Angiographic technique and projections for extra- and intracranial vesls Joachim Berkefeld
Institute of Neuroradiology
University of Frankfurt am Main, Germany
Endovascular treatment of pathologies of cerebral arteries is offered by different medical subspecialities. Multidisciplinary approaches harbour the risk that complex interventions are done by operators without adequate training in neuroangiographic techniques which are the basis for successful and safe performance of interventional therapy.
Despite of the progress of noninvasive vascular imaging cerebral angiography is still mandatory to prepare and to control interventions at the carotid artery and other cerebral vesls. Cerebral angiography still carries a specific risk of stroke between 0.5 and 4 %, especially in atherosclerotic patients or if performed by unexperienced operators. Detachment of plaque material or thrombus formation at the catheter tip are probably the main caus of thrombembolic complications.园林设计培训
六级成绩分布The following overview cannot replace adequate neuroangiographic training but may provide some guidelines for proper technique.
• Angiographic imaging of cerebral vesl requires high resolution digital angiography systems with the possibility of digital subtraction and road map.
Mobile C-arms for operating rooms do not provide fluoroscopy- and imaging
quality necessary for the control of neuroendovascular procedures. Digital
subtraction is standard for display of intracranial vesls to e fine details
such as occlusion of small branches or small aneurysms. The frame rate
膏子should be at least 2 f/s.
•Aortic arch angiography is widely replaced by contrast enhanced MRI and is only necessary for the evaluation of proximal stenos clo to the origin of
the cervicobrachial arteries. Aortic arch angiograms are performed with the
help of pigtail catheters placed into the ascending aorta. The best projection to show the origins of the vesls from the aortic arch is 40° LAO •Bifurcational carotid artery stenosis is the most frequent condition for endovascular treatment. Cerebral angiography demands lective
catheterization of the common carotid artery. In patients without major
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elongation of the aortic arch lective catheter with angulated tip (vertebral or multipurpo configuration) can be advanced easily over hydrophilic 0.035
guidewires with curved tip. If the aortic arch shows marked elongation
catheters with Headhunter, Sidewinder II, Hanafee or Vitek configuration may become necessary. Manipulation in the aortic arch should be kept to a
minimum and the plaque at the carotid bifurcation must not be touched during diagnostic angiography. Imaging of the carotid bifurcation is done in at least
declan galbraithtwo orthogonal projections, p. a. and lateral. The measurement of the
percentage of stenosis is dependent from the chon projection and additional oblique projections (45 ° ipsilateral anterior oblique) may be helpful for exact
measurement and for definition of a working projection for the performance of carotid interventions. Additional p. a. and lateral imaging of the high cervical
研究生招生报名internal carotid artery and the intracranial territory is necessary to exclude
tandem stenosis or intracranial pathologies. Nowadays routine four vesl
angiography for screening for other lesions or display of collateral pathways is not recommended, if the flow of the carotid artery to be treated is prerved
during the intervention. In balloon protected procedures it is helpful to know
美联航弄坏吉他potential collateral pathways to estimate the potential tolerance of temporary
否决权carotid occlusion.
米歇尔北大演讲•Angiography of the subclavian and vertebral arteries requires lective catheterization of the vesl which can be done with Vertebral- or Headhunter configurated catheters in most instances. In patients with tortuous vesls it
can be extremely difficult to access the right subclavian or vertebral artery
from a tranfemoral approach. Transbrachial retrograde catheterization may be easier than long lasting transfemoral trials with multiple catheter exchanges.
Frequent abnormalities are hypoplasia of one vertebral artery or direct origin of the left vertebral from the aortic arch between the origins of the left common
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carotid and the left subclavian artery. Angiographic imaging of the cervical
portion of the vertebral arteries requires two orthogonal projection. Due to
overlay by the shoulders lateral views are not uful for the subclavian and the origin of the vertebral artery. 45° anterior oblique projections should be ud to get a cond or third plane. The high cervical and intracranial portion of the
vertebrobasilar system should be included into the angiographic study at least with views in Towne`s (cranially angulated) and lateral projections. Conclusion
Conventional diagnostic cerebral angiography is widely replaced by noninvasive means of vascular imaging. The remaining patients are frequently candidates for neuroendovascular procedures which are necessarily performed under angiographic control. Adequate equipment, material and training of the operator are mandatory to make catheterization of cerebral vesls safely feasible. Diagnostic angiography is mainly perfomed in one ssion with interventional procedures for technical planning
of the best approach, for control of the result and to exclude complications involving intracranial branches. Extra- and intracranial vesls should be displayed at least in two orthogonal planes. Pre- and postinterventional ries should be obtained in the same projections to make vesl lumen, flow and filling of the vascular territory comparable.
