Conventional Intraarterial Digital Subtraction Angiography Research Articles

Intravenous versus intra-arterial digital subtraction angiography: Occlusion rate and complication assessment of experimental aneurysms after flow diverter treatment in rabbits.

Conventional intra-arterial digital subtraction angiography, which requires surgical exposure and ligation of the femoral or carotid artery, is a limited method of evaluating elastase-induced aneurysms in New Zealand white rabbits. The purpose of this study was to assess aneurysm morphology, occlusion rates and complications after flow diverter treatment comparing intravenous and intra-arterial digital subtraction angiography. We previously published a preclinical study in which we evaluated the occlusion rates of elastase-induced aneurysms after treatment with a prototype flow diverter, by using intra-arterial digital subtraction angiography at three months ( n = 9) and six months ( n = 9). In addition to that intravenous digital subtraction angiography before treatment, after one month (early follow-up group) and after three months (late follow-up group) was performed. Occlusion rates were compared within the two groups by means of residual contrast filling. Baseline aneurysm characteristics revealed no significant differences between intra-arterial digital subtraction angiography and intravenous digital subtraction angiography. Aneurysm occlusion rates in both follow-up groups using intravenous digital subtraction angiography were significantly higher compared to intra-arterial digital subtraction angiography (early follow-up group: intravenous digital subtraction angiography (one month) versus intra-arterial digital subtraction angiography (three months); p = 0.03 and late follow-up group: intravenous digital subtraction angiography (three months) versus intra-arterial digital subtraction angiography (six months); p = 0.04). Intravenous digital subtraction angiography is feasible to detect and reproduce device occlusions, in-stent stenosis and post-stent stenosis. Intravenous digital subtraction angiography can not give a sufficient statement on the aneurysm occlusion process compared to intra-arterial digital subtraction angiography and is therefore not recommended for imaging follow-up after flow diverter treatment in rabbits. Regarding untreated aneurysms and complications like device occlusions, in-stent stenosis and post-stent stenosis intravenous digital subtraction angiography proofed to be a good alternative to intra-arterial digital subtraction angiography in our study.

Intracranial Stent Restenosis Diagnosed on Routine Duplex Follow-Up Investigation: Fig 1.

We read with great interest the article of Turk et al,[1][1] in which the authors describe their experience with restenoses after intracranial stent placement. In this article, most of the restenoses were diagnosed by means of conventional intra-arterial digital subtraction angiography (DSA) on

Angiographic CT with intravenous administration of contrast medium is a noninvasive option for follow-up after intracranial stenting

Intracranial angioplasty and stenting (ICAS) is a therapeutic option in symptomatic intracranial atherosclerotic disease. Adequate follow-up examination is necessary to exclude in-stent restenosis. Conventional intraarterial digital subtraction angiography (ia-DSA) is the current gold standard, but it is an invasive technique and carries the risk of neurological complications. Angiographic CT (ACT) is a new technique that provides a volume dataset of the highest spatial resolution and high contrast resolution derived from a rotational acquisition of a c-arm-mounted flat-panel detector. The feasibility of ACT with intravenous administration of contrast medium (iv-ACT) for follow-up after ICAS is demonstrated. In two patients iv-ACT was performed as a follow-up examination 12 months after ICAS. High-resolution volume data from the rotational acquisitions were processed to provide delineation of the stent lumen as well as imaging of the brain parenchyma and vessels. In both patients the patency of the stent lumen was assessed successfully. In addition, all other brain vessels were displayed in a manner similar to their appearance on CT angiograms. The brain parenchyma was also adequately imaged in a manner similar to its appearance on CT images. We demonstrated the feasibility and diagnostic value of iv-ACT for follow-up imaging after ICAS. This new application has the potential to become the imaging method of choice after ICAS since it not only enables visualization of the patency of the stent lumen but also is minimally invasive and provides additional information about all brain arteries and the brain parenchyma.

Intra-venous digital subtraction angiography: an alternative method to intra-arterial digital subtraction angiography for experimental aneurysm imaging

Conventional intra-arterial digital subtraction angiography (IADSA), which necessitates surgical exposure and ligation of the femoral artery, is an invasive and expensive method of evaluation for experimental elastase-induced aneurysms in rabbits. The purpose of this study was to examine and validate intra-venous digital subtraction angiography (IVDSA) as an alternative to IADSA by comparing their diagnostic accuracies. We performed both IVDSA and IADSA for 24 elastase-induced saccular aneurysms in a rabbit model, 1 month following creation. Aneurysm sizes (neck, width and height) from both the IVDSA and IADSA procedures were evaluated and measured. Comparison of the aneurysm sizes between IVDSA and IADSA were performed with the Wilcoxon paired signed-rank test. All the aneurysms were seen clearly in both the IVDSA and IADSA techniques. Mean sizes of the IVDSA aneurysm neck, width and height were 3.41 +/- 0.80 mm, 3.61 +/- 0.93 mm and 8.07 +/- 2.11 mm, respectively. Mean sizes of the IADSA aneurysm neck, width and height were 3.43 +/- 0.80 mm, 3.66 +/- 0.92 mm and 8.16 +/- 2.25 mm, respectively. No significant difference was found in the sizes of the aneurysm neck, width and height between the two groups (P = 0.311, P = 0.086 and P = 0.258, respectively). IVDSA appears to be an alternative method for evaluating elastase-induced aneurysms in rabbits.

Imaging the vertebral artery

Although conventional intraarterial digital subtraction angiography remains the gold standard method for imaging the vertebral artery, noninvasive modalities such as ultrasound, multislice computed tomographic angiography and magnetic resonance angiography are constantly improving and are playing an increasingly important role in diagnosing vertebral artery pathology in clinical practice. This paper reviews the current state of vertebral artery imaging from an evidence-based perspective. Normal anatomy, normal variants and a number of pathological entities such as vertebral atherosclerosis, arterial dissection, arteriovenous fistula, subclavian steal syndrome and vertebrobasilar dolichoectasia are discussed.

Maximum stenosis of extracranial internal carotid artery: effect of luminal morphology on stenosis measurement by using CT angiography and conventional DSA.

To assess the luminal morphology of the extracranial internal carotid artery at three-dimensional (3D) computed tomographic (CT) angiography and how this factor affects measurement of maximum carotid arterial stenoses at conventional intraarterial digital subtraction angiography (DSA). Prospectively, conventional intraarterial DSA and 3D CT angiography were performed in 42 carotid arteries in 21 patients with suspected carotid artery disease. The longest axis length-perpendicular axis length (L/P) ratios of the arterial lumen on the cross-sectional images at the most stenotic area and distal nonstenotic area were analyzed by acquiring multiplanar reconstruction (MPR) images at 3D CT angiography. The maximum stenosis was measured at each modality with North American Symptomatic Carotid Endarterectomy Trial criteria. The L/P ratios in the most stenotic areas ranged from 1.0 to 3.2 (mean, 1.5 +/- 0.5 [SD]). The mean difference in maximum percentage of stenosis between the two modalities for L/P ratios of 2.0 or greater was significantly greater than that for L/P ratios of less than 1.5 (P < .05). Three carotid arteries with 70%-99% stenosis, with grades determined only with 3D CT angiography, had L/P ratios of 2.0 or greater. On MPR images at 3D CT angiography, the lumen of extracranial internal carotid artery stenosis showed a wide range of shapes. When a carotid artery has a high L/P ratio, the luminal morphology of the carotid artery stenosis may affect the assessment of maximum stenosis of the internal carotid artery at conventional DSA.

Duplex ultrasound, MR angiography and Conventional angiography in Carotid artery disease: interpretation of separate test results and their combinations.

107 Purpose: To compare duplex ultrasound (DUS) and MR angiography (MRA) with conventional intra-arterial digital subtraction angiography (DSA) in patients with carotid artery disease. Methods: Between 1996 and 2000 375 consecutive patients with symptomatic carotid artery stenosis undergoing evaluation prior to endarterectomy were included. All patients with a peak systolic velocity (PSV) > 150 cm/sec measured on DUS subsequently underwent DSA and MRA. In the last phase of our study a subgroup of 40 patients additionally underwent contrast-enhanced MRA (CE-MRA). Standardized cutoff criterions based on PSV s were used to asses the degree of stenosis with DUS. The degree of stenosis on MRA was analyzed by means of the criteria used in the North American Endarterectomy Trial (NASCET). DSA served as the standard of reference. Results: DUS analyzed with standardized PSV criterions resulted in a sensitivity of 90% and a specificity of 83% in identifying severe ICA stenosis (70–99%). Stenosis measurements (NASCET) carried out on 3D-TOF MR angiograms yielded a sensitivity of 90% and a specificity of 84%. MRA had a tendency to overestimate the degree of stenosis compared with DSA. Combining MRA and DUS results, agreement between these two modalities (80% of carotids) gave a sensitivity of 98% and a specificity of 90%. In case of disagreement these numbers strongly decreased precluding meaningful diagnosis, MRA however performed slightly better than DUS did. Preliminary results of CE-MRA indicated good visibility, decrease of artifacts and accurate diagnostic performance. Conclusions: Both DUS and MRA seem accurate diagnostic tests to detect carotid artery stenosis using DSA as the standard of reference. MRA has the tendency to overestimate stenosis. Combining test results gives additional value in diagnostic outcome. Agreement between DUS and MRA results in higher sensitivity and specificity then disagreement between these modalities does. In case of disagreement MRA performs better then DUS, but DSA still seems recommendable. CE-MRA shows promising preliminary results.

Duplex ultrasound, MR angiography and Conventional angiography in Carotid artery disease: interpretation of separate test results and their combinations.

107 Purpose: To compare duplex ultrasound (DUS) and MR angiography (MRA) with conventional intra-arterial digital subtraction angiography (DSA) in patients with carotid artery disease. Methods: Between 1996 and 2000 375 consecutive patients with symptomatic carotid artery stenosis undergoing evaluation prior to endarterectomy were included. All patients with a peak systolic velocity (PSV) &gt; 150 cm/sec measured on DUS subsequently underwent DSA and MRA. In the last phase of our study a subgroup of 40 patients additionally underwent contrast-enhanced MRA (CE-MRA). Standardized cutoff criterions based on PSV s were used to asses the degree of stenosis with DUS. The degree of stenosis on MRA was analyzed by means of the criteria used in the North American Endarterectomy Trial (NASCET). DSA served as the standard of reference. Results: DUS analyzed with standardized PSV criterions resulted in a sensitivity of 90% and a specificity of 83% in identifying severe ICA stenosis (70–99%). Stenosis measurements (NASCET) carried out on 3D-TOF MR angiograms yielded a sensitivity of 90% and a specificity of 84%. MRA had a tendency to overestimate the degree of stenosis compared with DSA. Combining MRA and DUS results, agreement between these two modalities (80% of carotids) gave a sensitivity of 98% and a specificity of 90%. In case of disagreement these numbers strongly decreased precluding meaningful diagnosis, MRA however performed slightly better than DUS did. Preliminary results of CE-MRA indicated good visibility, decrease of artifacts and accurate diagnostic performance. Conclusions: Both DUS and MRA seem accurate diagnostic tests to detect carotid artery stenosis using DSA as the standard of reference. MRA has the tendency to overestimate stenosis. Combining test results gives additional value in diagnostic outcome. Agreement between DUS and MRA results in higher sensitivity and specificity then disagreement between these modalities does. In case of disagreement MRA performs better then DUS, but DSA still seems recommendable. CE-MRA shows promising preliminary results.

Maximum Internal Carotid Arterial Stenosis: Assessment with Rotational Angiography versus Conventional Intraarterial Digital Subtraction Angiography

To assess how often rotational angiography depicts more severe internal carotid arterial stenosis compared with conventional intraarterial digital subtraction angiography (DSA) in two or three projections and how frequently this factor may affect patient treatment. Rotational angiography (16 or 32 projections) was performed in addition to DSA in 47 stenotic internal carotid arteries (ICAs) in 38 symptomatic patients. ICA stenosis was measured independently at DSA and at rotational angiography with North American Symptomatic Carotid Endarterectomy Trial criteria. The degree of stenosis was categorized as 0%-29%, 30%-49%, 50%-69%, or 70%-99%. In three ICAs, rotational angiography was nondiagnostic. In 28 of the remaining 44 ICAs, the degree of stenosis was categorized similarly with DSA and rotational angiography, whereas with rotational angiography, 15 ICAs were classified one category higher and one ICA was classified two categories higher, owing to the increased number of projections available. Seventy percent to 99% stenosis was demonstrated in 18 ICAs with DSA and in 25 ICAs with rotational angiography. Thus, rotational angiography could have facilitated a change in the optimal treatment (from nonsurgical treatment to carotid arterial endarterectomy) in seven ICAs. Compared with DSA in two or three projections, rotational angiography frequently depicts more severe ICA stenosis. This indicates a limitation of DSA in depicting the maximum ICA stenosis.

Magnetic resonance angiography of renal transplants

Stenosis of the artery of transplanted kidneys is an important cause of graft dysfunction. Diagnosis and follow-up of this condition normally requires intraarterial digital-subtraction angiography (IADSA), which is invasive and may cause complications. A possible alternative to IADSA is magnetic resonance angiography (MRA), and we have assessed this technique in 50 renal transplant patients who were referred for investigation of possible renal arterial stenosis. In every patient, MRA was compared prospectively with conventional IADSA. Compared with IADSA, MRA had a sensitivity of 83% and a specificity of 97%, and when all images were graded retrospectively for severity of stenosis, the two techniques showed a significant correlation ( r=0·74, p<0·001). MRA can provide an accurate image of the renal transplant artery in a non-invasive manner with a high sensitivity and specificity.