Final exam Flashcards
The 2003 FDA revision on RF absorption limits the absorption to ______________ for the head
C. 3.0W/kg for 10 minutes
Acquiring a bit more than half the phase k-space samples, then interpolating the data with zeroes for the remaining half is a technique known as:
A. Half Fourier
B. Fast spin echo
C. Zero Fill
D. Spoiled Gradient Echo
G. A and/or C only
Active shielding can be defined as:
D. Superconducting windings within the MR scanner, reducing the fringe magnetic field
An adverse reaction or complication caused by treatment from a healthcare professional is called:
C. Iatrogenic
All of the following are examples of INTRINSIC contrast parameters in tissues EXCEPT:
E. TR
All of the following artifacts except ________ occur along the phase encoding axis
D. Chemical shift
All of the following comprise the biliary tree EXCEPT:
D. Splenic duct
All of the following would aid in reducing scan time EXCEPT:
B. Reduction in ETL
All of the following yield a higher signal-to-noise ratio EXCEPT:
E. Increase in TE
Another term used for “fever” is:
D. Febrile
As the number of phase encodings is increased from 256 to 512, SNR (signal to noise ratio):
B. Decreases
As the TE is increased
B. The available number of slices is decreased
Calculate the available imaging time for a patient with a heart rate of 90 beats/min, trigger window 15% and trigger delay of 80ms.
A. 487 ms
Calculate the dose of contrast (0.1mmol/kg) that should be administered to a patient weighing 176 lbs with normal kidney function in a routine MR examination.
D. 16mL
As the TR is increased,
I. SNR is increased
II. Available number of slices is increased
III. T2 information is maximized
C. I and II only
Calculate the effective TR for a patient with a heart rate of 70 beats / min.
B. 857 ms
Calculate the pixel area for the following sequence: TR 4000, TE 120, FOV 36cm, 408 x 512 matrix, 2 NEX, ETL 12.
A. 0.62 mm2
Chemical or spectral fat suppression techniques suppress fat signal based on the:
D. Precessional frequency of fat
Choose the correct slice thickness to create an isotropic voxel for the following: TR 2000, TE 90, Matrix 272 x 272, FOV 24cm.
B. 0.88mm
Collecting the low frequency (high amplitude signal) data points in k- space at the start of the scan (in a spiral fashion) is known as:
D. Elliptic centric
Contrast in Diffusion Weighted Imaging (DWI) depends on:
I. The degree to which molecular mobility is impaired (water restriction)
II. The sensitivity of the sequence to Brownian motion
III. T1 relaxation time
IV. The direction of water diffusion V. T2 relaxation time
C. I, II and IV
The common carotid artery bifurcates into the internal and external carotid artery at the level of the:
B. C3-4 disc space
___________ could be used to line the walls and/or floors of the MR magnet room to reduce the fringe field, and is defined as __________ shielding
D. Steel; passive
Creating additional images in various planes from a 3D data set is accomplished by a technique known as:
D. Multi-Planar reconstruction (MPR)
CSF suppression is performed with which type of technique?
A. FLAIR
The difference in chemical shift is approximately ______ parts-per-million.
C. 3.5
A disadvantage of TOF MRA is high signal in some background tissues. To minimize signal from background tissues, TE should be selected that enable the signals from fat and water to be:
D. Out of phase
Diseases, such as malaria, in which microorganisms are transferred via an insect, come under the classification of __________ infections.
B. Vector borne
Droplet contamination frequently occurs via:
D. Coughing
During dynamic enhanced imaging for vasculature or visceral structures, contrast is administered and k-space is filled with __________ to ensure that the contrast enhancement is well visualized.
A. Centric
During movement or transfer of patients, a urinary collection bag should be placed:
D. Below the level of the urinary bladder
Dynamic enhanced MRA sequences of the mesenteric arteries are performed using:
D. Incoherent gradient echo
The energy used to form MRI images is ____________ the patient’s tissues
A. Emitted from
The Ernst angle can be defined as the optimal ___________ that yields the ____________ signal for a particular spin in the least amount of time.
C. Flip angle; maximum
The extent to which a material or tissue becomes magnetized in an external magnetic field is called:
B. Magnetic susceptibility
Fat has a _______ T1 relaxation time and a ________ T2 relaxation time.
B. Short; short
The final result in a perfusion study is:
D. A set of calculated images which indicate various flow characteristics
The final result in a spectroscopy study is:
A. A spectrum of specific detected metabolites
The first major branch of the abdominal aorta is the _______.
D. Celiac artery
Force on an object in an magnetic environment depends on:
I. Mass of the object
II. Strength of the magnetic field
III. Strength of the RF field
IV. Ferromagnetic properties of the object
E. I, II and IV
A gradient echo sequence in which all the remaining residual transverse magnetization is removed prior to the next excitation pulse is known as:
A. Incoherent or spoiled
Gradient echo sequences can yield either T1 or T2* characteristics, with influences caused by all of the following EXCEPT:
D. Inversion time
Gradient echo sequences requiring high signal from fluid are known as all of the following EXCEPT:
C. Coherent gradient echo
The gradient rise time is defined as the:
D. Time it takes for the gradient to reach its full amplitude
The gradient slew rate is the:
D. Rate of speed of ascent or descent of a gradient from zero to its maximum amplitude
Healthcare workers generally practice ___________, which states the “goal is to do no harm.”
B. Beneficence
The HEIGHT of a peak on an MR spectrum correlates to the _________ of a substance that was detected.
D. Amount
Hemangiomas in the liver are typically benign lesions, and are best visualized with:
D. Delayed images
If the desire is to null the signal from a specific tissue using an inversion recovery sequence, the inversion time (TI) selected should be ______ of the T1 relaxation time of that tissue.
D. 69%
If the flip angle is doubled, RF deposition increases by a factor of:
D. 4
If the third ventricle is dilated, but the fourth ventricle is not, there would then be pathology associated with:
A. Aqueduct of Sylvius
If the TR in a gradient echo sequence is less than the T2 (or T2*), the resulting condition is known as:
B. Steady state
The _____________ imaging plane would be the most optimal slice orientation for evaluation of Arnold Chiari Malformation and its inferior cerebellar tonsillar herniation.
D. Sagittal
The imaging technique that employs a very rapid pulse sequence while the patient is at rest or performing a task is:
B. Functional MRI
Immediately following the application of the 90° RF pulse, the precessing protons:
A. Begin to precess in phase
B. All move into a high energy state C. Tip into the transverse plane
D. All the above
E. A and C only
E. A and C only
In a contrast enhanced MR angiography of the abdominal arteries, the IV gadolinium would enhance in which order?
D. Celiac, superior mesenteric, renal, inferior mesenteric
If 192 phase resolution is required, the TR must then be repeated ____ times for 1 NEX.
A. 192
In a cross-sectional view of the MR magnet design, which coils are closest to the patient?
D. Radiofrequency coils
In a dual contrast spin echo sequence with echo times of 25ms and 90ms, the second echo image has __________ than the first echo image
A. more T2 contrast
In a Fast Spin Echo (FSE) sequence, acquired with a long TE, yielding T2 weighted images, scan time can be reduced by:
D. Using longer ETL
In a Fast Spin Echo (FSE) sequence, acquired with a short echo time (TE), yielding T1 or PD weighted images, blurring can be reduced by:
C. Using shorter ETL
In a Fast Spin Echo sequence, the number of shots is calculated by:
C. #Phase encodings / ETL
In a fast spin echo sequence with a 25 cm FOV, 224 x 320 matrix, TR 2500, 100 TE, 3mm slice thickness, 12 ETL and 4 NEX, the scan time
B. 3 minutes 7 seconds
In a medical malpractice lawsuit, the ______ must be able to prove medical malpractice.
A. Patient plaintiff
Patient nodding their head or by them showing up at the agreed upon time for surgery.
B. Implied consent
Health Insurance Portability and Accountability Act of 1996. Privacy, security, establishment of standards and requirements for the electronic transmission of certain health information.
A. HIPAA
In an MRA sequence, the removal of signal from vessels is accomplished by:
A. Spectral presaturation
In a superconducting magnet, the magnetic field strength is increased by increasing the:
D. Turns of wire
Increasing the flip angle:
C. Increases SNR up to the Ernst angle
In order to acquire an intracranial arterial blood flow sequence, a presaturation pulse would be applied in which location?
D. Superior to slice group
In order to generate thin slices, a ___________ is used.
A. Steep slice selection gradient
In the TMJ’s, the articular disc lies between what two anatomical structures?
D. Mandibular fossa and mandibular condyle
In what orientation would a tear of the collateral ligaments of the knee be best visualized?
D. Coronal
The _________ is defined as the resonant frequency, and is equal to the product of the magnetic field and the gyromagnetic ratio.
D. Precessional frequency
_______ is when only half the views of k-space are filled in the frequency axis.
D. Partial or fractional echo
The ligamentum flavum can be found in which part of the body?
B. Spine
Magnetic field inhomogeneity is expressed in:
C. Parts per million
Magnetic susceptibility artifacts are more prominent with _____________ sequences.
C. Gradient echo
A magnetic vector possesses attributes of both __________ and _____________.
D. Magnitude; direction
A major advantage of a 2D time of flight over a 3D time of flight sequence is the ability to:
D. Image larger areas without saturation of flowing blood
The medial and lateral rectus muscles are in the:
D. Eyes
The MRI system component that produces the magnetization of proton spins (alignment) is known as the:
B. Main magnet
The MRI system component that provides the ability to perform spatial encoding is the:
C. Gradient system
A narrow receiver bandwidth:
D. Increases susceptibility artifact
On a T2 weighted image, edema appears bright because it has a _________ relaxation time.
D. Long T2
On T1 weighted images of the spine, the CSF (cerebrospinal fluid) appears:
B. Hypointense to the spinal cord
The optimal imaging plane for visualization of a TFCC tear is:
B. Coronal
Permanent magnets with a vertical magnetic field use surface coils that are:
D. Solenoids
Phase contrast MRA techniques produce images in which the signal intensity within the vessel is dependent upon the:
B. Velocity of the flowing blood
The phase encoding step is performed:
C. Prior to frequency encoding
The pixel size of the images which result from a 3D acquisition using a 260mm FOV, a 320 x 320 matrix, 32 slices and a volume of 64 mm is:
B. 0.88 x 0.88 mm
The process that digitizes the MR signals is known as:
B. Fourier transform
The purpose of shimming the magnet is to:
B. Make the B0 field as homogenous as possible
The readout gradient is usually turned on during the sampling or readout of the peak echo and also during which other process?
D. Frequency encoding
The receiver bandwidth (rBW) affects:
A. Signal-to-noise ratio (SNR) B. Slice thickness
C. Chemical shift
D. Spatial resolution
A and C
A and C
Reducing the flip angle yields images with what change in image contrast?
D. Less T1 information
Reducing the FOV by a factor of 2 will reduce the voxel volume by a factor of:
E. 4
Reducing the FOV (field of view) only will result in:
A. Decreased spatial resolution
B. Increased signal-to-noise
C. Decreased signal-to-noise
D. Increased T1 contrast
E. More slices per TR
F. A and C
F. A and C
Reducing the number of lines filled in k-space will produce an image:
A. With a decrease in spatial resolution B. With an increase in spatial resolution
C. With a decrease in overall SNR
D. With an increase in overall SNR
E. With a reduced overall scan time
G. A, D and E only
Reducing the TE yields images with what change in image contrast?
D. Decreased T2 information
Referencing the Centers for Disease Control and Prevention (CDC), what type of isolation precautions should be used for HIV-positive patients in the MRI suite?
C. Standard (universal)
Referencing the White Paper on MRI safety, individuals identified as “Level 1” personnel include:
B. Those with limited MRI safety training
Referencing the White Paper on MRI safety, individuals identified as “Level 2” personnel include:
C. Those with extensive MRI safety training, including the magnetic, gradient and RF fields
A remedy for a Gibbs truncation artifact would be:
C. Increase the number of phase encodings
RF energy used in MRI is classified as:
A. Low energy, nonionizing radiation
The __________________ runs the length of the falx cerebri.
B. Superior sagittal sinus
________ sequences use T1 gradient echoes with TR and FA selections to suppress signal from stationary tissues, visualizing flowing blood by flow-related enhancement, whereas __________ sequences use T2 gradient echoes with parameter selections that suppress stationary tissue and rely on velocity-induced phase shifts for vascular signal.
D. TOF MRA; PC MRA
Shimming in MRI can be performed by all the following EXCEPT:
A. Turning the shim coil off and on rapidly
Short TAU inversion recovery (STIR) sequences are typically used for the evaluation of all the following EXCEPT:
C. Fluid (CSF)
Single order gradient moment nulling does not compensate for:
D. B and C
The smallest object that can be resolved in an image acquired with a 24cm FOV and a 272 x 272 matrix is _________ mm.
B. 0.88 mm
The source of infection where pathogens thrive in numbers sufficient to cause a threat is known as a:
D. Reservoir
A STIR sequence with a TI time of 160 ms will null signal from fat at what field strength?
D. 1.5 T
The structures that comprise the rotator cuff in the shoulder are:
I. Deltoid muscle
II. Subscapularis muscle and tendon III. Infraspinatus muscle and tendon IV. Teres minor muscle and tendon
V. Supraspinatus muscle and tendon VI. Trapezius muscle and tendon
C. I, III, IV and V
T2 weighted FLAIR (fluid attenuated inversion recovery) sequences are typically used for evaluation of:
E. White matter disease
A technique utilized to reduce the MRI scan time which requires the use of an array coil is:
B. Parallel imaging
A technologist may be permitted to administer oxygen in an emergency situation. The most common rate used is:
A. 2 L/min
To increase the voxel volume, which parameters would be adjusted?
B. FOV, slice thickness and matrix
To produce a high quality reformatted image, the:
B. Acquisition voxel should be isotropic
To produce an image based on differences in T1, the time interval between 90° excitation pulses should be:
B. Short
The transmit bandwidth of the RF pulse affects:
A. Spatial resolution
B. SNR
C. Image contrast
D. Slice thickness
A, B and D only
The unit of measurement of the magnetic field surrounding the periphery of the MR scanner is expressed as:
D. Gauss
The ___________ valve lies between the left atrium (LA) and the left ventricle (LV).
D. Mitral
Water has a __________ T1 relaxation time and a ________ T2 relaxation time.
A. Long; long
What effect would using a steep slice select slope and/or narrow bandwidth have on slice thickness?
B. Slices will be thin
What element in the body is the principal nucleus utilized in clinical MR imaging?
B. Hydrogen
What is the percentage of patients reported to have allergic reactions to gadolinium contrast agents?
A. 1%
What protocol would be selected to rule out islet cell tumor?
D. Pancreas
What would the scan time be in a 3D volume acquisition as follows: TR 24 ms, TE 7 ms, Flip Angle 15°, FOV 20cm, 2mm slice thickness, 76 slices, 176 x 256 matrix, 1 NEX?
D. 5 min 21 sec
When a gradient echo sequence is selected for fast, breath hold dynamic contrast-enhanced imaging of the abdomen, _____________ is utilized.
D. Spoiling
When imaging a geriatric patient, while performing a PCA MRA sequence, what imaging parameter might the operator adjust?
D. VENC
When imaging a hemorrhagic infarct in the brain, which pulse sequence would demonstrate the magnetic susceptibility effects better?
D. Gradient echo
When imaging the female pelvis, the most optimal view for evaluation of the ovaries is the:
B. Coronal
When imaging the female pelvis, the most optimal view for evaluation of the uterus is the:
C. Sagittal
When imaging the spine, to rule out metastatic lesions of the spinal cord, contrast enhancement is used with T1 weighted images because:
C. Metastatic lesions (in the cord) enhance and normal cord does not
When parallel imaging techniques are utilized, a low resolution __________ is acquired prior to the acquisition.
B. Calibration scan
When performing MRI to rule out brain tumors, the weighted images acquired to evaluate the extent of lesion involvement, after injection of gadolinium, are:
D. T1 weighted
Which fissure divides the frontal and parietal lobes from the temporal lobes?
D. Sylvian fissure
Which of the following best describes a FSE sequence?
D. A train of spin echoes
Which of the following best describes an EPI sequence?
C. A train of gradient echoes
Which of the following best describes an IR sequence?
A. A 180° pulse followed by a 90°/180° combination
Which of the following combinations of flip angle (FA) and TR would produce a T2 weighted gradient echo?
C. 450 TR; 30o flip angle
Which of the following field strengths would require the shortest TI time to suppress the signal from fat when performing a STIR sequence in an MRI of the ankle?
A. 0.5 T
Which of the following has been documented to cause muscle contractions, cardiac arrhythmias, mild cutaneous sensations and visual light flashes?
B. Time varying magnetic fields (TVMF – gradient)
Which of the following, in an MRA sequence, aids in minimizing the loss of signal due to dephasing within a voxel:
A. Long TE
B. Short TR
C. Smaller voxel size
D. Short TE
E. C and D
E. C and D
Which of the following is NOT affected by changing the slice thickness?
D. The T2 contrast
Which of the following is NOT a type of fomite found in an MRI environment?
A. Injection syringe
Which of the following is NOT a type of fomite found in an MRI environment?
A. Injection syringe
Which of the following parameter adjustments help to improve SNR in an MR image?
I. Increase TR
II.Reduce Phase Matrix
III. Reduce Pixel Size
IV. Increase FOV
V. Reduce rBW
VI. Increase rBW
VII. Increase NSA
VIII. Decrease NSA
IX. Increase ETL
X. Decrease ETL
A. I, II, IV, V, VII and X
Which of the following parameter adjustments reduce the overall SNR in an MR image?
I. Decrease TR
II.Reduce Phase Matrix
III. Reduce Pixel Size
IV. Decrease FOV
V. Reduce rBW
VI. Increase rBW
VII. Increase NEX
VIII. Decrease NEX
IX. Increase ETL
X. Decrease ETL
B. I, III, IV, VIII and IX
Which of the following parameter adjustments will LENGTHEN scan time in an MR pulse sequence?
I. Decrease TR
II. Increase TR
III. Increase ETL
IV. Decrease ETL
V. Decrease NEX
VI. Increase NEX
VII. Enable Half-fourier
VIII. Increase parallel imaging factor
C. II, IV, VI and IX
Which of the following parameter adjustments will SHORTEN scan time in an MR pulse sequence?
I. Decrease TR
II. Increase TR
III. Increase ETL
IV. Decrease ETL
V. Decrease NEX
VI. Increase NEX
VII. Enable Half-fourier
VIII. Increase parallel imaging factor
IX. Decrease parallel imaging factor
X. Enable anti-aliasing
D. I, III, V, VII and VIII
Which of the following sequences is the most insensitive to magnetic field inhomogeneity?
B. Spin echo
Which parameter combination will yield the best spatial resolution?
C. 3 mm slice thickness, 256 x 256 matrix
Which type of blood cell is responsible for phagocytosis?
A. Leukocyte
The image below is a ___ weighted image acquired in the ___ scan plane?
T1 Axial
What muscle the arrow show?
A. Pectineus
Which arrow points to the Posterior Labrum?
D
Which arrow points to the base of 2nd middle phalanx?
K
Which component of the ventricular system is indicated?
A. Frontal horn of the lateral ventricles
Which component of the ventricular system is indicated?
A. Cerebral aqueduct
Arrow 2 is pointing at
The liver
Arrow 5 is pointing at the
Transverse Colon
Arrow 5 is also pointing
Right kidney
The N is labeled :
Facet for head of rib
The J is labeled
In the vertebral body
