Imaging coils are radio frequency coils used in magnetic resonance imaging for sending and/or receiving electromagnetic radiation. Several MR imaging coils in different shapes and sizes are necessary for different body parts and to handle individual applications.
For Example:
Birdcage coils provide high homogeneity and good signal to noise ratio (SNR) in brain MRI scans.
Surface coils with small coil diameter and higher SNR enable to image the temporomandibular joints (TMJ).
The implemented body coil allows the scanning of body parts with large field of views.
Micro coils are available to image finger joints.
High performance phased array coils are today state-of-the-art for a wide range of applications from head, spine, knee or shoulder to cardiac MRI.
For different types of coils see Volume Coil, Sense Coil, Array Coil, Surface Coil, and Bird Cage Coil.

See also the related poll result: '3rd party coils are better than the original manufacturer coils'

From Siemens Medical Systems;
Received FDA clearance in 2010.
The MAGNETOM Aera is a patient friendly, comfortable 1.5 Tesla MRI system with advanced radio frequency chain.
The system is equipped with the Tim 4G and Dot system (Total imaging matrix + Day optimizing throughput), to enhance both productivity and image quality.
Tim 4G technology provides improved SNR. The standard system configuration of 48 radio frequency channels and 204 coil elements creates an imaging matrix that allows maximum use of coil elements at full field of view. Dot provides improved image consistency through new features like auto align, auto FoV and automatic bolus detection.

Multiple echoes acquired in a gradient echo scan are combined into an image, for less artifacts and higher SNR; the early echoes provide increased SNR, whilst later echoes boost contrast. This sequence type is also known as MERGE (Multiple Echo Recombined Gradient Echo)

See also Multi Echo Data Image Combination, Bipolar Gradient Pulse.

The number of data points collected in one, two or all three directions. Normally used for the 2D in plane sampling. The display matrix may be different from the acquisition matrix, although the latter determines the resolution. Measurement time may be saved by not acquiring raw data lines corresponding to high resolution. Not measured rows are filled with zeroes prior to the image calculation. A square image is the result of an interpolation in phase encoding direction. See also Zero Filling.

The chosen matrix size effects scan time, resolution and SNR. Reduced measurement matrixes decrease the scan time and the resolution by increased SNR.

(PE) The partial echo technique (also called fractional echo) is used to shorten the minimum echo time. By the acquisition of only a part of k-space data this technique benefits (like all partial Fourier techniques) from the complex conjugate symmetry between the k-space halves (this is called Hermitian symmetry).
The dephasing gradient in the frequency direction is reduced, and the duration of the readout gradient and the data acquisition window are shortened. Partial echo gives a better SNR at a given TE when a smaller FOV or thinner slices are selected, allows a longer sampling time, and a larger water fat shift (WFS, see also bandwidth) due to a lower gradient amplitude. The resolution is not affected. This is often used in gradient echo sequences (e.g. FLASH, Contrast Enhanced Magnetic Resonance Angiography) to reduce the echo time and yields a lower gradient moment. The disadvantage of using a partial echo can be a lower SNR, although this may be partly offset by the reduced echo time.
Also called Fractional Echo, Read Conjugate Symmetry, Single Side View.

See also Partial Fourier Technique and acronyms for 'partial echo' from different manufacturers.