Digital arteriography of the lower limbs by sequential, automatic table translation. Feasibility. Preliminary results

Digital subtraction angiography (DSA) as a method of evaluating lower limb arteries required examination of one limb at a time up to now. Moreover repeated injections of contrast material were necessary. This problem was mainly due to the relative small image intensifier field available and to the difficulty of repositioning the patient between mask and image acquisition. The authors report the preliminary results obtained with 24 patients studied on angiographic unit equipped with: A DSA system (DG 300-CGR) using 512 X 512 matrix size, an angiographic table (Angix M 200) allowing an automatic sequential translation, a removable image intensifier using a 16 inch field below the table. Thus, all those characteristics allow DSA of lower limb arteries. Only one injection of contrast material (Ioxaglate: 80 ml at 8-10 ml/second) was used per procedure. This, usually, allows good quality examination of lower limb arteries.     

Multidetector CT angiography of peripheral vascular disease: a prospective comparison with intraarterial digital subtraction angiography

OBJECTIVE: The purpose of this study was to determine the accuracy of CT angiography using a multidetector scanner in the evaluation of patients with peripheral vascular disease. SUBJECTS AND METHODS: Eighteen patients with peripheral vascular disease who were referred for elective digital subtraction angiography (DSA) also underwent CT angiography. We scanned patients from the level of the superior mesenteric artery to the pedal arteries in a single helical scan. CT angiograms were produced using maximum-intensity-projection reconstructions. Findings were graded according to six categories: 1, normal (0% stenosis); 2, mild (1-49% stenosis); 3, moderate (50-74% stenosis); 4, severe (75-99% stenosis); 5, occluded; and 6, nondiagnostic. CT angiography findings were compared with DSA findings for each arterial segment. RESULTS: We found agreement for the degree of stenosis in 77.7% of the arteries and discrepancy for 22.3% of the arteries when all categories were considered. Grouping the six categories according to the threshold for treatment (categories 1 and 2 as one group and categories 3, 4, and 5 as the second group) resulted in an agreement of 91.95%. Compared with DSA, CT angiography yielded a sensitivity of 90.9% and a specificity of 92.4%. CONCLUSION: Multidetector CT angiography is an accurate, noninvasive technique for the imaging of peripheral vascular disease.     

Tomographic digital subtraction angiography: initial clinical studies using tomosynthesis. Work in progress

We have developed a method for acquiring multiple tomographic subtraction images using a rapid, repetitive, circular tomographic motion. The method combines the principles of digital subtraction angiography (DSA) and electronic tomosynthesis. Fifteen patients were examined with the technique using single intravenous bolus injections of contrast material. The image sequence obtained during each injection was first processed with a nontomographic mask subtraction, and the result was then compared with the tomographic DSA scans synthesized from the same sequence. The effective section thickness was approximately 0.5 cm, with each section being 0.5-1.0 cm apart. Twelve of the intravenous DSA scans provided the necessary diagnostic or clinically useful information. Two of the three nondiagnostic scans were caused by avoidable technical reasons. In eight cases, the tomographic DSA scans were superior in quality to the nontomographic scans, exhibited significantly less artifact from patient motion and overlying bowel gas, and were effective in separating overlapping vessels. Tomosynthesis permits multiple electronic imaging of the area of interest without reinjection of contrast material and appears to be more informative than nontomographic intravenous DSA imaging.     

Subtracted versus non-subtracted digital imaging in peripheral angiography

Digital subtraction angiography (DSA) plays an important role in the management of vascular diseases of the lower extremities. A disadvantage is the lack of an automatically moving table top. We used a 1,024 x 1,024 matrix with a large-screen intensifier system and an automated "stepping" facility. In 161 examinations of the arteries of the lower extremity digital peripheral arteriography was performed with and without the subtraction technique. We compared the influence of different iodine concentrations in DA and DSA. Peripheral DA proved to be equal to peripheral DSA in the region of the pelvis, thigh and knee, with no adequate contrasting being obtained merely in the region of the lower leg arteries in about 45%. It is necessary to use contrast medium at a concentration of 300 mg I/ml. The installation of an automated "stepping" facility reduces the amount of contrast medium needed and the exposure time.     

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.     

Routine evaluation of arteriopathies of the lower extremities by digital subtraction angiography

Intravenous digital subtraction angiography (DSA) was performed in 119 patients with lower extremity ischemia using a 14" amplifier. Four injections of contrast medium were usually necessary for a complete evaluation of this vascular region. Images of good quality were obtained in most cases; movement artifacts and a faint opacification accounted for any poor results, which occurred mainly under the knee. The technique of pixel shifting turned out to be very useful to remove movement artifacts. The "measuring field" allowed us to minimize the problem of the inhomo geneous saturation of the amplifier. In 8% of the cases an intra-arterial DSA has been performed after an unsatisfactory intravenous examination. Conventional angiography appears to be no longer necessary.     

Pure and diluted contrast media in the visualization of the portal venous system using digital angiography

We report the results of intra-arterial digital subtraction angiography (DSA) in 100 patients with portal hypertension. The portal venous system was evaluated; all patients underwent angiography of the celiac and superior mesenteric arteries before surgery. Forty-four of them were also examined after Warren splenorenal shunts. Therefore, a total of 144 exams was evaluated. The authors always employed low-osmolality ionic and non-ionic contrast media (iodine concentration: 300-350 mg/ml). In 70 cases pure contrast medium was injected (20-25 ml); in the extant 74 cases it was diluted with an equal volume of saline solution (osmolality and iodine concentration reduced by 50%). Intra-arterial DSA always visualized portal venous system, collateral circulation, shunt location and postoperative changes. The major advantage of intra-arterial DSA is the smaller amount of contrast medium injected, so that local and systemic side effects are rare. According to our experience, it is best to dilute the contrast medium and inject the same amount as in conventional angiography, at the same rate. Other well-known advantages of intra-arterial DSA are quicker execution, less injury to arteries using smaller-caliber catheters, and low cost. The major disadvantage of intra-arterial DSA, as it appeared also in our study, is the field size of the intensifier, which in our case was limited to 6-9 inches. This is an insufficient coverage for the whole portal system to be studied, and some contrast medium injections become therefore necessary. An average of 3 injections were given to each patient. This problem reduces the advantage of less contrast medium per injection. At any rate, even though intra-arterial DSA exhibits this limitation, it can nevertheless yield important information in the pre- and postoperative evaluation of patients with portal hypertension.     

The value of digital subtraction angiography in peripheral vascular diseases

The iliac and subclavian arteries and their distal branches were studied by digital subtraction angiography (DSA) in 79 patients and the results compared with conventional angiograms for 35 patients. Techniques, results, advantages and disadvantages are described. DSA (both intravenous and intra-arterial) looks very promising in the diagnosis of peripheral vascular disease.     

Magnetic resonance angiography in the follow-up of distal lower-extremity bypass surgery: comparison with duplex ultrasound and digital subtraction angiography

PURPOSE: The danger of limb loss as a consequence of acute occlusion of infrapopliteal bypasses underscores the requirement for careful patient follow-up. The objective of this study was to determine the agreement and accuracy of contrast material-enhanced moving-table magnetic resonance (MR) angiography and duplex ultrasonography (US) in the assessment of failing bypass grafts. In cases of discrepancy, digital subtraction angiography (DSA) served as the reference standard. MATERIALS AND METHODS: MR angiography was performed in 24 consecutive patients with 26 femorotibial or femoropedal bypass grafts. Each revascularized limb was divided into five segments--(i) native arteries proximal to the graft; (ii) proximal anastomosis; (iii) graft course; (iv) distal anastomosis; and (v) native arteries distal to the graft-resulting in 130 vascular segments. Three readers evaluated all MR angiograms for image quality and the presence of failing grafts. The degree of stenosis was compared to the findings of duplex US, and in case of discrepancy, to DSA findings. Two separate analyses were performed with use of DSA only and a combined diagnostic endpoint as the reference standard. RESULTS: Image quality was rated excellent or intermediate in 119 of 130 vascular segments (92%). Venous overlay was encountered in 26 of 130 segments (20%). In only two segments was evaluation of the outflow region not feasible. One hundred seventeen of 130 vascular segments were available for quantitative analysis. In 109 of 117 segments (93%), MR angiography and duplex US showed concordant findings. In the eight discordant segments in seven patients, duplex US overlooked four high-grade stenoses that were correctly identified by MR angiography and confirmed by DSA. Percutaneous transluminal angioplasty was performed in these cases. In no case did MR angiography miss an area of stenosis of sufficient severity to require treatment. Total accuracy for duplex US ranged from 0.90 to 0.97 depending on the reference standard used, whereas MR angiography was completely accurate (1.00) regardless of the standard definition. CONCLUSION: Our data strongly suggest that the accuracy of MR angiography for identifying failing grafts in the infrapopliteal circulation is equal to that of duplex US and superior to that of duplex US in cases of complex revascularization. MR angiography should be included in routine follow-up of patients undergoing infrapopliteal bypass surgery.     

64层螺旋CT血管成像诊断脊髓血管畸形的价值

目的 探讨64层螺旋CT 血管成像(CTA)对脊髓血管畸形的诊断价值.方法 经临床和MR检查拟诊为脊髓血管畸形的15例患者进行了CTA.所有患者均在1周内进行了DSA检查.其中4例行于术治疗.将CTA图像与DSA和手术所见进行对照,从判定畸形的类型、显示病变累及的范围、供血动脉、引流静脉和可能存在的瘘口等方面,对CTA图像进行评价.结果 15例脊髓血管畸形经DSA和手术确诊,分别为6例髓内动静脉畸彤、2例髓周动静脉瘘、3例硬脊膜动静脉瘘和4例Cobb综合征.CTA对15例患者的分类和对病变累及范围的判断与DSA结果一致.CTA清晰显示了病变的主要供血动脉和引流静脉.5例动静脉瘘中4例CTA判断的瘘口位置与DSA所见一敛,另1例为复杂血管畸形,瘘口难以辨别.CTA还清晰显示了4例Cobb综合征位于椎旁和皮下的畸形血管团.结论 64层螺旋CTA可以判定脊髓血管畸形的类型,快速、无创地显示其主要病变特征,可作为该病的筛查手段.     

Digital subtraction angiography in the preoperative evaluation of patients with a renal tumor

Inguinal intravenous digital subtraction angiography (DSA) was performed in 14 patients referred for preoperative evaluation of a renal tumor previously diagnosed by CT and ultrasound. Conventional cavography and aortography were used as reference methods for comparison. Both DSA and conventional angiography were carried out following selective arterial injection to the abnormal kidney. The diagnostic value of DSA in examination of the inferior vena cava was generally comparable to that of conventional cavography. Intravenous aortography was unsuccessful in 2 patients due to motion artifacts. In all other patients, the information provided by DSA regarding the aorta, renal arteries and renal veins was similar to that of conventional aortography. Intrarenal vascular detail, however, was far superior on conventional films and was only useful with DSA when intra-arterial injection was implemented. In one of the 12 diagnostic examinations, localization of the renal mass could not be established by intravenous DSA, but was possible in all others. The inguinal approach advocated permits simultaneous inferior vena cavography and intravenous aortography with one single injection of contrast medium; the method is less traumatic than aortography , and does not require hospitalization of the patient. DSA may also be of value in those cases still requiring selective catheterization of the renal arteries, i.e. for angiotherapy . Intra-arterial DSA then allows reduction of the amount of contrast medium and a rapid processing of the images without detriment to the quality of the examination.     

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.     

Diagnostic performance of digital subtraction angiography (DSA) and magnetic resonance angiography (MRA): preliminary results in vascular occlusive disease of the abdominal and lower-extremity arteries

Fifty-nine patients with occlusive disease of the aorto-iliac and femoro-popliteal arteries were investigated prospectively by intravenous (IV) or intraarterial (IA) digital subtraction angiography (DSA) and magnetic resonance angiography (MRA). This was accomplished using a two-dimensional (2D) Inflow- (59 patients) and a 2D Phase Contrast- (RSE — rapid sequential excitation) sequence (29 patients). The spectrum of pathology included stenoses < 50%, stenoses 50–89%, stenoses 90–99%, occlusions, aneurysms and status following reconstructive surgery. MRA- and DSA-examinations were evaluated by four radiologists. The diagnoses were made by consent decisions of a radiologist and a vascular surgeon based on clinical and radiological findings. Diagnostic performance of IA-DSA was superior to all other imaging modalities. Vascular delineation of 2D Inflow-MRA was comparable to that of IV-DSA. The image quality of RSE-MRA was not adequate for diagnosis. In conclusion, 2D Inflow-MRA is a promising method for evaluating abdominal and peripheral arteriosclerotic disease. Interpretation of MR-angiograms, however, requires profound knowledge of MRA-techniques, X-ray angiography and hemodynamics.     

Peripheral arteries in diabetic patients: standard bolus-chase and time-resolved MR angiography

PURPOSE: To prospectively determine the diagnostic performance of a combination of standard bolus-chase magnetic resonance (MR) angiography and MR angiography with time-resolved imaging of contrast kinetics (TRICKS) for depicting severity of peripheral vascular disease of the lower extremity, including the pedal arteries, in diabetic patients with digital subtraction angiography (DSA) as the reference standard. MATERIALS AND METHODS: An ethical committee approved this study; written informed consent was obtained from patients. Standard three-station and TRICKS MR angiography of the calf and foot were performed in 31 consecutive diabetic patients (23 men, eight women; mean age, 67 years; range, 43-81 years). Two readers separately assessed images of arterial segments as diagnostic or nondiagnostic and graded stenosis. Results were compared with those at DSA when the corresponding arterial segments were considered diagnostic at DSA. Wilcoxon signed rank test was used to determine if a significant difference between imaging techniques existed, and kappa statistics were used to determine interobserver agreement. RESULTS: The difference between standard MR angiography and DSA regarding the number of diagnostic segments in the thigh was not significant (P = .50). A significantly higher number of calf and foot segments was considered diagnostic at TRICKS MR angiography than at standard MR angiography (P < .025). Sixteen of 26 segments in the foot that were considered nondiagnostic at DSA were considered diagnostic at TRICKS MR angiography. Average sensitivity of standard MR angiography for depicting hemodynamically significant arterial stenosis was 84% (reader 1) and 83% (reader 2) in the thigh and 78% (reader 1) and 80% (reader 2) in the calf. For both readers, average specificity was 97% in the thigh and 90% in the calf. Sensitivity and specificity of TRICKS MR angiography in the calf and foot were improved compared with those at standard MR angiography. CONCLUSION: TRICKS MR angiography of the distal calf and pedal vessels is superior to standard MR angiography regarding the number of diagnostic segments and assessment of the degree of luminal narrowing.     

Comparison of intravenous digital subtraction angiography to conventional aortography in patients with abdominal aortic aneurysm

Evaluation of intravenous digital subtraction angiography (IV DSA) in patients with abdominal aortic aneurysm was performed by obtaining catheter aortograms immediately before DSA studies in ten patients. Diagnostic images were obtained in nine of ten digital subtraction examinations. Although repeat injections were necessary in six DSA and three conventional aortography cases for adequate imaging of both cephalad and caudal extension of the aneurysm, average contrast dose was 53 cc (62 cc in standard catheter studies). Renal artery stenosis was diagnosed by DSA in two of three vessels, multiple renal arteries were demonstrated by both modalities in two cases. Digital subtraction and conventional aortographic findings were proved at surgery. Intravenous DSA was shown to be useful in the preoperative evaluation of patients with abdominal aortic aneurysm. This work was supported in part by U.S. Public Health Service Grant No. HL07334.     

The Usefulness of Three-Dimensional Angiography with a Flat Panel Detector of Direct Conversion Type in a Transcatheter Arterial Chemoembolization Procedure for Hepatocellular Carcinoma: Initial Experience

The purpose of this study was to assess the usefulness of a three-dimensional (3D) angiography system using a flat panel detector of direct conversion type in treatments with subsegmental transcatheter arterial chemoembolization (TACE) for hepatocellular carcinomas (HCCs). Thirty-six consecutive patients who underwent hepatic angiography were prospectively examined. First, two radiologists evaluated the degree of visualization of the peripheral branches of the hepatic arteries on 3D digital subtraction angiography (DSA). Then the radiologists evaluated the visualization of tumor staining and feeding arteries in 25 patients (30 HCCs) who underwent subsegmental TACE. The two radiologists who performed the TACE assessed whether the additional information provided by 3D DSA was useful for treatments. In 34 (94.4%) of 36 patients, the subsegmental branches of the hepatic arteries were sufficiently visualized. The feeding arteries of HCCs were sufficiently visualized in 28 (93%) of 30 HCCs, whereas tumor stains were sufficiently visualized in 18 (60%). Maximum intensity projection images were significantly superior to volume recording images for visualization of the tumor staining and feeding arteries of HCCs. In 27 (90%) of 30 HCCs, 3D DSA provided additional useful information for subsegmental TACE. The high-quality 3D DSA with flat panel detector angiography system provided a precise vascular road map, which was useful for performing subsegmental TACE .of HCCs.     

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.     

Outpatient transbrachial arterial DSA using a 4F catheter for the clarification of extracranial vascular processes

Experience with intravenous digital subtraction angiography (DSA) has proven disappointing in the outpatient evaluation of cerebrovascular disease. Variations in cardiac output, vessel superimposition, patient motion and poor vascular opacification frequently combine to produce nondiagnostic examinations. To assess the safety of nonselective intra-arterial DSA performed from a brachial artery approach, the complications of 103 examinations, most of which (85%) were performed on outpatients, were prospectively studied. The injection of contrast material into the aorta was made through a 4F multiple side-hole pigtail catheter, inserted percutaneously from the brachial artery. Images were good or excellent in nearly all cases. No permanent neurovascular complications or local artery complications such as thrombosis requiring surgery were encountered and only a few minor complications occurred. We believe that transbrachial intraarterial DSA is a safe, simple and well-tolerated out-patient procedure that can yield reliable, definitive, and complete cerebrovascular studies in nearly all patients referred for the examination.     

Coarctation proximal to both subclavian arteries in an adult: diagnosis by intravenous digital subtraction angiography

Severe coarctation proximal to both subclavian arteries, a rare entity previously reported only once in an adult, was successfully diagnosed preoperatively using intravenous digital subtraction angiography (DSA). The significance of this rare condition and the value of intravenous DSA for aortography in a patient with no peripheral pulses is discussed.     

Contrast-Enhanced Magnetic Resonance Angiography MoBI-trak in the Study of Peripheral Vascular Disease

Purpose: To evaluate the diagnostic accuracy of contrast-enhanced magnetic resonance angiography (CE-MRA) MoBI-trak of peripheral vessels in patients with peripheral vascular disease who were candidates for digital subtraction angiography (DSA). Methods: Eleven patients underwent CE-MRA with automated table movement (MoBI-trak) using a 1.5 T superconducting magnet (Philips Gyroscan ACS NT) equipped with a Power Trak 6000 gradient. Contrast medium (Gd-DTPA) was administered in two sequential boluses-20 cm3 at 0.6 cm3/sec (starting phase) and 20 cm3 at 0.3 cm3/sec (maintenance phase)-using a MedRad Spectris automatic injector. DSA was the gold standard and was performed using a Philips Integris 3000, with a brilliance intensifier of 38 seconds. DSA and MRA were evaluated on printed films. Results: DSA provided 213 diagnostic assessments: 144 negative, 30 stenosis <50%, 5 stenoses in the 51-70% range, 12 stenoses in the 71-99% range and 22 occlusions. CE-MRA MoBI-trak sensitivity, specificity, positive and negative predictive value and diagnostic accuracy were 94.1%, 99.2%, 98.4%, 80.0% and 97.5%, respectively. Conclusions: Our work is in accordance with the literature. Using this technique MoBI-trak has been shown to be a reliable technique for the detection of peripheral vascular disease up to the trifurcation, although it underlines the necessity for more diagnostic investigation and improvements in the technique.