If you were a MR technologist/radiographer scanning a patient with a knee replacement, it would be safe to proceed with the scan provided:
A. ) you test whether the metal implant is magnetic using a hand-held bar magnet
B. ) the patient tells you that the implant is non-magnetic
C. ) the referring doctor supplies evidence that the metal implant is non-magnetic and certified as MR safe at the field strength of the scanner
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The role of the Faraday cage in a magnet room is to:
A. ) attenuate radiofrequency signals from the external environment and contain radiofrequencies generated by the transmitter within the magnet room
B. ) shield the external environment from the strong magnetic field
C. ) align the nuclear spins along the horizontal axis of the magnet
Radiofrequency transmit coils are responsible for:
A. ) producing a magnetic field gradient across the sample
B. ) MR excitation of nuclei in tissue and detection of the MR signal
C. ) MR excitation of nuclei in tissue
In an MRI magnet system the gradient coils are placed:
A. ) between the magnet cryostat and the magnet coils
B. ) between the shim coils and the RF coil
C. ) between the RF coil and the patient
The direction of muscle fibres or neurons in the brain can be detected by:
A. ) measuring the wash-in and wash-out of the bolus of a contrast agent delivered.
B. ) measuring blood flow by encoding moving spins in the blood.
C. ) measuring the predominance of water diffusion in a particular direction.