1. Dissection of the craniocervical arteries and dural sinus thrombosis L. DIVANO, T. STADNIK, C. MABIGLIA Radiology Department Brugmann Hospital Bruxelles – Belgium XIX SYMPOSIUM NEURORADIOLOGICUM The World Congress of Diagnostic & Therapeutic Neuroradiology Bologna 2010 4-9 October

2. Dissection of the craniocervical arteries

3. INTRODUCTION 10%–25% of strokes in young patients spontaneous or traumatic variety of clinical presentations: stroke, headache, neck pain, tinnitus, Horner syndrome, and cranial neuropathies neurological emergency because of the risk of cerebral infarct

4. Before the development of MR imaging, catheter angiography was considered the study of choice for depiction of carotid and vertebral dissection (limits: cost and invasiveness). MR imaging/MRA and CT/CTA: alternatives for diagnosis and follow-up Arterial dissection: diagnostic considerations

5. Dissection of craniocervical arteries: MRI ADVANTAGES DWI  detection of acute stroke Axial T1-weighted fat- suppressed  depiction of subacute intramural hematoma (crescent sign) Differentiation between intramural hematoma and mural thrombus in an occluded vessel No X-Rays (youngs, pregnancy & Follow-Up) No iodine contrast administration LIMITS Access to MRI  availability, patient restrictions Need for the proper MR imaging protocol Isointensity of intramural hematoma in the acute phase Less sensitive for vertebral artery dissection Confusing high signal intensity caused by the venous plexus or fat surrounding the VAs Vertinsky AJNR 29 Oct 2008

6. T1PD TOF-MRA Arterial dissection: diagnostic considerations Diagnostic clue: intramural hematoma

7. Dissection of the craniocervical arteries: CT LIMITS Use of ionizing radiation (follow-up studies) Need for iodine contrast injection Vertinsky AJNR 29 Oct 2008 ADVANTAGES Rapid imaging time  multiplanar and volume reconstructions More widely available Greater spatial resolution Identification of intimal flaps and pseudoaneurysms Distinction between a tiny residual patent vessel lumen (string sign) and vessel occlusion

8. Findings of arterial dissection on CT angiography On source images: narrowing or occlusion of the contrast-filled lumen the hematoma appears isodense the residual lumen is generally eccentric Arterial dissection: diagnostic considerations

9. Findings of arterial dissection on CT angiography Always check the source images

10. PD FLAIR T2 DWI

11. CE-MRA CTA Both CT and MR angiography show parietal irregularity of the left ICA

12. Findings of arterial dissection on CT angiography thrombosis hematoma is isodense

13. In case of thrombosis, superiority of MRI AJNR 25:769-774, May 2004

14. Dural sinus thrombosis

15. INTRODUCTION relatively uncommon, but serious neurological complications: venous infarct may be associated with high morbidity and mortality frequently delayed clinical/radiological diagnosis potentially reversible with prompt diagnosis and appropriate medical care imaging plays a primary role in the diagnosis

16. limited value in the diagnosis of dural sinus thrombosis: Unenhanced CT: "cord sign" and "dense triangle sign“ - variability (25%) Contrast enhanced CT: "empty delta sign“ - present in only 20 to 30% of cases - false positive possible Giant arachnoid granulations Dural sinus thrombosis: diagnostic considerations CT

17. unenhanced CT can be immediately followed by venography, thus saving time to diagnosis and treatment. CT venography is an effective alternative to MRI American Journal of Roentgenology 169:1699-1707, 1997 Research Journal of Medicine and Medical Sciences, 4(2):284-289, 2009 Dural sinus thrombosis: diagnostic considerations CT

18. ADVANTAGES Widely accessible Rapid acquisition  no motion artifacts Not affected by slow flow No contraindication (pacemaker, claustrophobia) LIMITS Ionizing radiations Need for contrast injection Time consuming MIP reconstructions and bone subtraction Dural sinus thrombosis: diagnostic considerations CT-venography N. Khandelwal AJR:187, December 2006

19. CT-venography with Matched Mask Bone Elimination (MMBE)

20. high signal intensity of the venous sinuses with all routine sequences  reliable sign of thrombosis. RadioGraphics 2007; 27:95–108 Dural sinus thrombosis: diagnostic considerations MRI

21. After administration of contrast material, the central portion of the sinus typically fails to enhance MR venography shows absence of signal in the affected dural sinus Dural sinus thrombosis: diagnostic considerations MRI

22. ADVANTAGES Early detection of thrombosis Associated parenchymal lesions No radiations (No contrast injection) LIMITS Long acquisition time Sensitivity to patient motion Flow-related artifacts Anatomic variability (asymmetric transverse sinus) Dural sinus thrombosis: diagnostic considerations MRI RadioGraphics 2007; 27:95–108

23. Sudden onset of altered behaviour and consciousness Pseudotumoral appearance

24. superior sagittal sinus thrombosis associated with left frontal venous infarction T2 DWI T2*T1+C 3D-PC

25. There has been recent interest in evaluating the appearance of intraluminal venous thrombi on DWI. Signal hyperintensity in thrombosed sinuses on DWI has been described. RadioGraphics 2006; 26:S19–S43 T1 T1+GD DWI

26. IN CONCLUSION…

27. Take home messages: dissection of the craniocervical arteries Availability, contraindications, and patient tolerance will dictate the primary technique to be used: MRI or CT MRI better shows intramural hematoma and parenchymal lesions CTA allows better depiction of intimal flaps and pseudoanevrysmal lesions We must always check the source images MRI: only DWI and axial T1-weighted fat-suppressed images in patients with a highly suspected dissection on CT/CTA

28. Take home messages: dural sinus thrombosis Unenhanced CT may show hyperdense thrombosed dural sinus MRI/MRA is the most often used technique CT venography (with MMBE) in case of MRI contraindications or ambiguous MRI CT venography is at least equivalent to MRI in the diagnosis of dural sinus thrombosis

29. THANK YOU FOR YOUR KIND ATTENTION