Carotid_Artery_Ultrasound_Presentation.pptx

Carotid

1. CAROTID ARTERY ULTRASOUND MMed Radiology Presentation Non-invasive evaluation of carotid arteries Uses ultrasound and Doppler techniques

2. Introduction Non-invasive, safe, and widely available Evaluates carotid artery structure and blood flow Detects stenosis, plaque, and occlusion Useful in stroke prevention and follow-up

3. Anatomy Overview Common Carotid Artery (CCA) → bifurcates into: Internal Carotid Artery (ICA) – supplies brain External Carotid Artery (ECA) – supplies face and neck Carotid Bulb: frequent site of atherosclerosis

4. Indications Transient ischemic attack (TIA) or stroke Carotid bruit Suspected or known atherosclerosis Preoperative vascular assessment Post-surgical or stent follow-up Screening of high-risk patients

5. Equipment & Technique Transducer: Linear, 7–15 MHz Position: Supine, neck extended, head turned opposite Scanning: - Longitudinal and transverse planes - CCA, bifurcation, ICA, and ECA

6. Ultrasound Modes Used B-mode: Wall and plaque morphology Color Doppler: Flow direction, turbulence Spectral Doppler: Velocity measurement, waveform Power Doppler: Sensitive to low flow

7. Doppler Waveforms CCA: Low resistance pattern ICA: Low resistance, continuous diastolic flow ECA: High resistance, low diastolic flow Vertebral: Low resistance, antegrade flow

8. Normal Measurements CCA PSV: <125 cm/s ICA PSV: <125 cm/s ICA/CCA ratio: <2.0 Intima-media thickness (IMT): ≤0.8 mm

9. ICA Stenosis (NASCET Criteria) Normal: PSV <125 cm/s, ICA/CCA <2.0, No plaque <50%: PSV <125 cm/s, ICA/CCA <2.0, Plaque present 50–69%: PSV 125–230 cm/s, ICA/CCA 2–4, Visible plaque ≥70%: PSV >230 cm/s, ICA/CCA >4, Marked narrowing Occlusion: No flow

10. Plaque Characterization Echogenicity: - Hypoechoic → lipid-rich, unstable - Hyperechoic → calcified, stable Surface: - Smooth → lower risk - Irregular/ulcerated → higher embolic risk

11. Common Pathologies Atherosclerosis Dissection (intimal flap) Occlusion (no flow) Fibromuscular dysplasia – “string of beads” Pseudoaneurysm – “yin-yang” flow Carotid body tumor – splaying ICA and ECA

12. Limitations Calcified plaque may obscure lumen Operator-dependent technique Distal ICA may be difficult to visualize

13. Clinical Importance Identifies patients at risk of stroke/TIA Guides management: - <50% stenosis → medical therapy - >70% stenosis → surgery or stenting

14. Summary Combines B-mode and Doppler imaging Detects plaque, stenosis, and occlusion Essential for stroke prevention and follow-up Non-invasive, accurate, and reproducible