scholarly journals Chelating Agents and the Regulation of Metal Ions

1994 ◽  
Vol 1 (2-3) ◽  
pp. 87-106 ◽  
Author(s):  
Robert A. Bulman

Up to about the early 1980s it was perhaps still possible to summarize in a review of a moderate length the development of the medicinal applications of chelation chemistry and the exploitation of such chemistry in regulating the metal ion concentrations in the body. However, in the last few years there has a great surge in the development of chelation chemistry and its usage in medicine and related areas of life sciences research. It is no longer the case that such a review primarily concentrates upon the use of chelating agents in removing toxic metals from the body but it must now cover the use of chelating agents in the imaging procedures nuclear medicine and magnetic resonance imaging (MRI), the use of chelating agents in unravelling the biochemistry of reactive oxidative species (ROS) and the control and measurement of intracellular calcium ions. It is in the recent applications that there have been the greatest developments over the last ten years.

2020 ◽  
pp. 1-7
Author(s):  
Blaurock-Busch Eleonore

Gadolinium-Based Contrast Agents (GBCA) are intravenous drugs used in diagnostic imaging procedures to enhance the quality of Magnetic Resonance Imaging (MRI) or Magnetic Resonance Angiography (MRA). FDA alerts concerning potential side effects increased patient and medical concerns. More recent FDA information indicate that ionic gadolinium is released from some GBCAs, potentially causing gadolinium toxicity. We checked if gadolinium is excreted renally without intervention after previous administration of GBCAs, and if chelating agents are effective in removing gadolinium that may have remained in the body after GBCA administration. Through the evaluation of our internal database and the studies of others, we concluded that no clear consensus exists at this time. While the DTPAs may be the choice of chelators for the removal of gadolinium from the human body, further studies are needed to prove this. It seems clear, however, that microcyclic GBCAs provide a lesser risk of causing gadolinium retention and gadolinium toxicity symptoms.


Foot & Ankle ◽  
1987 ◽  
Vol 8 (3) ◽  
pp. 144-147 ◽  
Author(s):  
Ian J. Alexander ◽  
Kenneth A. Johnson ◽  
Thomas H. Berquist

Magnetic resonance imaging (MRI), a useful technique of studying soft tissues of the body, can be very effective in assessing the integrity of tendons. Usually a patient with a complete tear of the posterior tibial tendon has characteristic physical findings. In the patient presented, MRI demonstrated a complete disruption of the posterior tibial tendon, despite the absence of the commonly associated clinical findings. In view of the difficulties encountered with attempted tenography of the completely torn posterior tibial tendon, MRI provides a sensitive alternative diagnostic technique.


2021 ◽  
pp. 028418512110510
Author(s):  
Yousef W Nielsen ◽  
Henrik S Thomsen

This review focuses on the trends in contrast media (CM) research published in Acta Radiologica during the last 100 years, since the first edition in 1921. The main topics covered are the developments of iodine- and gadolinium-based CM. Other topics include manganese-based CM for magnetic resonance imaging (MRI) and barium for the investigation of the alimentary tract. From a historic point of view, special CM for use in cholegraphy and myelography are addressed in the review. Today, these imaging procedures are obsolete due to the development of computed tomography, MRI, and ultrasound. The historical use of radioactive thorium-based CM for angiography is also addressed. Furthermore, publications on adverse reactions to CM are reviewed.


2008 ◽  
Vol 36 (2) ◽  
pp. 315-319 ◽  
Author(s):  
Charles A. Nelson

Magnetic resonance imaging (MRI) is a noninvasive imaging tool that utilizes a strong magnetic field and radio frequency waves to visualize in great detail organs, soft tissue, and bone. Unlike conventional x-rays (including computed tomography [CT]), there is no exposure to ionizing radiation and at most field strengths (generally below 7 Tesla) the procedure is considered safe for nearly every age group. Because it is non-invasive (i.e., does not break the skin or harm the body) and possesses excellent spatial resolution (down to millimeters), the use of MRI as a research tool has increased exponentially over the past decade. Uses have ranged from add-ons to a clinical study (e.g., after scanning a child who has fallen from a bicycle, the radiologist might do an extra sequence to explore ways of obtaining higher resolution images) to studies of brain development in typically developing children. In addition, a major effort has been made in recent years to use MRI to study brain function (so-called “functional MRI” [fMRI]). Because the clinical utility of fMRI has not yet been realized, fMRI is still considered highly exploratory, and we cannot yet identify incidental findings of a functional (as opposed to structural) nature.


2003 ◽  
Vol 75 (9) ◽  
pp. 1343-1348 ◽  
Author(s):  
Yoshinori Yamamoto

The evaluation of the Gd-carborane DTPA complex as a magnetic resonance imaging (MRI) and boron carrier agent was carried out in vivo. The MRI revealed that the Gd-carborane DTPA was metabolized slower in the body in comparison with Gd-DTPA.


2008 ◽  
Vol 24 (04) ◽  
pp. 452-458 ◽  
Author(s):  
Mohammad Palesh ◽  
Sten Fredrikson ◽  
Hamidreza Jamshidi ◽  
Goran Tomson ◽  
Max Petzold

Objectives:Analysis of and understanding the utilization patterns of diagnostic imaging technologies is important for planning health systems especially in middle- and low-income countries. Almost all published studies have been focused on utilization trends or utilization rates of magnetic resonance imaging (MRI) over time and little has been published about utilization patterns of MRI. This study aims to identify and describe the utilization pattern of MRI in Iran.Methods:Data was collected from referrals and MRI reports of the population covered by one of the largest insurance organizations (Social Security Organization [SSO]) with more than 27 million beneficiaries in the Country. We focused on patients who had undergone an MRI examination during 1 month (October 13 to November 12), 2005. The data collected consisted of 1,656 referrals for MR imaging and 1,547 MRI reports.Results:No clear association was found between the number of referrals per 100,000 population and the number of MRI machines per 100,000 population (r = 0.30;p= .13). Neurosurgeons, orthopedists, and neurologists contributed to more than 88 percent of MRI utilization. The Spinal column (55 percent), brain (25.5 percent), and knee (11.0 percent) were the most common parts of the body scanned by MRI.Conclusions:Having identified some of the most frequent users of MRI technology, any plan for modifying or improving MRI use should focus mainly on these specialties. International evidence on using the technology for examining brain and spine indicate that MRI is mainly used in diagnosing the central nervous system (CNS) diseases.


2008 ◽  
Vol 65 (7) ◽  
pp. 1245-1249 ◽  
Author(s):  
Bonnie L. Rogers ◽  
Christopher G. Lowe ◽  
Esteban Fernández-Juricic ◽  
Lawrence R. Frank

The physical consequences of barotrauma on the economically important rockfish ( Sebastes ) were evaluated with a novel method using T2-weighted magnetic resonance imaging (MRI) in combination with image segmentation and analysis. For this pilot study, two fishes were captured on hook-and-line from 100 m, euthanized, and scanned in a 3 Tesla human MRI scanner. Analyses were made on each fish, one exhibiting swim bladder overinflation and exophthalmia and the other showing low to moderate swim bladder overinflation. Air space volumes in the body were quantified using image segmentation techniques that allow definition of individual anatomical regions in the three-dimensional MRIs. The individual exhibiting the most severe signs of barotrauma revealed the first observation of a gas-filled orbital space behind the eyes, which was not observable by gross dissection. Severe exophthalmia resulted in extreme stretching of the optic nerves, which was clearly validated with dissections and not seen in the other individual. Expanding gas from swim bladder overinflation must leak from the swim bladder, rupture the peritoneum, and enter the cranium. This MRI method of evaluating rockfish following rapid decompression is useful for quantifying the magnitude of internal barotrauma associated with decompression and complementing studies on the effects of capture and discard mortality of rockfishes.


2015 ◽  
Vol 5 (3) ◽  
pp. 168-172
Author(s):  
Amita Rahul Navalkar

ABSTRACT Forensic medicine aims for the documentation of medical and other forensic findings in living and deceased persons for the police and the judiciary system. Autopsy is the scientific examination of bodies after death, where whole surface of the body as well as all the body cavities are explored to record the findings. At the same time it is also equally important to consider the sentiments of the relatives of the deceased who may get upset at conventional autopsies. So, if there exists a means by which all the findings in the body can be established without hurting anyone's sentiments should be accepted. Virtopsy or virtual autopsy is one step ahead in this field where three-dimensional (3D) scans using computed tomography (CT) scans and magnetic resonance imaging (MRI) pictures are employed sans using the scalpel for performing autopsies on victims to receive more information aiding in diagnosis and contributing significantly toward forensic science. This review wishes to highlight virtopsy as an important tool in forensic imaging and identification. How to cite this article Navalkar AR. Virtopsy—The Scalpel Free Autopsy: A Review of Literature. J Contemp Dent 2015;5(3):168-172.


2020 ◽  
Vol 6 (1) ◽  
pp. 41-48
Author(s):  
Deepak Garg ◽  
◽  
Gaurav Jain ◽  
Virendra Sinha ◽  
◽  
...  

Background and Importance: Hydatid cyst is endemic in India, with different clinical presentations according to the site of involvement in the body. However, its occurrence in the brain without the involvement of other body parts is rare. Case Presentation: An eight-year-old female child presented with right-sided limb weakness and slurring of speech. The diagnosis of primary brain hydatid cyst was made with Magnetic Resonance Imaging (MRI) of the brain. The cyst was removed completely, resulting in improved post-operative slurring of speech and limb weakness. Conclusion: In countries where hydatid disease is endemic, brain hydatidosis should on top of the differential diagnoses for intracerebral cystic lesions and managed as per hydatid protocol until proved otherwise. This approach is critical to prevent rupture and dissemination.


2020 ◽  
Author(s):  
Bhumi Bhusal ◽  
Behzad Elahi ◽  
Boris Keil ◽  
Joshua Rosenow ◽  
Ehsan Kazemivalipour ◽  
...  

AbstractPatients with active implants such as deep brain stimulation (DBS) devices, have limited access to magnetic resonance imaging (MRI) due to risks of RF heating. With an aging population, the prevalence of neurodegenerative and vascular disease increases; and so does the indication for MRI exams in patients with such implants. In response to this growing need for MRI, many groups have investigated strategies to mitigate the RF heating of the implants. These efforts, however, have relied either on simulations with homogenous body models or simplified phantom experiments (box shaped phantom with single tissue). It is well established, however, that the shape and heterogeneity of human body affects the distribution of MRI electric fields, which by proxy, alters the RF heating of an implant inside the body. In this contribution, we applied numerical simulations and phantom experiments to examine the effectiveness of RF heating mitigation strategies under variant patient body compositions, focusing on two recently proposed techniques: (a) surgical modification of DBS lead trajectories inside the body, and (b) use of a patient-adjustable reconfigurable MRI coil, both aiming to reduce the coupling of implanted leads and MRI electric fields. Our results demonstrated that both techniques perform well under variant body compositions.


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