1. Combined Use of Color Duplex Ultrasonography and B-flow Imaging for Evaluation of Patients with Carotid Artery Stenosis
AJNR Am J Neuroradiol 25: , November/December 2004
Intern 潘師典

2. Introduction of carotid artery stenosis
High-grade ICA stenosis:
increased risk for TIA, stroke, carotid occlusion, embolism arising from thrombi forming at site of narrowing
Plaque forms in a blood vessel when cholesterol, fat and other substances build up in the inner lining of an artery. This process is called atherosclerosis

3. Stenosis measurement
Identify NASCET: 70~99% ICAS

4. How to evaluate Noninvasive: Color duplex ultrasonography (CDU)
B-flow imaging (BFI)
MRA
CTA
Invasive:
Digital subtraction angiography (DSA)

5. Methods 1/2
67 men and 28 women with mean age of 66 yrs (age range, yrs)
Be excluded: (29) 147
1. previous ipsilateral carotid endarterectomy
2. high bifurcation of CCA, or a short neck (6)
3. no role in duplex velocity measurement,
such as occlusion (10) or string sign (2)
4. calcification extensive enough to obscure
sonography single intensity in the stenotic area (11)

6. Methods 2/2
All CDU and BFI were performed by the same radiologists, who were unaware of each other’s test results, at the same day.
The radiologist who assessed the angiograms was blinded for the results of ultrasonography examination.
The results of CDU and BFI were first analyzed seperately and compared with standard DSA.

7. GE Logiq 700 with a
5- to 10- MHz
linear array transducer
ICA
ECA
CDU
60o
Dynamic range: 60dB
Gain: 50%
Transverse and
Longitudinal planes
CCA
BFI

8. DSA
Performed with a Polytron V 1000 angiographic unit by using a Seldinger technique
Each projection, 8mL of contrast medium, with a flow rate of 4mL/s

9. Result
33 (17%)

10. What’s different between CDU and BFI ?

11. Limitation CDU: BFI: CCA diameter variation and
Variable collateral flow
Extensive calcification
Backgroung flash
Slow flow…
Duplex velocity measurement
arrhythmia, valve insuffucincy,
Tandem plaques
AVM, carotid body tumor,
Carotid a. coiling or kinking,
Severe contralateral stenosis
Real-time hemodynamic flow
Excessive pulsation of vessel leads
to movement of surrounding tissues
(vessel wall: ill-defined)

12. Conclusion In the diagnosis of CAS:
1. Slightly better accuracy  CDU > BFI
2. combined use > alone
3. DSA> combined use