CNS Exam
Which statement is FALSE regarding tracers for regional cerebral perfusion? They are small, neutral lipophilic molecules They rapidly diffuse across the BBB They have a low brain extraction fraction They remain fixed in the brain None of the above
They have a low brain extraction fraction
Radionuclide CSF Studies are indicated for the assessment/evaluation of CSF hydrodynamics. True False
True
The physiological principle behind blood brain barrier imaging is that tracers stay within the blood pool and diffuse into the brain only when the BBB is disrupted. This is true when using 99m TcO4- & 99mTc DTPA. True False
True
The most characteristic pattern suggesting Alzeimer disease on a functional brain image is You Answered symmetric decrease in frontal perfusion asymmetic basal ganglia uptake symmetric decrease in anteroparietal perfusion symmetric decrease in posterior parietotemporal perfusion None of these are correct
symmetric decrease in posterior parietotemporal perfusion
In Alzheimer's Disease, symmetric decreases in perfusion and metabolism occur in the: You Answered frontal lobes posterior parietal lobe brain stem temporal parietal lobe none of the above
temporal parietal lobe
The general purpose of performing brain studies w/ the non-BBB penetrating Rphxs. is to evaluate: choroid plexus glucose metabolism cerebral uptake the BBB intactness
the BBB intactness
Which color arrow represents a gyrus?
red green yellow none of these arrows are pointing to the gyrus
A patient that requires a CSF shunt patency study should be injected into the subarachnoid space shunt reservoir shunt's distal tube end abdomen/peritoneal cavity.
shunt reservior
The critical organ with regards to cisternography, is the _____________. spinal cord choroid plexus You Answered bladder grey matter of the brain
spinal cord
The most important aspect of brain death imaging is_____________. the SPECT the Flow blood pool statics delayed imaging
the Flow
The dose which is commonly used for a radionuclide angiogram with 99mTc ECD or 99mTc HMPAO SPECT imaging is _____ 500 uCi-1 mCi 5mCi 20mCi 40mCi
20mCi
Planar images of the brain using 99mTc DTPA are obtained_______min after injection. 1 10 30 60
30
Which of the following does NOT describe the true NORMAL radionuclide cisternogram result? 2-4hr. = CSF RPHX activity gains access to the basal cistern 4-6 hr.= CSF appears as the "capping" or Rphx's thru longitudinal fissure to the SSS; top of hemispheres ~12-24hrs= basal cisterns are filled with activity and are well defined "trident". ~48hrs= activity moves up and into the Sylvain fissures= "capping"
4-6 hr.= CSF appears as the "capping" or Rphx's thru longitudinal fissure to the SSS; top of hemispheres
The maximum approved dosage of 111In DTPA for cisternography is: 50uCi 2mCi 250uCi 500uCi
500uCi
Which characteristic of 99mTC ECD enables it to cross the BBB? 99mTc ECD is neutral lipid soluble and crosses the BBB 99mTc ECD is water soluable 99mTc ECD is pH adjusted to be similar to the brain 99mTC ECD is a neutral lipid soluble substance 99mTc ECD is an ionic compound chemically attracted to the brain tissue
99mTC ECD is a neutral lipid soluble substance
Which of the following is used for cerebral perfusion scintigraphy? I-123 Ioflupane Correct! 99mTcO4-ECD (bicisate) In-111-DTPA Tl-210
99mTcO4-ECD (bicisate)
Cerebrospinal fluid: Provides some mechanical protection for the brain Normally contains red blood cells Drains into dural venous sinuses Is derived from blood plasma Correct! A, C and D are correct
A, C and D are correct
The cerebral vasodilator which can be administered IV or orally to better demonstrate affected ischemic vascular areas as regional areas of decreased perfusion is: Acetazolamide ACD solution Sincalide Urecholine
Acetazolamide
All of the following are true about acetazolamide/diamox for its use in brain imaging EXCEPT it acts as a vasodilator. You Answered it increases perfusion. it improves diagnostic accuracy in cerebral vascular disease. All of these are correct
All of these are correct
Brain perfusion imaging should be very helpful in the evaluation of all the following, except: Epilepsy/ Seizures Dementias or Alzheimers Cervical Neck Syndrome (the Kennedy) Brain tumors or metastases
Cervical Neck Syndrome (the Kennedy)
Extra Credit: Explain how methamphetamines and cocaine can interfere with a DaTSCan study and why patients must be off these medications:
Datscan is a dopamine transporter, methamphetamines and cocaine will compete with the uptake of the tracer, and as a result, it will show false negative. **** It will show a false positive!
Which of the following patient preparation procedures is required for an ioflupane study? Discontinuation of antiparkinsonism drugs for 10 d. Sensory-attenuated state for 30 min after injection. Discontinuation of all central nervous system stimulants for 4 wk. Fasting 8 h before the injection
Discontinuation of all central nervous system stimulants for 4 wk.
When imaging for epileptic foci, the radiopharmaceutical injections occurs: 2 hours prior to the actual scan time during the interictal state During the ictal state when the patient is in a quiet and dim room.
During the ictal state
180-degree acquisitions on 99mTc HMPAO studies are diagnostically comparable to 360 degree True False
False
99mTc HMPAO will not cross an intact BBB. True False
False
Following a nuclear medicine study to assess CSF dynamics, the patient should be instructed to get up immediately and do strenuous exercise. True False
False
For Brain Viability / death confirmation, dynamic perfusion images = 2 - 3 sec. frames are obtained for ~ 90sec. minimum, often w/ out need for any static or delayed images obtained. True False
False
For Brain Viability / death confirmation, dynamic perfusion images = 2 - 3 sec. frames are obtained for ~ 90sec. minimum, often w/ out need for any static or delayed images obtained. True False
False
In BBB imaging with 99mTcO4- & 99mTc DTPA, uptake in the brain parenchyma indicates a normal scan. True False
False
Radiotracers currently approved for cisternography include, 99mTc ECD and 99mTc HMPAO True False
False
123I ioflupane imaging parameters include: Lugol's solutions 1 hr prior to injection/3-5mCi IM/ scan immediately Lugol's solution 24hr prior to injection/5-10mCi IV/ scan 3-6 hrs post injection Lugol's solution 6 hrs prior to injection/5/10mCI IV/scan 3-6 hrs post injection Lugol's solution 1 hr prior to injection/3-5mCi IV/ scan 3-6 hrs post injection
Lugol's solution 1 hr prior to injection/3-5mCi IV/ scan 3-6 hrs post injection
Persistent ventricular filling and delayed transit around the brain convexity on a cisternogram is consistent with: High pressure hydrocephalus NPH (normal pressure hydrocephalus) a CSF leak a patent ventriculo-peritineal shunt
NPH (normal pressure hydrocephalus)
On a Brain death study, if intra-cerebral blood flow activity is seen, this would be indicative of: instrument malfunction Normal scan (viability) an abnormal scan (death) CSF leakage
Normal scan (viability)
Which of the following are NOT materials needed for a brain SPECT study: Pb markers on surface landmark SPECT imaging table w/ head extension . Non-attenuating type head restraint Computer system w/ SPECT capability and parameters
Pb markers on surface landmark
Which one of the following collimators is NOT useful for a performing Brain SPECT study? Fan beam High resolution Pinhole Slant hole type
Pinhole
Advantage of ECD over HMPAO, even though they are both brain SPECT Lipophilic agents that localize very similarly, the ECD is more stable & has slightly better T-n-T ratio. True False
True
An HMPAO kit should be made with the 99mTc eluate within 2 hours of the elution. True False
True
Between 99mTc HMPAO and 99mTc ECD, ECD has a faster blood clearance True False
True
If SPECT NM digital brain images use a filter cutoff that is set too high the resultant images will appear to be too "noisy" / "grainy". True False
True
For Brain death confirmation,, the method of administration is: a rapid intravenous bolus injection a slow IV push intrathecal injection active transport
a rapid intravenous bolus injection
Considerations for successful SPECT imaging of the brain include: You Answered minimizing sensory stimulation during injection minimizing patient to detector distance immobilizing the patient all of the above b and c only
all of the above
The main indications for a NM radionuclide CSF studies do NOT include: Diagnosis & localization of CSF leaks hydrocephalus dynamics of CSF CSF shunt patency/ prognosis assessment of the BBB integrity
assessment of the BBB integrity
The blood-brain barrier is created by tight junction seals around brain capillaries formed by the oligodendrocytes astrocytes CNS neurons pia mater
astrocytes
In a positive brain death study, the Rphx bolus goes through the common carotids but stops where? base of the skull due to raised pressure that exceeds pressure supplied by the internal carotid circle of Willis You Answered SSS MCA
base of the skull due to raised pressure that exceeds pressure supplied by the internal carotid
A patient scheduled for a SPECT brain procedure. Before the Rphx is administered, the patient should be well hydrated have received Lugols solution be placed in a quiet, dimly lit room have had a previous CT of the brain for comparison
be placed in a quit, dimly lit room
Why is 111In DTPA preferred over 99mTc DTPA for cisternography in adults? Because it has a lower energy photon Because it has 2 photopeaks because it has a longer half-life allowing delayed imaging because it has a superior biodistribution.
because it has a longer half-life allowing delayed imaging because it has a superior biodistribution.
Ictal SPECT and Ictal PET studies require an injection of rphx __________. You Answered during a seizure immediately after a seizure between seizures both a and b
both a and b
All of the following are radiotracer requirements for assessing rCBF except brain redistribution lipophilicity BBB retention You Answered brain retention
brain redistribution
The most superior part of the brain is the medulla oblongata cerebellum thalamus cerebrum
cerebrum
Which of the following statements about radionuclide cisternography with In-111 DTPA is FALSE? Choroid Plexus activity will not be evident Radioactivity will enter the ventricular system in patients with normal pressure hydrocephalus clearance of the radiotracer from the CSF space occurs by active transport in the meningeal membranes of the spinal cord near the cauda equina Reabsorbed by subarachnoid granulations to the dural sinus ti internal jugular. It normally takes 2-3 days for most of the radioactivity to clear from the CSF space.
clearance of the radiotracer from the CSF space occurs by active transport in the meningeal membranes of the spinal cord near the cauda equina Reabsorbed by subarachnoid granulations
Shunts that divert the flow of the CSF are often used to treat which disorder? dementia communicating & non- communicating hydrocephalus. seizures CSF leak
communicating and non- communicating hydrocephalus.
Which one of the following statements is true regarding a CSF VP shunt evaluation following the administration of 99mTc DTPA? Evidence of ventricle activity indicates patency of the distal limb of the shunt. Evidence of ventricle activity indicates obstruction of the distal limb of the shunt evidence of peritoneal activity indicates patency of the proximal limb of the shunt evidence of peritoneal activity indicates patency of the distal limb of the shun
evidence of peritoneal activity indicates patency of the distal limb of the shun
CSF dynamics are studied following administration of 111In DTPA via ________. intravenous injection intrathecal injection intraperitoneal injection intradermal injection
intrathecal injection
Which of the following is the main disadvantage of using 99mTcO4- for BBB imaging? radiation dose to the thyroid It localizes in the choroid plexus. It localizes in normal brain tissue It has a fast excretion rate from the tissue making imaging difficult
it localizes in the choroid plexus.
In which area is the radio-pharmaceutical NOT visible in a normal cisternogram? basal cisterns Sylvain fissure cerebral convexities lateral ventricles
lateral ventricles
In which area is the radiopharmaceutical not visible in a normal cisternogram? basal cisterns cerebral convexities Sylvain fissure lateral ventricles
lateral ventricles
Why is 111In DTPA preferred over 99mTc DTPA for cisternogram imaging in adults? lower energy photons 2 photopeaks longer T 1/2 for delayed imaging superior biodistribution
longer T 1/2 for delayed imaging
