Validity of carotid duplex scan perfomred with the patient seated

Abstract

Dr Lucia Pemble, Griffith University, Australia Carotid duplex ultrasound scanning is widely used in clinical practice for diagnosis of patients with symptoms of cerebrovascular disease. It has been extensively validated and is often the only diagnostic imaging performed prior to intervention. Carotid duplex ultrasound examination of the cerebrovasculature and angiographical studies used for correlation have been performed with subjects in the supine position. Clinically patients can present for carotid duplex ultrasound evaluation who may be unable to assume a supine position. They may be quadriplegic, suffer severe vertigo, spinal abnormalities or shortness of breath and are restricted in their ability to assume a supine position for the scanning procedure. Objective. The purpose of this study is to compare pulsed wave (PW) Doppler velocity measurements obtained from duplex ultrasound of the carotid arteries with subjects in the seated and supine positions. It will then postulate if this would change the category of stenosis interpreted using the current velocity criteria for the classification of the severity of disease as recommended by the Australasian Society of Ultrasound in Medicine. Conclusions. Duplex ultrasound PW Doppler derived velocity criteria are used to classify the severity of stenosis in turn impacting on patient treatment options. The carotid duplex scan can be adequately performed on patients in the seated position but velocities measured will be reduced and modification to the existing velocity criteria is needed.