Radionuclide Imaging in Ischemic Stroke

Targeted CE per ARRT’s Discipline, Category, and Subcategory classification for enrollments starting after February 24, 2023:
[Note: Discipline-specific Targeted CE credits may be less than the total Category A credits approved for this course.]

Computed Tomography: 0.50
Procedures: 0.50
Head, Spine, and Musculoskeletal: 0.50

Magnetic Resonance Imaging: 0.50
Procedures: 0.50
Neurological: 0.50

Nuclear Medicine Technology: 2.25
Procedures: 2.25
Other Imaging Procedures: 2.25

Registered Radiologist Assistant: 1.00
Procedures: 1.00
Neurological, Vascular, and Lymphatic Sections: 1.00

Outline

1. Introduction
2. Physiologic Variables Affected in Ischemic Stroke
3. Radioactive Tracers Used in Stroke
4. Applications of Radioisotope Studies in Stroke
   1. Detection of Ischemic Lesion
   2. Identification of the Ischemic Penumbra
   3. Noninvasive Imaging of the Penumbra
5. Radioisotope Imaging as a Surrogate Marker for Treatment Efficiency and for Selection of Patients for Special Therapeutic Strategies
6. Microglial Activation as an Indicator of Inflammation
7. Hemodynamic and Metabolic Reserve in Arterial Occlusive Disease
8. Deactivation of Remote Tissue (Diaschisis
9. Activation Studies in Stroke Patients
10. Conclusion and Future Perspectives

Objectives

Upon completion of this course, students will:

1. define the term malignant as it applies to brain infarction
2. identify the gas used in the first quantitative method of measuring CBF
3. list the radioactive gases used for imaging studies of rCBF
4. describe the xenon method of rCBF measurement
5. describe the percentage of total basal oxygen consumption used by the brain
6. list the vascular components of the CBV
7. describe the average CBF to the gray matter
8. describe the percentage of total-body glucose consumption used by the brain at rest
9. indicate the brain-tissue partial oxygen pressure at which loss of consciousness occurs
10. describe the time it takes for loss of consciousness to occur following stoppage of CBF
11. list the characteristics of SPECT radiopharmaceuticals used for stroke evaluation
12. list the SPECT radiopharmaceuticals used for imaging of CBF
13. list the isotopes used in PET radiopharmaceuticals for stroke evaluation
14. list the PET radiopharmaceuticals used for measuring CBF
15. describe the final structure of the PET radiopharmaceutical used for evaluation of glucose metabolism
16. identify the imaging modalities that produce morphologic images for coregistration with SPECT imaging
17. compare the sensitivities of SPECT, PET and CT for detection of the presence and extent of stroke
18. describe the effect of SPECT imaging on neurologic deficit scores
19. indicate the level of decreased perfusion in brain tissue that represents the flow threshold for reversible functional failure
20. identify the region of the brain with the potential for functional recovery without morphologic damage following acute ischemic stroke
21. list the three regions within a disturbed vascular territory that can be classified by PET
22. describe the difficulties with using SPECT perfusion studies in identifying hypoperfused tissue that is amenable to reperfusion therapy
23. list the radiopharmaceuticals used for PET imaging of the ischemic penumbra
24. compare the accuracies of MR DWI and PWI in identifying the ischemic penumbra and predicting infarcted tissue
25. describe the use of the PET radiopharmaceutical ¹⁸F-fluoromisonidazole
26. identify the radiopharmaceutical used to generate a penumbagram
27. describe the limitations of ¹⁸F-fluoromisonidazole evaluation of the ischemic penumbra
28. identify the vessel territory associated with malignant brain infarcts in 10% of patients
29. be familiar with the proposed stages of hemodynamic compromise
30. list the imaging techniques that can identify selective neuronal loss in the cortex resulting from exhausted metabolic reserve
31. describe the brain regions that demonstrate significant reductions of CBF and metabolism following Infarct of the parietal and frontal lobes
32. indicate the brain region most frequently affected by post-stroke aphasia in right-handed individuals with left hemispheric language dominance
33. identify the best method for imaging the morphology of the brain in health and disease
34. describe the advanced MR imaging technique used to evaluate the concentrations of defined substrates and chemicals
35. identify the PET radiopharmaceutical that is part of an innovative strategy for imaging evaluation of angiogenesis