Diffusion of MRI and CT Contrast Agents in Articular Cartilage under Static Compression

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.

Download Full-text

Toxicity of MRI and CT contrast agents

Expert Opinion on Drug Metabolism & Toxicology ◽

10.1517/17425250902873796 ◽

2009 ◽

Vol 5 (4) ◽

pp. 403-416 ◽

Cited By ~ 130

Author(s):

Kendra M Hasebroock ◽

Natalie J Serkova

Keyword(s):

Contrast Agents ◽

Ct Contrast

Download Full-text

CT Contrast Agents

Small Animal Imaging ◽

10.1007/978-3-642-12945-2_11 ◽

2011 ◽

pp. 141-149 ◽

Cited By ~ 4

Author(s):

Hubertus Pietsch

Keyword(s):

Contrast Agents ◽

Ct Contrast

Download Full-text

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

Science of Advanced Materials ◽

10.1166/sam.2021.4052 ◽

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.

Download Full-text