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(ACTUAL EXAM) ARMRIT (240 QUESTIONS
AND EXACT ANSWERS) 2025 LATEST
UPDATED AND APPROVED.
Different tissues that have signals that appear similar on an MR image are described as: A) hypo intense B) hyper intense C) isointense D) isodense - Exact answer C) isointense in a large main magnetic field such as those employed in MRI, the motion of a hydrogen proton has been described as wobbling like a spinning top. this motion is called A) precession B) resonance C) frequency D) angular momentum - Exact answer A) precession magnetic resonance imaging is derived from the process known as: A) magnetic resonance angiography B) magnetic relaxation imaging C) nuclear magnetic resonance D) nuclear resonance imaging - Exact answer C) nuclear magnetic resonance Once the nmv has moved away from equilibrium, the following will occur A) the longitudinal component will increase B) the transverse component will decrease C) the longitudinal component will stay the same D) the transverse component will increase - Exact answer D) the transverse component will increase In MR, substances respond to a specific radio frequency which is known as: A) magnetic frequency B) radio frequency
C) gyro-magnetic frequency D) resonance frequency - Exact answer D) resonance frequency the introduction of gadolinium based contrast enhancement agents by intra- venous injection can involve passing through an abnormal blood brain barrier. The tissue compartments involved are the: A) intravascular to interstitial B) extracellular to intracellular C) hepatobiliary to renal D) extradural to renal - Exact answer A) intravascular to interstitial T2 is the measurement of time for the transverse component of the NMV to decrease what percentage of its maximum value after the application of a 90 degree radio-frequency pulse A) 33% B) 63% C) 37% D) 67% - Exact answer C) 37% in the USA, the MRI system's magnetic field and vector that represents it is symbolized: A) B B) B C) B D) B0 - Exact answer D) B The resonance frequency of any substance in a magnetic field can be calculated by employing the A) damadian equation B) larmor equation C) faraday equation D) lauterbur equation - Exact answer B) Larmor equation in a pulse sequence, transmitting an initial 90 degree radio-frequency pulse will cause the NMV to: A) remain at equilibrium B) shift in both size and direction C) move to antiparallel D) rephase - Exact answer B) shift in both size and direction
In MR imaging, for chemical substances to be affected by the main magnetic field and the radio-wave, it must contain an: A) Odd number of electrons B) Odd number of total protons and neutrons C) Even number of total electrons and neutrons D) even number of protons - Exact answer B) Odd number of total protons and neutrons A 1.5T magnetic field is equal to: A) 150 gauss B) 1500 gauss C) 15,000 gauss D) 150,000 gauss - Exact answer C) 15,000 gauss the components of the gyromagnetic ratio are: A) stimulation to relaxation B) protons to electrons C) magnetic moment to angular momentum D) main magnetic field to radio-frequency signal - Exact answer C) magnetic moment to angular momentum fast transition phenomenon and entry phenomenon are theories that explain which of the following characterisitics: A) T1 effects B) T2 effects C) hydrogen concentration D) veolcity effects - Exact answer D) Velocity effects the effects of main magnetic field inhomogeneities on the FID signal are corrected for in the spin echo sequence by applying a second radio frequency pulse. the flip angle of this radio frequency pulse is: A) 45 degrees B) 60 degrees C) 90 degrees D) 180 degrees - Exact answer D) 180 degrees of the following statements, which describes part of the basic MR imaging process: A) a patient is placed isocenter to ionizing radiation B) the patient is exposed to ionizing radiation
C) the generated image contains hypersense and hypodense areas D) radio frequency signals interact with hydrogen protons - Exact answer D) radio frequency signals interact with hydrogen protons which type of electromagnetic coils correct inhomogeneities in the main magnetic field? A) gradient coils B) radio frequency coils C) shim coils - Exact answer C) shim coils immediately after an initial 90 degree radio frequency pulse is turned off, the hydrogen protons will begin to: A) Rephase B) Dephase C) Stay in the transverse plane D) Stay in phase - Exact answer B) Dephase tissues that are very efficient at spin-lattice interactions near the larmor frequency, such as fatty tissues should have: A) Low T1 values and produce hyperintense signals B) High T1 values and produce hyperintense signals C) High T1 values and produce hypointense signals D) Low T1 values and produce hypointense signals - Exact answer A) Low T1 values and produce hyperintense signals T1 is the measurement of time for the longitudinal component of the NMV to recover. What percentage of its original value after the application of a 90-degree radiofrequency pulse? A) 33% B) 63% C) 37% D) 67% - Exact answer B) 63% the tissue characteristic which depends more on the state (solid, liquid, gas) of a tissue than any other factor is: A) T1 effects B) T2 effects C) hydrogen concentration D) velocity effects - Exact answer B) T2 effects
an equation derived to predict the MR signal intensity of a particular tissue as the result of a spin echo pulse sequence is the: A) larmor equation B) bloch equation C) phase shifts formula D) resonance frequency formula - Exact answer A) larmor equation which statement is true of the relaxation process? A) T2* effects slow down T2 decay B) without the effects of T2, T2 decay continues C) T2 effects can not be corrected for D) T2* effects have no effect on T2 decay - Exact answer B) without the effects of T2*, T2 decay continues because of the spinning motion of the hydrogen proton it has the same properties as a bar magnent. the hydrogen protons spinning motion gives it a A) magnetic charge B) magnetic spin C) magnetic moment D) magnetic precession - Exact answer C) magnetic moment On a proton density image, 2 types of tissue that contain very low concentrations of hydrogen and appear very hypointense are A) Cerebral tissue and CSF B) fat and muscle C) medullary bone and kidney D) cortical bone and lung - Exact answer A) cerebral tissue and CSF in comparison to CT an advantage of MRI is: A) slower scan time B) higher cost of the MRI system C) superior soft tissue contrast resolution D) ionizing radiation - Exact answer C) superior soft tissue contrast resolution in a loop of conductor in which an electric current is introduced and maintained a magnetic field will be produced in the center perpendicular to the flow of the electric current. this is called: A) Damadian's Law
B) Gabillard's Law C) Larmor's Law D) Faraday's Law - Exact answer D) Faraday's Law which type of MRI magnet has attainable field strengths of 0.35T to 3T for clinical use in the USA and higher strengths elsewhere and in research? A) superconductive B) resistive C) permanent - Exact answer A) superconductive the process of relaxation begins when: A) B0 is turned off B) B1 is turned on C) B1 is turned off D) B0 is turned on - Exact answer C) B1 is turned off a sinewave is a symbol used to measure electromagnetic energy. A sinewave's 2 components of measurement are: A) transmit and receive B) wavelength and frequency C) stimulation and relaxation D) gauss and tesla - Exact answer B) wavelength and frequency magnetic fields have direction which are usually designated as north and south therefore magnetic fields are described as: A) vectors B) dipoles C) protons D) axes - Exact answer B) dipoles at any one time, human body tissue, in general, is made up of 50-90% of what substance A) c B) NA 23 C) H2O D) H - Exact answer D) H (Hydrogen) which of the following is the larmor equation? A) B0 = y + Wo B) B0 = y x Wo
C) precessional ratio D) angular momentum - Exact answer A) gyro magnetic ratio MRI systems require rooms that provide specific shielding requirements. these rooms are lined with what type of material? A) stainless steel or titanium B) copper or galvanized steel C) lead D) iron oxide or neodymium - Exact answer B) copper or galvanized steel which type of MRI magnet requires no electricity to maintain its magnetic field and can weigh from 18,000 to 200,000 lb.? A) superconductive B) resistive C) permanent - Exact answer C) permanent which type of electromagnetic coils are employed as a transmitter, receiver, or both? A) gradient coils B) radio frequency coils C) shim coils - Exact answer B) radio frequency coils which type of MRI magnet requires a special cooling system to dissipate heat produced by very large currents? A) superconductive B) resistive C) permanent - Exact answer B) resistive tissues that are efficient in both T1 an T2 interactions have low (short) relaxation times, and therefore have: A) high T1 values B) high relaxation rates C) high T2 values D) low relaxation rate - Exact answer B) high relaxation rates because of only 10-15% variation in most tissues, the tissue characteristic that does not provide much contrast resolution is: A) T1 effects B) T2 effects C) hydrogen concentration
D) velocity effects - Exact answer C) hydrogen concentration the tissue characteristics that is dependent on the strength of the main magnetic field and temperature is: A) T1 effects B) T2 effects C) hydrogen concentration D) velocity effects - Exact answer A) T1 effects the component Mz is most associated with: A) anti-parallel to B0; T2 relaxation; net magnetization B) transverse to B0; T2 relaxation; transverse magnetization C) parallel to B0; T1 relaxation; longitudinal magnetization D) perpendicular to B0; T2 decay; FID - Exact answer C) parallel to B0; T relaxation; longitudinal magnetization the component Mxy is most associated with: A) anti-parallel to B0; T1 relaxation; net magnetization B) transverse to B0; T2 relaxation; transverse magnetization C) parallel to B0; T1 relaxation; longitudinal magnetization D) perpendicular to B0; T2 decay; FID - Exact answer B) transverse to B0; T2 relaxation; transverse magnetization in the USA, MRI systems in clinical use have main magnetic field strengths that range from: A) 2T to 6T B) 0.06T to 3T C) 2 Gauss to 6 Gauss D) 0.006T to 0.03T - Exact answer B) 0.06T to 3T On a very basic level, the 3 basic components required to attain MR signals are: A) Magnetic field, proton, ionizing radiation B) magnetic field, electron, ionizing radiation C) magnetic field, electron, radio wave D) magnetic field, proton, radio wave - Exact answer D) 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 (dependent
the formula that described the relationship between the static magnetic field and the precessional frequency of the hydrogen proton is the: A) Hemholtz relationship B) nyquist theorem C) larmor equation D) bloch equation - Exact answer C) larmor equation to calculate the precessional frequency, the strength of the static magnetic field is multiplied by the constant known as: A) the gyromagnetic ratio B) Tau C) Alpha 1 D) linear attenuation coefficient - Exact answer A) the gyromagnetic ratio the field strength of an MR imaging magnet as measured within the bore is most typically expressed in terms of: A) tesla B) gauss C) Megahertz D) magneto-gyric ratio - Exact answer A) tesla the larmor, precessional or resonance frequency of hydrogen proton in a statc magnetic field of .5T is approximately: A) 42.576 MHz B) 63.864 MHz C) 25.5456 MHz D) 21.288 MHz - Exact answer D) 21.288 MHz following RF excitation, as transverse magnetization (Mxy) decays to zero, the MR signal ___________. A) increases exponentially B) becomes saturated C) decays to zero D) in phase coherent - Exact answer C) decays to zero RF pulses are identified according to the: A) gradient B) intensity C) duration D) flip angle - Exact answer D) flip angle
following the excitation pulse, the FID decays ____________. A) along the z axis B) exponentially C) during the 180 degree RF pulse D) linearly - Exact answer B) exponentially of the following tissues, which has the longest T2 value? A) fat B) muscle C) CSF D) white matter - Exact answer C) CSF of the following tissues, which has the shortest T1 value A) fat B) muscle C) liver D) white matter - Exact answer A) fat MRI magnets that require a steady current of electricity passed through coils wrapped around an iron or air core are: A) high field B) resistive C) permanent D) superconducting E) attach to a soft iron yoke - Exact answer B) resistive Coils that superimpose small magnetic fields within the patient during the MRI process and allow for spatial encoding are: A) shim coils B) radio frequency coils C) gradient coils D) resistive coils E) superconducting - Exact answer C) gradient coils a permanent magnet requires liquid helium and liquid nitrogen in a dedicated cooling system. A) True B) False - Exact answer B) False
C) no more than 0.4 w/kg D) a maximum spatial peak of 8 w/kg - Exact answer B) no more than 3. w/kg currently, there is evidence of a threat to fetal development from MRI exposure: true or false? - Exact answer False some older implanted ferromagnetic neuro-aneurysm clips, suture materials, and surgical clips will experience a force of _____________, as the material is passed through a strong magnetic field. A) deceleration B) torque C) acceleration D) inertia - Exact answer B) torque the factor, which determines the calculated SAR averages is: A) field strength B) the patients weight in kilograms C) an average calculation of heat per milisecond D) heat dissipated over time - Exact answer B) the patients weight in kilograms the receive bandwidth is related to the slope of which gradient? A) slice select B) phase encoding C) frequency encoding D) 90 degree RF pulse E) 180 degree RF pulse - Exact answer A) slice select in an inversion recovery pulse sequence, the NMV is rotated to the physical negative Z axis by applying a: A) 60 degree pulse B) 90 degree pulse C) 180 degree pulse D) 270 degree pulse E) 90 degree pulse pair - Exact answer C) 180 degree pulse
which of the following setting descriptions for the parameters TR and TE best describes a proton density image? A) short TR/ short TE B) long TR/ long TE C) short TR/ long TE D) long TR/ short TE E) long TR/ short TI - Exact answer D) long TR/short TE the inversion time, in an inversion recovery pulse sequence, is the time interval between the: A) 90 and 180 pulses B) 90 degree pulse and the echo signal C) 180 degree pulse and the echo signal D) 90 and 90 degree pulses E) 180 and 90 degree pulses - Exact answer E) 180 and 90 degree pulses in general, parameter settings of TR and TE for attaining T1 and T2 images are as follows: A) T1; TR 1600-3000ms, TE 70-100ms / T2; TR 100-100ms, TE 20-30ms B) T1; TR 100-1000ms, TE 70-100ms / T2; TR 1600-3000ms, TE 20-30ms C) T1; TR 100-1000ms, TE 20-30ms / T2; TR 1600-3000ms, TE 70-100ms D) T1; TR 1600-3000ms, TE 20-30ms / T2; TR 100-1000ms, TE 70-100ms
- Exact answer C) T1; TR 100-1000ms, TE 20-30ms / T2; TR 1600- 3000ms, TE 70-100ms the pulse sequence that replaces the second RF pulse with a magnetic field gradient to rephase the transverse vector and produce the echo signal is: A) spin echo B) gradient echo C) spin spin D) inversion recovery E) saturation recovery - Exact answer B) Gradient echo The artifact known as crosstalk can be corrected for by adjusting which parameter A) FOV B) TR C) slice thickness D) slice interval
the slice selection gradient 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 A) antiparallel B) parallel C) oblique D) perpendicular E) none - Exact answer D) perpendicular which method of providing spatial localization is employed during a pulse sequence when selecting only one slice at a time? A) FID B) FT C) FFT D) 2DFT E) 3DFT - Exact answer D) 2DFT which method of providing spatial localization is employed during a pulse sequence when selecting a volume of slices? A) FID B) FT C) FFT D) 2DFT E) 3DFT - Exact answer E) 3DFT for MRI magnets, the specification for field homogeneity that is considered acceptable is: A) 5-10ppm B) 10-15ppm C) 20-30ppm D) 40-50ppm - Exact answer C) 20-30ppm the primary factor of an inversion recovery pulse sequence is which of the following parameters? A) TR B) TE C) TI D) FSE E) MRA - Exact answer C) TI
of the different types of coils used in MRI, which type(s) are found only in the housing of the main magnet? A) surface coils B) radio frequency coils C) Heimholtz coils D) shim/gradient coils E) all - Exact answer D) shim/gradient coils which of the following causes of artifacts on MR images is most commonly mistaken for a pathological signal? A) eddy currents B) magnetic susceptibility C) chemical shift D) untuned RF coils E) ferromagnetic object - Exact answer C) chemical shift of the following anatomical structures, which is considered to be normally enhancing post gadolinium injection? A) cerebellum B) choroid plexus C) intervertebral disc D) auditory nerves E) corpus callosum - Exact answer B) choroid plexus cryogen levels should never fall below: A) 23% B) 30% C) 50% D) 66% E) 80% - Exact answer C) 50% the electromagnetic coil responsible for producing the strong magnetic field of a superconducting magnet is embedded in a _____________ which serves as an insulator from heat in the event of a quench. A) niobium-titanium matrix B) lead matrix C) carbon composite matrix D) steel matrix E) copper matrix - Exact answer E) copper matrix
