Diseases of the vessesls

Question 1

Diseases of the great arteries

Answer 1

Transposition
Aortic stenosis
Scimitar syndrome, where the right lung pulmonary veins drain to the IVC instead of the LA.

AV-malformations - contrast CT or MR

Pulmonary Embolism

• Ventilation Perfusion scans manditory,
• Contrast CT Angiography, triple rule out. CTA is the imaging method of choice.
• If patient is allergic to CT contrast, a contrast MRI can be used, its resolution is just a bit lower.

Pulmonary artery HTX - Enlargement of the central pulmonary arteries, smaller peripheral ones. “centroperipheral discrepancy”
CT method of choice for lungs. Can show fibrosis as well.

Pulmonary venous hypertension - Pulmonary edema develops. Interlobular septa visible as Kerley B lines.

Question 2

Peripheral vascular problems

Answer 2

AV malformations

• Shunt formation and bypassing of capillaries, lower resistance, higher flow speed and volume in the afferent arteries and efferent veins, visible by dopler US.
• Can also be shown by catheter angiography very clearly.
• MRA angiography

Carotid stenosis

Renovascular problems, Renal artery stenosis.

• Estimated by U|S
• Or by perfusion scintigraphy, 18FDG, showing differential perfusion of the two kidneys if there is significant unilateral stenosis.
• ACE inhibitors further decrease flow to the stenosed kidney. BUT, ACE-Is are contraindicicated for bilateral stenosis, so this is probably not a good idea.
• You can just do CTA or MRA, but contrast materials are also contraindicated in patients with significant kidney disease.

Mesenteric ischemia: CTA is best.

Peripheral artery disease: Best method is catheter angiography, and can intervene with balloon or stent. Also effectively done with CTA/ MRA

Aneurysms - greater than 50% of the normal artery diameter. Aortic aneurysms above 6cm demand intervention and have a higher risk of rupture than the risks of intervening.
CTA, MRA,

Dissections: MRA is the best imaging quality it can see the flap and lumen filling best, but it is NOT the choice method. CTA is the best because it is good enough quality and much faster.

Arteritis: Cuff-like theckening of the large vessels are seen by US, CT, or MRI

• Takayasu arteritis and Temporal arteritis
• Vascular segment will also show increased edema and restricted diffusion on DWI.

DVT: Ultrasound. Dilated non-compressible veins. Doppler shows no flow and a flat pulse curve. The thrombosis is hypoechoic. Compare with other side for confirmation.

Blunt force trauma to the neck -> possible carotid artery dissection or jugular vein thrombosis –> indicates for routine US examination of the neck vessels.

Vascular tumors –> CT

Question 3

Carotid stenosis

Answer 3

pre-stroke, risk is estimated by Carotid US for stenosis, most commonly near the bifurcation.
50% stenosis is a hemodynamically significant and raises the risk of stroke.
70% stenosis is indication for surgery or interventional stenting.

Question 4

Estimating atherosclerosis with US

Answer 4

Can estimate the size and lipid content of the lesion

Can estimate flow

Can visualize the post-stenotic turbulence.