1. WORLD FEDERATION OF NEUROSCIENCE NURSES Introduction to Neuro Imaging

2. Objectives Provide an overview of diagnostic imaging techniques commonly used in neuro patients Review common imaging findings associated with stroke, mass lesions, traumatic brain injury and neurodegenerative states Teach basic skills in recognizing abnormalities on CT and MRI images of the brain and spinal axis

3. You only see what you know.

4. Why perform imaging studies? To detect abnormalities in the brain or spinal canal To direct the treatment plan To evaluate a response to treatment To evaluate for disease progression

5. CT scans –With or without iodine based contrast (10mm though anterior fossa, 5mm through posterior fossa) –CT venogram- gold standard for evaluating venous flow

6. What types of imaging are available? CT angio –Provides excellent definition of vascular structures and abnormalities like aneurysm

7. Plain Xrays Plain films: good view of bony anatomy –Flexion and extension to rule out instability’ and clear the C spine –Evaluate for bony tumors –Evaluate for fracture (screen) –Evaluate for failure of hardware/fracture of shunt systems –Evaluate shunt setting

8. Spinal axis CT spine –Excellent for bony anatomy- fractures

9. CT Brain CT scans of the brain –Easy to detect new bleeding, calcification –Posterior fossa sometimes poorly visualized –Some low grade tumors poorly visualized

10. MRI MRI imaging –With or without gadolineum –MR angiography- with or without contrast, less detailed than CTA –MR venography- evaluates venous flow

11. MRI imaging MRI scan of the brain –Provides detailed information on uptake of water in the brain (swelling, new ischemia, peri-tumoral edema) –Edema best seen on T2/Flair sequence –Excellent visualization of posterior fossa structures –Blood poorly visualized, overestimates SDH

12. MRI imaging MRI spinal axis –Excellent visualization of disc and spinal canal, exiting nerves –Best for detection of tumor

13. How to interpret a CT scan Always use a systematic approach- don’t “LOOK for what you expect to be on the scan” Use the acronym BLOOD CAN BE VERY BAD.

14. How to interpret a CT scan B- BLOOD. Inspect the brain for any signs of bleeding C-CISTERNS. Examine the cisterns. Are they all open, any compression? B- BRAIN. Evaluate the brain parenchyma. Are there any masses, contusions, Is there any mid line shift? V- VENTRICLES. Evaluate the ventricles- are they symmetric? Is the size normal. B- BONE. Evaluate the bone- Are there any fractures of the skull or hyperostosis, is the skull shape normal?

15. CT Brain scan Blood Can- cisterns Be- brain Very- ventricles Bad- Bone

16. NEUROTRAUMA IMAGING

17. TBI imaging CT scan is considered standard of care initial imaging in moderate and severe brain injury Can detect most important findings –Fracture –Contusion –Hematoma –Cisternal compression –Subarachnoid hemorrhage –Intraparenchymal hemorrhage Not ideal for diffuse axonal injury Not ideal for posterior fossa injury.

18. TBI imaging

19. Blossoming of contusions

20. Localization of monitoring devices Risks of placement –Overshooting target –Bleeding –Infection Most receive CT post placement Portable CT- not so portable…. –Must be on special bed

21. TBI - EDH Classically described as “lucid interval” after period of unconsciousness Tempting to leave those alone that “look good” Hematoma volume >30 cm and MLS 5mm was associated with clinical decline and failed non-operative management regardless of initial GCS.

22. TBI- EDH Pupillary abnormalities occur in 20- 30% –Ipsilateral dilated pupil usually correctable and does not affect outcome IF operated within about an hour –Waiting more than 70 minutes after blowing a pupil predicted death –Most common vessel affected is the Middle Meningeal artery

23. Vascular injury Always consider the possibility of vascular injury –blunt carotid injury, – intimal dissections, –pseudoaneurysms, –thromboses, or fistulas Horners- Ptosis, anhydrosis, Miosis

24. STROKE IMAGING

25. Stroke imaging Hallmark symptoms: –Sudden onset weakness, numbness, difficulty talking or understanding, balance problems or change in vision

26. BE FAST Balance Eye findings Face Arm Speech Time of Onset

27. MRI- diffusion weighted imaging Highly sensitive in detecting early ischemia DWI changes can be seen within minutes of ischemia Very sensitive and specific for stroke 90-100% Often takes too long- not readily available

28. Stroke case 58 year old, symptoms started 30 minutes ago. NIHSS is 17 Not anticoagulated Cardiac rhythm: atrial fibrillation with controlled ventricular response (rate 82) BP 185/110 What other diagnostics do we need? Should we treat the pressure?

29. CT scan

30. TPA Successfully treated with TPA with improvement of Left hemiparesis (0.9mg/kg- 10% bolus- rest over 1 hour) No ASA/Plavix/Thrombin inhibitor for 24 hours Keep BP < 185/105. Hourly vitals Frequent neuro assessment – immediately rescan for any change in LOC, sudden onset of HA

31. ICH Represents about 15% of all stroke 6.4% risk with TPA Most common causes of advanced age and HTN –Also seen with methamphetamine/c occaine abuse Usually younger age

32. SAH Hallmark signs: “worst HA of their life New onset stroke like symptoms 50% die before reaching the ED 25% have permanent severe disability 25% return to normal function

33. SAH Fisher Grade 1- no hemorrhage 2- SAH < 1mm thick 3- SAH > 1mm thick 4- SAH with IVH CT slices are 10mm Ant fossa and 5mm in Posterior fossa

34. Vasospasm Risk the highest 3-14 days after SAH but can be up to 21 days after Fisher grade 3 highest risk Transcranial doppler (TCD) most common screening tool –Non-invasive –Uses natural windows

35. CT Angiography CTA provides excellent anatomical detail No data about flow dynamics Dependent on timing of the bolus Highest dose radiation/contrast

36. Digital Subtraction Angiography Gold standard for detecting vascular abnormalities Provides critical information about flow dynamics, surrounding vessels Requires contrast and flouro- dose depends on time

37. Aneurysmal SAH For coil embolization- must be followed for recanalization Imaging pattern, generally doubling time interval with each exam

38. HYDROCEPHALUS AND SHUNT IMAGING

39. Hydrocephalus Most common reason for pediatric neurosurgery Can be Communicating, Obstructive or Normal Pressure

40. Hydrocephalus Disorder characterized by too much CSF –C–Communicating- failure to absorb- SAH clogs the arachnoid villae –O–Obstruction- tumor –O–Overproduction- tumor of choroid plexus

41. Disorder characterized by too much CSF –C–Communicating- failure to absorb- SAH clogs the arachnoid villae –O–Obstruction- tumor –O–Overproduction- tumor of choroid plexus

42. Risks of overdrainage Blood Can- cisterns Be- brain Very- ventricles Bad- Bone

43. BRAIN TUMOR IMAGING

44. Brain tumors Lifetime risk of brain tumor is low (1%) Cause is unknown Represent 2.4% of all cancer related deaths Overall 33% survival rate at 5 years Survival tied to completeness of resection

45. Imaging in tumors Some tumors such as meningioma, acoustic schwannoma, can be identified largely based on radiographic characteristics Low grade astrocytoma usually non-enhancing, best seen on t2/flair High grade glioma usually has central necrosis with peripheral enhancement –PITFALL- To be sure, tumors require biopsy for a pathological diagnosis

46. -Dumbbell shape -Level of eighth cranial nerve Acoustic schwannoma Brain tumor imaging

47. -Homogenously enhancing -Extra-dural -Bony involvement -Calcifications Meningioma Brain tumor imaging Blood Can- cisterns Be- brain Very- ventricles Bad- Bone

48. -Heterogeneous enhancement pattern -Necrosis -Cytotoxic edema (contains tumor) -Crossing midline Glioblastoma Multiforme

49. SPINE IMAGING

50. Cervical degenerative disc disease Hallmark symptoms: -Neck pain with radiating arm pain -shoulder pain -Numbness or tingling in the arm or hands -Difficulty with hand dexterity -Balance problems -Hyper-reflexia

51. Lumbar degenerative disc disease LBP with pain radiating down one or both legs –Often described as burning Weakness of the leg/legs Numbness of tingling in the legs Difficulty walking Foot drop Bowel or bladder incontinence

52. Pearls for imaging Never “look for the finding you expect to see”- you will miss A LOT! Use a systematic approach Read the report and try to find what they saw Always trust your exam- if the patient is worse, report it!