From Millennium Technology Inc. This open C-shaped MRI system eases patient comfort and technologist maneuverability. This low cost scanner is build for a wide range of applications. The Virgo™ patient table is detachable and moves on easy rolling castors. Able to accommodate patient weights up to 160 kg, the tabletop has a range of motion of 30 cm in the lateral direction and 90cm in the longitudinal direction. Images generated with this scanner can only be viewed (without data loss) on Millennium's proprietary viewing software.

The mobile intraoperative iMotion system produces real-time images used for MR guided surgery and offers functional magnetic resonance imaging, MR spectroscopy, perfusion imaging, and diffusion weighted imaging capabilities.
The iMotion 1.5 T magnet moves to the patient, gliding in and out of place as needed, without affecting surgical, anesthetic, and nursing management.

See also Intraoperative Magnetic Resonance Imaging, MR Guided Interventions.

With this method irregular RR intervals in cardiac gating during cardiovascular imaging are rejected and then repeated to improve the image quality, whereby the cardiac frequency is used as a basis of the normal heart rate.
The RR interval window determines the percentage variation of the heart rate. Variations of the acquired data outside the window are rejected and not used in the image reconstruction. Also one interval after the arrhytmic beat will be rejected.
Arrhythmia rejection may be inappropriate for patients with certain pathologies, because if the RR interval is constant long, short, long, - all intervals would be rejected. Also a disadvantage is the time consume, but in some cases this function is mandatory, e.g. for diverse retrospective triggered sequences.

An image artifact is a structure not normally present but visible as a result of a limitation or malfunction in the hardware or software of the MRI device, or in other cases a consequence of environmental influences as heat or humidity or it can be caused by the human body (blood flow, implants etc.). The knowledge of MRI artifacts (brit. artefacts) and noise producing factors is important for continuing maintenance of high image quality. Artifacts may be very noticeable or just a few pixels out of balance but can give confusing artifactual appearances with pathology that may be misdiagnosed.
Changes in patient position, different pulse sequences, metallic artifacts, or other imaging variables can cause image distortions, which can be reduced by the operator; artifacts due to the MR system may require a service engineer.
Many types of artifacts may occur in magnetic resonance imaging. Artifacts in magnetic resonance imaging are typically classified as to their basic principles, e.g.:
Several techniques are developed to reduce these artifacts (e.g. respiratory compensation, cardiac gating, eddy current compensation) but sometimes these effects can also be exploited, e.g. for flow measurements.

See also the related poll result: 'Most outages of your scanning system are caused by failure of'

Blood pool agents (intravascular contrast agents) remain in the blood for a prolonged time compared with conventional contrast agents, which diffuse quickly into the interstitial space. Magnetic resonance angiography (MRA), cardiovascular imaging, or contrast enhanced MRIs are possible over an hour or more. This advantage over conventional MRI contrast media allows also higher resolution MRA of several territories using respiratory or cardiac gating techniques with a single contrast bolus.
Different types of blood pool contrast agents:
Blood pool MRI contrast agents with their longer intravascular circulation can be designed to be targeted to necrotic myocardium, to assess myocardial viability, or tumor directed to provide better diagnostic information for various tumors. A disadvantage of the use of blood pool agents for MRA is that the separation of arteries and veins is more difficult because they are present in both and the overlapping of those vessels is disturbing. This can be solved by e.g. different MIP segmentation algorithms.

See also Necrosis Avid Contrast Agent, Tumor Specific Agents, Feruglose, Gadofosveset Trisodium (Vasovist), Ultrasmall Superparamagnetic Iron Oxide and Contrast Medium.