Short name: P792, generic name: Gadomeritol, preliminary trade name: Vistarem™, central moiety: Gd
A macromolecular Gd-DOTA derivate under development as a MRI blood pool agent with rapid clearance. Phase II of the clinical trials on P792 (Guerbet SA) will make it possible to validate the performance of this agent in the fields of angiography, myocardial perfusion and tumor characterization.

The Mx and My data (digital MR signal) sampled and stored during data acquisition as a function of time and phase from an MRI sequence are called raw data. The horizontal axis is the frequency code, the vertical axis the phase code (of the protons).
Every point in the raw data matrix contains part of the information for the complete image. A point in the raw data matrix does not correspond to a point in the image matrix. The outer rows of the raw data matrix provide information regarding the borders and contours of the image, detailed structures, and also determine the resolution. This is also called k-space data.

(ROI) Keyboard controlled identification of a given area of an image for numerical analysis and the area of anatomy being scanned that is of particular importance in the image. This area can also be a volume, than called (VOI) volume of interest.

[This entry is marked for removal.]

Schering Alman, was a subsidiary of Schering AG, a local distributor of contrast media and pharmaceutical's in Turkey.
In June 2006 Bayer AG has bought the majority of shares of Schering AG. As a result of this take-over Schering AG has been renamed in December 2006 in Bayer Schering Pharma AG.

(STIR) Also called Short Tau (t) (inversion time) Inversion Recovery. STIR is a fat suppression technique with an inversion time t = T1 ln2 where the signal of fat is zero (T1 is the spin lattice relaxation time of the component that should be suppressed). To distinguish two tissue components with this technique, the T1 values must be different. Fluid Attenuation Inversion Recovery (FLAIR) is a similar technique to suppress water.
Inversion recovery doubles the distance spins will recover, allowing more time for T1 differences. A 180° preparation pulse inverts the net magnetization to the negative longitudinal magnetization prior to the 90° excitation pulse. This specialized application of the inversion recovery sequence set the inversion time (t) of the sequence at 0.69 times the T1 of fat. The T1 of fat at 1.5 Tesla is approximately 250 with a null point of 170 ms while at 0.5 Tesla its 215 with a 148 ms null point. At the moment of excitation, about 120 to 170 ms after the 180° inversion pulse (depending of the magnetic field) the magnetization of the fat signal has just risen to zero from its original, negative, value and no fat signal is available to be flipped into the transverse plane.
When deciding on the optimal T1 time, factors to be considered include not only the main field strength, but also the tissue to be suppressed and the anatomy. In comparison to a conventional spin echo where tissues with a short T1 are bright due to faster recovery, fat signal is reversed or darkened. Because body fluids have both a long T1 and a long T2, it is evident that STIR offers the possibility of extremely sensitive detection of body fluid. This is of course, only true for stationary fluid such as edema, as the MRI signal of flowing fluids is governed by other factors.

See also Fat Suppression and Inversion Recovery Sequence.