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ARRT MRI EXAMS 2025- 2026 (FINAL, PRACTICE &
STUDY GUIDE) 650+QUESTIONS AND
ANSWERS|GRADED A+
FINAL EXAM
The effects of main magnetic field inhomogeneities on the FID signal are corrected for in a Spin-echo sequence by applying a second radio- frequency pulse. The flip angle of this radio-frequency pulse is: ANS:->>>
- 180 degrees Of the following statements, which describes part of the basic MR imagingprocess? ANS:->>> - Radio-frequency signals interact with hydrogen protons Which type of electromagnetic coils correct inhomogeneities in themainmagnetic field? ANS:->>> - Shim coils Immediately after an initial 90 degree radio-frequency pulse is turned off,the hydrogen protons will begin to: ANS:->>> - Dephase Tissues that are very efficient at Spin-lattice interactions near the Larmor frequency, such as fatty tissues, should have: ANS:->>> - Low T1 valuesand produces
hyperintense signals T1 is the measurement of time for the longitudinal component of thenet magnetization vector to recover what percentage of its original value afterthe application of a 90 degree radio-frequency pulse? ANS:->>>- 63% The tissue characteristic which depends more on the state (solid, liquid,gas) of a tissue than any other factor is: ANS:->>>- T2 effects The basic process of MR signal generation contains two basic steps,theyare: ANS:->>> - Stimulation and relaxation The T1 Process is also known as: ANS:->>>- Spin-Lattice The T2 process is also known as: ANS:->>> - Spin-Spin Once in the main magnetic field, a majority of hydrogen protonswill alignthemselves: ANS:->>>- Parallel to B Magnetic resonance imaging is derived from the process known as:
- ANSWER--Nuclear magnetic resonance The tissue characteristic that depends heavily on the relative contentof
Magnetic susceptibility is defined as: (RESEARCH THIS) ANS:->>> - Tendency of a substance to attract or repel magnetic lines of force which isdecided by the magnetic properties of its electrons (RESEARCH THIS) In comparison to Computed Axial Tomography, an advantage ofMRI is: - ANSWER-- Superior soft-tissue contrast resolution Fast transition phenomenon and entry phenomenon are theoriesthat explain which of the following tissue characteristics? ANS:->>>- Velocityeffects In a loop of conductor in which an electric current is introduced and maintained, a magnetic field will be produced in the center perpendicular tothe flow of electric current. This is called: ANS:->>>
- Faraday's Law Which type of MRI magnet has attainable field strengths of 0.35 Tesla to 3Tesla for clinical use in the U.S.A, and higher strengthselsewhere and in research? - ANSWER— Superconcuctive The Process of relaxation begins when ANS:->>>-B1 is turned off A sinewave is a symbol used to measure electromagnetic energy. A sinewave's two components of measure are: ANS:->>>-Wavelengthandfrequency
Magnetic fields have direction which are usually designated as northandsouth, therefore magnetic fields are described as: ANS:->>>- Dipoles At any one time, human body tissue, in general, is made up of 50-90%: - ANSWER--H(Hydrogen) Once the net magnetization vector (NMV) has moved away from equilibrium the following will occur: ANS:->>>-The transverse componentwill increase The T1 process is also known as: ANS:->>>-Spin-Lattice Which of the following is the Larmor equation? ANS:->>>-W0=Y+B The mechanism of T2 contrast enhancement agents is to: ANS:->>>- Decrease T2 relaxation time, therefore producing lowsignal Which type of MRI magnet requires cryogen to cool magnetic coils to 4degrees Kelvin? ANS:->>>-Superconductive A time constant that characterizes the fast rate of transverse magnetization because of the inhomogeneities of the main magnetic field is: ANS:->>>-T2* As the net magnetization vector precesses within the transverseplane, itinduces an electrical current in a: ANS:->>>-Radio- frequency coil To symbolize the flow and area of a magnetic field, lines are usedwhichare called: ANS:->>>-Field or flux All chemical substances have an assigned constant known as the: - ANSWER--Gyro-magnetic ratio. MRI systems require rooms that provide specific shielding requirements. These rooms are lined with what types of materials? ANS:->>>-Copperor galvanized steel Which type of MRI magnet requires no electricity to maintain its
netmagnetization vector to decrease what percentage of its maximum value after the application of a 90 degree radio-frequencypulse: ANS:->>>- 37% In the USA, MRI systems in clinical use have main magnetic field strengthsthat range from: ANS:->>>-0.06 Tesla to 3 Tesla On a very basic level, the three basic components required to attainMRsignals are: ANS:->>>-Magnetic field, proton, radio-wave The main magnetic field of the MRI system is described as constant and always oriented in one set direction, either horizontal or vertical(dependenton type of magnet). The transmitted radio-frequency, in comparison, is described as: ANS:-
-Oscillating and always perpendicular to B Which of the following parameters controls the amount of contrastseen inan image due to T2 relaxation: ANS:->>>-TE A magnetic field strength of 0.5T is equivalent to: ANS:->>>-5000G An example of a dipole is: ANS:->>>-A hydrogen nucleus, a barmagnet,and the earth Hydrogen nuclei have a magnetic moment because they posses apropertycalled: ANS:->>>-Spin Protons that aligned in the anti-parallel direction are in: ANS:->>>-A highenergy state The formula that describes the relationship between the static magneticfield and the processional frequency of the hydrogen proton is the: ANS:->>>-Larmor equation To calculate the processional frequency, the strength of the static magneticfield is multiplied by a constant known as: ANS:->>>-The gyromagnetic ratio
The field strength of an MR imaging magnet as measured within the bore ismost typically expressed in terms of: ANS:->>>-Tesla The Larmor, processional or resonance frequency of hydrogen protons in astatic magnetic field of 0.5T is approximately: ANS:->>>
- 21.288 MHz Following RF excitation, as transverse magnetization (Mxy) decays tozero,The MR signal: ANS:->>>-Decays to zero RF pulses are identified according to the: ANS:->>>-Flip angle Following the excitation pulse, the FID decays: ANS:->>>- Exponentially Of the following tissues, which has the longest T2 value ANS:-
-Cerebrospinal fluid (1600) Of the following tissues, which has the shortest T1 value? ANS:->>>-Fat Nuclei in their natural environment (in absence of a significantmagneticfield) are aligned: ANS:->>>-Randomly -A hydrogen nucleus, a barmagnet,and the earth Hydrogen nuclei have a magnetic moment because they posses apropertycalled: ANS:->>>-Spin Protons that aligned in the anti-parallel direction are in: ANS:->>>-A highenergy state The formula that describes the relationship between the static magneticfield and the processional frequency of the hydrogen proton is the: ANS:->>>-Larmor equation To calculate the processional frequency, the strength of the static magneticfield is multiplied by a constant known as: ANS:->>>-The gyromagnetic ratio The field strength of an MR imaging magnet as measured within the bore ismost typically expressed in terms of: ANS:->>>-Tesla The Larmor, processional or resonance frequency of hydrogen protons in astatic magnetic field of 0.5T is approximately: ANS:->>> - 21.288 MHz Following RF excitation, as transverse magnetization (Mxy) decays tozero,The MR signal: ANS:->>>-Decays to zero RF pulses are identified according to the: ANS:->>>-Flip angle Following the excitation pulse, the FID decays: ANS:->>>- Exponentially Of the following tissues, which has the longest T2 value ANS:- >>>-Cerebrospinal fluid (1600) Of the following tissues, which has the shortest T1 value? ANS:->>>-Fat Nuclei in their natural environment (in absence of a significantmagneticfield) are aligned: ANS:->>>-Randomly The characteristic time constant for loss of phase coherence or transversemagnetization due to static magnetic field inhomogeneities is known as: ANS:->>>-T2* Which characteristic of tissue, in MRI is the result of fast transition phenomenon and/or entry phenomenon: ANS:->>>-Flow/velocityeffects MRI magnets that require a steady current of electricity passed throughcoils wrapped around an iron or air core are: ANS:->>>-Resistive
material ispassed through a strong magnetic field. ANS:->>>- Torque Currently, there is no evidence of a threat to fetal development from MRIexposure: ANS:->>>-False The factor, which determines the calculated SAR averages is: ANS:-
-The patients weight in kilograms The receive bandwidth is related to the slope of whichgradient? - ANSWER--Slice select In an inversion recovery pulse sequence the net magnetization vector isrotated to the physical negative Z axis by applying a: ANS:->>>- 180 degree pulse describes a proton density image? ANS:->>>-Long TR and Short TE The inversion time, in an inversion recovery pulse sequence, is the timeinterval between the: ANS:->>>- 180 and 90 degree pulse In general, parameter settings of TR and TE for attaining T1 and T imagesare as follows: ANS:->>>-T1; TR 100-1000ms, TE 20-30ms/ T2; TR 1600 - 3000, TE 70 - 100 The pulse sequence that replaces the second RF pulse with a magnetic field gradient to rephase the transverse vector and producethe echo signalis: ANS:- -Gradient Echo The artifact known as "cross-talk" can be corrected for by adjusting whichparameter? ANS:->>>-Slice interval In terms of time, the least expensive parameter to increase, of thosethat affect time, when attempting to improve image quality: ANS:->>>-Matrix By increasing the parameter, Matrix, the size of the pixel will: ANS:- -Decrease Increasing which parameter is considered the "best" technique for improving image quality? ANS:->>>-NEX Of the following techniques, which one is applied to prevent "crosstalk"between multi-slices with little or no interslice "gap"?
ANS:->>>- Interleaving The slice selection exposes the patient's body to a series of increasing or decreasing magnetic fields to select a slice. In what relation to the slice is this gradient introduced? ANS:->>>- Perpendicular Which method for providing spatial localization is employed during a pulse sequence when selecting only one slice at a time: ANS:->>>
- 2DFT Which method for providing spatial localization is employed during a pulse sequence when selecting a volume of slices: ANS:->>>- 3DFT For MRI magnets, the specification for field homogeneity that is consideredacceptable is: ANS:->>>- 20 - 30ppm The primary factor of an Inversion Recovery pulse sequence is whichof thefollowing parameters? ANS:->>>-TI Of the Different types of coils used in MRI, which type(s) are foundonly inthe housing of the main magnet? ANS:->>>-Shim/Gradient Which of the following causes artifacts on MR images is most commonlymistaken for pathological signal: ANS:->>>-Chemical shift Of the following anatomical structures which is considered to be normallyenhancing post gadolinium injection? ANS:->>>-ChoroidPlexus Cryogen levels should never fall below: ANS:->>>-50% The electromagnetic coil responsible for producing the strongmagnetic field of a superconducting magnet is embedded in a which serves as aninsulator from heat in the event of a quench ANS:->>>-Copper matrix
pulsesequence most commonly employed is a: ANS:->>>-T1weighted All FDA approved gadolinium enhancement agents for MRI areadministered at the same dose, it is: ANS:->>>-0.1mmols/kg On MRI images, an acute hemorrhage will have a bright signalintensity ina T weighted pulse sequence: ANS:->>>-False Employing an Inversion Recovery pulse sequence with a water suppression technique, a normal intervertebral disc will appear dark: - ANSWER--True A T2 weighted pulse sequence of the brain results in the white matterappearing brighter than the gray matter: ANS:->>>-False When describing overall image quality, which best describes the difference in signal intensity between two adjacent structures (A & B) divided by noise(N): ANS:->>>-Contrast-to-noise ratio In spatial localization, an efficient digital implementation of the mathematical method for converting a time-varying signal into its frequencyand/or phase components that is actually performed by theMRI computer is known as: ANS:-
-Fast Fourier transform A paramagnetic, rare, earth substance, attached to a chelating liquid forMRI enhancement purposes is: ANS:->>>-Gadolinium In understanding MRI enhancement agents it is important to knowthat tissues that have low (short) relaxation times, have: ANS:->>>- Higherrelaxation rates In 1990, Lauffer described two types of enhancement media, the mechanism of
the T1 agent is to: ANS:->>>-Increase T1 relaxationtime,therefore emitting high signal In 1990, Lauffer described two types of enhancement media, the mechanism of the T2 agent is to: ANS:->>>-Increase T2 relaxationtime,therefore emitting low signal Of the following enhancement agents, which is still investigational? - ANSWER--Hepatobiliary, liver/spleen, bloodpool, tumor specific The normal pituitary gland should appear bright following injection of agadolinium enhancement agent: ANS:->>>-True Gadolinium enhancement agents will readily pass their tendency to bind to proteins, enzymes or membranes. The degree to which they dissociate is ameasure of their: ANS:->>>-Toxicity Passing from one compartment to another is the process ofpassing through an abnormal blood-brain-barrier. The compartments involved arethe: ANS:-
-Intravascular tointerstitial Of the following MRI enhancement agents, which are FDA approved forclinical use? ANS:->>>-Gd-DTPA, Gd-HP-DO3A, Gd-DTPA-BMA Enhancement can be demonstrated on which of the followingpulse sequences post gadolinium injection: ANS:->>>-T1 weighted, gradientecho, inversion recovery SAR (Specific Absorption Rate), set by the FDA, is the rate that the RF energy is introduced to the body tissue, measured in watts per kilogram: - ANSWER--True The maximum exposure of the head and trunk to the main magneticfield(B0), is: ANS:->>>-3T The maximum exposure of extremities to the main magnetic field (B0) is: -
Local exposures to the Radiofrequency (RF) are: less than 38 degreesC inthe head, Less than 39 degrees C in the trunk, less than 40 degrees C in the extremities: ANS:->>>-True Patients with cardiac pacemakers are only contraindicated for an MRI scanin main magnets of more that 0.5T (>0.5T): ANS:->>>-False Magnetophosphenes are described as: ANS:->>>-Seeing flashes oflight Magnetically sensitive objects such as credit cards, magnetic tapes anddiscs, and EKG equipment should be kept beyond the gauss line: ANS:->>>- 5 Some fastened equipment such as pulse oximeters, and electrodeshavebeen reported to cause 3rd degree burns: ANS:->>>-True Being a relatively new field in medicine, the radio-biological questions about MRI, including delayed response concerns, are still unANSWERed:
- ANSWER--True In the environment of an MR main magnetic field, most implants thatcausea deflation are considered safe for imaging: ANS:->>>-False Once the MRI patient is comfortable and apparently has no problem withthe overall procedure, is is acceptable for the technologist to leave the scanning area while a long scan isunderway: ANS:->>>-False To avoid any possibility of a ferromagnetic object becoming a projectile, it would be advisable and safer to have the patient remove all metal objects from their person prior to the scan: ANS:->>>- True Given the tissue sample containing 10 mobile hydrogen protons, it can be safely
assumed that approximately of those protons will to the static magnetic field: ANS:->>>-10/ align parallel The field strength of an MR imaging magnet as measured within thebore ismost typically expressed in terms of : ANS:->>>-Tesla The Larmor, processional or resonance frequency of hydrogenprotons in astatic magnetic field of 1.0 T is approximately: ANS:->>>-42.576 MHz When the net magnetization in the XY plane has ceased to exist thecondition of the has been reached: ANS:->>>- Equilibrium Following the RF excitation, as transverse magnetization (MXy)decays tozero, the MR signal: ANS:->>>-Decays to zero An RF pulse transmitted with a strength and duration sufficient to flipthe Mvector from the Z axis to the XY plane is a: ANS:->>>- 90 degree pulse An MR signal is generated when the net magnetization
The and are terms which indicate the amount of macroscopic magnetization vector is rotated by an RF pulse withrespect to the staticmagnetic field: ANS:->>>-Flip angle/ nutation angle Nuclei having an of nucleons (neutrons or protons) will tend to possessmagnetic properties: ANS:->>>-Odd numbers Spin-lattice relaxation time is another term representing: ANS:-
-T1relaxation The tendency of a substance to become magnetized or to distort an appliedmagnetic field is: ANS:->>>-Magnetic susceptibility is the uniformity of the static magnetic field, expressed in termsof PPM(parts per million) over a defined volume ANS:->>>- Homogeneity Spin-spin relaxation is another term for: ANS:->>>-T2 relaxation is the property of most substances having paired orbital electronsresulting in these substances being weakly repelled by the applied magnetic field: ANS:->>>-Diamagnetic A spin-lattice occurs: ANS:->>>-The spinning nuclei begin to move out ofthe XY plane and realign toward the Z axis occurs when the frequency of the intermittent magnetic field, the RF pulse, matches the frequency of the precessing nuclei- the nucleiabsorbingthe energy of the RF pulse and flipping the nuclei at some alpha angle fromthe Z axis and into the XY plane: ANS:->>>- Resonance
- 90 degree pulse An MR signal is generated when the net magnetization The and are terms which indicate the amount of macroscopic magnetization vector is rotated by an RF pulse withrespect to the staticmagnetic field: ANS:->>>-Flip angle/ nutation angle Nuclei having an of nucleons (neutrons or protons) will tend to possessmagnetic properties: ANS:->>>-Odd numbers Spin-lattice relaxation time is another term representing: ANS:- >>>-T1relaxation The tendency of a substance to become magnetized or to distort an appliedmagnetic field is: ANS:->>>-Magnetic susceptibility is the uniformity of the static magnetic field, expressed in termsof PPM(parts per million) over a defined volume ANS:->>>- Homogeneity Spin-spin relaxation is another term for: ANS:->>>-T2 relaxation is the property of most substances having paired orbital electronsresulting in these substances being weakly repelled by the applied magnetic field: ANS:->>>-Diamagnetic A spin-lattice occurs: ANS:->>>-The spinning nuclei begin to move out ofthe XY plane and realign toward the Z axis occurs when the frequency of the intermittent magnetic field, the RF pulse, matches the frequency of the precessing nuclei- the nucleiabsorbingthe energy of the RF pulse and flipping the nuclei at some alpha angle fromthe Z axis and into the XY plane: ANS:->>>- Resonance Because of a variation of only 10-15%, in most tissue, which tissue characteristic does not allow for much contrast resolution on MR images: - ANSWER--Hydrogen concentration
Raw data (digitized echoes) is loaded into the array processor in a 2D dataacquisition matrix, commonly referred to as: ANS:->>>-K-space In MR, spatial resolution is determined by and : ANS:->>>- Slicethickness/ pixel size TR is defined as: ANS:->>>-The time interval between 90 degreepulses TE is defined as: ANS:->>>-The time interval between the 90 degreepulse and the echo signal During 2DFT, spin echo pulse sequences, fast flowing bloodusuallyappears: ANS:->>>-Hypointense During 2DFT, spin-echo pulse sequences, slow flowing blood usuallyappears: ANS:->>>-Hyperintense The measure of spin-spin interactions is: ANS:->>>-T2 relaxations TI is defined as: ANS:->>>-The time interval between the 180 degree andthe 90 degree pulses Which pulse sequences do not use Fourier Transform? ANS:->>>-Noneof the above In a 2DFT conventional spin-echo multislice pulse sequence, scan time isgiven by the following equation: ANS:->>>-TR x NEX x # ofphase
