Seeing with Sound: Diagnostic Ultrasound Imaging
Suzanne Amador Kane, Boris A. Gelman in Introduction to Physics in Modern Medicine, 2020
This use of color flow mapping supplements angiography, an x-ray method for imaging the circulatory system using an x-ray-absorbing contrast dye injected into the patient's heart, arteries, or veins (Chapter 5). This technique requires exposure to x-rays, and it exposes patients to a small risk of a serious reaction to the injected contrast medium. By comparison, echocardiography can be performed from outside the body (or in some instances through a transducer inserted into the esophagus) using portable imaging equipment that can be wheeled to the bedside, and it does not require the introduction of foreign substances into the circulatory system. In spite of this reduced invasiveness, it allows the cardiologist to see the heart's anatomy in motion, as well as many details of the blood's circulation. Many different imaging techniques are used to study the heart and circulatory system, each with its own advantages and disadvantages, so echocardiography does not entirely displace other imaging methods.
Diagnosis of coronary heart disease in the elderly
Wilbert S. Aronow, Jerome L. Fleg, Michael W. Rich in Tresch and Aronow’s Cardiovascular Disease in the Elderly, 2019
Despite the recent advances in noninvasive cardiac imaging discussed above, invasive coronary arteriography remains the accepted standard for detection and quantitation of CHD, although it may underestimate the extent of coronary atherosclerosis compared with intravascular ultrasound. Major complications of coronary arteriography include myocardial infarction, stroke, and death. In the Coronary Artery Surgery Study (CASS) registry, each of these endpoints was approximately three times as common in patients aged 65 and above than in younger individuals (6). A single-center study between 1980 and 1990 of 242 patients 80–92 years old reported a mortality of 0.8% and nonfatal complication rate of 5%, compared with respective rates of 0.15% and 1.5% in patients younger than 80 years (157). The increased risk in the elderly is largely explained by their generally greater severity of underlying cardiac and noncardiac disease. Although major complication rates from cardiac catheterization and coronary arteriography continued to decline through the 1990s (157), the elderly should still be considered at higher risk, especially those aged 80 years and beyond.
Vascular Assessment and Management
John C Watkinson, Raymond W Clarke, Christopher P Aldren, Doris-Eva Bamiou, Raymond W Clarke, Richard M Irving, Haytham Kubba, Shakeel R Saeed in Paediatrics, The Ear, Skull Base, 2018
Primary assessment is made by computed tomography (CT) and magnetic resonance imaging (MRI) in order to determine the following features: exact tumour locationrelationship to surrounding bone, nerves, major blood vessels, brain and durapattern of tumour extensiondegree of vascularitypresence of intratumoural vessels (MRI)vascular territories involved by the tumour. Diagnostic angiography and subsequent intervention can be performed in one session under general anaesthesia. Owing to the complex nature of these lesions, it is not uncommon to perform diagnostic angiography under local anaesthetic as a separate procedure prior to intervention. A size ‘4’ French sheath and catheter is used and is introduced by the trans-femoral route. Subtraction images, fluoroscopy and a map of the vascular structures – the ‘road map’ – are acquired. The road map superimposes fluoroscopic images onto a previously acquired image of the vessels. This enables the guidewire and catheter to be imaged in relation to the vessels and facilitates safe navigation.
Surgical management of primary parapharyngeal space tumors in 103 patients at a single institution
Published in Acta Oto-Laryngologica, 2018
Fenglin Sun, Yan Yan, Dongmin Wei, Wenming Li, Shengda Cao, Dayu Liu, Guojun Li, Xinliang Pan, Dapeng Lei
Imaging is essential to evaluate the location and extent of PPS neoplasms because of the limitations of physical examination in this anatomical area [11]. Arteriography is performed infrequently for the diagnostic purposes. In rare instances, it can be used to evaluate cervicocerebral collateral circulation, which may necessitate the sacrifice of major blood vessels [5]. DSA is helpful for surgeons to understand the compensation of the blood supply to the brain and Wills rings and then to properly assess the safety of resection of tumor adhering to the internal carotid artery. In this study, five patients underwent DSA and were diagnosed with carotid body paraganglioma postoperatively. Among them, three cases could not be resected directly because of severe adhesion to the internal carotid artery and common carotid artery, so vascular prosthesis bypass grafting was performed after resection. To reduce intraoperative blood loss, one patient with neurilemoma that invaded the intervertebral foramen underwent ascending cervical artery superselective embolization and vertebral artery balloon embolization. This provided strong protection for the complete resection of the tumor.
Intravenous fluids for the prevention of contrast-induced nephropathy in patients undergoing coronary angiography and cardiac catheterization
Published in Expert Review of Cardiovascular Therapy, 2020
Winston Y Hong, Mohamad Kabach, George Feldman, Ion S Jovin
Contrast-induced nephropathy (CIN) has been a well-studied phenomenon since its first description by Bartels et al. in 1954 [1]. Iodine-based contrasted studies have had multiple clinical applications, from diagnostic to therapeutic interventions in several organ systems. Angiography involves the injection of radiopaque contrast into the vasculature, in order to properly visualize both organs and blood vessels. Contrast is injected into either the arterial or venous systems depending on the study. The iodinated contrast is eventually renally cleared. The contrast exposure can often lead to side effects, the most common being CIN, making it the third-leading cause of acute kidney injury in the hospital [2]. Many studies define CIN as a 25% relative increase in serum creatinine within 3 days of contrast exposure while others define it as an absolute increase of 0.3 mg/dL above baseline [3], across the same timeframe. There is not a universally agreed-upon definition of CIN at this time. Essentially, it is an acute kidney injury (AKI) in the setting of contrast use.
Alternative Access for Mechanical Circulatory Support
Published in Structural Heart, 2020
Mir B. Basir, Marvin H. Eng, Pedro Villablanca, Mark B. Anderson, Mohammad Zaidan, Dee Dee Wang, Khaldoon Alaswad, William W. O’Neill, Mohammad Alqarqaz
Careful evaluation of the patient’s vasculature is required to determine the safest access for delivery of MCS. Patient selection, sheath size, and access strategies heavily rely on noninvasive imaging. Computed tomographic (CT) angiography is increasingly used for peri-interventional evaluation allowing for objective three-dimensional assessment of the access site. In patients with renal insufficiency, non-contrast CT scans can similarly provide important information including tortuosity, calcium burden, and vessel size.4 When CT is not available, ultrasound and intravascular ultrasound (IVUS) offer valuable information about plaque morphology, vessel size, calcium burden, and the presence of prior complications such as dissection or aneurysm.5 Ultrasound can be ideally combined with angiography to help ensure accurate assessment of vascular anatomy.6
Related Knowledge Centers
- Fluoroscopy
- Vein
- Blood Vessel
- Artery
- Medical Imaging
- Lumen
- Radiocontrast Agent
- X-Ray
- Radionuclide Angiography
- Carbon Dioxide Angiography