MRSO: Exam 3 Questions with 100% Correct Solutions Rated A+

Which of the following are physiologic factors that occur from an anaphylactic reaction? Select all that apply. a. Elevated creatinine levels b. Vasodilation c. Bronchial smooth muscle contraction d. Increased vascular permeability - b, c, d A non-emergent quench can take approximately how long? a. 1 minute b. 20 seconds c. 5-15 mins d. 2- 4 mins - c. 5-15 mins An emergent quench will take approximately 1 minute. The roaring sound heard during a quench is caused by what? a. The sound of the ignition of the coils of wire used to heat the cryogen b. The massive volume of helium boiling off through the quench vent c. If a loud noise is heard, something is going wrong and you should evacuate. d. The sound of the system shutting down. - b. The massive volume of helium boiling off through the quench vent Which of the following will reduce the risk of patient burning in a pacing wire? a. Place pacing wire outside RF field b. Advance patient into scanner head first c. Don't scan patient d. Place an ice pack on patient's chest - a. Place pacing wire outside RF field A patient has removed a vagus stimulator with the leads left in, and is having a MR knee performed with the transmit-receive coil. In terms of patient heating, is it safe to scan? a. No b. Yes, only with heat sink c. Yes d. Yes, only if that patient is less than 200lb. - c. Yes Heating can only occur in areas where RF energy is exposed to. If the implant is not exposed to RF energy, heating will not occur. Which of the following are NOT true? a. Screening process for non-MR personnel and MR personnel should be the same b. Unscreened patients should not enter Zone III c. Screening process for non-MR personnel and MR personnel should be different. d. Zone IV is the responsibility of Level 2 personnel - c. Screening process for non-MR personnel and MR personnel should be different. Which of the following is a true statement? a. A level 1 or 2 personnel should be available to help a MR personnel in Zone IV in non-emergent situations b. All level 2 personnel are MR techs c. A pregnant patient may not undergo an MR exam d. A level 1 personnel may scan a patient to relieve a level 2 personnel - a. A level 1 or 2 personnel should be available to help a MR personnel in Zone IV in non-emergent situations Lorenz's force can be used to describe what? a. Translation force b. The noise heard in the MRI c. Peripheral nerve stimulation d. Resonance heating - b. The noise heard in the MRI The rapids turning on & off of gradient coils causes a torque against the gantry. A contrast media with high relaxivity will do what when compared to contrast media with lower relativity? a. Produce more signal b. Produce less signal c. Improve resolution d. Produce more image noise - a. Produce more signal To reduce pressure in an MR scan room during a quench with a faulty vent, what can be done? a. Drill a hole into the wall to Zone IV b. Wait 20 minutes for pressure to dissipate c. Open the door to Zone IV d. Break the window to Zone IV - d. Break the window to Zone IV Which of the following concerns can be caused by the time-varying gradient magnetic field? a. Anaphylaxis b. Diaphragm contractions c. Difficulty swallowing d. All of the choices - b. Diaphragm contractions Peripheral nerve stimulation that affects the diaphragm can cause it to contract in patients. This can cause problems for our patient making it difficult to breathe. Typically, where is the area surrounding the MR unit with the highest spatial magnetic gradient field? a. At the 5 Gauss line b. MR table c. Isocenter d. MR table control panel - d. MR table control panel When we reach isocenter, no spatial gradient is detected. When performing an MR pelvis, which of the following would cause the most artifact in our exam? a. Titanium hip replacement b. Ureter stent c. Dacron iliac graft d. IUD - a. Titanium hip replacement Which of the following stainless steels are non-ferrous? a. Martenistic b. Austenitic c. Ferritic d. Duplex - b. Austenitic Which of the following will create localized patient heating? a. None of the choices b. Body RF coil c. Receive only coil d. Transmit-receive coil - d. Transmit-receive coil Eddy currents are produced from which of the following? a. Moving MR table b. Gradient magnetic field c. All of the choices d. Static magnetic field - b. Gradient magnetic field As gradient coils are activated and deactivated, currents can be produced in conductive materials in our MR unit. These are eddy currents and cause artifact in our images. Which of the following is true if we increase the image matrix from 256 x 256 to 512 x 512? a. We use a weak time-varying gradient magnetic field b. We reduce patient heating c. We reduce peripheral nerve stimulation d. We use a stronger time-varying gradient magnetic field - d. We use a stronger time-varying gradient magnetic field Larger image matrix will produce higher resolution exams. The size of the image matrix is dependent on the phase encoding gradient coil. When we increase the image matrix, we increase the amplitude of our gradient coil. The slew rate influences which of the following? a. Both the minimal TE and image matrix size b. The size of the image matrix c. The minimal matrix size d. Shorter echo spacing - d. Shorter echo spacing The speed of the gradient coils activating and deactivating will affect the speed of our scanner. Faster slew rates will decrease the minimal TE & TR. The faster our gradient coils can turn on & off means that the rise time is faster. This will allow our echo spacing to shorten and therefore promote faster imaging. What zone is the quench pipe located where it vents outside? a. Zone II b. Zone III c. Zone IV d. Zone I - c. Zone III