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What pulse sequence will produce the most patient heating? A. Inverse recovery sequence B. Single shot fast spin echo C. Conventional spin echo D. Gradient Echo - B. Single shot fast spin echo During acquisition, it is noticed that the T wave of the cardiac cycle is elevated. What is this artifact called? A. Magnetohydrodynamic Effect B. Excitation C. Teratogenesis D. Magnetophosphenes - A. Magnetohyrdodynamic Effect When can heating occur in a wire? A. Only in ferrous...

physical effects of STATIC FIELDS - translation rotation lenz physical effects of TIME-VARYING FIELDS - motion noise induced currents (on object/in person) lenz translation rotation everything NOT MR SAFE needs to be behind... - 5 gauss line earth's magnetic fiels - 0.5 gauss 1.5T = ___ gauss - 15,000 3 T = ___ gauss - 30,000 MR device can be considered non-significant risk IF: (list) - static mag field SAR dB/dt sound pressure level ^ are bel...

Zero Boil-Off - System that reduces/eliminates the need to recharge Helium in a magnet. Quench - Quickly eliminating the magnetic field. Not immediate, takes 3 to 5 minutes to completely eliminate magnetic field. Loud Noise as Helium rushes out of Quench Vent. Can cause crack in the wire (very costly to repair/replace). Ohm's Law - Resistance that is equal to Voltage divided by the amperage in a wire. V=IR Use of Cryogen reduces/eliminates heating with high voltage...

MR Safety Officer responsibilities - The role of MRSO is often carried out by the senior Radiographer (in the USA this will generally be an MR technologist), but other suitably trained individuals could also fill this role. Multiple MRSOs could be appointed, provided only one is in charge at a given time. His/her responsibilities include the following: To be readily accessible and available (eg, to the operators of the MR system) at all times that the MR facility is accessible. Ensuri...

How do magnetic flux lines travel? A. North to South B. South to North C. East to West D. West to East - A North to South Which of the following can be potential safety concerns to a patient in the static magnetic field? A. Electrically conductive materials B. Ferrous objects C. Magnetic objects D. All of the choices. - D. All of the choices An object that retains its magnetic field when exiting the static magnetic field is call what? A. Paramagnetic B. Diamagnetic C. Ferr...

Time Varying Magnetic Field Gradients are expressed as - dB/dt (vary in strength over time) Time Varying Magnetic Field gradients are produced by - three gradient coils inside the magnet The gradient coil is proximal to - the RF coil Maximum amplitude is expressed in - T/m or mT/m Time it takes gradient field to reach the max amplitude - Rise time Rise time is expressed in fractions of - seconds slew rate - max amp/rise time Slew rate is expressed in uni...

MRSO - Emergent Situations and Patient Considerations - Module 8 Questions with 100% Correct Answers Rated A+

What group issued the ACR white paper MRI safety? a. Food and drug association. b. OSHA c. EPA d. American college of radiology blue ribbon panel on MR safety. - d. American college of radiology blue ribbon panel on MR safety. This individual must have an in-depth understanding of the risks associated with the MRI environment? a. level 1 personnel b. level 2 personnel c. non-MR personnel d. the patient - b. level 2 personnel Which of the following statements is true of non-MR...

Static field metrics - 1T = 10,000G (0.5mT = 5G) Who published guidelines titled "Criteria for Significant Risk" that specifies what qualifies as significant risk of exposure to magnetic field associated with MRI. - FDA FDA guidelines state EXPOSURE to a static field that does not pose a significant risk is: - Limited to 8T for adults and infants > 1 month Limited to 4T for infants < 1 month Forces related to static field - -Torque/rotation -Translation/Displace...

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 wha...

Purpose of RF (B1) field - excite hydrogen protons RF energy is absorbed by tissues - within the volume of the RF transmit coil. This is a thermogenic process. Thermogenic process - Results in production of heat. Ex: RF energy absorption MRI local and whole-body tissue heating is due to - magnetic induction Types of RF coil designs - -linearly polarized -circularly polarized (quadrature) Function of coils - -transmit only -receive only -transmit/receive Mos...

The quench vent in the MR room should be inspected by who? a. facility engineers b. manufacturer engineers c. MR tech d. MRMD - b. manufacturer engineers The quench vent outside the MR facility is inspected by who? a. facility engineers b. manufacture engineer c. MR tech d. MRMD - a. facility engineers If a cryogen comes in contact with skin, what will happen? a. frostbite/necrosis b. nothing, in its gas form c. explode d. combust - a. frostbite/necrosis Why is asph...

IEC DB/DBA limits for MRI - 140 DB 99 DBA parameters to reduce noise in MRI - -thicker slices -larger FOV -smaller matrix -parallel imaging -reducing bandwidth (increasing TE) -active noise reduction -Low SAR RF mode (increase in echo spacing)-thicker slices MRI sequence that produces the most and least noise in MRI - Most noise EPI/DWI least noise spin echo sequence an increase in slew rate and gradient amplitude causes an increase in - Peripheral nerve stimulatio...

Slew rate - Speed at which gradient coil turns on and off Time-varying Gradient - Induced current in a patient Magnetic Flux Lines - Travel from North to South pole permanent magnet - Can not be turned off Very inexpensive; extremely heavy Approximately 0.4T Vertical vector Resistive magnet - Can be turned on and off Costly due to cooling Approximately 0.6T Vertical or horizontal vector Superconductive magnet - Approximately 10T Low electricity; reasonable...

Which of the following describe when a non-ferrous object is repulsed by static magnetic field? a. Fourier transformation b. Lenz's force c. Ohm's law d. Larmor equation - b. Lenz's force What is the FDA SAR limit for the whole body in first level controlled operating mode? a. 8 W/kg for 15 mins b. 4 W/kg for 15 mins c. 3 W/kg for 10 mins d. 7 W/kg for 20 mins - b. 4 W/kg for 15 mins Gadolinium contains what kind of magnetism? a. Diamagnetic b. Paramagnetic c. Ferroma...

All MR medical directors must report incidents to which of the following? a. FDA Medwatch Program b. ACR MR safety board c. None of the choices d. All of the choices - a. FDA Medwatch Program Which of the following is not true? a. Screening process for non-MR personnel and MR personnel should be different. b. Screening process for non-MR personnel and MR personnel should be the same. c. Unscreened patient should not enter zone III. d. Zone IV is the responsibility of the a level 2 ...

How do magnetic flux lines travel? A. North to South B. South to North C. East to West D. West to East - A North to South Which of the following can be potential safety concerns to a patient in the static magnetic field? A. Electrically conductive materials B. Ferrous objects C. Magnetic objects D. All of the choices. - D. All of the choices An object that retains its magnetic field when exiting the static magnetic field is call what? A. Paramagnetic B. Diamagnetic C. Ferr...

What is the name of the gradient coil used to produce sagittal and coronal images? a. Transverse coil b. Golay coil c. Maxwell coil d. Receiver coil - ️️ b. Golay coil ("saddle coil") Which of the following is able to handle the most RF heating? a. elderly b. adult c. obese adult d. neonate - ️️ d. neonate Which of the following techniques can be used to increase the echo spacing? Select all that apply. a. Increase the TR b. Decrease receiving bandwidth c. Increase...

The control room is found where? a. Zone I b. Zone II c. Zone III d. Zone IV - C. Zone III Which of the following describe when a non-ferrous object is repulsed by static magnetic field? a. Fourier transformation b. Lenz's force c. Ohm's law d. Larmor equation - b. Lenz's force Which of the following are recommended by the ACR Guidance document in MR safety 2013 in proper scanning of a patient? I. Metal detector II. Ferromagnetic detection system III. Written screen...

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