Siemens Safety Part 1

Which atomic nucleus is the primary source of the signal in clinical MRI imaging?. Carbon. Oxygen. Hydrogen. Nitrogen.

A 1.5 Tesla MRI magnet is approximately how much stronger than the Earth's natural magnetic field?. 300 times. 3,000 times. 30,000 times. 300,000 times.

Which magnetic field is responsible for creating the loud knocking or banging noise during a scan?. The gradient fields. The radiofrequency field (B1). The static main magnetic field (B0). The ultra-low fringe field.

Why is it critical to enter the patient's correct weight during the registration process?. To ensure the motorized table can lift the patient. To calculate the amount of contrast media needed. To determine the required thickness of the slice. To allow the system to calculate and limit the Specific Absorption Rate (SAR).

Which type of MRI magnet is "always on" and cannot be switched off electronically?. Permanent magnets. Superconducting magnets. Resistive magnets. Hybrid magnets.

What is the purpose of the liquid helium used in a superconducting MRI system?. To provide a contrast agent for the images. To lubricate the moving parts of the gantry. To cool the magnet coils to near absolute zero to eliminate electrical resistance. To muffle the sound of the gradient coils.

What is the "Faraday Cage" or RF enclosure designed to do?. To keep the strong magnetic field from leaving the room. To prevent external radio signals from interfering with the weak MR signals from the patient. To protect the patient from the loud noise of the scanner. To prevent the liquid helium from escaping from the room.

The international safety boundary for the public, where the magnetic field is considered "safe" for common electronic devices, is defined by which line?. The 5 Tesla line. The 1.0 Tesla line. The 0.5 mT (5 Gauss) line. The 50 Gauss line.

What physiological effect can occur due to the rapid switching of gradient magnetic fields?. Peripheral nerve stimulation (tingling or twitching). Permanent hearing loss. Deep tissue heating. Sudden drops in blood pressure.

In a superconducting magnet, how is the magnetic field maintained once it has been ramped up?. By a continuous supply of electricity from the building's power grid. By the constant rotation of the magnet inside the gantry. By the use of a backup battery system. By a persistent electrical current flowing through the coils with zero resistance.