Duplex carotid sonography. Peak systolic velocity in quantifying internal carotid artery stenosis.

Abstract

Duplex ultrasonography combining high‐resolution imaging and Doppler spectrum analysis was performed in 92 consecutive patients (total, 180 vessels) and compared with the findings of conventional arteriography. All duplex studies were categorized into four groups based upon the maximum internal carotid artery (ICA) velocity: group 1: less than 125 cm/sec; group 2: 125 to 224 cm/sec; group 3: greater than 225 cm/sec; and group 4: no flow. Sensitivities and specificities were highest when peak ICA velocity was used as one of several criteria in quantifying the degree of ICA stenosis. These additional criteria were: (1) the presence of extensive sonographically visible plaque within the ICA; (2) an abnormal spectral waveform with elevated diastolic velocity (greater than 100 cm/sec); (3) resistive pattern ("externalization") of the common carotid artery (CCA) waveform; and (4) the ratio of the right CCA peak velocity to the left of less than 0.7 or greater than 1.3. The overall accuracy for the combined groups using all criteria was 94%.

Changes of Time-Attenuation Curve Blood Flow Parameters in Patients with and without Carotid Stenosis

“…18,19 Doppler sonography illustrates the phenomenon, known as "tardus parvus," due to the widened and flatter poststenotic waveform. 20,21 rTmax values of arteries and veins (artery-vein) were prolonged in group A (defined by the presence of carotid stenosis). Proximal arterial stenosis may transit the slowdown effects on blood flow to the downstream areas of the brain parenchyma.…”

Accuracy of Color Duplex Ultrasound Diagnosis of Spontaneous Carotid Dissection Causing Ischemia

“…The criteria for Ͼ50% and Ͼ80% ICA stenoses have been published in peer-reviewed journals, developed in studies using CA as standard of reference, and elaborated with the same ultrasound equipment used in the present study. [15][16][17] The last criterion was used because different ultrasound machines have been shown to measure different flow velocities under identical conditions of examination in both flow phantoms and patients. 18 ICA occlusion was assessed as reported before.…”

Ultrasound Assessment of Cervical Artery Dissection

“…Therefore, severe stenoses are diagnosed using pre-and poststenotic hemodynamic criteria, and at least two of the following three have to be present: (1) the quotient of the resistance index (RI, PSV Ϫ peak diastolic velocity/PSV) of ipsilateral CCA/RI of contralateral CCA is Ͼ0.15; (2) reversal of flow in the ipsilateral OphA, and (3) cross-flow through the anterior communicating arteries. The criteria for 51-80 and 81-99% ICA stenoses have been published in peer-reviewed journals, developed in studies using catheter angiography as standard of reference, and elaborated with the same ultrasound equipment as is used in the laboratory of the present authors [27][28][29]. The last criterion is important, because different ultrasound machines have been shown to measure different flow velocities under identical conditions of examination in both flow phantoms and patients [30].…”