A RF pulse containing energy only within a specified frequency range. Usually used for slice excitation or for selective saturation pulses.

[This entry is marked for removal.]

General Electric (GE) agreed to buy diagnostic systems maker Lunar Corp. for $150m. in March 2000. In 2004/05 it seems that the integration process into GE Healthcare has been completed. (GE Medical Systems and Amersham announced in April 2004 the completion of a share exchange acquisition of Amersham Health by GE. The result of this acquisition is the new GE Healthcare, based in the UK, totally owned by General Electric (GE).

The U.S.-based company developed bone densitometers and scanning machines that measure bone density as a way of diagnosing osteoporosis and other metabolic bone diseases. GE Lunar marketed these products worldwide.
GE Lunar announced a distribution agreement with MagneVu for domestic sales of the MagneVu 1000, a portable MRI device for orthopedic use, under the trade name Applause™.
GE Lunar was the exclusive U.S. distributor of MR-devices manufactured by Esaote S.p.A. These compact in-office MRI™ machines are designed to fit all practice sizes in orthopedic imaging and complete the range of diagnostic imaging systems.

(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.

An oral suspension of synthetic crystalline aqueous orange-flavored MRI contrast agent to enhance delineation of the bowel. Gadolite contains gadolinium, a lanthanide metal with paramagnetic characteristics. The toxic Gd is bound to become inert, along with water, inside a zeolite crystalline lattice structure. Gadolite gives a bright signal, and provides improved definition of the gastrointestinal tract from adjacent tissues.
Pharmacyclics receives an approvable letter from the FDA for Gadolite® Oral Suspension and in the United Kingdom an European marketing agreement signed with E-Z-Em, Ltd. in Dec. 1996.

Macromolecular Gd labeled albumins are a new class of contrast agents with a wide range of use e.g., MR angiography, breast MRI, perfusion MRI, Lung perfusion, etc.
Marketed gadolinium-based albumin-bound contrast media are e.g., MultiHance®, and Vasovist™; other prototypes are in development. Malignant tumors often show an increased uptake and metabolism of plasma proteins, especially albumin. Contrast agents with large molecules are delivered to all tissues, but only accumulate in those with leaky vessels by tumor capillaries (tumor neovessels). MRI tumor perfusion studies with Gd labeled albumin can show the success of tumor therapy by quantitative decrease in MR signal of the malignant tissue after therapy compared to before. In addition, the study of tumor sensitivity to a therapy with drug-labeled albumins seems possible.
After renal transplantation, MRI may diagnose albuminuria caused by glomerular disease with an albumin-bound blood pool contrast agent

See also Blood Pool Agents, Intravascular Contrast Agents, Contrast Enhanced MRI.