1. NeuroImaging Dr. Norman Pay

2. CT Transmission

3. CT Transmission Density differences Ionizing radiation Iodinated contrast material Spatial resolution Fast scanning times and acquisition Appropriate in emergent situations, claustrophobic patients, body coverage Utilization for contraindications in MRI as aneurysm clips, cardiac pacemakers, etc. Biopsies Workstation compatibility CT angiography

4. RADIATION Sv (Sievert) – absorbed dose in biological tissue 2 mSv/ year – background radiation 24 mSv/ year –background radiation for airline cruising altitude 6.8 mSv – chest CT scan 10-30 mSv – single full body CT scan 21 Sv – fatal dose

5. CT Angiography CAROTID STENT CAROTID TRAUMATIC ANEURYSM

6. MRI Proton Relaxation Signal intensities Contrast resolution Gadolinium (Gd) contrast Nephrogenic Systemic Fibrosis (NSF) – Gd contraindicated in Low GFR states (<30) and renal failure Non-ionizing, non-invasive Workstation compatibility More complex, longer acquisitions and set-up Magnet bore - claustrophobia MR angiography

7. MR Angiography CAVERNOMACAROTID DISSECTIONCAROTID OCCLUSION

8. T1 T2Flair Diffusion GRE Contrast

9. MR sequences T1 – anatomy, CSF dark T2 – screening, CSF bright FLAIR (fluid attenuated inversion recovery) – similar to T2 MR diffusion – bright signal for restriction GRE (gradient echo) – susceptibility- dark signal Gadolinium, T1 – bright signal MR angiography and perfusion – Gadolinium utilization

10. Anatomy of the Brain Spatial Resolution –CT Density Contrast Resolution –MR Signal Intensity Intravenous Contrast –Iodinated contrast –Gadolinium contrast

11. NEURONAL MIGRATION

12. CORTICAL DYSPLASIA FLAIR T2

13. Stroke Acute ischemic stroke (AIS) – 3 rd leading cause of death, leading cause of disability in adults 700,000 ischemic strokes annually in the U.S. Reperfusion therapy is the only proven treatment of AIS

14. CT and MR Time to infarct Time to treatment Extent of infarct Hematoma Recovery

15. PRE THROMBUS LYSIS POST THROMBUS LYSIS

16. PRE THROMBUS LYSIS POST THROMBUS LYSIS CT

17. MOYA-MOYA FLAIR

18. Pattern Recognition Diagnostic Neuroradiology, pg 130-131. Osborn, Anne G., M.D. Mosby – Year Book, Inc., 1994.

19. Pattern Recognition Diagnostic Neuroradiology, pg 130-131. Osborn, Anne G., M.D. Mosby – Year Book, Inc., 1994.

20. MR DIFFUSION Diffusion refers to the general transport of molecules, mixing through agitation and randomly The driving force is the motion of water within water, driven by thermal agitation called Brownian motion If restricted as in acute infarcts, decreased diffusion results Decreased diffusion displayed as bright MR signal

21. MR DIFFUSION Failure of Na+/K+ ATPase and other ionic pumps – net shift of water from the extracellular to the intracellular space Cell swelling with decrease in extracellular space Increased intracellular viscosity and cell membrane permeability Temperature decrease Decreased diffusion in acute stroke

22. CTMR DIFFUSION CEREBELLAR INFARCT

23. CTMR MIDDLE CEREBRAL ARTERY INFARCT

24. DIFFUSION BASILAR ARTERY OCCLUSION MRA

25. FLAIR DIFFUSION ACUTE INFARCT

26. EMBOLIC DISEASE – ATRIAL FIBRILLATION MR DIFFUSION

27. T1 T2 CONTRAST POSTERIOR CEREBRAL ARTERY INFARCT

28. FLAIR T2 VASCULITIS

29. FLAIR DIFFUSION STATUS POST AORTIC VALVE SURGERY HYPOTENSION

30. Neuroimaging in acute ischaemic stroke: insights into unanswered questions of pathophysiology. Wardlaw, J. M. Journal of Internal Medicine 267; 172–190. Blackwell Publishing Ltd. 2010.

31. MR DIFFUSION Neuroimaging in acute ischaemic stroke: insights into unanswered questions of pathophysiology. Wardlaw, J. M. Journal of Internal Medicine 267; 172–190. Blackwell Publishing Ltd. 2010.

32. CTMR MIDDLE CEREBRAL ARTERY INFARCT

33. Hematoma Hemorrhagic transformation – dreaded complication Exclusion of hematoma -prerequisite for treatment Cue for emergent intervention

34. CT INFARCT HEMORRHAGE INTO INFARCT

36. EPIDURAL SUBDURAL HEMATOMA

37. ISODENSE REBLEED SUBDURAL HEMATOMA

38. Magnetic Resonance Imaging of the Brain and Spine, 3rd ed., Vol. 1, pg 788. Atlas, Scott W., M.D., editor. Lippincott Williams & Wilkins, 2002.

39. HEMATOMA GREFLAIR

40. CT T1T2 SUBDURAL HYGROMA AND HEMATOMA

41. SUBDURAL HEMATOMA T1CTT2 CHRONIC

42. CT FLAIR SUBARACHNOID HEMORRHAGE

43. ANTERIOR COMMUNICATING ARTERY (ACA) ANEURYSM

44. T1 FLAIR VENOUS THROMBOSIS AND VENOUS INFARCT

45. SIDEROSIS GRE

46. FLAIRCT BENIGN MALIGNANT HEMATOMA

47. MALIGNANT HEMATOMA T1T2CONTRAST

48. T1 GRE CT T2 CYST

49. SUMMARY CT and MR utilize different technologies, often complementary Advantages and disadvantages of CT and MR CT and MR advances pari-passu with computing capabilities Moore ’ s Law

50. REFERENCES Diagnostic Neuroradiology, pg 130-131. Osborn, Anne G., M.D. Mosby – Year Book, Inc., 1994. Magnetic Resonance Imaging of the Brain and Spine, 3rd ed., Vol. 1, pg 788. Atlas, Scott W., M.D., editor. Lippincott Williams & Wilkins, 2002. Neuroimaging in acute ischaemic stroke: insights into unanswered questions of pathophysiology. Wardlaw, J. M. Journal of Internal Medicine 267; 172–190. Blackwell Publishing Ltd. 2010.