Many MR imaging techniques using Motion Probing Gradients (MPG's) such as Spin Echo (SE), Stimulated Echo (STE), Rapid Acquisition with Relaxation Enhancement (RARE), Turbo-SE, and SE-EPI (Echo Planar Imaging for Spin echo acquisition), Spiral imaging, and Projection reconstruction including PROPELLER are applicable to DWI. In diffusion weighted imaging, 2 MPG's are required. The MPG's are put symmetrically into both sides of a 180° or 90° RF pulse to change the direction of the magnetized spin in the X-Y plane for spin echo or stimulated echo acquisition.

An undesirable background interference or disturbance that affects image quality.
The Noise is commonly characterized by the standard deviation of signal intensity in the image of a uniform object (phantom) in the absence of artifacts. The measured noise may depend on the particular phantom used due to variable effects on the Q of the receiver coil.
Noisy images appear when the SNR-Rate is too low - this is induced by the operator. Image artifacts and RF noise can often be caused by the presence and/or operation of a medical device in the MR environment. There are various noise sources in any electronic system, including Johnson noise, shot noise, thermal noise. Materials produce their own characteristic static magnetic field that can perturb the relationship between position and frequency essential to accurate image reconstruction.
RF noise, which often appears as static on the image, can be caused by a medical device located anywhere in the MR procedure room. RF noise is a result of excessive electromagnetic emissions from the medical device that interfere with the proper operation of the MR scanner. Since the MR procedure room is shielded from extraneous RF fields entering the room (Faraday cage), operation of electromagnetically noisy equipment outside the room does not typically affect the MR scanner.

See Signal to Noise Ratio and Radio Frequency Noise Artifact.

(NSA) The average number for each phase encoding step. The NSA determine each distinct position-encoded signal to be used in image reconstruction.

See also Signal Averaging.

From Philips Medical Systems;
the Panorama 0.23 T, providing a new design optimized for patient comfort, faster reconstruction time than before (300 images/second) and new gradient specifications. Philips' Panorama 0.23 T I/T supports MR-guided interventions, resulting in minimally invasive procedures, more targeted surgery, reduced recovery time and shorter hospital stays. Optional OptoGuide functionality enables real-time needle tracking. Philips' Panorama 0.23 TPanorama 0.2 R/T is the first and only open MRI system to enable radiation therapy planning using MR data sets. The Panorama also features the new and consistent Philips User Interface, an essential element of the Vequion clinical IT family of products and services.

From Philips Medical Systems;
Panorama 0.6 T is the Philips Mid-Field Open MRI system. It is the most open MR scanner in the market, optimized for patient comfort and faster reconstruction time.