Stroke CT imaging powerpoint presentation

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CAROTIDSTENOSIS3.ppt
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CAROTID STENOSIS

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What is Carotid Stenosis

  • Narrowing of the carotid artery in the neck
  • Build-up of plaque inside the carotid artery
  • Most serious consequence of carotid stenosis is a stroke
  • Narrowing in the artery reduces blood flow to the brain

Statistics

  • Approximately 750,000 strokes per year in the US
  • More than 150,000 patients die because of the stroke
  • Stroke is the third leading cause of death after coronary artery disease and cancer
  • Many patients have carotid stenosis after they had a stroke, many are found to have this problem before having a stroke

Factors that promote stenosis

  • Tobacco
  • Lack of physical activity
  • Alcohol
  • Diabetes
  • High cholesterol
  • Hypertension

Symptoms (TIA or Stroke)

  • Numbness or weakness in the face, arm or leg (especially on one side of the body)
  • Confusion or difficulty in talking or understanding speech
  • Trouble seeing in one or both eyes
  • Difficulty with walking, dizziness, or loss of balance and coordination

What is a TIA?

  • A transient stroke that lasts only a few minutes
  • It occurs when the blood supply to part of the brain is briefly interrupted
  • TIA symptoms are similar to those of a stroke but do not last long
  • TIA’s are often warning signs that a person is at risk for a more serious and debilitating stroke

Normal Carotid Artery

  • The Carotid Arteries are located on both sides of your neck and carry oxygen-rich blood to the brain

Vascular Anatomy

Internal Carotid External Carotid

Abnormal Carotid Artery

  • Although carotid stenosis accounts for about 20% of all cases of ischemic stroke, it has been considered as the single most preventable cause of stroke

Alternative Modalities

  • Doppler Ultrasound Imaging: Uses sound waves to check blood flow and measure the thickness of the carotid artery
  • Magnetic Resonance Angiography (MRA): Using Gadolinium and MRI techniques producing detailed pictures of the arteries in the neck and brain
  • Arteriography and Digital Subtraction (DSA): Subtracts the unwanted shadows from an angiogram by digital processing the image

Treatment

  • Carotid Endarterectomy:

Incision along the side of the neck to expose the carotid artery

Surgeon opens the artery, removes the plague, and stitches the artery and skin closed

Carotid Stenting:

A catheter is inserted into a blood vessel through an incision in the groin area

The catheter is placed gently through the vessels all the way to the neck

Once the catheter is in place at the site of the blockage, several steps occur

CASE STUDY

  • 75 yr old women
  • Complaint of dizziness and TIA symptoms
  • Emergency room physician ordered a CT Stroke Protocol

CT Head without contrast

CT Perfusion

CTA of the Head and Neck

CT Stroke Protocol

  • CT Head without contrast

R/O any bleed or ischemic events

  • CT Perfusion

Demonstrates hemodynamic status

Quality of collateral flow

  • CTA Head and Neck

Shows vascular pathology

Provides occlusion type and location

Imaging Protocols

  • CT Head unenhanced

5/5mm cuts, bass of skull to vertex

120 kVp, 400 mAs, 1 second

  • CT Perfusion

2x10mm slices at mid brain

Scan time is 1 image/sec for 50 seconds

80 kVp, 200mAs

  • CTA Head and Neck

1.5mm/.5mm/6mm, aortic arch to vertex

120 kVp, 160 mAs

Patient Care and Safety

  • Identify Patient
  • Screen and Consent Patient
  • Adequate IV gauge (18), IV site, and proper flushing
  • Inform Patient about the study, what to expect, and any specific instructions
  • Post procedure instructions

IV Contrast

  • Purpose: To enhance arterial input, capillary flow, venous drainage, and major intracranial vessels
  • Dual Head Injector
  • 150cc’s Omnipaque 350 total
  • CT Perfusion

40cc’s contrast, 8cc’s/second, 0 delay

  • CTA Head and Neck

110cc’s contrast, 4cc’s/second, 12-15 sec delay: (bolus tracking)

Reconstruction Methods

  • CT Head: Soft tissue algorithm
  • CT Perfusion: Soft tissue algorithm

Workstation

Segmentation, Perfusion CT Calculation

CBF, CBV, Time to peak

  • CTA Head and Neck: Soft tissue algorithm

Workstation

MPR Mips, SSD, VRT

Summary

  • Findings: CT Perfusion showed a decreased blood flow in the anterior circulation of the L hemisphere. CTA Head and Neck showed Left internal carotid stenosis causing reduced blood flow to the brain. No acute ischemic stroke
  • Recommendation: Blood thinners for now, either surgery: Left Carotid endarterioectomy or Carotid Stenting

Imaging

And that’s how you nail it!