RF Coils: Use and Safety Part 2

What is another term commonly used for a "Quadrature" coil?. Linearly polarized. Circularly polarized. Digitally synchronized. Magnetically shielded.

A quadrature receive coil is approximately how much more efficient than a linear coil of the same size?. 10%. 25%. 41% (square root of 2). 100%.

What is the primary benefit of the increased efficiency of a quadrature receive coil?. It makes the scan faster. It results in an increase in the signal-to-noise ratio (SNR). It allows the patient to wear metal jewelry. It reduces the acoustic noise of the scanner.

On the transmit side, why is a circularly polarized (quadrature) body coil safer and more efficient?. It allows for higher RF power. It requires lower RF power (lower SAR) and provides a more uniform B1 field. It prevents the magnet from quenching. It eliminates the need for liquid helium.

In high-field cylindrical bore systems, if you are using a receive-only coil, which coil is performing the RF transmission?. The receive-only coil itself. The integrated body coil. A handheld transmitter. The gradient coils.

For a Deep Brain Stimulator (DBS) system that is restricted to "head-only" imaging, what specific type of coil must be used?. Any receive-only coil. A transmit-and-receive (T/R) head coil. A standard body coil. A flexible surface coil.

If a DBS system is labeled as "Full-Body Eligible," which coil can be used for RF transmission?. Only a head coil. Only a knee coil. The integrated body coil. No coil is required.

In the case study mentioned, why did the patient suffer a permanent neurological defect after an MRI?. The magnet was too strong. The scan was performed using the RF body coil for transmission, which was outside the system's conditions of use. The patient moved too much during the scan. The patient had an allergic reaction to the table.

Why didn't the patient in the case study feel the heating at the tip of the DBS lead as it was happening?. They were under general anesthesia. The scan was too fast. There are no pain sensors in the brain tissue itself. The patient was wearing thick winter clothing.

What is the most critical labeling requirement for head coils to ensure safety for patients with specific implants?. The weight of the coil. The color of the plastic. Whether they are transmit-and-receive (T/R) or receive-only. The date the coil was manufactured.