Intraarterial digital subtraction angiography in diagnostic arteriography

Intraarterial digital subtraction angiography (DSA) was performed in 133 diagnostic arteriographic procedures during a 10-month period. The increased contrast resolution of DSA permitted the use of a dilute (15%) contrast material. A significant reduction in contrast material dose compared with conventional film-screen arteriography and intravenous DSA was thus achieved. This was especially advantageous in patients with diminished renal function. The dilute contrast material also resulted in less patient discomfort. Subtracted images were available immediately on cathode ray tube display, resulting in faster procedures, and a considerable saving in film cost compared with conventional arteriography. It is concluded that intraarterial DSA is a useful technique that may replace conventional film-screen arteriography in many applications.     

Work in progress. Intra-arterial digital subtraction angiography: evaluation in 150 patients

As part of an ongoing study comparing digital subtraction angiography (DSA) with conventional film-screen angiography, 150 patients were examined with arterial contrast material injections and digital filming techniques alone or combined with conventional angiography. Of 247 injections, the DSA study was good or excellent in 236, approaching the quality of conventional angiography for visualization of vessels greater than 1 mm in size. Advantages included improved vascular detail in selected areas such as the skull base, visualization of minimal contrast concentration in diseased vessels or postoperatively, and imaging of vessels distal to stenoses without the hazards of selective catheterization. DSA permitted rapid positioning under fluoroscopic control, instantaneous viewing of subtracted images, and reduced technologist time and film costs. Contrast material volume was reduced by 40 to 60%, allowing multiple studies in one sitting and study of patients with renal compromise.     

New diagnostic modalities in the diagnosis of primary and recurrent giant-cell tumors of bone

Computed tomography (CT) and/or digital subtraction angiography (DSA) were performed on four patients with primary or recurrent giant-cell tumor of bone. In three cases presented, the tumor was examined with CT and had a precontrast attenuation value of about +50 to +65 HU with unequivocal nonhomogeneous contrast enhancement. In both cases in which DSA was used, contrast-medium enhancement could be recorded by DSA that had definitely not been seen with conventional angiography. It is suggested that in the future CT and DSA may replace conventional angiography in the diagnostic workup of giant-cell tumors.     

Digital subtraction angiography of the thoracic aorta

Forty-three patients with acquired and congenital abnormalities of the thoracic aorta were studied using digital subtraction angiography (DSA) after an intravenous bolus injection of 40 ml of contrast material. Abnormalities studied included coarctation, pseudocoarctation, Marfan syndrome, cervical aorta, double aortic arch, aneurysm, dissection, and tumor. Twenty-four patients also had conventional angiography. DSA was accurate in 95% of cases; in the other 5%, involving patients with acute type I dissection, the coronary arteries could not be seen. The authors concluded that in 92% of their patients, DSA could have replaced the standard aortogram.     

Digital intraarterial subtraction technique of the extracerebral vascular system

We report the results from intraarterial digital subtraction angiography (IA DSA) of the extracerebral vessels with aortic arch injection of contrast medium via femoro-arterial puncture, instead of the more widely used intravenous digital subtraction angiography (IV DSA). Intraarterial DSA is performed using a lower contrast dose and rate, making this study less invasive and costly than the conventional arteriographic study of the aortic arch. Intraarterial DSA provides better resolution than IV DSA. The diagnostic accuracy is almost equivalent to conventional angiography and is largely superior to photographic subtraction angiography with intravenous injection of contrast media.     

Peripheral vascular disease: prospective study of intraarterial digital subtraction angiography using a 9-inch intensifier

A prospective randomized study was undertaken to evaluate the role of intraarterial digital subtraction angiography (IADSA) in the study of peripheral vascular disease. Patients underwent either conventional film-based angiography alone, digital subtraction angiography (DSA) alone, or a combined study. With a 9-inch image intensifier, DSA alone resulted in cost savings of film and contrast material but required a significantly longer examination period than the other groups and an increased iodine dose per examination. When the images were analyzed by a radiologist and a vascular surgeon, the DSA studies provided less detail in the aortoiliac region than the other techniques but had advantages in demonstrating the runoff vessels. IADSA examination should not replace conventional arteriography in patients with peripheral vascular disease but has a useful complementary role.     

Digital substraction angiography in the evaluation of intracranial and extracranial vascular disease

Digital subtraction angiography (DSA) is a method of visualizing the vessels of the body with the intravenous injection of contrast material. Improvements in computers, television systems, and image intensifiers have contributed to the increased image quality of DSA. With DSA, the vessels such as the carotid bifurcations and the intracranial vasculature can be visualized with a 2–3% concentration of contrast material, while with conventional angiography, the concentration of contrast in vessels is 40–50%. Using IV DSA, visualization of the carotid bifurcations is of good or excellent quality 85% of the time. In a high percentage of these cases, IV DSA replaces conventional angiography, although for imaging of the intracranial vessels, IV DSA is not as good as conventional angiography. In most tumor patients, however, conventional intracranial angiography is not needed because IV DSA combined with computed tomography gives sufficient information.     

Ocular lens dose in cerebral vascular imaging

Ocular lens dose was considered with respect to cerebral vascular imaging, using both digital subtraction angiography (DSA) and conventional angiography. A dose measurement study is described in which doses were found to be minimal (0.327 cGy) in DSA, but high (60 cGy) using conventional techniques. The use of an undercouch tube in DSA and an increased focus-lens distance, when compared with the conventional angiographic approach were considered the major factors contributing to the difference in lens dose. The implications for selection of technique are discussed.     

CO2—DSA的临床应用研究

目的：探索二氧化碳气体作为血管造影剂的临床应用效果。材料方法：对１６例患者行二氧化碳数字减影血管造影（ＣＯ２－ＤＳＡ）。其中肝动脉造影８例，腹主动脉造影１例，股动脉造影２例，直接门静脉造影３例，肾静脉造影２例，并与同一患者碘剂造影比较。结果：在８例肝肿瘤中，ＣＯ２－ＤＳＡ显示肝动脉－门静脉瘘（ＡＰＦ）６例（６／８），而碘剂显示１例（１／８）。ＣＯ２－ＤＳＡ显示肝内小动脉分支及肿瘤染色不如碘造影剂。但腹主动脉造影、股动脉造影和直接门静脉造影图像较满意，且副作用小。结论：ＣＯ２是一种安全的血管造影剂。ＣＯ２－ＤＳＡ可得到准确、有价值的血管图像，且危险性小。它是显示肝ＡＰＦ的可靠方法     

Digital subtraction angiography in interventional radiology

Intraarterial digital subtraction angiography (DSA) was used an an adjunct to interventional vascular procedures (embolotherapy and transluminal angioplasty) in 56 patients. The advantages of intraarterial DSA include improved contrast resolution, instantaneous subtraction capability, and immediate image availability. A considerable reduction in contrast dose and concentration, procedure time, and patient discomfort can be expected when interventional vascular procedures are performed with the assistance of intraarterial DSA.     

Computer processed fluoroscopic images for digital intravenous renal angiography

We investigated intravenous digital angiography using computer processed fluoroscopic images. Computer processed fluoroscopy (CPF) was compared to conventional digital subtraction angiography (DSA) in 39 patients referred for renal vessel evaluation. For assessment of CPF the anterior-posterior images were compared with the corresponding digital subtraction angiograms. 79% percent of DSA and 71% of CPF studies were diagnostic. Peripheral injection of contrast medium caused deterioration of CPF images. Skin dose measurements were obtained in 24 patients. The median dose for DSA was 8.2 rad, compared to 1.1 rad for CPF. It is concluded that sophisticated algorithms should be investigated for digital angiography, so that high image quality can be achieved with a reduced radiation exposure.     

Intravenous digital subtraction angiography of the precerebral and cerebral arteries in patients with TIA. A comparison with conventional angiography

A study of the diagnostic utility of both intravenous digital subtraction angiography (IV-DSA) and conventional angiography of precerebral and cerebral arteries is presented. The series comprised 60 patients with TIA, who underwent the two procedures with a mean interval of 16 days. Conventional angiography was generally superior to IV-DSA, and this was particularly marked in the siphons and cerebral arteries. Only the excellent IV-DSA examinations obtained in a few patients with TIA could be accepted as final pre-operative procedures. Accurate imaging of the lesions and collateral flow pattern usually required intra-arterial injections, and intra-arterial DSA is now usually preferred.     

Failing hemodialysis access grafts: evaluation of complete vascular tree with 3D contrast-enhanced MR angiography with high spatial resolution: initial results in 10 patients

Ten patients with failing hemodialysis access underwent contrast material-enhanced magnetic resonance (MR) angiography within 7 days before digital subtraction angiography (DSA). MR angiography was performed at 1.5 T by using a multistation multiinjection three-dimensional technique, and contrast material was injected via intravenous cannula. In all patients, MR angiographic images displayed the complete arterial inflow tract from the subclavian artery and access proper. The complete venous outflow tract up to the superior caval vein could be evaluated in all but one patient. DSA showed hemodynamically significant stenoses in 13 segments. MR angiography depicted all 13 stenoses and two false-positive findings, resulting in sensitivity of 100% and specificity of 94%.     

Digital subtraction angiography of the extremities using table translation

Digital subtraction angiography (DSA) of the extremities has been performed with both intravenous and intraarterial injections of contrast material. Intravenous studies are usually site specific and are limited by contrast material load; a complete intraarterial study with multiple injections of contrast material may be time consuming. A feasibility study to evaluate a DSA technique that would allow table translation and imaging of two contiguous regions following a single injection of contrast material--bolus-chase DSA--was performed. Forty-five examinations were performed, 13 intravenously and 32 intraarterially. Twelve intravenous and 16 intraarterial DSA examinations were totally satisfactory. Inadequate studies were predominantly caused by slow arterial clearance of contrast material in the distal calf and by operator error. Compared with conventional DSA, anatomic studies of lower-extremity vessels could be obtained faster and with lower contrast material loads using bolus-chase DSA.     

The application of matched filtering to contrast material dose reduction in digital subtraction angiography

Temporal filtering methods were applied to a 50% reduction of contrast material dose in intravenous digital subtraction angiography (DSA). The performance of matched filtering was reviewed, indicating a 50% reduction of noise through the integration of an entire (greater than 10 sec) DSA image sequence spanning the contrast material bolus arrival and washout. Used in conjunction with 50% contrast material dose reduction, matched filtering could provide final iodine signal-to-noise ratios (SNR) comparable to those of conventional DSA. Half-contrast-material-dose (20 ml) filtered DSA runs were compared with full-contrast-material-dose (40 ml) unfiltered runs for 5 carotid, 2 cerebral, and 4 peripheral studies. In all but 2 studies, the half-contrast-material-dose runs were judged to be diagnostic. In all 4 peripheral studies and in some of the 7 carotid and cerebral studies the 20-ml results were judged to be equivalent to the 40-ml results. It is concluded that the half-contrast-material-dose temporally filtered approach is appropriate for peripheral runoff studies. Matched filtering was experimentally compared with simple integrated remasking. If the identical image sequence was used for each, the two had virtually identical performance for integration times less than 10 sec, consistent with theoretical predictions. Two other applications of matched filtering, SNR enhancement and x-ray exposure reduction, are discussed schematically.     

The AAPM/RSNA physics tutorial for residents: digital fluoroscopy.

A digital fluoroscopy system is most commonly configured as a conventional fluoroscopy system (tube, table, image intensifier, video system) in which the analog video signal is converted to and stored as digital data. Other methods of acquiring the digital data (eg, digital or charge-coupled device video and flat-panel detectors) will become more prevalent in the future. Fundamental concepts related to digital imaging in general include binary numbers, pixels, and gray levels. Digital image data allow the convenient use of several image processing techniques including last image hold, gray-scale processing, temporal frame averaging, and edge enhancement. Real-time subtraction of digital fluoroscopic images after injection of contrast material has led to widespread use of digital subtraction angiography (DSA). Additional image processing techniques used with DSA include road mapping, image fade, mask pixel shift, frame summation, and vessel size measurement. Peripheral angiography performed with an automatic moving table allows imaging of the peripheral vasculature with a single contrast material injection.     

数字化摄影技术在非血管性介入术中的应用价值

目的　探讨数字化摄影技术在非血管性介入术中的应用价值及其特点。方法　搜集 2 0 4例次非血管性介入造影片 ,其中利用DSA组 12 6例次 ,数字化胃肠组 (CF) 78例次。根据其造影显影情况 ,图像质量 ,按两组进行观察、分析、评估、统计。结果　非血管性介入成像中 ,被检部位管腔充盈满意。管壁显示清楚者 ,DSA组有 10 4例次 ,占本组的 82 %。CF组有 6 6例次 ,占 85 %。对DSA组与CF组进行 χ2 检验 ,χ2 =7.32 6× 10 -4 (P >0 .0 5 )。结论　数字化摄影技术在非血管性介入术中与DSA有类似的图像清晰度。同时 ,在非血管性介入术中不需要快速的大量的连续摄影 ,利用数字化技术 ,用CF机作非血管造影 ,有一定的优越性     

Digital subtraction angiography for preoperative evaluation of extremity tumors

A retrospective study was undertaken to evaluate the role of digital subtraction angiography (DSA) in the surgical planning of musculoskeletal neoplasms. Thirteen patients with primary bone and soft-tissue tumors were examined by CT and DSA. Three patients also had conventional angiography. DSA yielded surgically useful information in 10 patients, comparable to that expected from conventional angiography. DSA was most helpful in demonstrating the presence or absence of major vessel involvement by tumor when this could not be ascertained definitely on CT. Demonstration of mass extent by CT was accurate in 11 patients. Results of this study suggest that the combination of CT and DSA is useful in the preoperative evaluation of selected extremity tumors and should diminish the need for conventional angiography.     

Contrast agent nephrotoxicity: comparison of ionic and nonionic contrast agents

The effects on glomerular and proximal tubular function of an ionic contrast agent (sodium meglumine diatrizoate) and a nonionic agent (iopamidol) were compared in 34 patients with normal renal function. The patients received large doses (2.5 ml/kg body weight) of contrast material for IV digital subtraction angiography. Urine samples, collected before, immediately after, and on the first and third days after digital subtraction angiography, were analyzed for albumin, alanil-aminopeptidase, alpha-glucosidase, and beta-2-microglobulin. The changes noted were mild and of short duration with both contrast agents, despite the high dose given. These results suggest that, at least as far as renal toxicity is measured by these tests is concerned, ionic monomers can be safely used instead of more expensive nonionic media in procedures, such as digital subtraction angiography, that require high doses of contrast material.     

Small hepatocellular carcinoma: diagnosis with US angiography with intraarterial CO2 microbubbles.

Ultrasonographic (US) angiography enhanced with intraarterial CO2 microbubbles, a contrast material used in US imaging, was performed of 103 histologically proved hepatocellular carcinomas (HCCs) smaller than 3 cm in diameter in 95 patients. The detection rate for hypervascular HCC with US angiography was compared with the rate of detection with conventional angiography, digital subtraction angiography (DSA), and computed tomography (CT) after intraarterial injection of iodized oil. Sensitivity in detection of hypervascular HCCs with US angiography was 86% (89 of 103 HCCs), compared with 63% (44 of 70 HCCs) detected with conventional angiography, 70% (23 of 33 HCCs) with DSA, and 82% (75 of 91 HCCs) with CT with iodized oil. US angiography depicted small hypervascular HCCs, especially those less than 1 cm in diameter, and helped clarify vascularity as isovascular or hypovascular in angiographically undetectable HCCs. Findings at US angiography assisted the choice of a therapeutic strategy for treatment of HCC, such as transarterial therapy, percutaneous ethanol injection therapy, or resection.