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RT 82
RT 82 Cerebral Angiography
Question | Answer |
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What is the name of the arterial needle used for angiography? What does it have that can be removed? | Potts Cournand.It's an arterial needle that has a stylet that can be removed. |
What are the steps of the Seldinger technique? | 1)Insertion of needle (thru incision). 2)Placement of needle lumen in vessel. 3) Insertion of guidewire into the needle (only placed in a forward motion. 4) Removal of needle over guidewire. 5) Thread catheter to area of interest. 6) Removal of guidewire. |
What are the 4 vessels typically considered for catheterization for angiography? | Femoral (preffered), Axillary, Brachial, Radial |
What is done by the tech & physician to prep the area prior to the Seldinger Technique. | Clean the area around the vessel site. Drape the area with aperture over the puncture site. Dr injects Lidocaine (superficially in epidermis 1st, then deeper into the dermis). Dr makes small incision (2mm). Dr spreads skin. |
What type of generator is used for angiography C-Arms? Why is this? | High Frequency, or 3 phase generator. The high speed rotating anode generates high heat & high heat requires a large generator. |
What type of focal spot do the angiography C-arms use? What size? Why is this? | A small focal spot starting with a 0.1 mm focal spot. Angiography requires high detail & anything smaller than the focal spot cannot be imaged. A penumbra will show up for anything smaller than the focal spot. |
What must the exposure time be angiography? How many images per second? | Duration of an x-ray image must be 1/3 of complete image acquisition cycle. 4-6 images per second. |
What angle is the anode for angiography? | around 20 degrees. |
What factor establishes the flow rate of contrast for angiography? What do I want the flow rate to overcome? | The flow rate is established dependent on the size of the vessel. I want a flow rate that overcomes the antegrade flow of blood. |
What does the automatic pressure injector maintain? | It maintains a consistent flow rate. |
What are the positioning & centering criteria for the AP Axial & Lateral projections for the anterior circulation? | For the AP axial, OML is perpendicular to the IR & CR 10-15 degrees caudadgoing through the level of the EAM. For Lateral the CR is centered superior to the EAM. |
What are the positioning & centering criteria for the AP Axial & Lateral projections for the posterior circulation or the vertebrobasilar artery? | For the AP axial the CR is 30-35 caudad to the OML while trying to keep the CR perpendicular to the floor & IR. May build up the head on a spong to keep the OML at an angle. For the Lateral, the CR is 2 cm superior & posterior to the EAM. |
For the SupraOrbital Obliques, how many degrees is the head rotated from the CR? Is the CR angled cephalic, or caudad? Which side of the bifurcation of the ICA to the ACA & MCA is demonstrated? | Head is rotated 30 degrees away from the CR. The CR is angled caudad. The side up bifurcation of ICA to ACA & MCA is demonstrated. |
For the TransOrbital Posterior Obliques how many degrees is the head rotated from the CR? Is the Cr angled cephalic, or caudad? Which bifurcation of the ICA to ACA & MCA is demonstrated? | The head is rotated 30 degrees from the CR. The Cr is angled 20 degrees cephalic. The side down bifurcation of the ICA to the ACA & MCA is demonstrated. |
Why is the bifurcation of the Internal Carotid artery to the Anterior Cerebral artery & Middle Cerebral Artery demonstrated? | Because it is the most common spot demonstrating an aneurysm on the Circle of Willis. |