Mock Test Flashcards
T2 weighted Flair sequences are typically used for evaluation of:
White Matter Disease
Which field strength would require the shortest TI time to suppress the signal from fat when performing a STIR sequence in an MRI of the ankle?
Weakest field strength
Which of the following sequences is the most insensitive to magnetic field inhomogeneity?
Spin Echo
The extent to which a material or tissue becomes magnetized in an external magnetic fiels is called:
Magnetic susceptibility
When imaging the female pelvis, the most optimal view for evaluation of the ovaries is the:
Coronal
When imaging the female pelvis, the most optimal view for evaluation of the uterus is the:
Sagittal
Reducing FOV will do what to SNR
Decreased FOV=Decreased SNR
RF energy used in MRI is classified as:
low energy, non ionizing radiation
If the flip angle is doubled, RF deposition increases by a factor of:
4
_____ is when only half the views of k-space are fills in the frequency axis.
Partial or fractional echo
A narrow receiver bandwidth does what to susceptibility artifact?
Increases susceptibility artifact
The process that digitizes the MR signals is known as:
Fourier transform
In the TMJs, the articular disc lies between what two anatomical structures?
Mandibular fossa and mandibular condyle
If the third centricle is dilated, but the fourth ventricle is not, there would then be pathology associated with:
Aqueduct of Sylvius
Which fissure divides the frontal and parietal lobes from the temporal lobes?
Sylvian Fissure
The _____ runs the length of the falx cerebri.
Superior Sagittal Sinus
In what orientation would a tear of the collateral ligaments of the knee be best visualized?
Coronal
On a T2 weighted image, edema appears bright because it has a ____ relaxation time.
Long T2
What protocol would be selected to rule out islet cell tumor?
Pancreas
The common carotid artery bifurcates into the internal and external carotid artery at the level of the:
C3-4 disc space
In order to acquire an intracranial arterial blood flow sequence, a presaturation pulse would be applied in which location?
Superior to slice group
A major advantage of a 2D time of flight over a 3D tie of flight sequence is the ability to:
Image larger areas without saturation of flowing blood.
Phase Contrast MRA techniques produce images in which the signal intensity within the vessel is dependent upon the:
Velocity of the flowing blood
In a contrast enhanced MRA of the abdominal arteries, the IV gadolinium would enhance in which order?
Celiac, superior mesenteric, renal, inferior mesenteric
The ligamentum flavum can be found in which part of the body?
Spine
On a T1 weighted image of the spine, the CSF appears ____ to the spinal cord
hypointense
In a cross sectional view of the MR magnet design, which coils are closest to the patient?
RF coils
The purpose of shimming the magnet is to:
Make the B0 field as homogenous as possible
Active shielding can be defined as:
Superconducting windings within the MR scanner, reducing the fringe magnetic field.
____ could be used to line the walls and/or floors of the MR magnet room to feduce the fringe magnetic field, and is defined as ____ shielding.
Steel, passive
Which magnetic field has been documents to cause muscle contractions, cardiac arrhythmias, mild cutaneous sensation and visual light flashes?
Time varying magnetic fields (Gradient)
The gradient rise time is defined as:
Time it takes for the gradient to reach its full amplitude.
The gradient slew rate is defined as:
The rate of speed of ascent or descent from zero to it maximum amplitude
A technique utilized to reduce the MRI scan time which requires the use of an array coil is:
Parallel imaging
Hemangiomas in the liver are typically benign lesions, and are best visualized with:
Delayed images
The MRI system component that provides the ability to perform spatial encoding is the:
Gradient system
When imaging the spine to rule out metastatic lesions of the spinal cord, contrast enhancement is used with T1 weighted images because:
Metastatic lesions enhance and normal cord does not.
____ sequences are 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.
TOF MRA, PC MRA
What describes an EPI sequence? Hint: Train
A train of gradient echoes
What best describes a FSE sequences? Hint: Train
A train of spin echoes
Reducing the FOV by a factor of 2 will reduce the voxel volume by a factor of:
4
Equation for Effective TR (R-R interval)
60,000 / Heart Rate = Effective TR (ms TR)
Equation for Cardiac imaging time
Imaging time=R-R interval - (trigger window+trigger delay)
(trigger window is percentage of R-R-interval)
