Cerebral angiography technique

dr prashant shringi DM neurology resident

1. Cerebral Angiography(DSA)- Technique and normal Anatomy Dr prashant shringi Senior resident neurology

2. NORMAL ANATOMY ARTERIAL SUPPLY 2 Internal Carotid Artery 2 Vertebral Arteries

3. CIRCLE OF WILLIS Grand Vascular Station of the Brain Classical –18% to 20 % Majority circles shows anomaly-52% Most frequent anomaly is hypoplasia of ACA-24% Accesory vessels in the form of duplication/ triplicationsof ACOM (2 M.C.) -12% Fetal posterior cerebral artery-10%

4. CIRCLE OF WILLIS

5. COMPONENTS : Internal carotid arteries Horizontal segments of Anterior cerebrals(A1) Anterior communicating artery Proximal segments of posterior cerebrals(P1) Posterior communicating arteries Basilar artery

6. Branches of ACA A1- medial lenticulostriate artery ACoA - Perforating branches A2- Recurrent artery of Heubner (RAH) Orbitofrontal artery Frontopolar artery A3- Pericallosal and Callosomarginal a. A4 & A5- Cortical branches

7. ACA

8. MIDDLE CEREBRAL ARTERY Larger terminal branch of ICA Run laterally in stem of lateral sulcus Curves on superolateral surface Runs backwards in depth of posterior ramus of lateral sulcus

9. M1 segment =horizontal segment from origin to its bifurcation (it is in sylvian fissure) M2 segment =lacunar segment -in the insula loops over insula—laterally to exit from sylvian fissure M3 segment = opercular branch-from sylvian fissure & ramify over cerebral cortex Anomalies of MCA are uncommon

10. POSTERIOR CEREBRAL ARTERY P1-Peduncular/ Precommunicating P2-Ambient segment P3-Quadrigeminal segment P4-Cortical branches

11. 2 major terminal br of PCA— parieto occipital art & calcarine art

12. POSTERIOR FOSSA Vertebral artery Basilar artrery Vertebral arteries Originate from the subclavian arteries Left VA is dominant in 60 % cases

13. Branches of vertebral artery Extracranial -numerous branches to the meninges,spinal cord & muscles -Posterior meningeal artery Intracranial- - Anterior spinal artery -Posterior inferior cerebellar Art. Anterior medullary Lateral medullary Tonsillomedullary Telovelotonsillar Cortical branches

14. BASILAR ARTERY Right and left VA unite to form basilar artery Courses infront of pons ( Prepontine cistern) terminates in the interpeduncular cistern 3cm in length,1.5 to 4mm in width

15. Branches of basilar artery Anterior inferior cerebellar artery (AICA) Superior cerebellar artery Pontine artery Labyrinthine artery

16. Normal VARIANTS Fenestrations and duplications Variants of the circle of Willis Persistent carotid-basilar anastomoses Anomalies identified in the skull base

17. Normal Variants of the Circle of Willis

18. CEREBRAL ANGIOGRAPHY Angiography – Radiological study of blood vessel in the body after the introduction of iodinated contrast media .

19. Imaging Techniques Vascular structures of brain can be imaged by 4 means: 1. DSA: gold standard Invasive and risk of nephrotoxic contrast,ionising radiation 2 . Vascular ultrasound : least invasive, can be done bedside, cost effective . B est choice for imaging vessels close to skin surface .

20. Drawback: limited anatomic coverage, deep vessels cant be imaged, operator dependent, requires skill.

21. 3 CT angio : main drawbacks are contrast use and radiation exposure, calcifications are overestimated. Preferred for aorta and coronaries 4 MRA : non invasive, no radiation exposure. Preferred for carotids and intracranial vessels as MRI brain can also be obtained widely used in neurological disorders

22. ANGIO ? ‘ANGIO means blood vessel’ SUBTRACTION? It is simply a technique by which bone structures images are subtracted or canceled out from a film of bones plus opacified vessels, “leaving an unobscured image of the vessels”

23. DSA Acquisition of digital fluoroscopic images combined with injection of contrast material and real time subtraction of pre- and post contrast images to perform angiography is referred to as digital subtraction angiography

24. HISTORY Portuguese neurologist Egas Moniz ,( Nobel Prize winner 1949 ), in 1927 developed the technique of contrast x-ray cerebral angiography to diagnose diseases, such as tumors and arteriovenous malformations .

25. Idea of subtraction images was first proposed by the Dutch radiologist Ziedses des Plantes in the 1935, when he was able to produce subtracted images using plain films .

26. HISTORICAL DEVELOPMENT CONVENTIONAL SUBTRACTION TECHNIQUE: Photographic method used to eliminate unwanted images . No addition of information ; only purpose to make diagnostically important information

27. Developed in 1970s, University of Wisconsin, University of Arizona , University of Kiel . USA Commercial systems introduced in 1980 .

28. 3 conditions: SCOUT FILM ANGIOGRAM FILM-CONTRAST NO MOTION OF HEAD

29. PRINCIPAL P rinciples of subtraction are based on the following: S cout film shows the structural details of the skull and the adjacent soft tissue. Angiogram film shows exactly the same anatomic details, if the patient does not move , plus the opacified blood vessels.

30. If all the information in the scout film could be subtracted from the angiogram film, only the opacified vessel pattern would remain visible.

31. DIGITAL IMAGE PROCESSOR

32. WHY DSA? Digital subtraction angiography (DSA) was developed to improve vessel contrast. Technique that uses a computer to subtract two images, obtained before and after contrast media is injected into the vessels of interest. Anatomical structures that are the same in the two images can be removed and the resulting image shows the vessels only

33. Modern DSA systems are based on digital fluoroscopy/fluorography systems, which are equipped with special software and display facilities

34. I mage before the contrast agent is administered is called the mask image . Once the contrast is administered, a sequence of images are taken by a television camera in analog form, which is then digitised by computer

35. DSA processor has two separate image memories, one for the mask and the other for the images with contrast medium . These two image memories are subtracted from one another arithmetically, and the result goes to an image processing and display unit.

36. Indications Diagnostic: Non traumatic Subarachnoid Hemorrhage (SAH ) Arterial dissection laceration Aneurysm

37. Indications Pseudoaneurysm Thrombosis ( Extracranial & Intracranial) Arterio -venous malformation (AVM). Arterio -venous fistula (AVF). Tumor vascularity

38. Therapeutic: Embolisation Stenting Thrombolysis Thrombectomy

39. Contra indications No absolute contraindication. Poor renal reserve. Deranged coagulogram . Allergic to contrast media

40. Contrast Media Blood vessels are not normally seen in an x-ray image, because of low tissue contrast . To increase image contrast, contrast agents, which are dense fluids with elements of high atomic numbers, such as iodine, are injected into a blood vessel during angiography . Because of its higher density and high atomic number, iodine absorbs photons more than blood and tissue .

41. Creates detailed images of the blood vessels in real time. First contrast media used for intravascular injection were called high- osmolar contrast media (HOCM).

42. High osmolarity caused adverse effects such as pain , endothelial damage, thrombosis, and increased pressure in the pulmonary circulation. Low- osmolar contrast media (LOCM) were first developed in the 1970's reduce side effects. Major risks of modern iodine contrast media is an allergic reaction to iodine

43. Non ionic Iso-osmolar contrast media. 30-40 % dilution with normal saline. 50 ml of diluted contrast media is enough to do a standard cerebral angiogram with total 8 projections. Approx . 5-8 ml diluted contrast / injection .

44. Materials used Catheters Arterial sheath Medicut Guidewires Contrast Connector/100 cm.tubing Surgical blade Saline Disposable syringes Local anesthesia Heparin Surgical gloves Elastoplast

45. Cathetars CATHETERS Picard Pigtail Sim -1

46. Guide Wires Medicut

47. PREPARATION Nil orally 4-6 hrs. On trolley In hospital gown Groin shave Records Should be well hydrated. Should void before procedure . Peripheral pulses marked. I.V line in place. Informed consent

48. PROCEDURE Gaining arterial access. Selective arterial catheterization. Image acquisition. Closure of arterial access. Post processing Hard copy

49. P atients may be sedated to reduce anxiety. Monitor of vitals Local anesthetic is usually used in the area where the catheter is to be inserted , Most common femoral artery

50. PROCEDURE Small incision given, medicut is inserted into the artery, F luoroscopy is used to guide the needle to the proper position . N eedle is then removed after placing guide wire in the artery and vascular sheath is inserted over the guide wire . Catheter is then inserted along the guide wire through the sheath

51. When the catheter is in the correct position, the wire is pulled out and dye is injected through the catheter . Images are acquired during contrast injection. Injections can be made directly into the artery of interest ( selective arteriography )

52. COMPLICATIONS 0.16% major complication rate . Local complications: hematoma, vessel laceration, dissection, pseudoaneurysm , AVfistula . Systemic complications: contrast reactions , fever, sepsis, dehydration, death. CNS complication: aggravation of preexisting complaints, neurological deficit .

53. POSTPROCEDURAL CARE After the catheter is removed compression is applied to the puncture site Bed rest for a minimum of 4 hours During rest patient is monitored and vital sign like peripheral pulse like distal to Puncture are regularly Extremity is also checked for warmth , color, numbness to ensure circulation has not been disrupted.

54. Cerebro -vascular anatomy as appreciated in DSA

55. Diagnostic usage Acom aneurysm:

56. ACA Aneurysm

57. MCA Aneurysm

58. Pcom Aneurysm

59. AV Malformation

60. Tumour vascularity

61. Digital subtraction angiography based advances Better visualization and less radiation exposure are key tenets in the development of digital subtraction angiography Complexity of disease types increases and more technically challenging, cutting-edge procedures are performed

62. Digital subtraction angiography systems with flat panel : ADVANTAGES- High spatial resolution, wide dynamic range, square field of view, and real-time imaging capabilities with no geometric distortion—all of which may be used for improve image quality, reduced patient exposure to radiation

63. Hatakeyama et al have shown that two-dimensional (2D) and three-dimensional ( 3D)digital subtraction angiography using the flat panel detector system of the direct conversion type, with low radiation dose, is superior in image quality for visualizing small intracranial vessels with significantly decreased radiation exposure compared with digital subtraction angiography with the conventional image intensifier television system Hatakeyama Y, Kakeda S, Korogi Y, et al. Intracranial 2D and 3D DSA with flat panel detector of the direct conversion type: initial experience . Eur Radiol 2006;16:2594 –2602.

64. Digital subtraction techniques Mask subtraction D ual energy subtraction Time interval differencing Temporal filtering

65. Allura Xper FD20/10 biplane flat detector system with integrated 3D for intricate neurovascular procedures. 3D- reconstructions Xper CT SPECTRA BEAM 3D Roadmapping multi-modality information integration

66. R edefines image clarity and captures information at a resolution four times greater than conventional X-ray systems .

67. Xper CT With XperCT clinicians can access CT-like imaging right on the angio system so can assess soft tissue, bone structure and other body structures before, during or after an interventional procedure. XperCT reconstruction is created from rotational acquisition performed on the Allura Xper system. This reconstruction can be overlaid with the 3D vascular image.

68. 3D soft tissue imaging supports diagnosis planning , interventions and treatment follow-up XperCT can be combined with Allura 3D-RA images to visualize soft tissue and vascular anatomy on one image.

69. Spectra Beam Basically a selectable copper beam filtration Combination of Spectra Beam with the MRC- tube allows increased X-ray output with better filtration of soft radiation . Reduces patient X-ray dose for cardiac and vascular applications, while maintaining the same image quality.

70. Disadvantage of DSA Limited spatial resolution Artifacts Small visual field Not a good technique for neoplasm

71. Conclusion Despite recent advances in CT angiography and MR angiography, DSA remains the standard imaging technique for evaluation of the cerebral vasculature . 3D reconstruction of the dataset acquired during rotational DSA represents the latest development in the neurovascular imaging .

72. 3D-DSA has taken a prominent role in treatment planning by enabling better appreciation of the morphology of complex vascular lesions before endovascular or surgical management. Superior in the performance of sophisticated tasks such as aneurysm volume measurement

73. On the other hand, inability of 3D-DSA to simultaneously image osseous and vascular structures is noted as a weakness of this technique compared with CT angiography .

74. Refrences - The Principle of Digital Subtraction Angiography and Radiological Protection; K. OKAMOTO, . IT, K. SAKAI, S. YOSHIMURA ; Interventional Neuroradiology 6 (Suppl1): 25-31, 2000 Advances in Interventional Neuroimaging; Vallabh Janardhan and Adnan I. Qureshi ; Vol. 4, 414–419, July 2007 c The American Society for Experimental NeuroTherapeutics , Intracranial Vascular Stenosis and Occlusive Disease: Evaluation with CT Angiography, MR Angiography, and Digital Subtraction Angiography; Bash et al; AJNR Am J Neuroradiol 26:1012–1021, May 2005 Uptodate.com Digital substraction Angiography ;John hopkins Medical university Gray’s text book of anatomy T eachme anatomy .com

75. THANK YOU