(N) The SI unit of force.
Definition: 1 newton will accelerate a mass of 1 kilogram at the rate of 1 meter per second per second.
The relationship between force (F), mass (m), and acceleration (a) is expressed by the formula F = ma.
The newton is named for Isaac Newton (1642-1727), the British mathematician, physicist, and natural philosopher.

[This entry is marked for removal.]

Nihon Schering KK, was a subsidiary of Schering in Japan.
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.

Nitroxide radicals (or nitroxyl spin labels) are stable organic compounds with theoretical potential for use as a paramagnetic MRI contrast agent. Similar to gadolinium they have an unpaired electron, a property that provides enhancement in T1 based MRI, and a comparable pharmacokinetic. Depending on their structure and chemical bonding, different nitroxides formula may have the potential for use as cardiovascular imaging agents, to enhance the MR imaging on joints (e.g., dendrimer-linked nitroxides have a strong affinity for cartilage), to evaluate brain tumors and infarction, and as a contrast enhancement agent of body/abdominal NMR imaging. Nitroxides are rapidly enzymatically reduced in tissues to products that do not enhance the NMR signal, which can be a problem for MR imaging. In animal experiments with EPRI (electron paramagnetic resonance imaging), tissue redox studies show differences between tumors and normal tissues, which reflect their respective redox status consistent with the reduction/clearance of nitroxides.

Nuclear magnetic resonance is a diagnostic procedure, based on the principles of magnetic resonance.

(NPW / PNW - Phase No Wrap) If the receiving RF coil is sensitive to tissue signal arising from outside the desired FOV, this undesired signal may be incorrectly mapped, or wrapped back to a location within the image and is seen as artifact. This problem occurs in the phase encoding direction, where the phases of signal-bearing tissues outside of the FOV in the y-direction are a replication of the phases that are encoded within the FOV.
A user-selectable parameter maps this signal to its correct location outside the FOV, then discards any signal from outside the FOV before displaying the image. No phase wrap works by filling k-space to the same extent, using twice as many phase encoding steps. In order to be able to choose this parameter, in most cases more than an average is necessary.

See Foldover Suppression and Oversampling.