Ability to Use Duplex US to Quantify Internal Carotid Arterial Stenoses: Fact or Fiction?

Abstract

Doppler US is excellent for classifying stenoses as above or below a single degree of severity but does not function well in stenosis subclassification.

Colour Doppler Evaluation of Extracranial Carotid Arteries: A Clinical and Radiological Correlation

“…PSV is considered the best parameter since it is easy to measure and due to the increase in specificity with increase in stenosis. Grant et al, also found that mean PSV increased with increased stenosis level [20]. As stated by Tahmasebpour et al, if the degree of stenosis is indeterminate according to the primary parameters, the ICA/CCA PSV ratio to be taken as an additional parameter [21].…”

Cognitive impairment in chronic obstructive pulmonary disease

“…At the time of the cognitive and SPECT study, subjects were in stable conditions defined as follows: the individual performance on Activities of Daily Living (ADL) was judged by the patient to be usual for him/her; limited to group H patients, an arterial oxygen saturation of at least 90 % had to be maintained by the usual inspired fraction of oxygen. Patients were administered the following standardized inhaled therapy: salbutamol 200 mcg b. i. d.; ipratropium bromide 250 mcg t. i. d.; beclomethasone 250 mcg t. i. d. In order to prevent the confounding effect of cerebral hypoperfusion on data interpretation, left ventricular dysfunction and carotid artery stenosis > 50 % qualified as criteria of exclusion from both groups; inherent diagnoses relied upon validated criteria and 2D-echographic measurement, respectively [6,22]. COPD patients having a clinical diagnosis of dementia were excluded from the study [1].…”

Numerical analysis of pulsatile blood flow and vessel wall mechanics in different degrees of stenoses

“…The results from our simulation show that the peak velocity at the throat of the stenosis is about 1.47 m/s in 30% stenosis, 2.3 m/s in 50% stenosis and 3.2 m/s in 70% stenosis against a value of 0.78 m/s in healthy arteries. The authors are not aware of any published experimental data for the external iliac stenoses, however, a qualitative comparison can be made with the ultrasound measurements for the arterial stenoses in other parts (Grant et al, 2000;de Smet et al, 1996). From Fig.…”