Abdominal Aortic Aneurysm

Presented By: Dr. Syed Shoaib Muhammad

Subject:Applied Doppler, Vascular Doppler.

Topic Anatomy Of The Abdominal

Aorta Aneurysm Definition & Types. Probe Selection Patient Preparation Method Measurments.

Abdominal Aortic Aneurysm

ANATOMY OF THE ABDOMINAL AORTA

Normal Blood Vessel Wall.

Vessel walls are organized into three concentric layers: intima, media, and adventitia.

These are present to some extent in all vessels but are most apparent in larger arteries and veins.

Aneurysm Definition. An abnormal blood-filled dilatation of a blood vessel and

especially an artery resulting from disease of the vessel wall.

Aneurysm Types. Saccular Fusiform Dissecting

Saccular

Saccular aneurysm a distended sac affecting only part of the arterial circumference.

Fusiform

A localized dilation of an artery in which the entire circumference of the vessel is distended. The result is an elongated, tubular, or spindle like swelling.

Dissecting:

one resulting from hemorrhage that causes lengthwise splitting of the arterial wall, producing a tear in the inner wall (intima) and establishing communication with the lumen of the vessel.

Probe: Use The 3--5 MHz Transducer For The Abdominal Aorta Color

Doppler.

Patient Preparation

No special preparation is required, although some units use bowel preparation to improve visualization of the aorta; however, for screening scans this is rarely necessary. The patient should lie supine with the head supported on a pillow.Patient should be fasting 12-14 hour.Before the scan patient must be relaxed 20-30 mint.

Method:1. Transverse image of the mid-aorta and

IVC.

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Method:2. Sagittal image of the aorta.

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Method:3. Coronal imaging plane.

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Method:4. Imaging through the liver to identify the proximal aorta and IVC.

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Method:5. Imaging the aortic bifurcation in longitudinal plane from a right oblique position enables both common iliac arteries to be seen in the same image.

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Before Meal After MealPSV EDV PI PSV EDV PI

Superior Mesenteric Artery

100 16 3.6 120 30 1.5

Celiac Artery 125 23 1.8 130 40 1.5

Measurements:

Superior Mesenteric A.

Celiac Axis

Normal 125 ± 25 123 ± 27Atherosclerosis 163 ± 59 138 ± 38Stenosis (70-99%) PSV ≥ 275 PSV ≥ 200

Velocity (Mean ± SD cm/s)

Inferior Mesenteric Artery Measurements:

PSV 0.98 ± 0.30 m/s or (98.0 ± 30.0 cm/s)

EDV 0.11 ± 0.05 m/s or (11.0 ± 5.0 cm/s)

Mean Velocity 0.25 ± 0.08 m/s or (25.0 ± 8.0 cm/s)

R.I (SD) 0.89 ± 0.06 m/s or (89.0 ± 6.0 cm/s)

P.I 4.50 ± 1.53 m/s or (450 ± 153 cm/s)

Pulsatility Index

PI = S – D Mean

Resistive Index

RI = S – D D

Criteria For Mesenteric Artery Stenosis.

Celiac ArteryPSV ≥ 200 cm/s = ≥ 70 % stenosisFlow is Absent. = OccludedEDV ≥ 55 cm/s = ≥ 50 % stenosis

Superior Mesenteric Artery

PSV ≥ 275 cm/s = ≥ 70 % stenosisFlow is Absent. = OccludedEDV ≥ 45 cm/s = ≥ 50 % stenosis

Common Hepatic Artery Retrograde Flow = severe celiac artery

stenosis or occlusion

Paul L. Allen (3rd Edition) http://medical-dictionary.thefreedictionary.com/saccular+aneurysm http://www.nlm.nih.gov/medlineplus/mplusdictionary.html http://dictionary.reference.com/browse/saccular+aneurysm?s=t http://www.ultrasound-images.com