SU-D-18C-04: The Feasibility of Quantifying MRI Contrast Agent in Pulsatile Flowing Blood Using DCE-MRI

2014 ◽  
Vol 41 (6Part4) ◽  
pp. 121-121
Author(s):  
Gwilliam M N ◽  
Collins D J ◽  
Leach M O ◽  
Orton M R
Author(s):  
Agnes Schröder ◽  
Lisa Seyler ◽  
Elisabeth Hofmann ◽  
Lina Gölz ◽  
Jonathan Jantsch ◽  
...  

Abstract Purpose It is thought that orthodontic forces initially reduce periodontal blood flow during orthodontic tooth movement (OTM) via tissue compression with cells responding to concomitant oxygen deprivation with expression of vascular endothelial growth factor (VEGF) triggering angiogenesis via binding to its receptor VEGFR‑2. To test this hypothesis, we performed a pilot study to establish a protocol for molecular magnetic resonance imaging (MRI) of rat jaws administering a VEGFR-2-specific contrast agent. Methods Mesial OTM of a first upper left rat molar was initiated in one male Fischer 344 rat 4 days prior to MRI by insertion of an elastic band between the first and second upper molars with the contralateral side left untreated (internal control). T1-weighted MRI sequences including dynamic contrast-enhanced MRI (DCE-MRI) were recorded before and after administration of a molecular VEGFR‑2 MRI marker with a 7 T MRI dedicated for small animal use. Results After injection of anti-VEGFR2-albumin-gadolinium-DTPA, volume enhancement on T1-weighted images was increased at the OTM side distally of the moved first upper molar (M1) compared to the control side, whereas the T1 relaxation time was reduced on the OTM side. DCE-MRI resulted in an increased area under the curve (AUC), whereas time-to-peak (TTP) and washout rate were reduced during OTM distally of the moved M1 compared to the contralateral side. Conclusions OTM resulted in uptake of the VEGFR-2-specific MRI contrast agent in tension areas of the periodontal ligament. The imaging protocol presented here is useful for the assessment of VEGFR‑2 expression in tension areas of the periodontal ligament in vivo.


RSC Advances ◽  
2019 ◽  
Vol 9 (25) ◽  
pp. 14051-14059
Author(s):  
Abdulrahman Ahmed Mahmood ◽  
Jianqi Zhang ◽  
Rufang Liao ◽  
Xiwei Pan ◽  
Dan Xu ◽  
...  

The acid-responsive pHLIP modified SPION as an MRI contrast agent for liver cancer diagnosis requires the validation of both the tumor-specific enhancement and a safe profile in cirrhosis.


Author(s):  
N. Riyahi-Alam ◽  
J. Behrouzkia ◽  
S. Haghgoo ◽  
A Seifalian ◽  
R Zohdi Aghdam. ◽  
...  

Nanomaterials ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 1235
Author(s):  
Xiaohui Nan ◽  
Wenjia Lai ◽  
Dan Li ◽  
Jiesheng Tian ◽  
Zhiyuan Hu ◽  
...  

Derived from magnetotactic bacteria (MTB), magnetosomes consist of magnetite crystals enclosed within a lipid bilayer membrane and are known to possess advantages over artificially synthesized nanoparticles because of the narrow size distribution, uniform morphology, high purity and crystallinity, single magnetic domain, good biocompatibility, and easy surface modification. These unique properties have increasingly attracted researchers to apply bacterial magnetosomes (BMs) in the fields of biology and medicine as MRI imaging contrast agents. Due to the concern of biosafety, a long-term follow-up of the distribution and clearance of BMs after entering the body is necessary. In this study, we tracked changes of BMs in major organs of mice up to 135 days after intravenous injection using a combination of several techniques. We not only confirmed the liver as the well-known targeted organs of BMs, but also found that BMs accumulated in the spleen. Besides, two major elimination paths, as well as the approximate length of time for BMs to be cleared from the mice, were revealed. Together, the results not only confirm that BMs have high biocompatibility, but also provide a long-term in-vivo assessment which may further help to forward the clinical applications of BMs as an MRI contrast agent.


Author(s):  
Juliette Moreau ◽  
Maité Callewaert ◽  
Volodymyr Malytskyi ◽  
Céline Henoumont ◽  
Sorina N. Voicu ◽  
...  

2021 ◽  
Vol 11 (3) ◽  
pp. 1165
Author(s):  
Wen-Tien Hsiao ◽  
Yi-Hong Chou ◽  
Jhong-Wei Tu ◽  
Ai-Yih Wang ◽  
Lu-Han Lai

The purpose of this study is to establish the minimal injection doses of magnetic resonance imaging (MRI) contrast agents that can achieve optimized images while improving the safety of injectable MRI drugs. Gadolinium-diethylenetriamine penta-acetic acid (Gd-DTPA) and ferucarbotran, commonly used in clinical practice, were selected and evaluated with in vitro and in vivo experiments. MRI was acquired using T1-weighted (T1W) and T2-weighted (T2W) sequences, and the results were quantitatively analyzed. For in vitro experiments, results showed that T1W and T2W images were optimal when Gd-DTPA-bisamide (2-oxoethyl) (Gd-DTPA-BMEA) and ferucarbotran were diluted to a volume percentage of 0.6% and 0.05%; all comparisons were significant differences in grayscale statistics using one-way analysis of variance (ANOVA). For in vivo experiments, the contrast agent with optimal concentration percentages determined from in vitro experiments were injected into mice with an injection volume of 100 μL, and the images of brain, heart, liver, and mesentery before and after injection were compared. The statistical results showed that the p values of both T1W and T2W were less than 0.001, which were statistically significant. Under safety considerations for MRI contrast agent injection, optimized MRI images could still be obtained after reducing the injection concentration, which can provide a reference for the safety concentrations of MRI contrast agent injection in the future.


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