Angiographic Anatomy

Angiographic Anatomy - Vascular Roadmaps

• Angiography: X-ray visualization of blood vessel lumens using radiopaque contrast agents; creates a "vascular roadmap".
  • Diagnostic: Identifies stenosis, occlusion, aneurysms, arteriovenous malformations (AVMs), dissections, vasospasm.
  • Interventional: Guides procedures like angioplasty, stenting, embolization, thrombolysis.
• Technique & Access:
  • Seldinger Technique: Standard for percutaneous arterial access (e.g., femoral, radial, brachial arteries).
    • Steps: Needle puncture → Guidewire insertion → Sheath/Catheter placement over wire.
  • Contrast Agents: Iodinated (non-ionic preferred for lower osmolality & fewer reactions), CO2 (for renal impairment), Gadolinium (MRA).
    • ⚠️ Risks: Contrast-Induced Nephropathy (CIN), allergic reactions, access site complications (hematoma, pseudoaneurysm).
• Key Arterial Systems & Branches:
  • Aorta: Ascending, Arch, Thoracic, Abdominal.
    • Aortic Arch Branches (Right to Left): 📌 ABCS - Aortic arch gives Brachiocephalic trunk, Left Common carotid artery, Left Subclavian artery.
  • Cerebral Circulation: Internal Carotid Arteries (anterior), Vertebrobasilar system (posterior).
  • Visceral: Celiac trunk, Superior Mesenteric Artery (SMA), Inferior Mesenteric Artery (IMA), Renal arteries.
  • Peripheral: Iliac, Femoral, Popliteal, Tibial arteries.

⭐ Digital Subtraction Angiography (DSA) is the gold standard for detailed vascular imaging, allowing real-time visualization and "road-mapping" by subtracting pre-contrast images from post-contrast images for clarity of vessels.

• Common Views: AP, lateral, obliques (RAO, LAO) to profile specific vessel origins/segments without overlap (e.g., LAO for left coronary artery ostium).

Angiographic Anatomy - Brain & Heart Pipes

Cerebral Arterial System (Circle of Willis):

• Anterior: ICA → ACA (medial frontal/parietal), MCA (lateral hemispheres, basal ganglia).
• Posterior: Vertebral → Basilar → PCA (occipital, thalamus).
• Comms: ACom, PCom.
• Views: AP, Lateral, Oblique.

Coronary Arterial System:

• Origins: Aortic sinuses.
• LCA: LMCA → LAD (📌 "Widow maker"; ant. wall, septum, apex) & LCx (lat./post. LV).
• RCA: RV, inf. LV, SA/AV nodes (majority).
• Dominance: PDA origin (RCA ~85%, LCx ~10%).
• Key Views:
  • LAO Caudal (Spider): LMCA bifurcation.
  • RAO Caudal: LCx.
  • LAO Cranial: LAD.

⭐ The Left Anterior Descending (LAD) artery is the most commonly occluded coronary artery in Myocardial Infarction.

Angiographic Anatomy - Return & Supply Lines

• Venous Systems (Return):
  • Superior Vena Cava (SVC): Drains upper body. Formed by R/L brachiocephalic veins.
  • Inferior Vena Cava (IVC): Drains lower body. Formed by common iliacs. Tributaries: renal, hepatic.

    ⭐ IVC filters: Placed infra-renally (below renal veins) to trap emboli.

  • Portal Vein: Drains GI tract, spleen, pancreas to liver. Formed by Splenic V. + SMV. )
• Arterial Systems (Supply):
  • Celiac Trunk: Foregut supply (stomach, liver, spleen). Branches: L. Gastric, Splenic, Common Hepatic A. (📌 LSC)
  • Superior Mesenteric Artery (SMA): Midgut supply (small intestine, prox. colon).
  • Inferior Mesenteric Artery (IMA): Hindgut supply (distal colon, rectum).
  • Limb Arteries:
    • Upper: Subclavian → Axillary → Brachial → Radial/Ulnar A.
    • Lower: Ext. Iliac → Femoral → Popliteal → Ant/Post Tibial A.

Angiographic Anatomy - Spotting Trouble

• Goal: Detect vascular abnormalities using contrast agents and fluoroscopy.
• Key Pathologies & Signs:
  • Stenosis: Luminal narrowing; often appears as a "string sign".
  • Occlusion: Complete blockage; abrupt termination of contrast.
  • Aneurysm: Abnormal focal dilation; saccular or fusiform.
  • AVM (Arteriovenous Malformation): Tangle of dysplastic vessels; early draining veins.
  • Dissection: Intimal flap creating true/false lumens.
  • Extravasation: Contrast leakage outside vessel; indicates active bleeding.
• Interventional Radiology: Utilizes angiographic findings for targeted treatments.

⭐ "Beading" or "string of beads" appearance on renal angiography is characteristic of Fibromuscular Dysplasia (FMD).

High‑Yield Points - ⚡ Biggest Takeaways

• Seldinger technique is fundamental for arterial access.
• Common femoral artery is preferred access; radial artery is an alternative.
• Specific catheter shapes (Judkins, Amplatz) are key for selective angiography, especially coronaries.
• Iodinated contrast media used; watch for allergies and contrast-induced nephropathy (CIN).
• Digital Subtraction Angiography (DSA) enhances vessel imaging by removing background.
• Aortic arch: brachiocephalic, LCC, LSA are key branches.
• Identify normal anatomy and common variants like a bovine arch.