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At least 19 recordsLinked to original sources
PubMed1988

Acute pulmonary embolism: diagnostic value of digital subtraction angiography.

Digital subtraction angiography (DSA) performed via a peripheral vein was compared prospectively with selective conventional pulmonary angiography (CPA) in 54 patients suspected of having pulmonary embolism (PE). All patients also underwent ascending venography. In contrast to the conventional pulmonary angiograms, all of which were considered satisfactory, 13 of 54 digital subtraction angiograms (24%) were technically unsatisfactory. The interpretable digital subtraction angiograms had 81% sensitivity and 64% specificity. With DSA, one cannot exclude the diagnosis of PE on the basis of normal angiograms (27% false-positive results) as one can with perfusion scanning. On the other hand, DSA showed good sensitivity (94%) in medium to major PE. Therefore it may be the technique of choice in the screening of life-threatening PE for which curative emergency treatment with thrombolytic agents or embolectomy is often necessary.

Acute Disease↗
PubMed1986

Parametric imaging using digital subtraction angiography.

Digital subtraction angiography following an injection of iodinated contrast material can regularly produce good quality images. In addition to the conventional anatomical information, the timed sequence of digital images also contains useful temporal information which hitherto has been largely ignored. A simple method of image processing is described which utilises this timing information and presents it as a colour-coded set of functional images. Three parameters MAX, T-MAX and T-1/2 MAX are extracted from time-density curves, analogous to the time-activity curves of Nuclear Medicine, on a pixel-by-pixel basis. These parameters are used as a measure of overall organ perfusion, blood transit time between different vascular compartments, and as an indication of the initial delivery of contrast material to an organ. They have found use in the analysis of myocardial perfusion, before and after pharmacological intervention, and in the examination of the cerebral and renal circulations. The potential advantages of this technique derive from its superior spatial, temporal and contrast resolution.

Angiography↗
PubMed1989

[Limits of the diagnostic capability of pulmonary digital subtraction angiography].

Digital subtraction pulmonary angiography was performed in 70 patients suspected of having pulmonary emboli. In 35 patients this diagnosis proved to be correct. The technical quality of all ECG-gated studies was scored and was found to be satisfactory in 31 patients (44%), moderate in 23 (33%) and unsatisfactory in 16 patients (23%). This was mainly due to the lack of patient cooperation. In patients with direct injection into the pulmonary artery (27%) the motion artifacts were less disturbing. We therefore suggest that even when using ECG-gated acquisitions, the injection should be performed into the pulmonary artery to overcome technical problems in the diagnosis of pulmonary embolism.

Adult↗
PubMed1987

Quantitation of aortic regurgitation by computer analysis of digital subtraction angiography.

Digital subtraction angiography provides the potential to determine aortic regurgitant fraction by computer analysis of time-intensity curves generated from regions of interest positioned over the aorta and left ventricle after aortography. To validate this ability, we studied six dogs instrumented with an electromagnetic flow probe on the ascending aorta. Aortic regurgitation of varying severity was produced by a basket catheter introduced through the right carotid artery. Aortograms were performed using continuous fluoroscopy at 30 frames/s and stored in digital format in a 256 x 256 pixel matrix. An image-processing computer was utilized to plot summated pixel intensity versus time for both the aortic and the left ventricular regions of interest. Regurgitant fraction was calculated from the time-intensity curves using an algorithm analogous to that employed by dye-dilution methods. Regurgitant fraction determined from digital angiography was compared with that obtained by electromagnetic flow and was found to correlate well (r = 0.94, SEE = 7.4%) over a wide range of values. Thus, these data indicate that aortic regurgitant fraction can be accurately determined from computer analysis of digitally acquired aortograms in an animal model of acute aortic regurgitation.

Animals↗
PubMed1987

[Quantitative analysis of the left ventricular volume curve by digital subtraction angiography].

Digital subtraction angiography (DSA) not only permits visualizing the left cardiac and arterial systems after injecting contrast media intravenously, but enables quantitative and functional analyses of the data collected. This report describes our experiences with several videodensitometric analyses for assessing global and regional left ventricular (LV) functions. 1. Analyses of LV volume curves with contrast media In the conventional cineventriculogram, construction of LV volume curves by the area-length method requires tedious efforts, but with DSA, such curves are provided automatically using videodensitometric analyses. The advantages of the DSA method include; 1) DSA has better contrast resolution than radionuclide angiography. 2) The densitometric technique may offer more accurate results than methods based on geometric assumptions, especially when the LV shape is irregular or when it changes during a single cardiac cycle. 2. Analyses of LV volume curves without contrast media Computer analyses of DSA images without contrast media facilitated the noninvasive evaluation of global and regional LV functions. The method is based on the ability to detect small differences in X-ray absorption by the cardiac silhouette during a single cardiac cycle, without any contrast media. We applied this capability to Fourier analysis using radionuclide angiographic computer programs and succeeded in evaluating regional wall motion abnormalities in patients anterior myocardial infarction. In summary, the videodensitometric analysis of the DSA image is a promising new approach for the clinical of LV function, due to its combined capability of automated computerized analysis similar in radionuclide study, and due to higher contrast resolution just like as LV cineangiography.

Absorptiometry, Photon↗
PubMed1987

Digital subtraction angiography.

Digital Subtraction is a computerised radiological technique to demonstrate the vascular tree by removing unwanted background information and enhancing dilute contrast medium within the blood vessels. Contrast may be introduced intravenously or intra-arterially. The relative merits of these two methods, together with the advantages and limitations of the technique are discussed.

Angiography↗
PubMed1988

[Angiography in peripheral arterial occlusive disease. Comparison between large-format angiography, digital subtraction angiography and intermediate-format technic].

With peripheral venous injection of contrast medium, DSA serves to diagnose occlusive peripheral arterial disease in some 90% of cases. Indications for iv-DSA are occlusions and stenoses in the area of the iliac and femoral arteries, as well as in the proximal lower leg. Intraarterial DSA with fine needle is additionally indicated in some 10% of patients for examination of the distal lower leg arteries. In non-diagnostic DSA, conventional angiography using 100-mm technique may be performed with the same angiographic unit.

Angiography↗
PubMed1986

[New diagnostic possibilities of postmortam coronary angiography by digital subtraction angiography].

Postmortal digital subtraction angiography permits vessels filled with a contrast agent to be visualized selectively in a video film shot and the contrast agent flow to be observed directly in the coronary arteries. Compared to conventional static methods of postmortal coronary angiography, the judgment on the hemodynamic effects of stenosis and occlusion, as well as of collaterals and anastomosis, will be improved and therefore the diagnosis of acute coronary death. The diagnostic possibilities and advantages of DSA are demonstrated in two cases.

Adult↗
PubMed1988

Preoperative diagnosis of ovarian malignancies with intravenous digital subtraction angiography.

Intravenous digital subtraction angiography was performed on 59 patients with ovarian tumors. Dilatation of the uterine artery and its ovarian branch was relatively frequent in both benign and malignant tumor groups, while dilation of the ovarian artery, and hypervascularity from the uterine artery or the ovarian artery were fairly specific to the malignant tumor group. These five abnormal vascular patterns were evaluated by a scoring system and approximately 75% of malignant and 87% of benign ovarian tumors were correctly diagnosed preoperatively by digital subtraction angiography alone. Intravenous digital subtraction angiography can be applied as an easy, safe, and valuable diagnostic method for ovarian malignancies and can replace conventional pelvic angiography.

Adult↗
PubMed1989

[Evaluation of internal mammary artery graft patency by intraarterial digital subtraction angiography].

Intraarterial digital subtraction angiography (DSA) was performed to evaluate graft patency in 45 patients undergoing coronary artery bypass grafting with the use of internal mammary artery (IMA). Fourty-five IMA grafts and 59 saphenous vein grafts were evaluated using a DSA equipment with a pulse mode of 2 frames per second. A 4F catheter was introduced percutaneously into the left brachial artery. Nonionic contrast medium was nonselectively injected into the left subclavian artery for visualization of IMA grafts and also into the aortic root for visualization of vein grafts. No serious complications occurred. Forty-four IMA grafts and 53 vein grafts were patent. The patency rate was 97.8% for IMA grafts, 89.8% for vein grafts, and 93.3% for all grafts. In 11 patients (24%), intercostal or pericardial branches were visualized. Two patients showed a string sign of the IMA. Intraarterial DSA with nonselective injection of contrast medium into the subclavian artery is a new method for evaluation of IMA graft patency with a low risk.

Adult↗
PubMedDate not supplied

Biplane digital subtraction angiography.

Biplane digital subtraction angiography was performed by placing a rapid switch between the anteroposterior and lateral T.V. cameras and the A-D converter. Alternate exposures from two X-ray tubes were employed. Excellent anteroposterior and lateral DSA was obtained especially for the brain and neck. Although there was more time required for positioning, biplane imaging saved the second or the third injection in many occasions. The technique has been especially valuable for intravenous DSA of the brain and the neck.

Angiography↗
PubMed1989

Clinically unsuspected complications of arterial surgery shown by post-operative digital subtraction angiography.

Intravenous digital subtraction angiography was performed within 20 days of 678 vascular reconstructions as a routine post-operative evaluation. After 339 carotid endarterectomies, 34 patients showed a stenosis of greater than 30% and six occlusions were seen. In 157 patients after aortic aneurysm repair, we found five anastomotic aneurysms and seven stenoses of greater than 30%. After aortic bypass surgery, 77 patients were evaluated and nine stenoses were found; no anastomotic aneurysms were seen. In 105 patients with femoro-distal bypass procedures, occlusion was reported in 11 cases and stenosis in 13 cases. One patient had two anastomotic aneurysms. To summarize, major abnormalities were present in 81 cases (12.7%) and consisted of 59 stenoses of greater than 30%, 17 occlusions and six patients with anastomotic aneurysms. Most of these were unexpected and were reason for more critical follow-up or re-operation.

Aorta, Abdominal↗
PubMed1986

Intravenous digital subtraction angiography.

Intravenous digital subtraction angiography (ivDSA) is a method whereby arterial images are produced following a peripheral or central venous injection of contrast medium. It is a safe and relatively simple procedure to undertake and is becoming more widely available. The purpose of this article is to review its clinical applications, its advantages and limitations.

Angiography↗
PubMed1988

Left ventricular imaging by digital subtraction angiography.

Digital radiography is a rapidly developing new approach to cardiovascular imaging that converts radiographic and fluoroscopic video images into digital format for subsequent image enhancement analysis, and storage. Left ventriculography can be performed by this method using either intravenous or low-dose intraventricular contrast administration. Advantages over standard radiography include reduced radiation and contrast medium burden, visualization of very low contrast medium concentrations, and an image format that can be directly analyzed by quantitative techniques. As these cardiac applications are developed and improved archiving is implemented, it is likely that the digital left ventriculography will replace standard cardiac angiography.

Angiography↗
PubMed1991

Left ventricular dual-energy digital subtraction angiography: a motion immune digital subtraction technique.

Digital subtraction angiography (DSA) allows quantitative analysis of ventricular function via densitometric and parametric imaging techniques. However, DSA is limited by the artifacts in temporal subtraction images that result from patient and cardiac motion. Dual-energy subtraction imaging is insensitive to motion. This study evaluated the initial application of dual-energy subtraction in cardiac patients. The image quality of dual-energy subtraction left ventriculograms obtained from a pulmonary artery injection of contrast was assessed in 13 patients, ranging in weight from 54 to 100 kg. The dual-energy images were compared with left ventricular images obtained using standard left ventricular injection cine angiography. End-systolic and end-diastolic ventricular volumes calculated from the cine (C) and dual-energy (DE) images using the Area-Length method were compared. The resulting regression line was DE = 0.98 C+ 7.0 ml, and the r value was 0.987. Dual-energy subtraction provided good left ventricular visualization, free from misregistration artifacts, even during patient motion.

Adult↗
PubMed1989

Operative angiography by intraarterial digital subtraction angiography: a new technique for quality control of carotid endarterectomy.

Fifty patients who had carotid bifurcation endarterectomy as their sole surgical procedure underwent intraoperative completion angiography by means of portable intraarterial digital subtraction angiography. All had subsequent intravenous digital subtraction angiography or duplex scanning during early follow-up. After the endarterectomy site was closed and before the wound was closed, 6 to 8 ml of contrast was injected through a 21-gauge needle while fluoroscopy was performed with a conventional C-arm. The C-arm was coupled to a Quantel IDIS Mobile Digital Subtraction Angiogram Unit (Quantel Medical Products Group, Clemmons, N.C.) for image enhancement and immediate playback. There were no postoperative deaths or neurologic complications. Abnormal radiographic results led to reopening of endarterectomy sites in eight patients, which resulted in successful correction of the defects. There was a single asymptomatic occlusion of the internal carotid artery at 3 weeks in the patient with the only false-negative result on the completion study. Intraarterial digital subtraction angiography is a safe and useful technique for intraoperative quality control of carotid endarterectomy. It provides visual images that can be easily repeated in several projections, uses small volumes of contrast, and has no timing requirements for filming and injecting.

Carotid Artery Diseases↗
PubMedDate not supplied

Evaluation of aortic aneurysms and dissection of aorta by intravenous digital subtraction angiography.

Intravenous (IV) digital subtraction angiography (DSA) was performed in 12 patients with suspected aortic aneurysm/dissection. Bolus injection of 30-40 ml of contrast in mid right atrium/main pulmonary artery at a flow rate of 18-20 ml/sec. during DSA accurately localised the site and extent in all 7 patients of aortic aneurysm and in 4 patients of aortic dissection. In one patient, radiological opacity was unrelated to aorta. There were no complications. IV-DSA should be the preferred mode of evaluation for aortic aneurysm and dissection of aorta.

Adult↗