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Result : Searchterm 'T1' found in 10 terms [] and 165 definitions []
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Searchterm 'T1' was also found in the following services: 
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Density Weighted ImagingInfoSheet: - Sequences - 
Intro, 
Overview, 
Types of, 
etc.
 
(PDWI) In density weighted imaging, the contrast is dependent on the density of protons in the tissue. Proton density weighted images are generated by choosing TR greater than T1 (typically ≥ 2 000 ms) and TE less than T2 (typically ≤ 30 ms), the two exponential terms are both close to one and therefore M is relatively independent of T1 and T2, thereby emphasizing Mxy0, which is proportional to the proton density. Also called (Rho) ρ-weighted.

See also Proton Density Weighted Image.
 
Images, Movies, Sliders:
 Knee MRI Coronal Pd Spir 001  Open this link in a new window
    
 MRI - Anatomic Imaging of the Ankle 3  Open this link in a new window
    
SlidersSliders Overview

 
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Further Reading:
  Basics:
IMAGE CONTRAST IN MRI(.pdf)
   by www.assaftal.com    
MRI Resources 
Databases - Calculation - - Research Labs - Supplies - MRI Centers
 
FerriSeltz®InfoSheet: - Contrast Agents - 
Intro, Overview, 
Characteristics, 
Types of, 
etc.MRI Resource Directory:
 - Contrast Agents -
 
A solution of ferric ammonium citrate (Geritol) used to enhance the delineation of the bowel. With T1 weighted magnetic resonance imaging (MRI) the predominantly positive enhancement helps to distinguish organs and tissues that are adjacent to the upper regions of the gastrointestinal tract. Product name found as both Ferriseltz® and FerriSeltz®.
Drug Information and Specification
NAME OF COMPOUND
DEVELOPER
CENTRAL MOIETY
Fe2+
CONTRAST EFFECT
T1, Predominantly positive enhancement
Paramagnetic
PHARMACOKINETIC
Gastrointestinal
PREPARATION
Dissolve
INDICATION
Bowel marking
DEVELOPMENT STAGE
For sale
DISTRIBUTOR
See below
PRESENTATION
Bags with powder
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
USA
FerriSeltz®
for sale
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• View the DATABASE results for 'FerriSeltz®' (4).Open this link in a new window

MRI Resources 
Fluorescence - Functional MRI - Resources - Nerve Stimulator - Databases - Knee MRI
 
FerumoxideInfoSheet: - Contrast Agents - 
Intro, Overview, 
Characteristics, 
Types of, 
etc.
 
Short name: AMI-25, generic name: Ferumoxide (SPIO)
Ferumoxides are superparamagnetic (T2*) MRI contrast agents, so the largest signal change is on T2 and T2* weighted images.
The agent distributes relatively rapidly to organs with reticuloendothelial cells primarily the liver, spleen and bone marrow. The liver shows decreased signal intensity, as does the spleen and marrow. The agent is taken up by the normal liver, resulting in increased CNR between tumor and normal liver. Hepatocellular lesions, such as adenoma or focal nodular hyperplasia, contain reticuloendothelial cells, so they will behave similar to the liver, with decreased signal on T2 weighted images. On T1 images, there is typically some circulating contrast agent, and blood vessels show increased signal intensity.
Current MRI protocols involve T1 weighted breath-hold gradient echo images of the liver, and fast spin echo T2 weighted pictures. This requires about 15 minutes. The patient is then removed from the scanner, and the contrast agent administered. After contrast administration, the same pulse sequences are again repeated.
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• View the DATABASE results for 'Ferumoxide' (5).Open this link in a new window

 
Further Reading:
  Basics:
Comparison of Two Superparamagnetic Viral-Sized Iron Oxide Particles Ferumoxides and Ferumoxtran-10 with a Gadolinium Chelate in Imaging Intracranial Tumors
2002   by www.ajnr.org    
Optimized Labelling of Human Monocytes with Iron Oxide MR Contrast Agents
Sunday, 30 November 2003   by rsna2003.rsna.org    
Searchterm 'T1' was also found in the following services: 
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Field Inhomogeneity ArtifactInfoSheet: - Artifacts - 
Case Studies, 
Reduction Index, 
etc.MRI Resource Directory:
 - Artifacts -
 
Quick Overview
Artifact Information
NAME
Field inhomogeneity
DESCRIPTION
Image distortion signal loss
REASON
HELP
Larger FOV, oversampling
A disturbance of the field homogeneity, because of magnetic material (inside or outside the patient), technical problems or scanning at the edge of the field.
When images were obtained in a progression from the center to the edge of the coil, the homogeneity of the field observed by the imaged volume, changes when the distance from the center of the volume increase. The same problem appears by scanning at a distance from the isocenter in left-right direction or too large field of view.
There are different types of bad image quality, the images are noisy, distorted or the fat suppression doesn't work because of badly set shim currents.
E.g. by using an IR sequence, changes in the T1 recovery rates of the tissues are involved. The inversion time at the center of the imaged volume is appropriate to suppress fat, but at the edge of the coil the same inversion time is sufficient to suppress water. Since the inversion time is not changed, the T1 recovery rates will increase.
mri safety guidance
Image Guidance
Take a smaller imaging volume (and for fat suppression a volume shimming), take care that the imaged region is at the center of the coil and that no magnetic material is inside the imaging volume.
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• View the DATABASE results for 'Field Inhomogeneity Artifact' (3).Open this link in a new window

 
Further Reading:
  Basics:
MRI Artifact Gallery
   by chickscope.beckman.uiuc.edu    
MRI Resources 
MRI Training Courses - Spectroscopy - Stimulator pool - MR Guided Interventions - Spectroscopy pool - Abdominal Imaging
 
Flow Sensitive Alternating Inversion RecoveryInfoSheet: - Sequences - 
Intro, 
Overview, 
Types of, 
etc.
 
(FAIR) In this sequence 2 inversion recovery images are acquired, one with a nonselective and the other with a slice selective inversion pulse. The z-magnetization in the first sequence is independent of flow. Inflowing spins give z-magnetization from second pulse. A major signal loss in FAIR is the T1 relaxation of tagged blood in transit to the imaging slice. Sharper edges of the inversion pulse give narrow spacing between the inversion edge and the 1st slice because reduced transit time gives lower T1 relaxation induced signal loss. The difference of the images in a consequence contains information proportional to flow (blood partition coefficient). Standard adiabatic inversion RF pulse does not have good slice-profile, because of power/SAR limitation. A c-shaped frequency offset corrected inversion (FOCI) RF pulse can help to increase the signal.
Perfusion imaging, e.g. myocardial, using tissue water as endogenous contrast is suggested.
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MRI Resources 
Collections - - Abdominal Imaging - Spine MRI - Quality Advice - Shielding
 
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