ASMIRT MRI Accreditation Practice Test

These questions are part of the practice quiz. Start practicing

• What can an unusual appearance in MRI images indicate?
• What is the current understanding of the effects of MRI on fetuses?
• What is a notable concern for patients with metallic implants in an MRI?
• What is the purpose of pre-saturation in MRA?
• What aspect of k-space data acquisition does peak symmetry rely on in Partial / Fractional Echo?
• What does T1 measure in the context of MRI signal?
• How can gadolinium be made safe for contrast administration?
• What occurs during analog to digital conversion in MRI?
• Which term refers to the time it takes for 63% of transverse magnetisation to be lost?
• What role do MIP processes play in Time of Flight MR Angiography?
• What distinguishes areas of restricted diffusion on DWI and ADC maps?
• What happens to SNR when only half of the phase encodings are performed?
• How is the time measured for T1 relaxation represented?
• What is the primary cause of susceptibility artefacts?
• What does a Fourier transform accomplish in MRI?
• What is precession in the context of hydrogen nuclei in a magnetic field?
• Which relaxation process involves the exchange of energy between neighboring protons?
• What occurs to hydrogen protons as a result of resonance?
• How is SAR measured?
• What does SAR stand for in the context of MRI?
• What principle forms the basis of MRI signal generation?
• In MRI, which of the following organs is noted to be particularly sensitive to heating?
• What happens to SNR when TE is increased?
• What can occur if ferromagnetic objects are not properly controlled during an MRI?
• How does the patient's thermo-regulatory system affect SAR?
• Which of the following is an advantage of using a small coil in MRI?
• What is a potential risk associated with helium gas displaced during a quench?
• How is the contrast in an MRI image primarily derived?
• What benefit does magnetisation transfer provide in MR angiography?
• What does increasing the field of view (FOV) do to SNR?
• What is the role of a saturation pulse in magnetisation transfer?
• What is a key characteristic of Time of Flight (TOF) MRA?
• What is the purpose of flow compensation in MR imaging?
• What is the function of the gradient system in MRI?
• How does doubling the slice thickness affect voxel volume and SNR?
• For which type of examinations is 2D TOF MRA particularly effective?
• What does a decrease in T1 time indicate about the tissue?
• Which of the following is a concern related to patient heating during MRI?
• What characterizes Time of Flight MR angiography?
• What is the state of the net magnetization vector (NMV) before a sample is introduced to a magnetic field?
• Which of the following describes a property of iron core resistive magnets?
• What is a primary benefit of increasing TR during MRI scanning?
• What happens to the hydrogen nuclei during precession?
• What happens if TI is set to a point where a tissue’s T1 curve crosses the zero line?
• Why is it necessary to have kick-out panels in the scan room during a quench?
• What is the optimal flip angle range for PD weighting in GRE sequences?
• What is T2 shine through in DWI imaging?
• What are reconstruction artefacts generally caused by?
• How does proton density affect signal strength in MRI?
• What is the effect of partial volume averaging in MRI imaging?
• What is Gadolinium primarily used for in medical imaging?
• What is t-wave artefact and how does it occur?
• What is one potential outcome of using pre-saturation bands for a superior slab in a study?
• What effect do TR and TE have on image weighting in gradient echo imaging?
• What is the minimum lethal dose of GBCA for rats and mice compared to patient imaging doses?
• In standard MRI sequences, what does 'TR' stand for?
• For T1 weighting in a GRE sequence, what parameters should be used?
• What process causes the MRI signal to fade over time?
• What can be done to reduce chemical shift artefact in MRI?
• Why are eddy currents considered problematic in MRI?
• Which component of MRI technology is primarily responsible for signal reception?
• What is a common effect of gradient magnetic fields during an MRI scan?
• What is one of the key benefits of using flow compensation in MRA?
• How do individual cells in k-space correspond to pixels in an image?
• Which characteristic defines gradient echo sequences?
• How is the contrast produced in T1 weighted images largely affected?
• How does magnetisation transfer (MT) benefit MRA imaging?
• What type of tissue typically has an intermediate T1 time?
• What artefacts result from sampling-related issues in MRI?
• What is a disadvantage of lower receiver bandwidth in MRI?
• What effect does a short TE have on T2 weighted images?
• What effect does increasing TE (echo time) have on SNR?
• Which of the following methods can reduce magnetic susceptibility artefacts?
• What can happen if phase oversampling is implemented in an MRI scan?
• What strategy can be used to keep gradient effects to a minimum during MRI?
• In what condition are gradients effectively utilized in imaging?
• What effect do shielded gradients have in MRI?
• What characteristic of fat based tissues leads to their short T1 times?
• How does TR (repetition time) affect SNR?
• What determines in-plane resolution in MRI?
• What characteristic makes muscle tissue have an intermediate T2 time in MRI?
• In k-space, how can the SNR be affected?
• What happens to intra-axial areas in the brain with an intact blood-brain barrier after contrast administration?
• Where is phase shift most commonly identified in blood vessels?
• What areas in the brain are enhanced following contrast administration?
• What is the greatest concern regarding MRI safety?
• How do areas of unrestricted diffusion appear on ADC maps?
• What effect does increasing the flip angle in gradient echo sequences generally have?
• What does the rise time of a gradient system refer to?
• What is a limitation of decreasing the matrix size from 512x512 to 256x256?
• Which MRI sequences are most likely to produce eddy currents?
• How long does it typically take for 95% of GBCA to be excreted via the kidneys?
• Which factor does NOT influence SAR according to MRI practices?
• What must be ensured about the electrical insulation of cables in an MRI environment?
• What is a disadvantage associated with PCA imaging?
• Which parameter must be minimized to achieve quick T1 recovery in a GRE sequence?
• When do signals from fat and water become completely out of phase?
• How can one decrease the thickness of an MRI slice?
• Given FOV = 20 cm x 20 cm and matrix = 256 x 224, what is the frequency resolution?
• What does STIR stand for in MRI imaging?
• What is the primary focus of Fourier analysis in MR imaging?
• What is the primary effect of balanced gradients on static versus moving protons?
• Which factor does NOT influence scan time in MRI?
• What is the effect of a 90-degree flip angle on the NMV?
• For obtaining DWI images, which sequences are typically employed?
• Which type of coil consists of two or more coils with individual receiver channels?
• Which term is used to describe the modern version of the spin echo sequence?
• In a stronger magnetic field, what happens to the number of protons aligning anti-parallel?
• How is signal detected in an MRI system?
• Which type of magnet maintains a magnetic field without an electrical power supply once ramped?
• How are 2D MRA images typically generated?
• What is the renal clearance rate of GBCA?
• What can happen if the vapour pressure during a quench exceeds a predetermined value?
• What causes T2* decay to occur faster than T2 decay?
• What is the impact of reduced phase encodings in a rectangular FOV?
• What is the primary benefit of using an EPI sequence in MRI?
• Which type of tissue is characterized by low transverse magnetization following an RF pulse in a T2 sequence?
• What kind of artefact can arise when tissues with different susceptibilities are adjacent?
• What is the significance of a shorter rise time in an MRI gradient system?
• What purpose do pre-saturation bands serve in MRI?
• Why is it important to understand the effects of flowing nuclei in MRI imaging?
• What is a primary benefit of decreasing TE in MRI?
• How does passive shielding in MRI work?
• What factors influence the strength of the phase encoding gradient?
• What is meant by the 'transverse plane' in MRI?
• How can motion artefacts be effectively reduced in MRI?
• What technology is used to address motion artefacts in MRI imaging?
• What is the role of a Faraday Cage in MRI?
• What does a 3D volumetric k-space filling technique acquire?
• What is the typical range of gradient slew rates in MRI systems?
• What is the typical value of the flip angle in MRI?
• What is the main characteristic of T2 decay?
• What mild sensory effects can be caused by static magnetic fields?
• Gradient echo sequences are primarily based on which aspects?
• Which parameters are standard for a PD weighted axial knee spin echo sequence?
• What happens to SNR as the size of the surface coil decreases?
• 3D TOF MRA is best utilized to visualize which anatomical structure?
• How does a lower bandwidth affect chemical shift artifact?
• For GRE coherent T2* weighted scans, what is the suggested long TE value?
• What is a benefit of increasing the matrix size from 256x256 to 512x512?
• What is the main function of TE in MRI?
• What is the term used to describe the speed at which the NMV rotates around B0?
• What does the echo train length (ETL) indicate in a fast spin echo sequence?
• What does T1 relaxation primarily involve?
• What benefit is associated with increasing the field of view (FOV)?
• Which patient group should be strictly monitored when in the MRI vicinity?
• What is the scan time formula specifically for EPI images?
• What is the significance of using long TRs for T2 weighted images?
• Which of the following is NOT a recognized risk from gradient magnetic fields?
• What is a major limitation of using a large coil in MRI?
• What indicates a possible failure in the transmit or receive RF chain?
• Which method can help reduce cross-talk artefact?
• What is the main advantage of using quadrature coils over linear coils?
• What benefit comes from decreasing slice thickness?
• To achieve T2* weighting in a GRE sequence, which parameters are recommended?
• What role does the RF pulse play in MRI?
• What is the significance of the maximum amplitude in a gradient system?
• What is the primary excretion pathway for GBCA?
• Which of the following is a use of pre-saturation bands in MRA studies?
• What does MIP stand for in the context of MRA?
• How is echo planar imaging (EPI) typically characterized?
• What is the relationship between TR and T1 weighting?
• How does chemical fat suppression work in MRI?
• Which of the following is a recommended strategy to minimize risks from static magnetic fields?
• Which statement best represents the requirements for T2 weighted images?
• What is a key characteristic of surface coils in MRI?
• How is chemical shift calculated with regards to receiver bandwidth and pixel frequency range?
• Why is T1 relaxation significant in MRI imaging?
• What occurs during a quench of an MRI magnet?
• How do GRE images differ from SE images regarding blood flow?
• What is one consequence of an increase in echo spacing when using lower receiver bandwidth?
• Which type of flow is characterized by a velocity gradient from slowest at the walls to fastest at the center?
• Which of the following is an advantage of PCA?
• What does SNR stand for in the context of MRI?
• What is turbulent flow?
• What role does the 90° pulse play at the TI time during an IR sequence?
• In MRI, what is the main impact of using a smaller matrix size on spatial resolution?
• What effect can Helium have on the examination room during a quench?
• In the context of MRI, what does 'ETL' stand for when calculating scan time for FSE images?
• What determines the alignment of hydrogen protons in a magnetic field?
• What defines the key differences between spin echo and gradient echo imaging?
• What does the Nyquist Theorem state regarding sampling rate?
• How does a T1 weighted sequence create a higher signal from fat compared to fluid?
• Which of the following best describes the relationship of the NMV in a magnetic field?
• In what unit is precessional frequency measured?
• What is the primary purpose of incoherent/spoiled gradient echo sequences?
• In SE MRA, what occurs when blood is moving at an intermediate speed?
• How is a quadrature coil signal readout achieved in MRI?
• What is a primary benefit of increasing NEX in MRI?
• What factors contribute to acoustic noise during an MRI scan?
• What is one way to reduce SAR during an MRI scan?
• What is a noted risk factor when administering GBCA to pregnant women?
• What is the definition of cross-talk artefact in MRI?
• What effect occurs due to adjacent fluid layers gliding past each other without mixing?
• How many directions can a hydrogen proton align in a magnetic field?
• What effect does a larger field of view (FOV) have on chemical shift?
• How can eddy currents be minimized during MRI scans?
• What is the correct formula for calculating scan time of FSE images?
• What governs the value of the precessional frequency?
• What equation represents the relationship between precessional frequency and magnetic field strength?
• What is a disadvantage of using Gradient Moment Nulling in MRI?
• What effect does doubling the NEX have on SNR?
• What characterizes metal artefacts in MRI images?
• What is meant by high velocity signal loss in SE MRA?
• What role does the acquisition matrix play in the accuracy of MRI signals?
• What is the purpose of applying two equal gradient pulses in diffusion-weighted imaging?
• What are gradient coils responsible for in MRI imaging?
• What effect does gadolinium's large magnetic moment have in the presence of water protons?
• How can spatial resolution be maximized in MRI imaging?
• What is the protocol for pregnant staff working in an MRI environment?
• What is the impact of a long TR on T1 weighted imaging?
• When would the Ernst angle be less than 90°?
• What is a limitation of decreasing TR?
• What is a common application for using phased array coils in MRI?
• What does flow compensation achieve in MRA?
• How is the sampling time defined in MRI terms?
• Which parameter is crucial for coherent gradient echo sequences to maintain coherence?
• What happens when fresh blood moves into an imaging slice in GE MRA?
• In which direction is phase wrap artefact most commonly observed?
• What does MRA stand for in medical imaging?
• What does TR stand for in the context of MRI sequences?
• What principle allows for the manipulation of k-space to decrease scan times?
• Which method allows for adjustments to the magnetic field in the shimming process?
• What is the outcome of Fourier transformation in relation to quadrature coil signal data?
• How does the use of a rectangular FOV affect the imaging process?
• What effect does gadolinium have on T1 and T2 relaxation times in MRI?
• What is meant by "sampling" in the context of MRI?
• Given FOV = 22 cm x 16 cm and matrix = 512 x 192, what is the phase resolution?
• What is the primary function of a MIP in MRA imaging?
• In what scenario must surface coils be decoupled?
• What is a consequence of increasing echo spacing during FSE scans?
• How do areas affected by a subacute stroke appear on DWI and ADC maps?
• What is the primary effect of short TR on the imaging of different tissues?
• What characteristic of superconductive magnets allows for high magnetic fields?
• What is the likelihood of serious complications following GBCA administration?
• What technique allows for the acquisition of 3D TOF MRA?
• What factors determine spatial resolution in MRI?
• What does the frequency encoding gradient achieve in MRI?
• What is the measure for TR in MRI typically expressed as?
• What is the purpose of the 180 degree refocusing pulse in a spin echo sequence?
• How does a linear coil differ from a quadrature coil?
• What type of coil can operate in a quadrature fashion?
• What is the primary use of diffusion weighted imaging (DWI) sequences?
• Which imaging modality can reveal T2 shine through phenomena?
• Why is T2 contrast in GRE imaging referred to as T2* contrast?
• What is the purpose of shimming in MRI technology?
• What does a steady state condition imply in MR imaging?
• What is a key characteristic of a spin-echo sequence?
• What characterizes free protons in MRI?
• What is the appearance of sampling artefacts in MRI?
• What major issue arises due to varying blood velocities in vessels?
• How is intervoxel phase dephasing reduced in MRI?
• Which of the following defines resonance?
• What advantage do phased array coils provide in MRI imaging?
• Which factors contribute to increased imaging time in Phase Contrast Angiography?
• How much SNR improvement does a quadrature coil offer over a linear coil of the same size?
• What is the primary purpose of the phase encoding gradient in MRI?
• Which coil is specifically designed to improve SNR over the area of interest?
• What is a limitation of decreasing the field of view (FOV)?
• What does the Partial Fourier Transform technique accomplish in k-space?
• What limitation is associated with increasing NEX in MRI?
• What is the primary purpose of using FLAIR in MRI?
• What effect does the strength of the frequency encoding gradient have on image resolution?
• What is the primary role of the RF coil in MRI?
• What happens if the sampling rate is too low according to the Nyquist Theorem?
• Why must TE be long for a T2 weighted image?
• How is scan time calculated for 2D images?
• What is the motion characteristic of stagnant flow?
• What is a characteristic feature of 2D k-space filling?
• What is a common approach to managing SAR warnings during an MRI examination?
• Coherent gradient echo pulse sequences primarily produce images that are:
• What advantage does 2D TOF MRA have over 3D TOF MRA?
• What imaging drawback is associated with the MOTSA technique?
• What is a primary benefit of increasing the receiver bandwidth in MRI?
• What is a benefit of decreasing NEX?
• Which part of k-space data contributes most to the contrast of an MRI image?
• What can cause a skewing effect in MRI images?
• Why is contrast not recommended for pregnant patients undergoing MRI?
• What type of coils can transmit and receive signals in MRI?
• What happens to noise and motion artefact when using surface coils?
• What does the slew rate of a gradient system indicate?
• What is the effect of using a 180° pulse in spin echo imaging?
• What is the purpose of the RF pulse in slice excitation during MRI?
• In a PD weighted image, what must be the appropriate settings for TE and TR?
• Why does MRI receive poor signal from lung tissue?
• What is the TE and TR for a standard T2 weighted axial brain SE sequence?
• What increase in TR is often required when using magnetisation transfer in MRA?
• Which of the following is a key advantage of 3D TOF MRA?
• How does increasing slice thickness affect spatial resolution?
• How does increasing the number of slices in a 3D scan affect SNR?
• Which side effect is associated with changing gradient magnetic fields?
• What is the precessional frequency difference between fat and water attributed to?
• What influences the relative signal strength in proton density (PD) weighting?
• What phenomenon is responsible for the phase shift effect in flow?
• What is a key concern regarding the use of RF exposure in MRI?
• What are potential side effects associated with GBCA?
• How is residual transverse magnetisation removed in a steady state sequence?
• How does the strength of the RF field impact safety concerns?
• How does the efficiency of spin-spin interactions differ between fat and water in MRI?
• Which direction is the phase encoding matrix typically smaller than the frequency encode direction?
• In T2 weighted imaging, why do fluids appear bright compared to fat?
• Why is gadolinium not suitable for use as a contrast agent in its free ionic form?
• What is the goal of using Partial / Fractional Echo in MRI?
• What causes the phase cancellation effect in MRI imaging?
• What are ghosting artefacts primarily caused by?
• What happens to individual protons after an RF pulse is applied?
• What is the typical TI used in STIR to suppress fat signals?
• What is the purpose of placing a pre-saturation slab over the aorta during lumbar spine studies?
• Which type of coil typically provides a very uniform SNR over the volume?
• What risks does the static magnetic field pose in regard to implants and objects?
• What distinguishes RF shielding from magnetic shielding in MRI?
• What is a key feature of permanent magnets in MRI technology?
• What happens during a quench in a superconductive magnet?
• Why might shallow gradient slopes be beneficial in k-space filling?
• Which of the following describes T1 relaxation in MRI?
• What is a limitation of decreasing receiver bandwidth?
• In 2DFT imaging, what does each horizontal row in k-space represent?
• What are air core resistive magnets characterized by?
• What is the maximum SNR achieved at the "Ernst Angle" for sequences where TR is greater than T1?
• What is a benefit of using lower receiver bandwidth in MRI?
• How can the reliability of preventing phase wrap artefact be improved?
• How can k-space content be adjusted to suit examination requirements?
• The gyromagnetic ratio of hydrogen at a 1.0T field strength is what value?
• What is the impact of reducing bandwidth on SNR?
• What is a disadvantage of using thin slices in 2D MRA?
• In MRI, which type of imaging sequence typically shows restricted diffusion clearly?
• What effect does a magnetic field have on the net magnetization vector (NMV) of protons?
• How does the presaturation pulse influence signal in TOF MRA?
• How does magnetic susceptibility relate to detecting cerebral hemorrhage?
• What does the "Duty Cycle" refer to in MRI gradient systems?
• What is the formula for calculating scan time for 3D images in MRI?
• What does velocity encoding (VENC) accomplish in PCA imaging?
• What is the primary method to minimize the TOF effect in MRI?
• What is inversion recovery in MRI?
• What is the effect of reducing bandwidth during MRI imaging?
• What typically causes zipper artefact in MRI imaging?
• How is the signal strength affected in surface coils?
• Why are surface coils often purpose-built?
• What principle does Phase Contrast Angiography operate on?
• In diffusion weight imaging (DWI), what does restricted diffusion indicate?
• Which gradient orientation is applied to produce a sagittal slice in 2D MRI?
• What is a disadvantage of increasing slice thickness?
• What type of signal does stationary blood produce in a SE MRA?
• In terms of T2 relaxation, what does a high proton density in a tissue indicate?
• What is the effect of voxel volume on SNR?
• Which of the following practices can help avoid patient burns during an MRI procedure?
• What does FSE optimisation help to prevent in MRI scans?
• At 1.5 Tesla, what is the approximate difference in precessional frequency between fat and water?
• What is the primary function of volume coils in MRI?
• What characteristic allows ADC maps to differentiate between old and recent strokes?
• Why is ramped angle excitation used in MRA?
• Where are chemical shift cancellation artefacts most commonly observed?
• What is one technique used to minimize breathing artefacts in MRI studies?
• How can k-space be best described?
• What does MOTSA stand for in MRA?
• What effect does respiratory motion have on MRI image quality?
• What factor contributes significantly to the occurrence of sampling artefacts?
• What forms the net magnetization vector (NMV) in a magnetic field?
• How many unpaired electrons does Gadolinium have?
• What are some contraindications for administering GBCA?
• What is a requirement for the echo time (TE) in T1 weighted images?
• Which type of artefact occurs due to anatomy extending beyond the Field of View in MRI?
• What is a characteristic appearance of chemical shift artefact in MRI images?
• What happens to protons in a DWI sequence if there is no net movement between gradient pulses?
• When considering SNR improvements with coil design, which offers the best theoretical results?
• What can be said about the signal output of phased array coils when combining signals?
• What is the maximum SAR limit for whole-body exposure recommended by the FDA?
• What happens to the hydrogen protons in the human body when exposed to a magnetic field?
• What do the values collected at the ends of each horizontal row in k-space represent?
• What are standard parameters for a T1 weighted axial brain spin echo sequence?
• How does the strength of the magnetic field affect the sensory effects experienced?
• What is a major disadvantage of GRE sequences?
• How should pregnant patients be evaluated for MRI procedures?
• Which component primarily affects T1 times in tissues during MRI?
• What is the primary contribution of the peripheral rows in k-space to an MRI image?
• What is one limitation of having a higher receiver bandwidth in MRI?
• What is an effect of increasing slice thickness on partial voluming?
• What is the standard dose for gadolinium-based contrast agents (GBCA)?
• What role does the field of view (FOV) play in determining imaging parameters?
• Which type of magnet is defined as a hybrid of permanent and resistive designs?