Carotid artery: Ready for the unexpected

Transcription

1 Carotid artery: Ready for the unexpected Poster No.: C-1802 Congress: ECR 2010 Type: Educational Exhibit Topic: Head and Neck Authors: K. J. Au Yong, E.-M. Fanou, N. Coupe, C. Jadun; Stoke-on-Trent/ UK Keywords: Carotid, MRA, CTA DOI: /ecr2010/C-1802 Any information contained in this pdf file is automatically generated from digital material submitted to EPOS by third parties in the form of scientific presentations. References to any names, marks, products, or services of third parties or hypertext links to thirdparty sites or information are provided solely as a convenience to you and do not in any way constitute or imply ECR's endorsement, sponsorship or recommendation of the third party, information, product or service. ECR is not responsible for the content of these pages and does not make any representations regarding the content or accuracy of material in this file. As per copyright regulations, any unauthorised use of the material or parts thereof as well as commercial reproduction or multiple distribution by any traditional or electronically based reproduction/publication method ist strictly prohibited. You agree to defend, indemnify, and hold ECR harmless from and against any and all claims, damages, costs, and expenses, including attorneys' fees, arising from or related to your use of these pages. Please note: Links to movies, ppt slideshows and any other multimedia files are not available in the pdf version of presentations. Page 1 of 64

2 Learning objectives To provide an overview o the various pathologies affecting the carotid artery. To highlight the strengths and limitations of the different imaging modalities. Background Atherosclerotic disease is still the most common pathology affecting the carotid artery. However, other pathologies should also be considered when assessing the carotid artery. Our exhibit uses CT and MRI angiogram (with multiplanar reformats) and intra-arterial angiography to demonstrate the common and uncommon pathologies of the carotid artery. Imaging findings OR Procedure details Imaging Techniques Ultrasound Doppler Page 2 of 64

3 This is an inexpensive and accurate means of initial evaluation of the extra-cranial carotid arteries. Morphology of the plaque and flow dynamic can be demonstrated. But it has the limitations of having high inter-operator variability and difficulty in differentiating subtotal occlusion from total occlusion. The presence of dense calcifications in the carotid plaque can make study less accurate. The accuracy of using ultrasound Doppler in the diagnosis of internal carotid artery dissection remains debatable. The low false negative rate makes it an ideal screening tool. CT angiography(cta) Using post processing technique, angiographic images similar to those produced from DSA can be obtained. CTA enables rapid assessment of the carotid vessels and is gaining popularity. It requires iodinated contrast agents to be injected at a relatively high flow rate and therefore may not be suitable for patients with renal disease. Due to the higher spatial resolution, CTA is good in imaging near occlusion. There are reports of CTA underestimating the stenosis of artery as compared to DSA, but this is debatable with the used of newer scanner and better 3D reformat algorithm technique. MR angiography(mra) MRA images can be presented with the format comparable to digital subtraction angiography. Plaque characteristic can be assessed. It is contraindicated in patients who have cardiac pacemakers or cerebral aneurysm clips. Current techniques include the use of time-of-flight MR angiography (TOF MRA), contrast-enhanced MRA and black blood fast spin echo (BB FSE). TOF and BB FSE can fail to portray areas of slow flows. TOF has a long imaging time and therefore prone to motion artefact. Degree of stenosis can be overestimated. Contrast-enhanced MRA is relatively independent of flow dynamics but involved the use of contrast agent making it unsuitable for patient with renal problems. The spatial resolution of contrast enhanced MRA is two to three times less than DSA/ CTA. The extent of collateral flow via leptomeningeal anastomoses cannot be judged by MRA. Page 3 of 64

4 Intra-arterial digital subtraction angiography(dsa) It is still considered as the gold standard and most accurate method for assessing carotid artery stenosis. This technique is highly depended on the skill and experience of the angiographer. It is invasive, expensive and time intensive. Overall major morbidity rates are 0.1-1%. The use of DSA is declining due to the increasing use of other non-invasive techniques for investigating carotid artery disease. PET The combination of CT and MRI with PET can provide structural and metabolic information about the plaque status. Pathology Case 1 Page 4 of 64

5 Fig.: Figure 1a. A 75 year old female presented with increasing headache and new right third nerve palsy. Axial view CT angiogram shows a right cavernous carotid aneurysm. References: K. J. Au Yong; Radiology, University Hospital of North Staffordshire, Stoke-on-Trent, UNITED KINGDOM Page 5 of 64

6 Fig.: Figure 1b. CT 3D reformat shows the multi-lobulated shaped right carvenous carotid aneurysm. References: K. J. Au Yong; Radiology, University Hospital of North Staffordshire, Stoke-on-Trent, UNITED KINGDOM The common causes of aneurysm include hemodynamically induced or degenerative vascular injury, atherosclerosis, vasculopathy and high-flow states. Uncommon causes include trauma, infection, drugs, carotid endarterectomy and neoplasms. Case 2 Page 6 of 64

7 Fig.: Figure 2a. A young 40 year old patient who presented with acute left hemiplegia. Intra-arterial DSA shows right non-occlusive dissection of the cervical ICA at the skull base. References: K. J. Au Yong; Radiology, University Hospital of North Staffordshire, Stoke-on-Trent, UNITED KINGDOM Page 7 of 64

8 Fig.: Figure 2b. Axial view CT angiography of the same patient after 6 weeks shows a false aneurysm (arrow)in the cervical part of the left ICA. References: K. J. Au Yong; Radiology, University Hospital of North Staffordshire, Stoke-on-Trent, UNITED KINGDOM Page 8 of 64

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10 Fig.: Figure 2c. Intra-arterial catheter angiogram shows a large pseudoaneurysm with almost a windsock appearance in the left cervical ICA. Endovascular procedure was later performed. References: K. J. Au Yong; Radiology, University Hospital of North Staffordshire, Stoke-on-Trent, UNITED KINGDOM Case 3 Page 10 of 64

11 Fig.: Figure 3a. 70 female patient presented with right opthalmoplegia after minor head injury 3 weeks ago.ct angiogram shows 22 x 24mm size right giant cavernous carotid aneurysm. Note the associated dilated right superior opthalmic vein and orbital proptosis, suggesting a carvenous carotid fistula. References: K. J. Au Yong; Radiology, University Hospital of North Staffordshire, Stoke-on-Trent, UNITED KINGDOM Page 11 of 64

12 Fig.: Figure 3b. Direct communications between the cavernous segment of the intracavernous carotid artery and the cavernous sinus demonstrate on intra-arterial DSA. References: K. J. Au Yong; Radiology, University Hospital of North Staffordshire, Stoke-on-Trent, UNITED KINGDOM Page 12 of 64

13 Fig.: Figure 3c. MRI image of the same patient after undergone coiling and stenting (noted the blooming artefact)of the right carvenous-carotid fistula shows occlusion of the right carvennous carotid fistula. A small medially pointing left cavernous carotid aneurysm is also demonstrated. References: K. J. Au Yong; Radiology, University Hospital of North Staffordshire, Stoke-on-Trent, UNITED KINGDOM Page 13 of 64

14 Carotid-cavernous fistulas (CCFs) are abnormal communications between the carotid arterial system and the venous cavernous sinus. Direct carotid-cavernous fistulas (CCFs) result from a direct connection between the cavernous segment of the intracavernous carotid artery and the cavernous sinus itself. Indirect (dural) CCFs arise from abnormal shunts to the cavernous sinus from the meningeal branches of the carotid artery Type A are direct communications between the cavernous segment of the intracavernous carotid artery and the cavernous sinus Type B are shunts from the meningeal branches of the intracavernous carotid artery to the cavernous sinus Type C are shunts from the meningeal branches of the external carotid artery to the cavernous sinus Type D are shunts from the meningeal branches of both the intracavernous carotid artery and the external carotid artery Case 4 Page 14 of 64

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16 Fig.: Figure 4a. A 60 year old female presented with right visual problem. CT angiogram shows a possible right carotid cavernous fistula but there is no dilatation of the superior opthalmic vein or orbital proptosis. References: K. J. Au Yong; Radiology, University Hospital of North Staffordshire, Stoke-on-Trent, UNITED KINGDOM Page 16 of 64

17 Fig.: Figure 4b. Selective intra-arterial DSA of the right external carotid artery shows a dural fistula supplied by the sphenopalatine branches of ECA and draining through the right cavernous sinus. References: K. J. Au Yong; Radiology, University Hospital of North Staffordshire, Stoke-on-Trent, UNITED KINGDOM Page 17 of 64

18 Case 5 Page 18 of 64

19 Fig.: Figure 5a. Axial non-contrast CT scan of a 40 year old man presented with right hemiplegia shows increase density and calibre of the left internal carotid artery suggestive of acute occlusion. References: K. J. Au Yong; Radiology, University Hospital of North Staffordshire, Stoke-on-Trent, UNITED KINGDOM Fig.: Figure 5b. Axial CT angiograom of the smae patient shows occlusion of the distal left ICA with an internal flap seen proximally. References: K. J. Au Yong; Radiology, University Hospital of North Staffordshire, Stoke-on-Trent, UNITED KINGDOM Page 19 of 64

20 Fig.: Figure 5c. Sagittal CT reconstruction shows the typical flame shape/rat tail appearance of carotid artery dissection with total occlusion of left distal ICA. References: K. J. Au Yong; Radiology, University Hospital of North Staffordshire, Stoke-on-Trent, UNITED KINGDOM Page 20 of 64

21 Carotid artery dissection is an important cause of stroke in young adults with an estimated incidence of 10-15%. A dissection is considered spontaneous if there is no history of trauma. Predisposing risk factors include Marfan syndrome, fibromuscular dysplasia and familial predisposition. Other than CTA non-invasive technique like MRA is sensitive in detecting intramural haematoma in early stages of dissection using fat-suppressed axial and coronal T1 weighted sequence. Case 6 Page 21 of 64

22 Fig.: Figure 6a. Axial CT on bone window in a 20 year old polytrauma patient shows facial and basal skull fracture. The skull base fracture involves the right petrous temporal bone, note the fluid in the right mastoid air cell. Page 22 of 64

23 References: K. J. Au Yong; Radiology, University Hospital of North Staffordshire, Stoke-on-Trent, UNITED KINGDOM Fig.: Figure 6b. An intra-arterial DSA was performed after the patient complaining of left sided neurological symptoms. Non-occlusion post-traumatic dissection was demonstrated at the cervical ICA. References: K. J. Au Yong; Radiology, University Hospital of North Staffordshire, Stoke-on-Trent, UNITED KINGDOM Case 7 Page 23 of 64

24 Fig.: Figure 7a. Coronal 3D chest CT recontruction of a 49 year old patient presented with acute chest pain shows Stanford Type A aortic dissection. References: K. J. Au Yong; Radiology, University Hospital of North Staffordshire, Stoke-on-Trent, UNITED KINGDOM Page 24 of 64

25 Fig.: Figure 7b. CT axial view of the same patient shows extension of the aortic root dissection to the right brachiocephalic artery causing occlusion of the right common carotid artery origin. References: K. J. Au Yong; Radiology, University Hospital of North Staffordshire, Stoke-on-Trent, UNITED KINGDOM Case 8 Page 25 of 64

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27 Fig.: Figure 8a. A 50 year old lady presented with increasing swelling of the neck. Sagittal CT 3D recontruction shows a lobulated mass splaying the right internal and external carotid arteries at the bifurcation.(similar findings on the left) References: K. J. Au Yong; Radiology, University Hospital of North Staffordshire, Stoke-on-Trent, UNITED KINGDOM Page 27 of 64

28 Fig.: Figure 8b. Axial T1W MRI image shows bilateral carotid body tumours. Page 28 of 64

29 References: K. J. Au Yong; Radiology, University Hospital of North Staffordshire, Stoke-on-Trent, UNITED KINGDOM Carotid body paraganglioma (CBP) extends cephalad. CBP rapidly enhance homogeneously on post contrast images.mr imaging usually show a mass isointense with muscle, slightly hyperintense on T2 weighted images, and intense enhancement on post-contrast images. If larger than 1.5 cm, CBP tumors may infrequently exhibit a "salt and pepper appearance. Case 9 Page 29 of 64

30 Fig.: Figure 9. A 70 year old patient who presented with headache. Non-contrast CT head shows a large meningioma causing mass effect and encasing the left internal carotid artery. References: K. J. Au Yong; Radiology, University Hospital of North Staffordshire, Stoke-on-Trent, UNITED KINGDOM Page 30 of 64

31 Case 10 Fig.: Case 10. MRA of a 20 year old patient who presented with limb weakness and headache shows narrowing of the supraclinoid ICA bilaterally consistent with Moya moya disease. References: K. J. Au Yong; Radiology, University Hospital of North Staffordshire, Stoke-on-Trent, UNITED KINGDOM Case 11 Page 31 of 64

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33 Fig.: Figure 11. MIP MRA image of a 60 year old patient shows fusiform dilatation of the keft ICA. The patient have a history of previous endarterectomy, and this appearance is post surgical. References: K. J. Au Yong; Radiology, University Hospital of North Staffordshire, Stoke-on-Trent, UNITED KINGDOM Case 12 Page 33 of 64

34 Fig.: Figure 12a. A 50 year old patient presented with recurrent left sided transient ischaemic attack. Axial view CT angiogram shows a intraluminal defect in the right ICA. References: K. J. Au Yong; Radiology, University Hospital of North Staffordshire, Stoke-on-Trent, UNITED KINGDOM Page 34 of 64

35 Fig.: Figure 12b. Sagittal 3D recontrauction of the same patients shows atherosclerotic disease of the right internal carotid with a free floating thrombus.free-floating thrombus (FFT) of the carotid artery is an acute emergency.medical and surgical management have both been used, with neither clearly superior to the other. Page 35 of 64

36 References: K. J. Au Yong; Radiology, University Hospital of North Staffordshire, Stoke-on-Trent, UNITED KINGDOM Case 13 Page 36 of 64

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38 Fig.: Figure 13. Angiogram of a young 30 year old female patient with hisotry of multiple TIA shows multiple saccular dilatations (arrow)of the internal carotid artery. There are 3 types of FMD: intimal, medial, and subadventitial (perimedial) of the arterial wall. Medial FMD is classically diagnosed on the basis of a "string of beads" appearance on angiography. References: K. J. Au Yong; Radiology, University Hospital of North Staffordshire, Stoke-on-Trent, UNITED KINGDOM Images for this section: Page 38 of 64

39 Fig. 1: Figure 1a. A 75 year old female presented with increasing headache and new right third nerve palsy. Axial view CT angiogram shows a right cavernous carotid aneurysm. Page 39 of 64

40 Fig. 2: Figure 1b. CT 3D reformat shows the multi-lobulated shaped right carvenous carotid aneurysm. Page 40 of 64

41 Fig. 3: Figure 2a. A young 40 year old patient who presented with acute left hemiplegia. Intra-arterial DSA shows right non-occlusive dissection of the cervical ICA at the skull base. Page 41 of 64

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43 Fig. 4: Figure 2c. Intra-arterial catheter angiogram shows a large pseudoaneurysm with almost a windsock appearance in the left cervical ICA. Endovascular procedure was later performed. Fig. 5: Figure 3a. 70 female patient presented with right opthalmoplegia after minor head injury 3 weeks ago.ct angiogram shows 22 x 24mm size right giant cavernous carotid Page 43 of 64

44 aneurysm. Note the associated dilated right superior opthalmic vein and orbital proptosis, suggesting a carvenous carotid fistula. Fig. 6: Figure 3b. Direct communications between the cavernous segment of the intracavernous carotid artery and the cavernous sinus demonstrate on intra-arterial DSA. Page 44 of 64

45 Fig. 7: Figure 3c. MRI image of the same patient after undergone coiling and stenting (noted the blooming artefact)of the right carvenous-carotid fistula shows occlusion of the right carvennous carotid fistula. A small medially pointing left cavernous carotid aneurysm is also demonstrated. Page 45 of 64

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47 Fig. 8: Figure 4a. A 60 year old female presented with right visual problem. CT angiogram shows a possible right carotid cavernous fistula but there is no dilatation of the superior opthalmic vein or orbital proptosis. Page 47 of 64

48 Fig. 9: Figure 4b. Selective intra-arterial DSA of the right external carotid artery shows a dural fistula supplied by the sphenopalatine branches of ECA and draining through the right cavernous sinus. Fig. 10: Figure 5a. Axial non-contrast CT scan of a 40 year old man presented with right hemiplegia shows increase density and calibre of the left internal carotid artery suggestive of acute occlusion. Page 48 of 64

49 Fig. 11: Figure 5b. Axial CT angiograom of the smae patient shows occlusion of the distal left ICA with an internal flap seen proximally. Page 49 of 64

50 Fig. 12: Figure 5c. Sagittal CT reconstruction shows the typical flame shape/rat tail appearance of carotid artery dissection with total occlusion of left distal ICA. Page 50 of 64

51 Fig. 13: Figure 6a. Axial CT on bone window in a 20 year old polytrauma patient shows facial and basal skull fracture. The skull base fracture involves the right petrous temporal bone, note the fluid in the right mastoid air cell. Page 51 of 64

52 Fig. 14: Figure 6b. An intra-arterial DSA was performed after the patient complaining of left sided neurological symptoms. Non-occlusion post-traumatic dissection was demonstrated at the cervical ICA. Page 52 of 64

53 Fig. 15: Figure 7a. Coronal 3D chest CT recontruction of a 49 year old patient presented with acute chest pain shows Stanford Type A aortic dissection. Page 53 of 64

54 Fig. 16: Figure 7b. CT axial view of the same patient shows extension of the aortic root dissection to the right brachiocephalic artery causing occlusion of the right common carotid artery origin. Page 54 of 64

55 Fig. 17: Figure 8b. Axial T1W MRI image shows bilateral carotid body tumours. Page 55 of 64

56 Fig. 18: Figure 9. A 70 year old patient who presented with headache. Non-contrast CT head shows a large meningioma causing mass effect and encasing the left internal carotid artery. Page 56 of 64

57 Fig. 19: Case 10. MRA of a 20 year old patient who presented with limb weakness and headache shows narrowing of the supraclinoid ICA bilaterally consistent with Moya moya disease. Page 57 of 64

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59 Fig. 20: Figure 11. MIP MRA image of a 60 year old patient shows fusiform dilatation of the keft ICA. The patient have a history of previous endarterectomy, and this appearance is post surgical. Page 59 of 64

60 Fig. 21: Figure 12a. A 50 year old patient presented with recurrent left sided transient ischaemic attack. Axial view CT angiogram shows a intraluminal defect in the right ICA. Fig. 22: Figure 12b. Sagittal 3D recontrauction of the same patients shows atherosclerotic disease of the right internal carotid with a free floating thrombus.freefloating thrombus (FFT) of the carotid artery is an acute emergency.medical and surgical management have both been used, with neither clearly superior to the other. Page 60 of 64

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62 Fig. 23: Figure 13. Angiogram of a young 30 year old female patient with hisotry of multiple TIA shows multiple saccular dilatations (arrow)of the internal carotid artery. There are 3 types of FMD: intimal, medial, and subadventitial (perimedial) of the arterial wall. Medial FMD is classically diagnosed on the basis of a "string of beads" appearance on angiography. Page 62 of 64

63 Conclusion 1)This article reviews the radiological findings and diagnostic pitfalls of wide range of pathologies affecting the carotid artery. 2)The recognition of the imaging findings is important to facilitate diagnosis and allow for prompt and timely intervention where required. Personal Information Kong.Au Yong Mb ChB, MRCS (Glas), FRCR (Lon) Specialist registrar University Hospital of North Staffordshire Stoke-on-Trent UK References Bhatti A et al. Free-floating thrombus of the carotid artery: Literature review and case reports. Journal of Vascular Surgery, Volume 45, Issue 1, Pages Page 63 of 64

64 El-Saden S M. Imaging of the Internal Carotid Artery: The Dilemma of Total versus Near Total Occlusion.Radiology. 2001; 221: Flis C M. et al. Carotid and vertebral artery dissections: clinical aspects, imaging features and endovascular treatment. European Radiology. March, 2007/Volume 17, Number 3 Kerr J T. Pitfalls in imaging: differentiating intravagal and carotid body paragangliomas. Ear Nose Throat Journal June;84(6): Gardner D J et al. Internal carotid artery dissections: duplex ultrasound imaging. Journal of Ultrasound in Medicine, 1991.Vol 10, Issue Provenzale J M. Dissection of the Internal Carotid and Vertebral Arteries: Imaging Features. American Journal of Radiology;165: U-King-Im J M. Carotid-artery imaging in the diagnosis and management of patients at risk of stroke. Lancet Neurology. 2009; 8: Yamada L et al. Moyamoya disease: comparison of assessment with MR angiography and MR imaging versus conventional angiography. Radiology. July Radiology, 195, Page 64 of 64