Quiz: Cross Cutting & Emerging Technologies 4

Cross Cutting & Emerging Technologies Part 4:
MR-Guided Radiotherapy
by Rob H.N. Tijssen

Objectives: Online MRI guidance is the new disruptive technology for radiotherapy that will facilitate online and real-time adaptive treatments. An overview of the current hybrid MRI-guided treatment machines will be given. The MRI-Linac, which combines a 1.5T closed bore system with a modern 7MV linear accelerator will be described. Its clinical introduction is highlighted and the potential for future treatments and research is outlined.
1. MRI for radiotherapy typically requires _________ resolution with _________ spatial integrity compared to diagnostic imaging.*
- higher; higher
- higher; equal
- lower; equal
Jump to the relevant part of the video for question 1:
2. To decouple the Linear accelerator (Linac) from the MRI scanner...*
- The frequency of the microwave on the Linac is modified to prevent RF noise within the receiver bandwidth at 1.5T
- The electron gun is placed outside the Faraday cage, and the active shielding is modified to create a region of zero field
- Electrons are accelerated to nearly the speed of light to mitigate the Lorentz force effects created by the main magnetic field of the scanner.
Jump to the relevant part of the video for question 2:
3. The MR-linac is equipped with a set of split gradient coils, because...*
- The gradient coils would attenuate the electron beam too much
- The gradient coils would attenuate the photon beam too much
- The gradient coil performance drops while being irradiated
Jump to the relevant part of the video for question 3: