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Result : Searchterm 'Relaxivity' found in 1 term [] and 50 definitions []
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Relaxivity
 
The ability of magnetic compounds to increase the relaxation rates of the surrounding water proton spins.
Relaxivity is used to improve the contrast of the image, and to study tissue specific areas where the contrast agent better diffuses or to perform functional magnetic resonance imaging.
The relaxivity of MRI contrast agents depends on the molecular structure and kinetic of the complex. To increase the number of water molecules that are in the inner sphere of the complex, or to slow down the molecular rotational correlation time, are possibilities to improve the water relaxivity.
Relaxivity units (r1, r2) are mM-1 * sec-1 (at varying temperatures).
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• Related Searches:
    • T1 Weighted Image
    • T2 Relaxation
    • T2 Weighted Image
    • Relaxation Time
    • Relaxation Effect
 
Further Reading:
  News & More:
Measurements of the relaxivity of gadolinium chelates in tissues in vivo(.pdf)
2001   by cds.ismrm.org    
MRI Resources 
Coils - MRI Physics - Stimulator pool - Abdominal Imaging - Jobs - Chemistry
 
ABLAVARâ„¢InfoSheet: - Contrast Agents - 
Intro, Overview, 
Characteristics, 
Types of, 
etc.
 
ABLAVAR™ (formerly named Vasovistâ„¢) is a blood pool agent for magnetic resonance angiography (MRA), which opens new medical imaging possibilities in the evaluation of aortoiliac occlusive disease (AIOD) in patients with suspected peripheral vascular disease.
ABLAVARâ„¢ binds reversibly to blood albumin, providing imaging with high spatial resolution up to 1 hour after injection, due to its high relaxivity and to the long lasting increased signal intensity of blood.
As with other contrast media: the possibility of serious or life-threatening anaphylactic or anaphylactoid reactions, including cardiovascular, respiratory and/or cutaneous manifestations, should always be considered.

WARNING:
NEPHROGENIC SYSTEMIC FIBROSIS
Gadolinium-based contrast agents increase the risk for nephrogenic systemic fibrosis (NSF) in patients with acute or chronic severe renal insufficiency (glomerular filtration rate less than 30 mL/min/1.73m2), or acute renal insufficiency of any severity due to the hepato-renal syndrome or in the perioperative liver transplantation period.

See also Cardiovascular Imaging, Adverse Reaction, Molecular Imaging, and MRI Safety.
Drug Information and Specification
NAME OF COMPOUND
Diphenylcyclohexyl phosphodiester-Gd-DTPA, gadofosveset trisodium, MS-325
CENTRAL MOIETY
Gd2+
CONTRAST EFFECT
T1, predominantly positive enhancement
20-45 mmol-1sec-1, Bo=0,47T
PHARMACOKINETIC
Intravascular
825 mOsmol/kg H2O
CONCENTRATION
244 mg/mL, 0.25mmol/mL
DOSAGE
0.12 mL/kg, 0.03 mmol/kg
PREPARATION
ready to use
DEVELOPMENT STAGE
FDA approved
DISTRIBUTOR
See below
PRESENTATION
10 mL vials
DO NOT RELY ON THE INFORMATION PROVIDED HERE, THEY ARE
NOT A SUBSTITUTE FOR THE ACCOMPANYING PACKAGE INSERT!
Distribution Information
TERRITORY
TRADE NAME
DEVELOPMENT
STAGE
DISTRIBUTOR
EU
Approved
USA, Canada, Australia
ABLAVARâ„¢
Approved
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• View the DATABASE results for 'ABLAVAR™' (3).Open this link in a new window


• View the NEWS results for 'ABLAVARâ„¢' (1).Open this link in a new window.
 
Further Reading:
  Basics:
Ablavar Prescribing Information
   by www.ablavar.com    
  News & More:
The first FDA-approved blood-pool MR agent offers additional time for imaging and possibly some new applications
Thursday, 1 July 2010   by www.radiologytoday.net    
MRI Resources 
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GadoliniumForum -
related threadsInfoSheet: - Contrast Agents - 
Intro, Overview, 
Characteristics, 
Types of, 
etc.
 
(Gd) Gadolinium is a Lanthanide element that is paramagnetic in its trivalent state.
This paramagnetic substance is used for MR imaging because of the effect of strongly decreasing the T1 relaxation times of the tissues to which gadolinium has access. When injected during magnetic resonance imaging, gadolinium will tend to change signal intensities by shortening the T1 time in its surroundings.
The relaxivity of gadolinium is an important measure of its efficacy, which is dependent on the chemical properties of the complex. The gadolinium ion cannot be used in its chloride, sulfate, or acetate forms because of poor tolerance and low solubility in water in the neutral pH range. Although toxic by itself, gadolinium can be given safely in a chelated form such as DTPA, that still retains much of its strong effect on relaxation times (relaxivity).

See also Dotarem®, Gadovist®, MultiHance®, Omniscan®, OptiMARK®, and Contrast Agents, the info sheet gives an overview and more in-dept information about different types of MRI contrast agents.
 
Images, Movies, Sliders:
 Normal Lung Gd Perfusion MRI  Open this link in a new window
      

Courtesy of  Robert R. Edelman

 Breast MRI Images T1 Pre - Post Contrast  Open this link in a new window
 Delayed Myocardial Contrast Enhancement from Infarct  Open this link in a new window
      

Courtesy of  Robert R. Edelman
 
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• View the DATABASE results for 'Gadolinium' (66).Open this link in a new window


• View the NEWS results for 'Gadolinium' (17).Open this link in a new window.
 
Further Reading:
  Basics:
DNA-SEEKING GADOLINIUM COMPLEXES FOR NEUTRON CAPTURE THERAPY (NCT) (.pdf)
A LANTHANIDE LANTHOLOGY(.pdf)
   by www.phy.davidson.edu    
Gadolinium-Based Agents Safe for MRI Use
Monday, 18 April 2011   by www.renalandurologynews.com    
  News & More:
Stable Spherical Lanthanide Cluster for Magnetic Resonance Imaging Assembly
Wednesday, 26 April 2023   by www.miragenews.com    
Artificial Intelligence Processes Provide Solutions to Gadolinium Retention Concerns
Thursday, 30 January 2020   by www.itnonline.com    
Contrast Agents: Safety Profile
   by www.clinical-mri.com    
Contrast MRIs cause claims, concern, over residual metal in brain
Tuesday, 8 December 2015   by www.afr.com    
Contrast agent linked with brain abnormalities on MRI
Tuesday, 17 December 2013   by www.sciencecodex.com    
FDA Approves First Macrocyclic and Ionic Gadolinium-Contrast Agent for MRI
Friday, 22 March 2013   by www.itnonline.com    
Multimodal Nanoparticles for Quantitative Imaging(.pdf)
Tuesday, 13 December 2011   by alexandria.tue.nl    
Gadolinium oxide nanoparticles enhance MRI contrast
Thursday, 29 September 2011   by nanotechweb.org    
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Gastrointestinal Superparamagnetic Contrast AgentsInfoSheet: - Contrast Agents - 
Intro, Overview, 
Characteristics, 
Types of, 
etc.MRI Resource Directory:
 - Contrast Agents -
 
Gastrointestinal (GI) superparamagnetic contrast agents are used in MRI to improve the visualization of e.g., the intestinal tract, the pancreas (see MRCP), etc. Disadvantages are susceptibility artifacts e.g., dependent on delayed imaging or large volumes resulting in artifacts in the colon and distal small bowel loops related to higher concentration of the particles and absorption of the fluid.
Different types of MRI gastrointestinal superparamagnetic contrast agents:
•
Magnetite albumin microsphere

Usually gastrointestinal superparamagnetic contrast media consist of small iron oxide crystals (ferrites), which produce a signal reduction in the stomach and bowel after oral administration. The T2 shortening caused by these particles is produced from the local magnetic field inhomogeneities associated with the large magnetic moments of superparamagnetic particles. Ferrites are iron oxides of the general formula Fe203.MO, where M is a divalent metal ion and may be mixed with Fe3O4 in different preparations. Ferrites can produce symptoms of nausea after oral administration, as well as flatulence and a transient rise in serum iron. Embedding in inert substances reduce side effects by decreasing the absorption and interaction with body tissues. Combining these contrast materials with polymers such as polyethylene glycol or cellulose, or with sugars such as dextrose, results in improved T1 and/or T2 relaxivity compared with that of the contrast agent alone.

See also Negative Oral Contrast Agents, Gastrointestinal Diamagnetic Contrast Agents, Relaxivity, and Combination Oral Contrast Agents.
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• View the DATABASE results for 'Gastrointestinal Superparamagnetic Contrast Agents' (6).Open this link in a new window

 
Further Reading:
  Basics:
Negative GI Contrast Agents
   by www.mritutor.org    
MRI Resources 
Used and Refurbished MRI Equipment - IR - DICOM - Brain MRI - MRCP - Health
 
MultiHance®InfoSheet: - Contrast Agents - 
Intro, Overview, 
Characteristics, 
Types of, 
etc.MRI Resource Directory:
 - Contrast Agents -
 
MultiHance® is a paramagnetic contrast agent for use in diagnostic magnetic resonance imaging (MRI) of the liver and central nervous system. MultiHance® is a small molecular weight chelate, which tightly binds the Gd atom. The substance is excreted partly by the kidneys, partly by the biliary system, which is especially unique.
MultiHance® is indicated, for the detection of focal liver lesions in patients with known or suspected primary liver cancer (e.g. hepatocellular carcinoma) or metastatic disease.
MultiHance® is also indicated in brain MRI and spine MRI where it improves the detection of lesions and provides diagnostic information additional to that obtained with unenhanced MRI.
Gd-BOPTA-enhanced MRA can provide superior vascular signal intensity and SNR, as compared with Gd-DTPA, due to its higher relaxivity, even at lower doses.
1 ml of solution MultiHance® contains: (0.5M) gadobenate dimeglumine 529 mg = gadobenic acid 334 mg + meglumine 195 mg. Viscosity at 37°C: 5.3 mPa

WARNING: NEPHROGENIC SYSTEMIC FIBROSIS Gadolinium-based contrast agents increase the risk for nephrogenic systemic fibrosis (NSF) in patients with acute or chronic severe renal insufficiency (glomerular filtration rate less than 30 mL/min/1.73m2), or acute renal insufficiency of any severity due to the hepato-renal syndrome or in the perioperative liver transplantation period.
Drug Information and Specification
NAME OF COMPOUND
Gadobenate dimeglumine, Gd-BOPTA, E7155
DEVELOPER
CENTRAL MOIETY
Gd2+
CONTRAST EFFECT
T1, predominantly positive enhancement
r1=9.7, r2=12.5, B0=0.5 T
PHARMACOKINETIC
Extracellular, hepatobiliary
1970 mosm/kg
CONCENTRATION
334 mg/ml
DOSAGE
0.05 mmol/kg for Liver MRI
0.1 mmol/kg for CNS MRI
PREPARATION
Solution for injection
INDICATION
CNS, Liver MRI
DEVELOPMENT STAGE
For sale
DISTRIBUTOR
See below
PRESENTATION
Vials of 5, 10, 15 and 20 mL, 50 and 100 mL Multipacks (Pharmacy Bulk Package)
DO NOT RELY ON THE INFORMATION PROVIDED HERE, THEY ARE
NOT A SUBSTITUTE FOR THE ACCOMPANYING PACKAGE INSERT!
Distribution Information
TERRITORY
TRADE NAME
DEVELOPMENT
STAGE
DISTRIBUTOR
EU
MultiHance®
for sale
USA
MultiHance®
for sale
Australia
MultiHance®
for sale
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• View the DATABASE results for 'MultiHance®' (9).Open this link in a new window


• View the NEWS results for 'MultiHance®' (1).Open this link in a new window.
 
Further Reading:
  Basics:
Important Drug Warning for Gadolinium-Based Contrast Agents
Wednesday, 12 September 2007   by www.ismrm.org    
MultiHance Package Insert(.pdf)
   by www.fda.gov    
  News & More:
FDA Expands Pediatric Age Range for MultiHance Contrast Agent
Tuesday, 30 January 2018   by www.empr.com    
MAGNETIC RESONANCE IMAGING OF FOCAL LIVER LESIONS(.pdf)
2002
BRACCO DIAGNOSTICS' MULTIHANCE EARNS FDA APPROVAL
Wednesday, 24 November 2004   by salesandmarketingnetwork.com    
MRI Resources 
Developers - Implant and Prosthesis pool - DICOM - MR Guided Interventions - Liver Imaging - Quality Advice
 
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