Intravenous digital subtraction angiography with iohexol

Iohexol is a nonionic water-soluble iodinated contrast medium with chemical and physical properties similar to those of metrizamide. A randomized double-blind study was performed in 40 patients undergoing intravenous digital subtraction angiography for suspected carotid and vertebral disease to compare the radiographic imaging quality and side effects of iohexol with those of Renografin-76 (diatrizoate meglumine and diatrizoate sodium). The use of iohexol yielded a higher percentage of "excellent" images with a lesser incidence of image degradation due to swallowing and motion. Iohexol was also associated with milder and less frequent patient discomfort. No clinically significant changes in laboratory data parameters were observed with either contrast medium.     

Intravenous digital subtraction angiography in intracranial aneurysms

Intravenous digital subtraction angiography was undertaken in 121 patients with known intracranial aneurysms. Its role in the management of these patients and its diagnostic accuracy have been assessed.     

Intravenous digital subtraction angiography in non-specific aorto-arteritis

We have studied 40 patients with non-specific aorto-arteritis (Takayasu's disease) using intravenous digital subtraction angiography (DSA). The aorta, its major branches and (in 18 patients) pulmonary arteries were evaluated to determine the degree and extent of involvement. No complications related to the procedure were encountered. Good quality diagnostic images were obtained in 39 out of 43 instances. The unsuccessful examinations were in patients with congestive cardiac failure, and in one patient who would not co-operate. Aortic wall thickness and mild involvement of the descending aorta in the region of the diaphragm could not be assessed. Intravenous DSA is acceptable for the diagnosis and follow-up of aorto-arteritis in suitable patients.     

Intravenous digital subtraction angiography by peripheral injection

We describe a technique for performing intravenous digital subtraction arteriography by peripheral injection and review our experience of 504 studies in 469 patients. The technique gave adequate opacification for anatomical definition of vessels in 93% of patients studied and was suitable for studies of the pulmonary arteries and left ventricle as well as the major systemic arteries. The chief causes of failure were impaired cardiac performance (2.4%) and poor patient cooperation (1.4%). Premature termination was caused by angina pectoris in 1.6% of our cases. These limitations apply also to central venous injection.     

Intravenous digital subtraction angiography. A criteria of brain death

The absence of cerebral blood flow is the best criteria of cerebral death. Intravenous digital subtraction angiography (DSA) was performed in 110 patients with clinical signs of brain death. In 105 cases DSA, confirmed the stop of the intracranial circulation. In the other 5 cases, repeated examination a few hours later demonstrated arrested cerebral circulation. Organs transplantations were performed in 30 cases. DAS represents a relatively non invasive and quick to perform method to demonstrate brain death.     

Intravenous angiography using digital video subtraction: intravenous cervicocerebrovascular angiography

The clinical application of intravenous angiography to study the cervicocerebrovascular system using the digital video subtraction system described in a companion article is reported. About 0.75 ml/kg of a standard 76% iodine contrast solution is injected into an antecubital vein using a power injector. Then 15-20 exposures of the head and neck region at a 1/sec rate are made on the image intensifier. The images are recorded by a high performance video system and the output signal is digitized for subsequent computer manipulation. The subtraction images of these vessels produced by the computer show the vessels clearly, even though they contain very low concentrations of contrast media. Standard exposure factors of 75-80 kVp, 9-10 msec at 800-1,000 mA are used. Clinically pertinent features of the data alteration and flow through the system and the step-by-step computer procedures used to achieve and analyze the various forms of subtracted images are described. Five experimental and clinical cases demonstrate appropriate applications to cervicocerebrovascular disease: (1) evaluating the effects of surgical and medical therapy on atherosclerosis; (2) providing a screening angiographic test for patients with asymptomatic bruits and/or positive noninvasive studies; (3) evaluating patients who have significant generalized vascular disease either precluding or presenting hazardous contraindications to transarterial catheterization; (4) evaluating significantly aged patients in whom standard angiography has higher risk; and (5) evaluating currently asymptomatic patients who are medically at higher risk for developing atherosclerotic lesions. Numerous examples of the various types of image manipulations are presented: (1) linear subtraction; (2) logarithmic subtraction; (3) alterations of electronic contrast enhancement (map slope); (4) the usefulness of a series of angiographic images; and (5) the importance of multiple projections with this technique.     

Intravenous digital subtraction angiography of arteriosclerotic vertebrobasilar disease

Intravenous digital subtraction angiography (DSA) was performed in 111 patients with vertebrobasilar ischemia. Ninety percent of the vertebral images were of diagnostic quality; 23% of the basilar images were good quality and 53% fair quality; and 58% of the posterior cerebral images were poor. Compared with selective film arteriography in 23 patients, DSA tended to underestimate the degree of atheromatous disease. Segments of the basilar artery were often poorly seen, which could result in false-negative errors. DSA can provide a general assessment of atheromatous disease of the brachiocephalic vessels, including the vertebral and carotid arteries, and in many cases can exclude occlusion or critical stenosis of the vertebrobasilar system. However, it does not adequately image the posterior cerebral or cerebellar artery.     

Intravenous digital subtraction angiography in diagnosis of vascular graft occlusion

Differentiation is often difficult between vascular graft occlusion and progression of underlying disease in patients after vascular surgery. We have studied 57 patients after surgery for traumatic and atherosclerotic arterial occlusion and other vascular anomalies using a commercial digital subtraction angiography (DSA) unit; no complications occurred. Indications for examination included pain, diminished pulse, and failure of catheter angiography. Graft patency was established if proximal and distal anastomoses were visualized; occlusion was diagnosed if no graft was imaged or vascular stump found—noted in 31 grafts. Our diagnosis was proved surgically in 24 patients (two refused operation); three others were confirmed angiographically and one by Doppler ultrasonic examination. In our experience DSA is a safe, specific means of following postoperative grafts and diagnosing their occlusion. This work was supported in part by U.S. Public Health Service Grant No. HL07334     

Intravenous angiography using digital video subtraction: x-ray imaging system

An x-ray imaging system, using digital subtraction techniques, has been developed. The system requires: (1) high output generation equipment; (2) an image intensifier capable of receiving high output exposures, 1 mR (2.58 X 10(-7) C/kg) at the face of the intensifier, without loss of either contrast or resolution; (3) a precision digital video camera; (4) processing computer with sufficient storage capacity; and (5) digital image storage. With this system it is possible to visualize the major arteries after intravenous contrast injection. The system, angiography technique, and early results are described.     

Intravenous digital subtraction angiography in the diagnosis of brain death

The diagnosis of brain death requires: (1) the performance of all appropriate and therapeutic procedures; (2) the presence of cerebral unresponsivity, apnea, dilated pupils, absent cephalic reflexes, and electrocerebral silence; and (3) if one of these criteria cannot be tested or is met imprecisely, the performance of a confirmatory test to demonstrate the absence of cerebral blood flow. Selective cerebral arteriography has been the most widely used method of assessing cerebral blood flow. Digital intravenous angiography was used as a means of evaluating cerebral blood flow, and it was found to be a useful confirmatory test in the diagnosis of brain death.     

Intravenous digital subtraction angiography in the investigation of intracranial disease

Eighty-six patients who presented with a variety of intracranial lesions were examined with intravenous digital subtraction angiography (IV-DSA). A grading system was used to evaluate the ability of IV-DSA to answer specific diagnostic questions regarding intracranial tumors, vasospasm following subarachnoid hemorrhage, lesions of the sella, dural sinus occlusion, and post-therapeutic embolization. Eighty-four per cent of the examinations provided clinically useful information. In 15% of the cases limited but useful information was obtained; only 1% of the examinations provided no useful information. We conclude that IV-DSA can routinely provide useful information in the evaluation of the variety of intracranial lesions described above.     

Intravenous digital subtraction angiography in patients with aortic isthmus stenoses

The authors report on 18 patients with stenoses of the aortic isthmus in whom digital subtraction angiography had been carried out. In three patients DSA yielded the primary diagnosis of a postductal stenosis of the aortic isthmus. In all postoperative patients, restenosis of the aorta could either be excluded or confirmed. In three cases with complications after an operation, DSA supplied diagnostic information which was decisive for proceeding further. According to the authors' experience, intravenous DSA can replace conventional angiography in the majority of postoperative controls and in future also in primary diagnosis.     

Intravenous digital subtraction angiography of the thoracic and abdominal aorta

Intravenous digital subtraction angiography (IV DSA) is a new imaging modality that utilizes techniques of video image acquisition and computer image manipulation to provide anatomic information about blood vessels and organs. In many ways, it represents an electronic version of classic intravenous and film-subtraction angiography. As a means of imaging the thoracic and abdominal aorta, IV DSA has demonstrated great potential, particularly in vessels originally imaged by the former techniques. We have imaged the aorta in over 300 cases at Brigham and Women's Hospital, either alone, or in combination with other vessels in the course of work-up for vascular disease. Although experience has been limited, intravenous imaging of the aorta can be routinely performed, providing reliable and clinically significant information. Supported in part by CV Training Grant 201-HL20895-06     

Intravenous digital subtraction angiography in Takayasu's disease. A report of 32 cases

IVDSA appears to be a reliable method and should therefore be considered as a first step examination when Takayasu's disease is suspected. The simplicity and safety of the method provide a rationale for the use of this technique in Takayasu's disease. Therapeutic decisions can usually be obtained without further radiological investigation, and conventional arteriography has to be performed only when data obtained with IVDSA are insufficient. In these rare cases, conventional arteriography aims at the investigation of a particular area. The site of arterial puncture can be precisely guided by IVDSA.