7 Central Nervous System Scintigraphy

1) The venous phase of a cerebral blood flow study is signaled by: a. visualization of the jugular veins. b. appearance of the radiopharmaceutical in the superior sagittal sinus. c. disappearance of radiopharmaceutical from the carotid arteries. d. appearance of radiopharmaceutical in the middle cerebral arteries.

2) The localization of 99mTc HMPAO is related to: a. a breakdown of the blood brain barrier. b. cerebral blood flow. c. glucose metabolism. d. distribution of neurorecepters.

3) CSF is made mostly of: a. protein. b. water. c. glucose. d. blood.

4) The function of cerebrospinal fluid is to: a. protect the brain and spinal cord against shock. b. filter plasma. c. produce neurotransmitters. d. all of the above.

5) When positioning for a radionuclide angiogram, the patient should be positioned: a. posteriorly. b. anteriorly. c. with as much facial activity as possible excluded. d. none of the above.

6) Exametazime is also known as: a. DTPA. b. MAG3. c. HMPAO. d. EDC.

7) Bicisate is also known as: a. DTPA. b. MAG3. c. HMPAO. d. EDC.

8) CSF dynamics are studied following administration of 111In DTPA: a. via intravenous injection. b. via intraperitoneal injection. c. via intrathecal injection. d. via intradermal injection.

9) The dose which would commonly be used for a radionuclide angiogram with 99mTc DTPA is: a. 5 mCi. b. 10 mCi. c. 20 mCi. d. 25 mCi.

10) Which of the following are true regarding injection of the radiopharmaceuticals for SPECT brain imaging?. a. lights should be dimmed during injection. b. the patient should encouraged to read or watch TV during injection to take his or her mind off any pain. c. family members should be allowed to talk to the patient during injection. d. injection should be made immediately after venous puncture to avoid clot formation.

11) Which dose could be used for 99mTc ECD or 99mTc HMPAO for SPECT brain imaging?. a. 2–5 mCi. b. 5–7 mCi. c. 7–10 mCi. d. 20 mCi.

12) Ictal SPECT and PET studies require an injection of radiopharmaceutical: a. during a seizure. b. immediately after a seizure. c. between seizures. d. both a and b.

13) HMPAO and EDC are lipophilic agents that do not significantly redistribute in the brain. a. true. b. false.

14) Advantages of using ECD over HMPAO for SPECT imaging of the brain include. a. can be injected up to 6 hours after preparation. b. more rapid clearance from bloodstream. c. better target to background ratio. d. all of the above. e. none of the above.

15) White matter has about 4 times greater blood flow than gray matter. a. true. b. false.

16) Planar images of the brain using 99mTc DTPA are obtained: a. 15 minutes after injection. b. 30 minutes after injection. c. 1 hour after injection. d. 1.5 hours after injection.

17) The purpose of placing an elastic band around a patient’s head just above the orbits during a radionuclide angiogram is to: a. to decrease the activity from the orbits. b. to increase intracranial pressure. c. to decrease blood supply to small scalp vessels. d. to immobilize the patient.

18) All of the following statements regarding static planar brain images are true except: a. both laterals are normally obtained. b. images may be acquired for 500 K cts. c. facial activity should be completely included. d. the sagittal sinus is usually seen on both anterior and posterior views.

19) The images obtained with a PET study using 18FDG can best be described as: a. anatomical. b. perfusion. c. metabolic. d. dynamic.

20) In a Diamox challenge study, vascular disease will appear as decreased perfusion after the use of Diamox. a. true. b. false.

21) The injection for a CSF shunt patency study is: a. intravenous. b. subcutaneous. c. intrathecal. d. into the shunt reservoir or tubing.

22) Shunts which divert the flow of CSF are often used to treat: a. obstructive communicating hydrocephalus. b. noncommunicating hydrocephalus. c. CSF leak. d. all of the above. e. a and b only.

23) Which of the following agents will cross an intact blood brain barrier?. a. 99mTc DTPA. b. 99mTc GH. c. 99mTc pertechnetate. d. 99mTc HMPAO.

24) Which radiopharmaceutical is not commonly used for brain perfusion imaging with SPECT?. a. 99mTc DTPA. b. 99mTc HMPAO. c. 99mTc ECD.

25) A technologist neglects to give a patient potassium perchlorate before injection with 20 mCi of 99mTc pertechnetate. How will this affect the static brain images taken at 1 hour after injection?. a. thyroid activity may be seen. b. choroid plexus may be seen. c. salivary glands may be seen.

26) Radionuclide angiography is most commonly used to: a. locate neoplasms. b. investigate brain perfusion. c. evaluate cerebrovascular reserve. d. confirm brain death.

27) In which area is the radiopharmaceutical not visible in a normal cisternogram?. a. basal cisterns. b. cerebral convexities. c. lateral ventricles. d. sylvian fissure.

28) CSF dynamics are studied following administration of 111In DTPA: a. via intravenous injection. b. via intradermal injection. c. via intraperitoneal injection. d. via intrathecal injection.

29) What is the usual dose for a radionuclide cisternogram in adults?. a. 5 mCi of 111In DTPA. b. 100 μCi of 111In DTPA. c. 500 μCi of 111In DTPA. d. 2.5 mCi of 111In DTPA.

30) What is the purpose of pledget placement in suspected CSF leak?. a. to make the patient more comfortable during subarachnoid puncture. b. to alter the biodistribution of the radiotracer. c. to test them for contamination suggesting the presence of leaking CSF in the nose or ears. d. to avoid contamination of the scintillation detection system.

31) Why is 111In DTPA preferred over 99mTc DTPA for cisternography in adults?. a. because it has lower energy photons. b. because it has 2 photopeaks. c. because it has a longer half life allowing delayed imaging. d. because it has a superior biodistribution.

32) 99mTc labeled lipophilic radiopharmaceuticals are preferable to radioiodinated amines because: a. they are more rapidly extracted from the bloodstream. b. they deliver a lower radiation dose to patients. c. administered activity is higher, providing superior images. d. all of the above. e. b and c only.

33) Considerations for successful SPECT imaging of the brain include: a. minimizing sensory stimulation during injection. b. minimizing patient to detector distance. c. immobilizing the patient. d. all of the above. e. b and c only.