RF Coils: Use and Safety Part 3

In a standard circularly polarized or quadrature transmit configuration, how many RF transmitters are used?. A single RF transmitter. Two RF transmitters. Four RF transmitters. Eight RF transmitters.

A "multi-transmit" system is defined by having: Multiple receiving antennas. More than one RF transmitter. Multiple liquid helium tanks. More than one patient table.

What is the most common configuration for multi-transmit systems currently in use?. Single channels transmit. Two-channel (Dual-channel) transmit. Eight-channel transmit. Sixteen-channel transmission.

What does a major clinical application of dual channel transmit technology?. To make the magnet quieter. To reduce or eliminate RF inhomogeneities (dielectric effect/shading), especially in 3T body imaging. To allow patients to wear metal zippers. To decrease the total weight of the scanner.

How does the image uniformity change when switching from conventional CP transmission to two-channel transmission in 3T body imaging?. The image becomes much darker. The image becomes blurrier. Shading is reduced, and the signal becomes more uniform across the image. There is no noticeable difference in uniformity.

If an implant's "Conditions of Use" specify "Quadrature Transmit Only," and you are using a multi-transmit 3T system, what must you do?. Proceed with the scan as normal. Switch the system to a quadrature or CP (Circularly Polarized) transmit mode. Use a higher power setting to overcome the restriction. Cancel the scan entirely as it is impossible to comply.

Multi-transmit technology may also be referred to in clinical practice as: B1 or RF shimming. Magnetic gradient leveling. Cryogenic balancing. Signal-to-noise amplification.

Why have concerns been raised regarding the use of multi-transmit mode in pregnant patients?. It makes the scan take too long for the patient to lie still. Differences in local SAR (Specific Absorption Rate) compared to CP transmit are not yet fully understood. It causes the room temperature to rise too quickly. It interferes with the fetal heart monitor.

According to the research papers cited in the video, what mode is currently recommended for scanning pregnant patients until more is known?. Dual channels transmit mode. Multi-nuclear transmit mode. High-SAR research mode. CP (Circularly Polarized) transmit mode.

Research suggests that using multi-transmit mode instead of CP mode can potentially lead to what effect on a fetus?. A decrease in image resolution. Significant increase in fetal RF exposure. No change in exposure levels. Improved fetal visualization at the cost of safety.