Wieweora ◽

Maximilian Volk ◽

Elizabeth Kenyon ◽

...

Keyword(s):

Computed Tomography ◽

Contrast Agents ◽

Mesoporous Silica Nanoparticles ◽

Sol Gel ◽

Tantalum Oxide ◽

High Signal ◽

Drug Delivery Vehicles ◽

X Ray Computed

Here we describe the synthesis, characterization and in vitro and in vivo performance of a series of tantalum oxide (TaOx) based nanoparticles (NPs) for computed tomography (CT). Five distinct versions of 9-12 nm diameter silane coated TaOx nanocrystals (NCs) were fabricated by a sol-gel method with varying degrees of hydrophilicity and with or without fluorescence, with the highest reported Ta content to date (78%). Highly hydrophilic NCs were left bare and were evaluated in vivo in mice for micro-CT of full body vasculature, where following intravenous injection, TaOx NCs demonstrate high CT contrast, circulation in blood for ~ 3 h, and eventual accumulation in RES organs; and following injection locally in the mammary gland, where the full ductal tree structure can be clearly delineated. Partially hydrophilic NCs were encapsulated within mesoporous silica nanoparticles (MSNPs; TaOx@MSNPs) and hydrophobic NCs were encapsulated within poly(lactic-co-glycolic acid) (PLGA; TaOx@PLGA) NPs, serving as potential CT-imagable drug delivery vehicles. Bolus intramuscular injections of TaOx@PLGA NPs and TaOx@MSNPs to mimic the accumulation of NPs at a tumor site produce high signal enhancement in mice. In vitro studies on bare NCs and formuated NPs demonstrate high cytocompatibility and low dissolution of TaOx. This work solidifies that TaOx-based NPs are versatile contrast agents for CT.

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Zr- and Hf-based nanoscale metal–organic frameworks as contrast agents for computed tomography

Journal of Materials Chemistry ◽

10.1039/c2jm32299d ◽

2012 ◽

Vol 22 (35) ◽

pp. 18139 ◽

Cited By ~ 108

Author(s):

Kathryn E. deKrafft ◽

William S. Boyle ◽

Laurel M. Burk ◽

Otto Z. Zhou ◽

Wenbin Lin

Keyword(s):

Computed Tomography ◽

Contrast Agents ◽

Metal Organic Frameworks ◽

Metal Organic

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Nanoparticulate Computed Tomography Contrast Agents for Blood Pool and Liver-Spleen Imaging

Academic Radiology ◽

10.1016/s1076-6332(12)80011-0 ◽

1994 ◽

Vol 1 (4) ◽

pp. 373-376 ◽

Cited By ~ 19

Author(s):

G. Scott Gazelle ◽

Gerald L. Wolf ◽

Gregory L. McIntire ◽

Edward R. Bacon ◽

Elkan F. Halpern ◽

...

Keyword(s):

Computed Tomography ◽

Contrast Agents ◽

Blood Pool

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Quantitative dual contrast photon-counting computed tomography for assessment of articular cartilage health

Scientific Reports ◽

10.1038/s41598-021-84800-x ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Petri Paakkari ◽

Satu I. Inkinen ◽

Miitu K. M. Honkanen ◽

Mithilesh Prakash ◽

Rubina Shaikh ◽

...

Keyword(s):

Computed Tomography ◽

Articular Cartilage ◽

Contrast Agent ◽

Contrast Agents ◽

Photon Counting ◽

Spectral Imaging ◽

Ct Scanning ◽

Photon Counting Detector ◽

Tissue Contrast ◽

Reference Parameters

AbstractPhoton-counting detector computed tomography (PCD-CT) is a modern spectral imaging technique utilizing photon-counting detectors (PCDs). PCDs detect individual photons and classify them into fixed energy bins, thus enabling energy selective imaging, contrary to energy integrating detectors that detects and sums the total energy from all photons during acquisition. The structure and composition of the articular cartilage cannot be detected with native CT imaging but can be assessed using contrast-enhancement. Spectral imaging allows simultaneous decomposition of multiple contrast agents, which can be used to target and highlight discrete cartilage properties. Here we report, for the first time, the use of PCD-CT to quantify a cationic iodinated CA4+ (targeting proteoglycans) and a non-ionic gadolinium-based gadoteridol (reflecting water content) contrast agents inside human osteochondral tissue (n = 53). We performed PCD-CT scanning at diffusion equilibrium and compared the results against reference data of biomechanical and optical density measurements, and Mankin scoring. PCD-CT enables simultaneous quantification of the two contrast agent concentrations inside cartilage and the results correlate with the structural and functional reference parameters. With improved soft tissue contrast and assessment of proteoglycan and water contents, PCD-CT with the dual contrast agent method is of potential use for the detection and monitoring of osteoarthritis.

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