Introduction Carotid occlusion is one of the most important diagnoses that is made in the vascular laboratory or imaging department. The distinction between carotid occlusion and near-total occlusion or high-grade stenosis is critical as treatment options remain available for severe…
Introduction The identification of carotid artery stenosis is the most common indication for cerebrovascular ultrasound. The majority of stenotic lesions occur in the proximal internal carotid artery (ICA); however, other sites of involvement in the carotid system may or may…
Introduction The ultrasound evaluation of carotid artery atherosclerosis has evolved over the years. At the start, B-mode (gray-scale) images were used to evaluate the severity of carotid artery disease in the hope of supplementing traditional arteriography. Unfortunately, it became apparent…
B-Mode Ultrasound of the Normal Carotid Artery Wall The carotid artery wall is composed of three layers: the intima, the media, and the adventitia. The intima is the innermost layer abutting the lumen. It is thin and is covered with…
Introduction The vascular system of the human brain differs significantly, both anatomically and physiologically, from that of other organs. Although it accounts for only 2% of the body weight, the brain receives 15% of the cardiac output and consumes 20%…
Introduction In this chapter, we review the concepts and principles necessary for understanding and interpreting color Doppler images and pulsed Doppler waveforms and discuss the key elements needed for the interpretation of Doppler spectral waveforms. This includes a study of…
Introduction This chapter serves as an introduction to the physical and technical aspects of vascular sonography, including the following: (1) ultrasound principles, (2) transducers, (3) instruments, (4) advanced features, and (5) Doppler principles. These subjects are discussed in greater detail…
Overview The human circulatory system is extremely complex. Blood flow is influenced by many factors: 1. The heart influences the strength and amount of ejected blood. 2. The elastic arteries store energy during systole and maintain blood flow during diastole.…
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Synonyms/Description Early menopause Ovarian insufficiency Etiology Premature ovarian failure (POF) occurs in women under the age of 40 and is characterized by amenorrhea, hypoestrogenism, and elevated gonadotropins. It affects an estimated 1% of women, including 0.1% under age 30. Most…