Dynamic computed tomography with low- and high-molecular-mass contrast agents to assess microvascular permeability modifications in a model of liver fibrosis

2002 ◽  
Vol 103 (2) ◽  
pp. 213 ◽  
Author(s):  
Roland MATERNE ◽  
Laurence ANNET ◽  
Stéphane DECHAMBRE ◽  
Christine SEMPOUX ◽  
Anne M. SMITH ◽  
...  
2002 ◽  
Vol 103 (2) ◽  
pp. 213-216 ◽  
Author(s):  
Roland MATERNE ◽  
Laurence ANNET ◽  
Stéphane DECHAMBRE ◽  
Christine SEMPOUX ◽  
Anne M. SMITH ◽  
...  

Interstitial collagen formation and transformation of the fenestrated hepatic sinusoids into continuous capillaries are major ultrastructural changes that occur in liver cirrhosis and fibrosis. These modifications lead to progressive restriction of blood–liver exchanges. The purpose of our study was to evaluate the permeability changes in a model of hepatic fibrosis by using dynamic computed tomography (CT) enhanced with contrast agents of different molecular masses. Dynamic single-section CT of the liver was performed after intravenous bolus administration of a low-molecular-mass contrast agent (iobitridol) and an experimental high-molecular-mass agent (P840) in normal control rabbits and in rabbits with hepatic fibrosis. Hepatic, aortic and portal venous time–density curves were fitted with a dual-input one-compartmental model to calculate the hepatic mean transit time and distribution volume of the contrast agents. In the rabbits with liver fibrosis, the mean transit time of the high-molecular-mass agent was shorter than that of the low-molecular-mass agent (10.0±1.8s and 12.0±1.2s respectively; P<0.05). The distribution volume accessible to the high-molecular-mass agent was also smaller (22.2±4.8% compared with 32.0±6.7%; P<0.01). In the normal rabbits, the mean transit times of the high- and low-molecular-mass agents did not differ significantly, and nor did their distribution volumes. Our results demonstrate decreased sinusoidal permeability for the high-molecular-mass agent P840 in a model of hepatic fibrosis. Non-invasive assessment of permeability changes in liver fibrosis can be performed with dynamic CT and contrast agents of different molecular masses.


2017 ◽  
Vol 48 (1) ◽  
pp. 87-93 ◽  
Author(s):  
Takeshi Suzuki ◽  
Akira Yamada ◽  
Daisuke Komatsu ◽  
Masahiro Kurozumi ◽  
Yasunari Fujinaga ◽  
...  

1995 ◽  
Vol 108 (4) ◽  
pp. A1179
Author(s):  
S. Sugano ◽  
Y. Yamazaki ◽  
T. Okajima ◽  
T. Kawafune ◽  
Y. Sumino ◽  
...  

2017 ◽  
pp. 118-129
Author(s):  
I. A. Kondrashov ◽  
V. Mandal

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.


2020 ◽  
Author(s):  
Shatadru Chakravarty ◽  
Jeremy Hix ◽  
Kaitlyn Wieweora ◽  
Maximilian Volk ◽  
Elizabeth Kenyon ◽  
...  

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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