1. Project: Ghana Emergency Medicine Collaborative Document Title: Systematic Evaluation to Non-Traumatic Head CTs Author(s) Rashmi U. Kothari, MD (KCMS/MSU), 2012 License: Unless otherwise noted, this material is made available under the terms of the Creative Commons Attribution Share Alike-3.0 License: http://creativecommons.org/licenses/by-sa/3.0/ We have reviewed this material in accordance with U.S. Copyright Law and have tried to maximize your ability to use, share, and adapt it. These lectures have been modified in the process of making a publicly shareable version. The citation key on the following slide provides information about how you may share and adapt this material. Copyright holders of content included in this material should contact open.michigan@umich.edu with any questions, corrections, or clarification regarding the use of content. For more information about how to cite these materials visit http://open.umich.edu/privacy-and-terms-use. Any medical information in this material is intended to inform and educate and is not a tool for self- diagnosis or a replacement for medical evaluation, advice, diagnosis or treatment by a healthcare professional. Please speak to your physician if you have questions about your medical condition. Viewer discretion is advised: Some medical content is graphic and may not be suitable for all viewers. 1

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3. Systematic Evaluation to Non-Traumatic Head CTs Rashmi U. Kothari, MD KCMS/MSU Source Undetermined

4. Why do you need to be able to evaluate a CT  Radiology report is not immediately available  Need immediate intervention  Don’t trust anyone

5. Course Outline  Basic principles of CT  Basic anatomy  Systematic approach  CT Potpourri

6. Course Goals  Learn “Blood Can Be Very Bad” approach to reading CTs  Identify classic CT findings

7. Disclaimer  Make you a neuroradiologist  Teach you cause of finding of abnormality  Help you with contrast CTs

8. Basic Principles of CT Imaging Source Undetermined

9. X-rays Absorbed Differently by Different Tissues Radiodense Bone Metal Calcium Blood Grey matter Radiolucent Air Spinal fluid Ischemic infarct Edema White matter Source Undetermined

10. Attenuation (amount of radiation blocked by tissue) Air Blood Bone -1000 HU +1000 HU HU=Hounsfield Units 50-100 HU

11. Windowing  Blood Brain Blood Bone Source Undetermined

12. CT Anatomy  Six levels of cuts  Cortical sulci  Lateral Ventricles  Basal Ganglia  3 rd Ventricle  Midbrain  Pons Source Undetermined

13. CT Anatomy: Cortical Sulci & Lat. Ventricle Falx Cortical sulci Frontal lobe Parietal lobe Lateral ventricles Occipital lobe Source Undetermined

14. CT Anatomy: Basal Ganglia & 3 rd Ventricle Anterior horns Insular ribbon Sylvian fissure 3 rd ventricle Quadrigeminal cistern Anterior horns Choroid plexus. Source Undetermined

15. CT Anatomy: Midbrain & Pons Frontal sinus Suprastellar cistern Pons 4 th ventrical Sylvian fissure Insular ribbon Ambient cistern (cirummesenphalic cistern) Source Undetermined

16. Systematic Approach to Head CTs  Perron et al: Carolina’s Medical Center  “Blood Can Be Very Bad” pnemonic  Course reviewing 12 scans & short histories  Pre-test 60% to Post-test 78%  http://www.uic.edu/com/ferne/pdf/acep_2005 _peds/perron_ich _acep_2005_peds_ course.pdf

17. “Blood Can Be Very Bad”  Blood  Cisterns  Brain  Ventricles  Bone Perron et al: Ann Emerg Med 1998:32:554-562

18. “Blood Can Be Very Bad”  Acute blood = hyperdense (white)  50-100 HU  As it ages it becomes hypodense  At 1-2 weeks it is isodense with brain

19. “Blood Can Be Very Bad” Source Undetermined

20. “Blood Can Be Very Bad”  4 cisterns:  Suprasellar  Quadrigeminal  Slyvian  Ambient Source Undetermined

21. Andrew D. Perron, MD, FACEP 21 Cisterns: Is there blood? Are they open? Source Undetermined

22. “Blood Can Be Very Bad” Brain Source Undetermined

23. “Blood Can Be Very Bad” Ventricle Source Undetermined

24. Andrew D. Perron, MD, FACEP “Blood Can Be Very Bad” Bone Source Undetermined

25. Classic CT Findings Source Undetermined

26. Subdural Concave shape Venous bleeds Crosses suture line Epidural Lens shape 85% arterial bleeds Middle meningeal art Lucid period Source Undetermined

27. Intracerebral Hemorrhage  10% of all strokes  2 major causes  Hypertension  Blacks & Asians  50% basal ganglia  Pons  Cerebellum  Amyloid  Caucasians  Lobar  Recurrent Source Undetermined

28. Subarachnoid Hemorrhage  5-10% of all strokes  Aneurysms, AVMs, trauma  Hyperdense, fuzzy  Locations of blood C- –Sulci –Sylvian fissure –Circle of Willis –Falx –Tentorium Source Undetermined

29. ICHNormalICH SAHSAHSAH Source Undetermined

30. Findings Suggestive of ICH  Normal Calcification  Basal ganglia  Choroid plexus  Pineal gland C- Source Undetermined

31. Findings Suggestive of ICH  Metal  Very hypodense  “Sparks”  Clips, bullets, metallic catheters C- Source Undetermined

32. Findings Suggestive of ICH C- ? Source Undetermined

33. Volume Averaging (Technical Issues Mimicking ICH)  Orbital roof  Petrous portion of temporal bone  Pituitary fossa  Brainstem Source Undetermined

34. Findings Suggestive of ICH/SAH ? ? C- Source Undetermined

35. Motion Artifact (Technical Issues Mimicking ICH or SAH)  Streaky  Hyperdense  Boney prominence Source Undetermined

36. Evolution of an Infarct Ultra-Acute 0-3 hours Acute-Subacute 6hrs-days Chronic 1 year Source Undetermined

37. Ultra-Early CT Findings  Normal  Sulcal effacement  Loss of insular ribbon  Loss of grey-white interface  Acute hypodensity Source Undetermined

38. Sulcal Effacement Source Undetermined

39. Loss of Insular Ribbon Source Undetermined

40. Loss of Sulci & Acute Hypodensity Source Undetermined

41. Acute Hypodensity Source Undetermined

42. Acute-Subacute Stroke (hours-days)  Hypodense  Well demarcated  Mass effect  Midline shift  Loss of sulci Source Undetermined

43. Old Infarct (months to years)  Density of CSF  Well demarcated  Ventrical enlargement  Sulci enlargement  No sulcal effacement  No mass effect Source Undetermined

44. Suggestive of an Infarct? Source Undetermined

45. Suggestive of an Infarct? Tumor Stroke Source Undetermined

46. Case Presentations

47. Thalamic ICH Source Undetermined

48. Normal Source Undetermined

49. Chronic Frontal Subdural Source Undetermined

50. Subacute Right Parietal Infarct Source Undetermined

51. continued Source Undetermined

52. SAHNormal Source Undetermined

53. Acute Subdural Source Undetermined

54. Normal Source Undetermined

55. Closed Ventricles Source Undetermined

56. Andrew D. Perron, MD, FACEP Cisterns: Are they open? Source Undetermined

57. Metallic Artifact Source Undetermined

58. Brainstem SAH Source Undetermined

59. Chronic MCA Infarct Source Undetermined

60. Left IVH Source Undetermined

61. Epidural Source Undetermined

62. Rt Subacute Epidural Source Undetermined

63. Sagital Sinus Source Undetermined

64. Subacute Infarct Source Undetermined

65. Renal Cell Metastasis Source Undetermined

66. continued Source Undetermined

67. SAH Normal Source Undetermined

68. 48 hr old Right Temporal Infarct Source Undetermined

69. Acute on Chronic Subdural Source Undetermined

71. SAH Source Undetermined

72. Rt Parietal Fx with Air Source Undetermined

74. Brain Abscess Source Undetermined

75. Calcification Basal Ganglia Source Undetermined

77. continued Source Undetermined

78. hours 3-4 days 7-10 days months Source Undetermined

79. Trauma with Air Source Undetermined

80. Dense MCA Sign Source Undetermined

81. Subacute Brainstem Infarct Source Undetermined

82. Atrophy Source Undetermined

83. Trauma with SAH Source Undetermined

84. Bitemporal Edema (Herpes) Source Undetermined

85. Meningioma Source Undetermined

86. Caudate Infarct Source Undetermined

87. IVH Left Lateral Horn Source Undetermined

88. Ultra-Early Right Parietal Infarct Right Sulcal Effacement Source Undetermined

89. Continued Source Undetermined

91. Subacute Infarct (Rt Temporal Lobe) Source Undetermined

92. Periventricular White Matter Disease Source Undetermined

93. Chronic Rt Occipital Infarct Source Undetermined

94. Subacute Subdural Source Undetermined

95. Traumatic Petechae Source Undetermined

96. Loss of Sulci & Sylvian Fissure Source Undetermined

97. Old Lt Lacunar Infarct Source Undetermined

98. Subacute Lt Subdural Source Undetermined

99. Rt MCA Infarct with Hemorrhage Source Undetermined

100. Lt Sagital Vein Thrombosis Source Undetermined

102. SAH with Blood along Falx & in Ventricle Source Undetermined

103. Tumor Source Undetermined

104. Tumor Source Undetermined

105. CT Ground Rule Radiodense Bone Blood Calcium Grey matter Metal Radiolucent Spinal fluid Ischemic infarct Edema White matter Air Source Undetermined

106. “Blood Can Be Very Bad”  Blood  Cisterns  Brain  Ventricles  Bone Perron et al: Ann Emerg Med 1998:32:554-562

107. Intracerebral Hemorrhage  Appearance  Hyperdense  Well demarcated  Globular  Location  Intraparenchyma l  Mimics  Normal Calcification  Basal ganglia  Choroid plexus  Pineal gland  Artifacts  Metal  Catheters  Volume Averaging  Motion Source Undetermined

108. Subarachnoid Hemorrhage  Appearance  Hyperdense  Fuzzy  Locations of blood  Sulci  Sylvian fissure  Circle of Willis  Falx  Tentorium  Mimics  Contrast  Calcified Falx  Normal Tentorium  Motion artifact Source Undetermined

109. Ultra-Early Infarct Normal Sulcal effacement Loss of insular ribbon Loss of grey-white interface Acute hypodensity Acute-Subacute Hypodense Well demarcated Mass effect Midline shift Loss of sulci Old Infarcts Density of CSF Well demarcated Ventrical enlargement Sulci enlargement No sulcal effacement No mass effect Source Undetermined