Neuroradiology Flashcards
A patient with severe renal failure but not on dialysis required CT angiogram. In addition to keeping the patient well hydrated, what may be given to the patient to minimize contrast nephropathy?
a. Hydrocortisone
b. Magnesium sulfate
c. N-Acetylcysteine
d. Ramipril
e. Sodium bicarbonate
c. N-Acetylcysteine
True diffusion restriction is best assessed by looking at which one of the following MR sequences?
a. Diffusion tensor imaging
b. Diffusion weighted image and apparent diffusion coefficient map
c. Fractional anisotropy map
d. T2 gradient echo
e. T1 with gadolinium
b. Diffusion weighted image and apparent diffusion coefficient map
Diffusion restriction is assessed with a diffusion weighted imaging protocol which includes a T2 weighted sequence (low b¼0), diffusion weighted sequence (high b¼1000) and apparent diffusion
coefficient map. The b-value parameter identifies the measurement’s sensitivity to diffusion and determines the strength and duration of the diffusion gradients. A b value of 0 produces a T2 weighted image for anatomical reference. In the range of clinically relevant b values (i.e. up to 1000) the greater the b value the stronger the diffusion weighting and the higher the contrast in pathogenic regions. A minimum of two b-values must be acquired for an apparent diffusion coefficient map, which is a measure of the strength of diffusion in tissue after eliminating any overlying T2 shine through/contrast effects. T2 shinethrough refers to high signal on DWI images that
is not due to restricted diffusion, but rather to high T2 signal which “shines through” to the DWI image. T2 shine through occurs because of long T2 decay time in some normal tissue. This is most
often seen with subacute infarctions due to vasogenic edema but can be seen in other pathologic abnormalities e.g. epidermoid cyst. To confirm true
restricted diffusion one should always compare the DWI image to the ADC. In cases of true restricted diffusion, the region of increased DWI signal will
demonstrate low signal on ADC. ADC is a value that measures the effect of diffusion independent of the influence of T2 shine-through. ADC maps thus portray restricted diffusion, such as in ischemic
injury, as hypointense lesions relative to normal brain. In contrast, in cases of T2 shine-through, the ADC will be normal or high signal.
A ring-enhancing lesion on contrast CT has the below appearance on DWI (C- DWI, D- ADC map) sequence. Which one of the following is of most concern?
a. Cerebral abscess
b. Encephalitis
c. Glioblastoma multiforme
d. Metastasis
e. Radiation necrosis
a. Cerebral abscess
Which one of the following combinations of findings on perfusion weighted MR suggests early infarction
a. Bright on DWI, low rCBF, long rMTT,
low CBV
b. Bright on DWI, high rCBF, long rMTT,
low CBV
c. Bright on DWI, low rCBF, short rMTT,
low CBV
d. Bright on DWI, low rCBF, long rMTT,
high CBV
e. Dark on DWI, low rCBF, long rMTT,
low CBV
a. Bright on DWI, low rCBF, long rMTT,
low CBV
Which one of the following tracts is most likely depicted in the figure below?
a. Cingulum
b. Corona radiata
c. Corpus callosum
d. U fibers
e. Vertical occipital fasciculus
c. Corpus callosum
The corpus callosum facilitates interhemispheric interactions for communicating and integrating perceptual, cognitive, learned, and volitional information. It is important for the performance of visual and tactile tasks that require transfer of sensory information between the cerebral hemispheres. Commissural fibers crossing through the anterior portion and body of the corpus callosum are essential to perform temporally independent bimanual finger movements. Commissural fibers passing through the posterior corpus callosum play an important role in visual and visuospatial integration. Callosal fibers are also important for higher-order cognition, including normal social, attentional, and emotional
function.
Which one of the following tracts is most likely depicted in the figures below?
a. Anterior commissure
b. Extreme capsule
c. Fornix
d. Posterior commissure
e. Posterior limb of internal capsule
c. Fornix
The fornix is part of the dorsal limbic system and the Papez circuit. It participates in high-level mental processes relevant to episodic memory and emotion. It also provides the main cholinergic input to the hippocampus.
Which one of the following tracts is most likely depicted in the figure below?
a. Corpus callosum
b. Corona radiata
c. Corticospinal tract
d. Inferior frontooccipital fasciculus
e. Superior frontooccipital fasciculus
b. Corona radiata
The fibers of the corona radiata interconnect the
cerebral cortex with the thalamus and brainstem
in both directions. From anterior to posterior,
they include (1) the thalamic connections to
the frontal lobes and the frontopontine motor
fibers that pass through the anterior limb of the
internal capsule; (2) the thalamic connections to
the anterior parietal lobe and the corticonuclear
motor projections that pass through the genu;
and (3) the thalamic connections to the central
parietal and occipitotemporal lobes and corticospinal, corticopontine, and corticotegmental motor
fibers that pass through the posterior limb of the
internal capsule. The thalamic radiations to and
from the cortex are grouped into four thalamic
peduncles.
Which one of the following tracts is most likely depicted in the figure below?
a. Corona radiata
b. Corticospinal tract
c. Medial longitudinal fasciculus
d. Reticulospinal tract
e. Spinothalamic tract
b. Corticospinal tract
The corticospinal tract is the predominant
pathway for the relay of impulses for voluntary
skilled movements of the upper extremities,
trunk, and lower extremities. It connects pyramidal Giant cells of Betz in layer V of primary
motor cortex to alpha motor neurons, decussating in the medulla.
Which one of the following tracts is most likely depicted in the figure below?
a. Arcuate fasciculus
b. Cingulum bundle
c. Corona radiata
d. Corticospinal tract
e. SFOF
b. Cingulum bundle
The cingulum bundle is the major component of
the dorsal limbic pathway. It is involved in a wide
range of motivational and emotional aspects of
behavior and participates in spatial working
memory. It interconnects the hippocampus and
parahippocampal gyrus (critical for memory) with
the (1) prefrontal areas (important for manipulating information, monitoring behavior and working memory) and (2) rostral cingulate gyrus
(involved in motivation and drive). It can be
lesioned or stimulated to treat pain, obsessive
compulsive disorder or depression. The limbic
system is also important for high-level mental
processes relevant to memory and emotion. It is
part of the Papez circuit that links the hippocampus, parahippocampal gyrus, mammillary bodies,
thalamus, and cingulate gyrus. Other structures
subsequently integrated into the limbic system
include the amygdala, septal region, and olfactory
bulb. These structures have been implicated in
dementia, epilepsy, and schizophrenia.
Which one of the following tracts is most likely depicted in the figure below?
a. Inferior fronto-occipital fasciculus
b. Inferior longitudinal fasciculus
c. Fornix
d. Superiorlongitudinal fasciculus (II and III)
e. U-fibers
d. Superiorlongitudinal fasciculus (II and III)
The SLF is significant for initiation of motor
activity and higher-order control of bodycentered action. It connects the superior parietal
lobule (important for limb and trunk location in
body-centered space) with premotor areas
(engaged in higher aspects of motor behavior).
The SLF is also significant for spatial attention,
because it connects the inferior parietal lobule
(concerned with visual spatial information) with
the posterior prefrontal cortex (important for
perception and awareness). Furthermore, the
SLF is relevant to gestural components of language and orofacial working memory, because
it connects the supramarginal gyrus (concerned
with higher order somatosensory information)
with the ventral premotor area (containing mirror
neurons for action imitation).
Which one of the following tracts is most likely depicted in the figure below?
a. Arcuate fasciculus
b. Cingulum bundle
c. Fornix
d. Inferior longitudinal fasciculus
e. Superior longitudinal fasciculus
a. Arcuate fasciculus
The classical (direct) arcuate fasciculus interconnects Wernicke’s receptive, auditory word processing area in the superior temporal lobe with Broca’s
speech production area in the inferior frontal lobe.
This connection provides for the ability to recognize language and respond to it appropriately. Individuals with more symmetric patterns of connection perform better overall on word tasks of semantic association. It has been considered by some to be the fourth portion of SLF.
Which one of the following tracts is most likely depicted in the figure below?
a. Cingulum
b. Posterior commissure
c. Superior fronto-orbital fasciculus
d. Superior longitudinal fasciculus
e. U association fiber
c. Superior fronto-orbital fasciculus
The SFOF is significant for peripheral vision,
visual perception of motion, and visual spatial processing. The SFOF connects the superior parietal
gyrus (parastriate areas important for peripheral
vision and visual appreciation of motion) with
the dorsolateral prefrontal cortex of the middle
and inferior frontal gyri (necessary for attention)
Which one of the following tracts is most likely depicted in the figure below?
a. Arcuate fasciculus
b. External capsule
c. Fornix
d. Inferior fronto orbital fasciculus
e. Inferior longitudinal fasciculus
e. Inferior longitudinal fasciculus
The inferior longitudinal fasciculus has a role in
the ventral visual stream for object recognition,
discrimination, and memory. It appears to mediate the fast transfer of visual signals to anterior
temporal regions and neuromodulatory backprojections from the amygdala to early visual
areas. It likely plays a role in linking object representations to their lexical labels. Face recognition
probably depends on the ILF, because disruption
of the tract has been implicated in associative
visual agnosia, prosopagnosia, visual amnesia,
and visual hypoemotionality.
Which one of the following tracts is most likely depicted in the figure below?
a. Commissure of Probst
b. Corona radiata
c. Inferior fronto orbital fasciculus
d. Inferior longitudinal fasciculs
e. Internal capsule
c. Inferior fronto orbital fasciculus
This fascicle may be a major component of the
ventral subcortical “what” pathway important
for object recognition and discrimination. The
IFOF most likely also has a significant role in
semantic processing, because it interconnects
the occipital associative extrastriate cortex with
the temporobasal region, two areas important
to semantic processing. The IFOF also functions
in visuospatial processing and enables the interaction between emotion and cognition
Which one of the following tracts is most likely depicted in the figure below?
a. Anterior commissure
b. Anterior region of the corona radiata
c. Fornix
d. Optic tract
e. Uncinate fasciculus
e. Uncinate fasciculus
The uncinate fasciculus is a ventral limbic
pathway that is critical for processing novel
information, for positive/negative valuations
of the emotional aspects of data, and for
self-regulation. The fibers of the uncinate
fasciculus link the rostral superior temporal
gyrus (important for sound recognition),
the rostral inferior temporal gyrus (important for object recognition), and the medial
temporal area (important for recognition
memory) with the orbital, medial, and prefrontal cortices (involved in emotion, inhibition, and self-regulation). The uncinate
fasciculus may also be critical in visual
learning.
In MR Spectroscopy, Hunter’s angle is best described as which one of the following?
a. The rough angle formed with the x axis
when a line is drawn between choline
and creatine peaks
b. The rough angle formed with the x axis
when a line is drawn between NAA and
creatine peaks
c. The rough angle formed with the x axis when a line is drawn between choline, creatine and NAA peaks
d. The rough angle formed with the x axis
when a line is drawn between lactate and
lipid peaks
e. The rough angle formed with the x axis when a line is drawn between choline and lactate peaks
c. The rough angle formed with the x axis when a line is drawn between choline, creatine and NAA peaks
The rough angle formed with the x axis
when a line is drawn between choline, creatine
and NAA peaks. Hunter’s angle is the formed
by a line approximately joining the ascending
peaks of the metabolites in MR spectroscopy
and is roughly 45°. Myoinositol, Choline,
Creatine and N-Acetyl aspartate peaks are
ascending in normal spectrum, any alteration
in the ascending nature of the peaks means
spectrum is abnormal.
