A quench is the rapid helium evaporation and the loss of superconductivity of the current-carrying coil that may occur unexpectedly, or from pressing the emergency button in a superconducting magnet. As the superconductive magnet becomes resistive, heat will be released that can result in boiling of liquid helium in the cryostat. This may present a hazard if not properly planned for.
The evaporated coolant requires emergency venting systems to protect patients and operators. Quenching can cause total magnet failure and cannot be stopped. MRI systems are designed such that all of the escaping cryogenic gas is directed out of the building (quench pipe through the roof or the wall). In the event of a burst of the tank (possible in the case of an accident) or a blockage of the pipes, the helium gas will be forced into the scanner room, giving rise to a large white cloud of chilled gas. Under such circumstances it is essential that the scanner room is evacuated, also caused by the displacement of oxygen, which under extreme conditions could lead to asphyxiation. The force of quenching can be strong enough to destroy the walls of the scanner room or the MRI equipment.

Quick Overview

This artifact is uncommon with modern MRI equipment, but possible. It can occur if there are bad memory locations or bad connectors in the parallel data bus of the computer.

This artifact is the result of a hardware failure and must be addressed by a service representative.

Inert hyperpolarized gases are under development for imaging air spaces, including those in the lungs. Because they mostly contain air and water, lungs are difficult organs to image.
These ventilation agents (gases) have potential in lung imaging and are currently used in studies of the pulmonary ventilation:
Specific isotopes of inert gases can be hyperpolarized. Hyperpolarized is a state in which almost all of the atoms nuclei are spinning in the same direction. Once the nuclei in the isotope 3He have been hyperpolarized using a laser, they remain in this state for several days. The inert, hyperpolarized gas can then be used in a lung imaging study, where the high concentration of polarized nuclei provides a sharp contrast in MRI. The technique is already being developed with a view to commercialization by Magnetic Imaging Technologies in Durham, North Carolina. According to the company, existing MRI equipment can be used with a few minor modifications, along with a gas polarizer. The technique could provide early detection and monitoring of pulmonary disease.
Hyperpolarized 129Xe can also be used as a magnetic resonance tracer because of its MR-enhanced sensitivity combined with its high solubility. This isotope differs from 3He in that it can dissolve in the blood. Strong enhancement of the nuclear spin polarization of xenon in the gas phase can be achieved by optical pumping of rubidium and subsequent spin-exchange with the xenon nuclei. This technique can increase the magnetic resonance signal of xenon by five orders of magnitude, thus allowing NMR detection of xenon in very low concentration. MR spectroscopy and imaging of optically polarized xenon shows considerable potential for medical applications (see also back projection imaging).
Nycomed Amersham anticipated the market for inert gases in pulmonary imaging. The company obtained an exclusive license for the use of helium (He) and xenon (Xe) as MRI contrast agents. Currently, the US FDA has not yet approved the commercial distribution of inert gas imaging equipment, because the technique is still undergoing trials.

From Aurora Imaging Technology, Inc.;
The Aurora® 1.5T Dedicated Breast MRI System with Bilateral SpiralRODEO™ is the first and only FDA approved MRI device designed specifically for breast imaging. The Aurora System, which is already in clinical use at a growing number of leading breast care centers in the US, Europe, got in December 2006 also the approval from the State Food and Drug Administration of the People's Republic of China (SFDA).
'Some of the proprietary and distinguishing features of the Aurora System include: 1) an ellipsoid magnetic shim that provides coverage of both breasts, the chest wall and bilateral axillary lymph nodes; 2) a precision gradient coil with the high linearity required for high resolution spiral reconstruction;; 3) a patient-handling table that provides patient comfort and procedural utility; 4) a fully integrated Interventional System for MRI guided biopsy and localization; and 5) the user-friendly AuroraCADâ„¢ computer-aided image display system designed to improve the accuracy and efficiency of diagnostic interpretations.'

From GE Healthcare;
GE Healthcare has added the Signa HDe 1.5T™, a compact MRI device at an affordable price to its family of MRI products. It has a single electronic cabinet that can be positioned inside the scanner room rather than in a separate equipment room. The Signa HDe 1.5T can be installed in the same physical location as 0.5T MRI systems with minimal construction costs. According to GE, the installation has been simplified to last only 7 days and has a 30 percent smaller footprint than a typical 1.5T system.
The 1.5T Signa™ HDe MRI system is substantially equivalent to the currently marketed GE 1.5T machines. The data acquisition system supports 1, 4, 8 independent receive channels and multiple independent coil elements per channel during a single acquisition series. The gradient specifications of HDe are lower than other GE Signa 1.5T MRI systems, but it can support clinical applications in cardiac and spectroscopy imaging.