Intraarterial digital subtraction angiography: A comparative view

Intraarterial digital subtraction angiography (IA DSA) was performed in 122 patients undergoing a variety of diagnostic and interventional angiographic procedures. Owing to the increased contrast resolution of DSA, diluted contrast material in concentrations of from 12-19% could be employed, thereby significantly reducing contrast material doses compared to doses used with conventional film-screen angiography or intravenous DSA. Patient discomfort was convincingly reduced due to the injection of dilute contrast material. Subtracted digital images could be viewed immediately on a cathode ray tube (CRT) resulting in faster procedures with less catheter time. Savings in film costs relative to conventional angiography were also achieved.     

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     

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.     

Carbon dioxide contrast agent for CT arteriography: results in a porcine model

PURPOSE: To test the feasibility of carbon dioxide (CO(2))-enhanced computed tomographic (CT)-arteriography in an animal model. MATERIALS AND METHODS: Five domestic swine underwent digital subtraction angiography (DSA), conventional CT angiography with iodinated contrast material, and CO(2)-enhanced CT arteriography. For each CO(2)-enhanced DSA image series, 100 mL of pressurized CO(2) was injected at 1.3 bar. CT imaging was performed according to a standardized scan protocol (2 x 32 x 0.6 mm; 120 kV, 210 mAs(eff), 330 msec gantry rotation time). Iodinated contrast material was administered intravenously according to a biphasic injection protocol. For CO(2)-enhanced CT arteriography, CO(2) was administered intraarterially via a catheter placed in the juxtarenal aorta. An injection pressure of 0.65 bar (volume flow rate, 7.5 mL/sec) was applied. Images were assessed visually by two observers on a four-point grading scale. Absolute intraarterial attenuation values were measured. RESULTS: Image quality was rated to be the best for standard DSA. CO(2)-enhanced DSA was rated slightly superior to CO(2)-enhanced CT arteriography. No examination was considered to be nondiagnostic. The average multislice spiral CT (MSCT) scan duration was 7.9 sec +/- 0.6. The average amount of gas required for CO(2)-enhanced CT arteriography was 104 mL +/- 4, compared with 400 mL for CO(2)-enhanced DSA. Absolute attenuation values were significantly higher with CO(2)-enhanced CT arteriography (aorta, -928 HU +/- 39) than with standard CT angiography (490 HU +/- 40; P < .0001). CONCLUSIONS: CO(2)-enhanced CT arteriography is feasible. In a porcine model, this technique is capable of depicting the aortoperipheral vessels down to the lower limb. These results warrant further studies of the diagnostic value of CO(2)-enhanced MSCT arteriography for the detection of arterial pathologic processes.     

Intravenous digital subtraction angiography in patients with Aorto-arteritis (Takayasu's)

Aorto-arteritis is one of the commonest vascular diseases in China as well as in Japan and other parts of Asia. The results of digital subtraction angiography (DSA) in 50 patients with aortoarteritis are reported, and the merits and demerits of intravenous (IV) DSA in the diagnosis of this entity are evaluated. Among the 51 studies performed on 50 patients, IV DSA was used in 48, intraarterial (IA) DSA in 3, and good-to-excellent visualization was obtained in 96% of patients. Aorto-arteritis of varying severity and involving the thoraco-abdominal aorta, the iliac arteries, and other major branches was clearly demonstrated by IV DSA. IV DSA, as compared to our previous experience with conventional arteriography in this entity, may be substituted for conventional arteriography in most patients. A large dose of contrast media needed for a complete study is a major deficiency of IV DSA, and it also has limitations for showing the intrarenal arterial branches.     

二氧化碳数字减影血管造影技术现状及临床应用

目的：评价二氧化碳数字减影血管造影技术（ＣＯ２－ＤＳＡ）在临床上的应用和效果。材料和方法：对８５例患者行ＣＯ２－ＤＳＡ，包括肝、肾、脾、肠系膜上动脉造造影７５例，腹主及四肢动脉造影３例直接门静脉造影６例，肝静脉造影１例。采用与气体造影相适应注射方法、投照条件及后处理方法以取得较好困难，同时行碘剂造影对照。结果：ＣＯ２－ＤＳＡ可较好显示靶血管的主干及１、２级分支，且可引导介入插管，尽管对细微结构对照     

Digital subtraction angiography of the portal venous system

Venous-phase arteriography after celiac or superior mesenteric artery injection is the most common technique used to demonstrate portal venous anatomy, flow direction, and portal systemic shunts. Large-volume contrast material injections and intraarterial vasodilators or balloon occlusion technique are required for optimal examinations using film-screen recording. A technique for performing venous-phase arteriography with digital subtraction imaging after celiac and superior mesenteric artery injection is described. The major advantage of intraarterial digital subtraction technique in comparison to film-screen recording is sensitivity to intravascular iodine with a consequent reduction in contrast material load and examination time. Technical success is limited only by motion artifact and should approximate the 80%-90% figure achieved for intravenous digital subtraction angiography of the aortorenal vessels.     

Arterial DSA of liver masses

A total of 58 patients underwent intra-arterial hepatic DSA. 42 patients with hepatic masses were preselected by ultrasound or CT. In addition a conventional arteriography was performed in 34 of 58 cases. DSA without diagnostic quality occurred in 4 cases, in 4 other cases a diffuse metastatic disease of the liver was not detected in spite of good image quality. Comparing DSA with conventional angiograms our results demonstrated that DSA had a reduced imaging of intrahepatic small vessels but without negative influence on diagnostic value. Intra-hepatic DSA imaging could be improved using on-line image documentation, small size of image-intensifier and contrast material with an iodine concentration of 300 mg/ml. Advantages of DSA were observed in vascularized tumors and indirect splenoportograms. Contrast material with an iodine concentration of 200 mg/ml was sufficient for hepatic "vascular mapping" or demonstration of vascular diseases including main arteries.     

Optimized diagnostic angiography in high-risk patients with severe peripheral vascular disease.

Conventional arteriography remains the usual method for preoperative assessment of severe peripheral vascular disease (PVD). Unfortunately, many peripheral arteriograms are still performed with a suboptimal technique, which can cause significant diagnostic errors in patients with severe PVD. A suboptimal technique may be due to poor collimation (causing incorrect exposure and incorrect gray scale), excessive patient-film distance (magnification unsharpness), inadequate volume or density of contrast material, poor contrast resolution (screen-film arteriography), nonselective injection, patient movement, and pressure from restraints or incorrect patient position (failure to profile lesions, pseudo-occlusion from external pressure or plantar flexion). The technique of selective digital subtraction arteriography (DSA) allows one to avoid these errors. The superior contrast resolution of DSA allows use of lower concentrations of contrast material. Selective injection into the external iliac artery allows proper positioning and improves image quality. Demonstration of distal vessels is best achieved by using biplane arteriography. For patients with severe resting ischemia, especially those with diabetes, high-quality selective DSA is essential to ensure that all distal vessels suitable for distal bypass grafting are identified. When properly performed, selective DSA remains the investigation of choice for reliably demonstrating arterial anatomy in high-risk patients with severe PVD.     

Demonstration of pedal arterial arcades in occlusive arteriosclerotic disease. Conventional and digital subtraction angiography compared

Conventional arteriography, intraarterial digital subtraction angiography (DSA), and intravenous DSA were used in the evaluation of the patency of the pedal arterial arcades in 15 patients with advanced peripheral arteriosclerotic disease. Intraarterial DSA was found to be superior to conventional arteriography. In 12 of 15 patients, excellent or good results were achieved by intraarterial DSA compared with 5 or 15 patients examined by conventional arteriography. All intravenous DSA studies performed in 6 patients were classified as poor.     

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.     

Comparison of intra-arterial digital subtraction angiography and conventional filming in peripheral vascular disease

We studied a series of 114 patients with ischemic peripheral vascular disease angiographically by conventional film-screen (CF) and by intra-arterial digital subtraction (DSA) techniques. The quality of films and images was evaluated at four anatomic levels. We reached the following conclusions: a) in most patients a DSA study will suffice for diagnosis; b) an ability to see arteries was related to the film or image quality; c) in the pelvis, although most studies were of excellent quality, more CF than DSA were of excellent quality; d) in the thigh, both CF and DSA studies were mostly of excellent quality; e) in the leg and foot, more DSA than CF studies were of excellent quality; f) patients preferred DSA to CF studies; g) physician acceptance of DSA was mixed; and h) good patient hydration can reduce the potential renal complications of the larger contrast loads used in CF studies.     

Digital celiac arteriography

Sixty patients underwent intraarterial DSA with injection into the celiac artery for evaluation of various hepatic, pancreatic, and splenic lesions. Twenty of these patients also underwent conventional arteriography for comparison. Excellent images during the early arterial phase (free of bone superimposition and artifacts) were obtained with DSA. The late arterial and parenchymal phases of the examination were less definitive when compared with conventional angiography. The venous phases of the liver studies were good and compared favorably in contrast and resolution to conventional methods. In the late venous phase, good images of the portal system were obtained using a small amount of contrast medium. Respiratory movements and artifacts were overcome with postprocessing. Most of the studies were performed using the 12-inch mode of the image intensifier, which represents the best choice between the size of the field examined and the spatial resolution of the system. We believe that DSA is a suitable substitute for conventional angiography in most patients in whom celiac trunk angiography would be used.     

Digital subtraction angiography with an Isocon camera system: clinical applications

A new imaging system for digital subtraction angiography (DSA) was evaluated in 30 clinical studies. The image receptor is a 25 X 25 cm, 12 par gadolinium oxysulfate rare-earth screen whose light output is focused to a low-light-level Isocon camera. The video signal is digitized and processed by an image-array processor containing 31 512 X 512 memories 8 bits deep. In most patients, intraarterial DSA studies were done in conjunction with conventional arteriography. In these arterial studies, images adequate to make a specific diagnosis were obtained using half the radiation dose and half the amount of contrast material needed for conventional angiography. In eight intravenous studies performed either to identify renal artery stenosis or for evaluation of congenital heart anomalies, the images were diagnostic but objectionably noisy.     

An economic comparison between digital luminescence radiography and conventional film processing in intensive care medicine]

The costs of a conventional film-screen radiography daylight-system and storage-phosphor computed radiography (Fuji AC-1) are compared. In 1990, 3841 radiologic procedures (mostly portable chest X-rays) were performed in 3474 patients of a surgical intensive care unit. With conventional film-screen radiography 6.8% retakes were necessary for diagnostic or technical reasons. Comparing the fixed and variable costs of both systems conventional film-screen radiography was more economic under the given conditions of the test. It is concluded that computed radiography in intensive care patients has definite advantages in terms of image quality and reproducibility, however, in order to compete successfully in the economic turf CR has to be implemented in a picture archiving and communication system (PACS).     

Intra-arterial digital subtraction angiography

DSA is an imaging technique that should be integrated into a state-of-the-art angiographic system for proper application and utilization. This results in improvements in both efficiency and diagnostic accuracy. However, from the physician's viewpoint, the proper use of a DSA imaging facility mandates not only an understanding of angiographic principles as applied with conventional film-screen systems but also an in-depth understanding of the factors that affect DSA performance. In particular, factors affecting spatial resolution and contrast sensitivity are crucial. This knowledge has to be applied interactively and "on-line" to achieve optimal IA-DSA image quality.     

Nonselective digital subtraction angiography. Compact contrast material bolus for improved image quality

Digital subtraction angiography (DSA) examinations of major aortic branch vessels traditionally have been performed with aortic injections of dilute contrast material (70-150 mg I/mL) over approximately 2 seconds. This study examines a technique employing rapid boluses of undiluted contrast material (282-300 mg I/mL) in small volumes and compares the quality of the images to those obtained using conventional methods. Twenty intra-aortic DSA angiograms of the renal arteries were performed in 10 patients. In each patient, both compact bolus and conventional injections were performed. Injections of 12 or 15 mL of diatrizoate meglumine-60% at 30 mL/second (duration = 0.4 or 0.5 seconds) were compared with injections of 24 or 30 mL of diatrizoate meglumine-30% at 12 mL/second (duration = 2 seconds). Aside from injection technique and image projection, no other variables were altered, and the iodine loads were the same for the two injections in each patient. The images were paired and rated by four radiologists without knowledge of the technical parameters. The radiologists overwhelmingly preferred the images corresponding to the compact bolus technique (Chi-square analysis P less than .001). Visualization of the main renal arteries and the intrarenal branches was improved (P less than .001 for both). A reduction in misregistration artifact is suggested but not statistically significant. We conclude that image quality in nonselective, intra-arterial DSA can be improved without an increase in iodine dosage by the rapid administration of undiluted contrast material in small volumes.     

Use of digital subtraction angiography for evaluation of vascular access for hemodialysis

We used digital subtraction angiography (DSA) with conventional methods of contrast injection to evaluate 13 failing vascular accesses in 12 patients undergoing hemodialysis. DSA results were confirmed in all cases by surgical findings and/ or clinical follow-up. The DSA technique is extremely flexible and rapid and requires the injection of only small amounts of dilute contrast with much less patient discomfort. DSA is an excellent alternative to film screen angiography for the evaluation of vascular access complications.     

Digital urography using stimulable phosphor. An experimental study in the rabbit

In a urographic experimental study in six rabbits conventional film-screen images were compared with digitized images. Two digitized images were examined, one simulating the conventional film-screen combination, and one frequency modified. The nephrographic and excretory phases of four different doses of contrast medium (iohexol, 350 mg I/ml) were investigated in each rabbit (4, 2, 1, and 0.5 ml/kg body weight). No differences were found between the different doses of contrast medium for the two imaging systems. With digitized images the exposure (radiation dose) could be decreased to 12.5 per cent of the conventional film-screen combination without any loss of information.     

Imaging of the digital arteries: digital subtraction angiography versus conventional arteriography

A retrospective study of 95 patients was undertaken to compare digital subtraction angiography (DSA) and conventional arteriography of the hand. Eighty patients had conventional angiography and 15 had DSA. In comparison with conventional angiography, DSA is more cost-efficient and facilitates outpatient angiography. It provides images as acceptable as those of conventional angiography. We conclude that intra-arterial DSA is now the procedure of choice for angiographic mapping of the digital arteries.