Effect of the geometry of atherosclerotic carotid artery lesions on their angiography image--an arteriography study

Atherosclerotic lesions of the carotid arteries are frequently located eccentrically and are of asymmetric configuration. For their angiographic detection at least two orthogonal views are mandatory. The carotid bifurcations, the proximal internal carotid artery and the carotid siphon can be visualised free from vessel overlap only via often mandatory lateral views that must be obtained by selective arteriography (IA DSA). Smaller lesions and ulcerations of the carotid bifurcation area may be misinterpreted with nonselective IA DSA and IV DSA because of their geometry.     

Intravenous DSA examination of patients with suspected cerebral ischemia

We analyzed the role of intravenous digital subtraction angiography (DSA), with neck and intracranial views as a definitive pretherapy study, in patients who had symptomatic cerebral ischemia. Eighty-six patients, 25 of whom had subsequent carotid thromboendarterectomy, were examined. An adequate pretherapy intravenous DSA study allowed us to define each carotid bifurcation as either normal, having insignificant stenosis, or having significant stenosis, and the examination excluded significant tandem stenosis in the intracranial internal carotid arteries. Adequate pretherapy intravenous DSA studies were obtained in 73% of patients, including 50% of those in the presurgical group. Selective carotid arteriography was not required in these patients. Inadequate presurgical studies were predominantly due to plaque misregistration, inadequate projection, and superimposition that obscured the proximal internal carotid arteries. Selective carotid arteriography was performed in these patients prior to surgery. Inadequate studies prior to initiation of medical therapy were predominantly due to soft tissue misregistration artifact, and superimposition. Intravenous DSA is a valuable screening test and can be used to guide therapy in the majority of patients who have symptomatic cerebral ischemia.     

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.     

Digital radiography

DSA has quickly made the transition from an experimental examination performed in a research institution to a routine procedure performed in a community hospital. Diagnostic quality images for screening applications are obtained in over 90% of patients, and in many instances DSA is the only angiographic study that need be done.

The applications of IV DSA have broadened to encompass many angiographic procedures for which selective injections are not mandatory. When IA studies must be performed, digital equipment offers the advantages of speed, safety, and lessened patient discomfort. New technological developments will increase the advantages and applications.     

High definition imaging of carotid arteries using a standard commercial ultrasound "B" scanner. A preliminary report.

Sixteen carotid arteries in nine patients with transient ischaemic attacks and carotid bruits were examined by direct scanning grey scale ultrasound using a 10 HMz probe attached to a standard commercial apparatus. Findings using ultrasound were compared with a contrast arteriogram performed on the following day and, in two cases, with the surgical appearances during endarterectomy. Atheromatous plaques were demonstrated in five common carotid arteries by ultrasound. Arteriography failed to show proximal plaques in two common carotid arteries and extension of bifurcation disease into the adjacent common carotid in a third patient. Ultrasound detected four stenotic and one occluded internal carotid artery. One internal carotid artery with a 25% stenosis was shown by arteriography but not by ultrasound. Of the five external carotid stenoses, one with a minimal stenosis of less than 10% was not demonstrated. In all cases, stenoses in excess of 30% were shown by ultrasound. Surgical findings correlated more closely with details of the plaques as shown by ultrasound than by arteriography. It is suggested that ultrasound might be used to pre-select reliably those patients who would benefit from a contrast arteriogram and, thus, to protect those with normal carotid arteries from a potentially hazardous invasive investigation.     

Complementary roles of a noninvasive test battery and DSA in evaluating carotid artery disease

Initial comparisons of the results of digital subtraction angiography (DSA) and a battery of tests for noninvasive diagnosis of carotid artery disease indicate the two techniques are complementary, rather than competitive. DSA provides important morphologic information at the carotid bifurcation and siphon, but the images are sometimes difficult to interpret with precision. Noninvasive testing gives discrete physiologic information related to hemodynamics, but the findings are less specific for the level of the lesion in the carotid/ophthalmic system. Noninvasive tests may be more useful than DSA for determining if a lesion is hemodynamically significant and whether advanced disease shows evidence of progression on sequential studies. The noninvasive tests are not definitive procedures, but are useful in selecting patients for a contrast study. They are the initial procedure of choice for the patient with asymptomatic bruit. Depending on the clinical situation and quality of the study, DSA can sometimes be a definitive procedure, but in some situations correlative noninvasive test results are necessary to assess whether the patient is a candidate for arteriography and/or surgery.     

Imaging of carotid arterial diseases with contrast-enhanced ultrasound (CEUS)

Carotid duplex ultrasound is the standard of care for the initial diagnosis of carotid artery bifurcation diseases. But in difficult examinations, carotid abnormalities are commonly encountered and may represent a diagnostic challenge in patients with clinical symptoms as well as in the follow up after carotid endarterectomy or carotid artery stenting. Contrast enhanced ultrasound (CEUS) with low mechanical index (low MI) is a promising new method in the diagnosis and follow up of pathological carotid diseases.Unlike most contrast agents used for magnetic resonance imaging or computed tomography, the microbubbles used in CEUS with SonoVue^® remain within the vascular space and hence can be used to study vascular disease. In addition to improving current carotid structural scans, CEUS has potential to improve or add extra information on carotid arterial diseases.This review describes the current carotid duplex ultrasound examination and compares the pathological findings with CEUS.     

Incremental dynamic computed tomography: practical method of imaging the carotid bifurcation

A simple, practical method of applying incremental dynamic computed tomography (CT) to the imaging of 20 carotid bifurcations is described. The results are compared with those obtained by conventional carotid angiography and intravenous digital subtraction angiography (DSA). Conventional angiography provided additional information about the carotid bifurcation in only one of 14 cases, while incremental dynamic CT provided information not available from intravenous DSA in two of eight cases. Conventional brain CT is being used increasingly in the workup of patients with transient ischemic symptoms, and dynamic CT scanning at 3-mm increments requires only an extra 5 min of scanner time. The addition of incremental dynamic CT through the carotid bifurcation to the conventional brain CT scan procedure may obviate other screening tests before more definitive angiographic procedures.     

Duplex ultrasonography: its expanding role in noninvasive vascular diagnosis

Duplex scanning is only beginning to achieve widespread acceptance. On the positive side, it offers anatomic and physiologic information that cannot be obtained by any other method. The examination is totally noninvasive and is well accepted by both patients and referring physicians. The accuracy in the carotid bifurcation, the only area adequately investigated thus far, is quite good in comparison with arteriography, but the exact relationship between arteriography and duplex scanning in the carotid system demands further investigation. Duplex scanning is also cost-effective, and judicious use of the modality may considerably lessen the cost of a frequently expensive cerebrovascular evaluation. On the negative side, duplex scanning is extremely operator-dependent and is difficult to master effectively. At this time, few institutions or companies even offer the novice a place to learn and make their early mistakes out of sight. Limitations of the technique also exist. This is particularly problematic in the head, where the cerebral vasculature is not generally accessible to the ultrasound beam. Areas of stenosis contained within dense calcific plaque may also be completely hidden, and as already discussed, the deep abdominal vessels, particularly the iliac arteries, are not visible in an unacceptable number of patients. These technical limitations, however, may be circumvented; authors are already seeking sonic portals into the brain. Scanning from multiple vantage points usually overcomes the problem of acoustic shadowing from calcific plaque, and newer ultrasound technology may facilitate penetration of the sound beam deep into the abdomen. Overall, duplex sonography holds great promise for the future and may be destined to completely change the face of noninvasive vascular diagnosis.     

Value of a contrast agent in equivocal carotid ultrasound studies: pictorial essay

The aim of the present study was to assess the use of an echo-enhancing agent (Levovist; Schering AG) in equivocal carotid bifurcation ultrasound studies and compare the information obtained with digital subtraction angiography (DSA). Contrast-enhanced carotid ultrasound studies were performed on 30 carotid bifurcations in 28 patients. The standard carotid ultrasound examinations were considered equivocal for two reasons: apparent acute internal carotid artery occlusions (n = 10), and possibly patent but critically stenosed internal carotid arteries with the residual flow lumen being incompletely visualized (n = 20). All patients underwent subsequent carotid digital subtraction angiography. All patients with apparent acute carotid occlusions (n = 10) were correctly characterized on contrast-enhanced ultrasound when compared with DSA. The majority were complete occlusions (n = 8) although in two cases there were critical carotid stenoses requiring surgical endarterectomy. In the 'incompletely visualized lumen' group (n = 20), the majority (n = 16) were correctly characterized on contrast enhanced ultrasound: 13 cases of critically stenotic but patent internal carotid arteries, two cases without a haemodynamically significant stenosis and one case of a carotid occlusion with patent vasa vasorum. One of the critical carotid stenoses was prospectively reported as occluded on the 'gold standard' angiography. In three cases the flow lumen was still incompletely visualized due to calcified plaque despite an echo-enhancing agent; angiography revealed no significant stenosis in all cases. There was one false negative for internal carotid occlusion. This occurred early in the series and could be considered to be a technical error. Importantly, there were no false positives for carotid occlusion. Contrast-enhanced carotid ultrasound significantly improves diagnostic confidence in equivocal carotid ultrasound studies. In appropriate clinical settings this may reduce the need for subsequent carotid angiography.     

Karotisendarteriektomie und Karotisstenting Pilotstudie eines prospektiven, randomisierten und kontrollierten Vergleichs

INTRODUCTION: A prospective, randomized and controlled trial is conducted to compare carotid endarterectomy and carotid stenting in high grade symptomatic carotid artery stenoses. METHODS: According to the study design symptomatic patients with a angiographically high-grade (> or = 70%) internal carotid artery stenosis are included. Pre- and postinterventional diagnostics during the hospitalization period includes neurological assessment, duplex sonography of the cervical and cerebral arteries and magnetic resonance imaging of the brain. Follow-up examinations are scheduled after 1, 6 and 12 months and consist of a neurological assessment and duplex sonography. After 12 months selective angiography and magnetic resonance imaging of the brain will be performed additionally. During a period of 9 months up to now 23/137 patients treated for a carotid artery stenosis were included in the study, 11 patients underwent surgery and 12 patients carotid stenting. RESULTS: Carotid stenting and endarterectomy was primarily successful without residual stenosis > 30% in each patient without the occurrence of stroke or death. In 18 follow-up examinations (neurological assessment including duplex sonography) of 13 patients (13 follow-up examinations after 30 days, 5 after 6 months) no relevant restenosis and no stroke occurred. CONCLUSION: As of yet, carotid stenting was a safe procedure. Due to the small number of patients a definitive conclusion can not be drawn.     

Gray-scale ultrasound detection of carotid body tumors. Report of 2 cases.

Ultrasonography may be useful as a screening test for carotid body tumors before arteriography. Such tumors are seen as solid, well-circumscribed, weakly echogenic masses located at the carotid bifurcation.     

颅外颈动脉螺旋CT血管造影的临床意义(附45例报告)

目的 报告颅外颈动脉ＣＴ血管造影（ＣＴＡ）的初步经验,探讨该技术对各种颅外颈动脉病变的诊断意义,并在可能范围内与数字减影血管造影（ＤＳＡ）作小样本的对照。方法 ４５例颈动脉ＣＴＡ,经最大密度投影（ＭａｘＩＰ）及表面灰度成像法（ＳＳＤ）行三维重建,其中５例在１周内作了ＤＳＡ检查。结果 ４５例颈动脉ＣＴＡ检查,共得到９０支血管图像。其中正常血管５５支,狭窄血管３１支,闭塞血管２支,颈内动脉动脉瘤１支,     

Ultrasound examination of carotid and vertebral arteries

Ultrasound is the most widespread diagnostic procedure in obstructive disease of the arteries supplying the brain. The combined non-invasive information on morphology and function makes duplex ultrasound the procedure of choice in screening and follow-up of carotid artery disease. This review deals with all relevant aspects of color duplex ultrasound of the carotids and the vertebral arteries. After a short introduction into the clinical background, the paper focuses on aspects of examination technique. In the main part of the review the relevant ultrasound findings in carotid artery disease are discussed. The different methods for grading stenoses of the internal carotid artery are explained in detail. Other relevant pathologies, such as vertebral artery disease, dissection and aneurysms, are briefly mentioned. The clinical value of ultrasound in the work-up of carotid and vertebral artery disease is briefly discussed in comparison with other imaging procedures.     

The role of imaging in the management of cerebral and ocular ischaemia

Summary The last decade has seen several major technological advances in vascular neuroradiology, the most clinically significant of which have been the facility to image the brain and the extracranial carotid bifurcation noninvasively with accuracy and safety. Another major advance has been unequivocal evidence from formal statistical overviews that antiplatelet therapy, particularly aspirin, reduces the risk of serious vascular events by about 25%. These advances have changed clinical practice such that most patients presenting with symptoms suggestive of cerebral ischaemia should now have cranial CT to exclude intracerebral hemorrhage, not only because the causes and prognosis of cerebral ischaemia differ from those of intracerebral hemorrhage, but because many patients with cerebral ischaemia should be considered for antiplatelet therapy. Besides the use of long term antiplatelet therapy. Besides the use of long term antiplatelet therapy and control of vascular risk factors, other acute treatment options are limited with the possible exception of anticoagulation, thrombolysis, cytoprotective agents and carotid endarterectomy. If, as seems likely, the current clinical trials show that carotid endarterectomy plus medical therapy improve upon the stroke-free survival of patients treated medically, at least in symptomatic patients with severe stenosis, the number of carotid endarterectomies performed will increase considerably because carotid bifurcation disease is the most common cause of cerebral and ocular ischemic events. It will then be even more important to be able to obtain accurate anatomical and physiological information about the extracranial and intracranial circulations with utmost safety. Duplex ultrasound is currently the noninvasive screening method of choice for carotid bifurcation disease because it is available, relatively cheap, and reasonably accurate. It not only images the vessel lumen and degree of stenosis, but also the morphology of the vessel wall and associated plaque, the relevance of which is still uncertain in the pathogenesis of cerebral and ocular ischaemia. A major limitation of duplex sonography is that it cannot reliably distinguish tight stenosis from occlusion and it does not image the proximal or distal carotid circulation. The aim of newer techniques will be to distinguish tight extracranial carotid stenosis from occlusion and to provide anatomical, physiological and phathological information about the intracranial circulation and ischemic lesions (in view of potential for thrombolytic therapy of major intracranial vessel occlusion) with safety and reproducible accuracy.     

Neurological morbidity of arch and carotid arteriography in cerebrovascular disease. The influence of contrast medium and radiologist

A prospective study of 230 arch and carotid arteriograms in 229 patients with symptomatic cerebrovascular disease revealed that neurological morbidity was not significantly affected by patient age, nature of neurological symptoms, duration of procedure, volume of contrast medium or degree of arterial stenosis. The total neurological morbidity of 132 examinations carried out with non-ionic contrast medium (iohexol) was slightly lower than that of 98 examinations carried out with ionic contrast medium (meglumine and sodium iothalamate) but the difference was not statistically significant. However, the morbidity of 185 examinations performed by an experienced vascular radiologist was significantly lower (p less than 0.025) than the morbidity of 45 examinations performed by a series of radiologists in training and the mean time required for the procedure was 18 min longer in the latter group (p less than 0.001). These findings suggest that the neurological morbidity of arch and carotid arteriography in patients with cerebrovascular disease depends largely upon catheter technique and will not be significantly reduced by the use of non-ionic contrast medium.     

Inflammatory pseudotumor of the carotid artery: radiologic findings

The radiologic appearance of inflammatory pseudotumor in the two cases presented was a fusiform mass surrounding the carotid bifurcation. The masses showed an avascular mass with focal narrowing of the carotid bifurcation on carotid arteriography, a homogeneous hypoechoic mass on ultrasound, less enhancement on contrast-enhanced computed tomography, and relatively intense enhancement on magnetic resonance imaging.     

Venous digital subtraction angiography in the diagnosis of arteriosclerotic diseases of the supra-aortic extracranial vessels

In addition to non-invasive sonographic examinations the slightly invasive transvenous DSA has been shown to be useful in outpatients to demonstrate acceptable images of the supraaortic extracranial vessels. In preselected patients (n = 140) different atherosclerotic lesions of the examined angiographic region could be diagnosed by DSA. Images of diagnostic quality including the carotid bifurcation could be found in 88% using three examination-sequences in different standardized projections; only 43% of cases could be diagnosed following two sequences. Compared with conventional angiography DSA showed an identical imaging of the carotid bifurcation in 22 of 25 cases. Using an additional o.m. projection of the skull base (n = 80) internal carotid arteries could be analyzed in all cases, vertebral arteries in 80% and the basilar artery in 82%.     

MR和CT血管造影在诊断颈动脉狭窄及内膜切除术后随访中的价值

目的 探讨磁共振血管造影（MRA）、CT血管造影（CTA）在诊断颈动脉狭窄及内膜切除术后随访中的价值。方法 11例22支颈动脉行MRA、CTA、CT仿真内窥镜（CTVE）、多普勒超声（DUS）检查。12支结果与DSA对照。3支颈动脉重度狭窄者行内膜切除术,MRA采用二维、三维时间飞越法。CTA经最大强度投影（MIP）及遮盖表现显示法（SSD）三维重建。应用导航功能行CTVE成像。结果 颈动脉轻度狭窄8支,中度狭窄3支,重度狭窄5支,闭塞1支,5支正常。12支颈动脉与DSA对照：CTA评估血管狭窄与DSA相符者11支,MRA与DSA相符者9支,DUS与DSA相符者7支。CTA、CTVE显示斑块、壁血栓6支,3支手术证实。术后MRA示狭窄解除,CTA示斑块消失。结论 MRA、DUS可用于颈动脉狭窄的筛选及术后随访。CTA评估血管狭窄程度与DSA、手术比较有较好的一致性,并能直接显示钙化斑块。     

The assessment of carotid and vertebral arteries: a comparison of CFM duplex ultrasound with intravenous digital subtraction angiography.

The use of duplex ultrasound with colour flow mapping is compared with that of intravenous digital subtraction angiography (IVDSA) in the investigation of carotid and vertebral artery disease. Ninety-nine carotid and vertebral arteries were examined independently by IVDSA and ultrasound for location and degree of disease in 30 men (mean age 58) and 20 women (mean age 53). For purposes of comparison the carotid tree was divided into six segments. In 46% of cases no disease was detected by either modality. In 36% of cases where disease was found, ultrasound found mild disease in arteries reported as normal by IVDSA. Both modalities detected the six cases of total occlusion found in the study. IVDSA underestimated five cases of major disease found by ultrasound at the bifurcation or in the bulb. Overall agreement in grading vessel segments was good, with 74.5% in complete agreement and 90.3% grading stenoses to within +/- 25% of the other modality. There was good qualitative agreement in the findings for vertebral arteries. In four patients conventional arteriography was also available for comparison.