This method synchronize the heartbeat with the beginning of the TR, whereat the r wave is used as the trigger. Cardiac gating times the acquisition of MR data to physiological motion in order to minimize motion artifacts. ECG gating techniques are useful whenever data acquisition is too slow to occur during a short fraction of the cardiac cycle.
Image blurring due to cardiac-induced motion occurs for imaging times of above approximately 50 ms in systole, while for imaging during diastole the critical time is of the order of 200-300 ms. The acquisition of an entire image in this time is only possible with using ultrafast MR imaging techniques. If a series of images using cardiac gating or real-time echo planar imaging EPI are acquired over the entire cardiac cycle, pixel-wise velocity and vascular flow can be obtained.
In simple cardiac gating, a single image line is acquired in each cardiac cycle. Lines for multiple images can then be acquired successively in consecutive gate intervals. By using the standard multiple slice imaging and a spin echo pulse sequence, a number of slices at different anatomical levels is obtained. The repetition time (TR) during a ECG-gated acquisition equals the RR interval, and the RR interval defines the minimum possible repetition time (TR). If longer TRs are required, multiple integers of the RR interval can be selected. When using a gradient echo pulse sequence, multiple phases of a single anatomical level or multiple slices at different anatomical levels can be acquired over the cardiac cycle.
Also called cardiac triggering.

From Toshiba America Medical Systems Inc.;
the EXCELART is a superconducting whole body MRI system with a short wide-bore magnet, operating at 1.5 T. It features powerful high-speed gradients with a revolutionary gradient acoustic noise reduction system: Pianissimo. The dramatic reduction of gradient acoustic noise by Pianissimo greatly enhances patient comfort during exams. The standard array platform and a wide range of array coils ensure excellent images. A powerful 64-bit RISC-based computer system and newly developed array processor realize high productivity.

From Toshiba America Medical Systems Inc.;
the EXCELART is a superconducting whole body MRI system with a short wide-bore magnet, operating at 1.5 T. It features powerful high-speed gradients with a revolutionary gradient acoustic noise reduction system: Pianissimo. The dramatic reduction of gradient acoustic noise by Pianissimo greatly enhances patient comfort during exams. The standard array platform and a wide range of array coils ensure excellent images. A powerful 64-bit RISC-based computer system and newly developed array processor realize high productivity.

From Siemens Medical Systems;
the 3 T MAGNETOM Allegra is a dedicated MR headscanner, perfect as a research system in cognitive and neuroscience with MRS and fMRI. MAGNETOM Allegra is a full member of the MAGNETOM product family. It uses many common components, i.e. electronics, computer system, software and pulse sequence concepts.

From Siemens Medical Systems;
the MAGNETOM Harmony system is a high-performance MR imaging system based on 1.0 T field strength for best clinical routine MRI. It combines patient-friendly design features with the benefits of short imaging time, high anatomical resolution, and highest productivity.