Part C Flashcards
Ferrous material
a) is strongly attracted to the magnet
b) is not attracted to the magnet
c) exhibits a slight positive magnetic attraction
d) is repelled by the magnet
a) is strongly attracted to the magnet
Paramagnetic materal
a) is strongly attracted to the magnet
b) is not attracted to the magnet
c) exhibits a slight positive magnetic attraction
d) is repelled by the magnet
c) exhibits a slight positive magnetic attraction
Ferrous material can exhibit the following behaviour in an MRI system:
a) torque or twist
b) heat up
c) absorb RF
d) all of the above
D) all of the above
The recommended method for clearing a patient who may have metal in the eye is:
a) physical exam
b) plain film of the orbits
c) split lamp examination
d) ultrasound examination
b) plain film of the orbits
To protect patients from hearing damage it is recommended that hearing protection by used:
a) when scanning pregnant patients
b) when using fast spin echo sequences only
c) when doing EPI studies
d) with all patients
d) with all patients
For patient safety, an ECG gating leads should be:
a) run straight out of the bore without touching the patient
b) looped tightly under the patients clothing
c) wrapped around an extremity for stability
a) run straight out of the bore without touching the patient
Patients with VP shunts are safe to scan
a) YEs
b) No
c) under specified conditions
c) under specified conditions
Only MR compatible monitoring equipment is used in the MR suite because:
a) other monitor will cause an RF artefact on scan images
b)They do not have metal in them
c) They have fibre optic pulse oximeter leads which are not a conductive material and this reduces the likelihood of skin burns.
d) A and C
D) A and C
A patient had a tubal ligation many years ago and cannot recall whether the clips were used were metal or plastic. Which of the following statements is true:
a) All fallopian clip are metal and cannot be scanned
b) any force that may be exerted on the clips by the magnetic field is not going to be any more than the forces exerted upon them normally by peristalsis etc. so it is OK for her to have the scan.
c) As she is unsure, we should cancel the scan
d) She should have an x-ray of her pelvis to determine the nature of the clips.
b) any force that may be exerted on the clips by the magnetic field is not going to be any more than the forces exerted upon them normally by peristalsis.
A patients presents with heavy black tattoos on his body. Do we show concern?
a) No. The tattoos are of no significance to MRI imaging
b) Yes. The pigments, especially black and dark colours can be ferrous and can result in oedema and skin irritation around the tattoo site.
c). No. Even though the tattoos are often made with pigments containing ferrous particles, if they have been there for more than 6 weeks they will not cause irritation to the skin and can be safely scanned.
b) Yes. The pigments, especially black and dark colours can be ferrous and can result in oedema and skin irritation around the tattoo site.
An unconscious patient presents for a spinal MRI examination with a suspected history of previous brain surgery. The patient should therefore:
a) go through a thorough screening process including inspection for other surgical scars and performing spot radiographs
b) not undergo an MRI scan
c) only if the referring doctor has stated the patient is safe to scan.
d) A and C
d) A and C
A quench refers to the sudden loss of magnet superconductivity when its temperature is raised. Associated with this there:
a) is a rapid boil off of cryogens into the atmosphere associated with a loud roaring noise.
b) may be a release of some cryogenic gasses into the MR room resulting in a drop of temperature and increased pressure.
c) A and C
c) A and C
A patient presents with sternal wires in-situ as a result of cardiac bypass surgery three years previous. The sternal wires are a contraindication for scanning. True or False
False
Both gadolinium contrast will cause a _________ in T1 and T2 relaxation times of tissues.
a) Increase
b) decrease
c) no change
b) decrease
Gadolinium contrast at clinically approved doses are __________ contrast agents
a) ferromagnetic
b) diagmagnetic
c) paramagnetic
c) paramagnetic
In clinical doses the resultant change on T1 weighted spin echo images of the tissues affected by the contrast media will be _________ signal intensity
a) decreased
b) increased
c) no change in
b) increased
The use of IV contrast media can improve the visibility of small vessels on 3D TOF MR angiography?
a) False
b) True
b) true
Gradient magnetic fields are of a safety concern because they ________
a) produce high amounts of RF energy
b) induce current in conductors
c) cause short-term memory loss
d) a and b
b) induce current in conductors
The amount of RF power deposited into the body is dependent upon _________
a) the duration of the RF pulse
b) the TE selected
c) the receive bandwidth
d) a and c
a) the duration of the RF pulse
Increasing the gradient slew rate can cause an increase probability for ________
a) RF burn injury
b) peripheral nerve stimulation
c) increased tissue heating
d) reduced acoustic noise
b) peripheral nerve stimulation
gradient slew rate = time it takes for GE to achieve max amplitude.
Which of the following patients should be monitored using pulse oximetry?
a) patients who are unconscious
b) patients at high risk for contrast reaction
c) patients who do not speak English
d) any/all of the above
d) all of the above
Which of the following devices are contraindicated with respects to MRI?
a) metallic intra-ocular foreign body
b) nonferrous intracranial aneurysm clip
c) sternal wires from coronary artery bypass surgery
d) a and b only
a) metallic intra-ocular foreign bodies
As the result of the RF absorption an increase in body temperature is ________?
a) rarely detectable
b) greatest on the outside and becoming less at the center
c) greatest at the centre and becoming less on the surface
d) evenly distributed throughout the body.
b) greatest on the outside and becoming less at the centre
Which of the following sequences is more likely to result in high SAR?
a) FSE with an ETL of 24
b) FSE with an ETL of 8
c) EPI with an ETL of 128
d) Fast 3D GRE
c) EPI with an ETL of 128
Precautions for administration of Gadolinium-based contrast agents include:
a) high creatinine
b) high blood pressure
c) pregnancy and breast feeding
d) no known precautions
b) high blood pressure
Which of the following cannot cause a patient burn injury?
a) fiber optic cable
b) surface coil wire
c) EKG electrodes
d) a and b only
a) fiber optic cable
MRI contrast is designed to cross and in-tact brain blood barrier. True or false
False, large molecules such as gad cannot cross and intact brain blood barrier.
