Imaging and Angiography Flashcards
Originally, axial CT scan slices were taken parallel to the orbitomeatal line which connects the lateral canthus of the eye to the midpoint of the external auditory meatus. Current volumetric CT scanners tend to create axial slices parallel to what?
● A. McRae’s line
● B. Chamberlain’s line
● C. AC-PC line
● D. McGregor’s baseline
● E. Wackenheim’s clivus-canal line
C. AC-PC line
A noncontrast CT scan is usually employed in emergency situations for diagnosis and screening. However, diffusion-weighted (DWI) MRI is preferred in which of the following?
● A. Acute stroke
● B. Subarachnoid hemorrhage
● C. Intraparenchymal hemorrhage
● D. Acute subdural hemorrhage
● E. Pneumocephalus
A. Acute stroke
For CT perfusion to assess cerebral blood volume and flow, which of the following tests is used?
● A. Acetazolamide challenge test
● B. Dexamethasone challenge test
● C. Insulin tolerance test
● D. Oral glucose tolerance test
● E. Water deprivation
A. Acetazolamide challenge test
In fluid-attenuated inversion recovery (FLAIR), the gray/white intensity pattern is reversed from T1WI and it resembles a T2WI except the CSF which is more what?
● A. Bright
● B. Hyperintense
● C. Same density
● D. Dark
● E. White
D. Dark
Regarding gradient echo MRI, which of the following appears white?
● A. Bone
● B. Calcium
● C. Heavy metals
● D. Intraparenchymal blood
● E. CSF
E. CSF
Which of the following is the most sensitive study for ischemia of the brain?
● A. DWI MRI
● B. Fluid-attenuated inversion recovery (FLAIR)
● C. Perfusion-weighted (PWI) MRI
● D. CT of brain with intrathecal contrast
● E. EEG
C. Perfusion-weighted (PWI) MRI
Regarding peaks on magnetic resonance spectroscopy (MRS), which of the following is the marker of membrane synthesis?
● A. Lipid
● B. Acetate
● C. Creatinine
● D. Choline
● E. N-acetyl aspartate
D. Choline
Which of the following is the most useful to permit planning surgical approaches that minimize disruption of critical white matter tracts during brain surgery for deep lesions?
● A. DWI MRI
● B. Fluid-attenuated inversion recovery (FLAIR)
● C. PWI MRI
● D. Diffusion tensor imaging (DTI) MRI
● E. Proton magnetic resonance spectroscopy (MRS)
D. Diffusion tensor imaging (DTI) MRI
Usual convention for color coding tracts on diffusion tensor imaging (DTI). Superior longitudinal fasciculus is colored what?
● A. Red
● B. Blue
● C. Green
● D. White
● E. Black
C. Green
Three-phase bone scan uses technetium 99m-HDP and has three phases: flow phase, blood pooling, and bone imaging. Osteomyelitis causes increased uptake in which phase?
● A. 1st phase
● B. 2nd phase
● C. 3rd phase
● D. All three phases
● E. No intake
D. All three phases
Attenuation of the X-ray beam on a CT scan is quantified in Hounsfield units. What are the Hounsfield units for air and dense bone, respectively?
● A. + 1000,−1000
● B.−1000, + 1000
● C.−100, + 100
● D. + 5,−5
● E. 0, + 1000
B.−1000, + 1000
CT perfusion (CTP) uses iodinated contrast (40 mL IV at 5 mL/sec) in which scans are repeated through region of interest at small intervals. Acetazolamide challenge is given (1000 mg IV) and scans are repeated at intervals again. Which of the following parameters can be calculated by this method?
● A. Cerebral blood volume
● B. Cerebral blood flow
● C. Mean transit time
● D. Time to peak
● E. All of the above
E. All of the above
The radiation dose to a fetus from head or cervical spine CT is small and can be reduced by lead shielding. The risk from fetal exposure to X-rays is highest during which time of pregnancy?
● A. The first 2 weeks of gestation
● B. Between 8 and 16 weeks of gestation
● C. In the first 3 months of gestation
● D. In the 4th and 5th months of gestation
● E. Both A and B
E. Both A and B
Following statements are correct regarding T1WI MRI except?
● A. Fat including bone marrow, blood > 48 hours old, and melanin appears bright
● B. CSF and bone appear dark
● C. Anatomic image which somewhat resembles CT
● D. Most pathology is high signal
● E. White matter has higher signal than gray matter
D. Most pathology is high signal
Which of the following statements are true regarding T2WI MRI images?
● A. Most pathology shows up as high signal including surrounding edema
● B. Brain edema, water, and fat appear bright
● C. Bone appears dark
● D. Clues to recognize are CSF is white, long TR and TE
● E. Fluid-attenuated inversion recovery (FLAIR) resembles T2WI except that CSF is nulled out (appears dark)
● F. All of the above
F. All of the above
Following statements are correct except?
● A. GRASS (gradient recalled acquisition in a steady state) MRI images are useful for visualizing myelographic cervical spine image, bony spurs, and small old cerebral blood
● B. STIR (short tau inversion recovery) is a fat suppression image which is good to visualize bone edema, periventricular lesion, or intraorbital fat
● C. FIESTA (fast imaging employing steady state acquisition) is useful to visualize pathology at cerebellopontine angle
● D. CISS (constructive interference in steady state) is useful for imaging cranial nerves, CSF leaks, and aqueductal stenosis
● E. Gradient echo images also known as T2 GRE images are useful for seeing brainstem lesions
E. Gradient echo images also known as T2 GRE images are useful for seeing brainstem lesions
MRI with pituitary protocol is used to visualize pituitary gland with detailed imaging. It has all of the following components except?
● A. MRI is done without contrast
● B. Thin coronal cuts are taken through sella, cavernous sinus, and optic chiasma
● C. Dynamic images at intervals are taken to differentiate adenoma from pituitary as pituitary enhances before adenoma
● D. Microadenomas can be visualized using this method
● E. It is done by using MRI with and without contrast
A. MRI is done without contrast
All of the following are common contraindications to MRI except?
● A. Cardiac pacemakers, defibrillators, implanted neurostimulators, cochlear implants, and infusion pumps
● B. Nonferromagnetic aneurysm clips
● C. Ferromagnetic aneurysm clips
● D. Metallic implants or foreign bodies with iron in it
● E. Placement of vascular stents, coil, filter within past 6 weeks
B. Nonferromagnetic aneurysm clips
Intraparenchymal areas of bright signal on DWI that are not bright on apparent diffusion coefficient (ADC) map are abnormal and represent regions of restricted diffusion. It is useful in the diagnosis of which of the following pathologies in brain?
● A. Ischemic brain tissue
● B. Cerebral abscess
● C. Active MS plaques
● D. Some tumors like epidermoids, lymphoma, or some meningiomas
● E. All of the above
E. All of the above
All of the following are true regarding magnetic resonance spectroscopy (MRS) except?
● A. Lactate is a marker of hypoxia and indicates ischemia, infection, or demyelinating disease
● B. N-acetyl aspartate (NAA) is decreased in brain tumor, MS, brain abscess, and brain injury
● C. Choline is increased in brain neoplasms
● D. Abscess causes decreased succinate and acetate peaks
● E. Tumor causes increased lactate, lipid, choline, and decreased NAA
D. Abscess causes decreased succinate
and acetate peaks
Diffusion tensor imaging also known as diffusion tensor tractography is an MRI technique that demonstrates white matter tracts in brain. Surgical trajectory is kept parallel to the long axis of white matter tract to avoid its damage. What are the fibers that connect regions within the same hemisphere?
● A. Optic radiations
● B. Uncinate fasciculus
● C. Arcuate fasciculus
● D. Cingulum
● E. All of the above
E. All of the above
All of the following are the contraindications to myelography except?
● A. Anticoagulation
● B. Allergy to iodinated contrast
● C. Obese patient
● D. Infection at desired puncture site
● E. Extensive midline lumbar spinal fusion
C. Obese patient
Technetium-99 is a radioisotope that may be attached to various substrates for use in bone scan. Bone scan can be used to aid in the diagnosis of which of the following?
● A. Bone infections
● B. Bony tumor
● C. Craniosynostosis
● D. Fracture
● E. All of the above
E. All of the above
