The validation of duplex scanning and continuous wave doppler imaging: A comparison with conventional angiography

Colour-coded continuous wave (CW) Doppler imaging and duplex scanning have been assessed prospectively in comparison with biplanar angiography for their accuracy in detecting significant arterial disease in the extracranial circulation. Of 96 comparisons with biplanar angiography, the sensitivity of Doppler imaging was 90% and specificity 98% in the detection of >50% internal carotid stenosis and 86 and 100%, respectively, in the diagnosis of internal carotid occlusion. Of 85 comparisons with biplanar angiography, the sensitivity of duplex scanning was 93% and specificity 98% in the detection of >50% internal carotid stenosis and 92 and 100%, respectively, in the diagnosis of internal carotid occlusion. The value of the peak systolic Doppler shift frequency of the internal carotid artery signal has proved to be the most reliable indicator of >50% stenosis and is utilised in conjunction with a periorbital examination. It is concluded that both Doppler imaging and duplex scanning are effective screening techniques for the presence of significant (>50%) internal carotid artery disease.     

彩色多普勒超声诊断外周血管动脉瘤与栓塞

采用彩色多普勒超声检查外周血管动脉瘤与栓塞，选择１０例手术证实的患者，其中５例做过血管造影。两维图像显示动脉瘤易伴血栓形成，本文６例动脉瘤中１例右颈内动脉瘤因血栓充填血管造影误诊为软组织肿瘤，彩色多普勒发现瘤内彩色血来包绕血凝块旋转。５／６例外伤性及感染性假性动脉瘤可直接显示破裂的血管血流喷向肿块内，与手术发现完全一致．脉冲频谱呈动脉高速血流、双相。１例骼动脉及１例股动脉栓塞显示血管暗区消失，管壁模糊，血管内彩色血流，脉冲多普勒信号减弱及消失。２例蔓状血管瘤表现边界不清，多条迂曲管状的无回声暗区连成一片，形成蜂窝团样，彩色多普勒显示暗区均被血流充填。作者认为该检查方法诊断周围血管动脉病变能得到可靠和有价值的信息。     

Carotid duplex and transcranial color-coded sonography in evaluation of carotid-cavernous sinus fistulas.

We performed carotid duplex and transcranial color-coded sonography in three patients with traumatic and one patient with spontaneous carotid-cavernous fistulas. High flow and low resistance were detected by carotid Doppler imaging in the extracranial internal carotid artery in three cases and in the external carotid artery in one case. The fistula could be demonstrated directly as heterogenous color flashes with turbulent flow by transcranial color-coded sonography through the orbital or temporal window. The transorbital approach showed that the ophthalmic venous flow was normal or to-and-fro bidirectional in patients without proptosis and was retrograde, away from the cavernous sinus with arteriolization in patients with proptosis. Combination of carotid duplex and transcranial color-coded sonography provides a noninvasive method for more accurate hemodynamic study of cerebral circulation and direct imaging of CCF.     

Diagnosing and monitoring carotid cavernous fistulas with color Doppler imaging

Color Doppler imaging allows simultaneous bidimensional imaging and Doppler evaluation of blood flow in orbital vessels. We report 4 cases in which color Doppler imaging was used to diagnose and monitor carotid cavernous fistulas. In all cases, color Doppler imaging demonstrated dilated, arterialized superior ophthalmic veins; these findings were confirmed by angiography. Two patients underwent embolization with complete regression of the clinical findings. After embolization, color Doppler imaging revealed normal, laminar flow in the superior ophthalmic vein. This noninvasive technique represents a safe and fast method that is useful in the diagnosis and post-treatment follow-up of carotid cavernous fistulas. © 1997 John Wiley & Sons, Inc. J Clin Ultrasound 25 : 448–452, 1997.     

Carotid Pseudostring Sign From Vasa Vasorum Collaterals

Objective . To describe the spectral and color Doppler imaging findings in 2 cases of internal carotid artery occlusion with vasa vasorum collateral flow, which we term the “pseudostring sign.” Methods . Spectral and color Doppler imaging findings in both cases were reviewed. Magnetic resonance angiography in 2 cases and conventional angiography in 1 case were also reviewed. Results . Both patients had color Doppler images showing that the internal carotid artery was a narrow, stringlike vessel with arterial flow that had normal spectral Doppler features (velocity <125 cm/s with a normal waveform). Magnetic resonance angiography in 1 patient showed total occlusion of the proximal internal carotid artery with patent vasa vasorum collaterals reconstituting the lumen distally. In the second patient, magnetic resonance angiography showed total occlusion of the proximal internal carotid artery, and conventional angiography showed proximal occlusion with collateral flow through the vasa vasorum. Conclusions . Proximal internal carotid artery occlusion with vasa vasorum collateral flow should be considered when color Doppler imaging shows a seemingly narrow internal carotid artery with tortuosity and normal spectral Doppler features. Patients with these features should not undergo carotid endarterectomy directly on the basis of only the Doppler findings.     

Characterisation of carotid artery disease: comparison of duplex scanning with histology

The ability of duplex scanning to characterise the component tissue of atheromatous lesions of the internal carotid artery and to detect ulceration has been examined in a histological study of 42 carotid endarterectomy specimens. The results suggest that the only component of atheromatous lesions of the internal carotid artery which can be characterised from the B-scan is calcification. The presence of ulceration, intraluminal and intramural thrombus, fibrous intimal thickening and necrosis are not related to the echogenic appearance of internal carotid stenoses and may not be detected reliably. B-mode imaging alone cannot reliably grade >50% internal carotid stenoses, but when this is combined with pulsed Doppler in the technique of duplex scanning, accurate results may be obtained.     

Doppler-ophthalmomanometry in patients with obstruction of the carotid arteries

A novel noninvasive method to determine simultaneously ophthalmic artery pressure (OAP) and flow direction based on Doppler ultrasound principles is presented: ophthalmomanometry-Doppler (OMD). Studies performed on 25 angiographically proven normal subjects with direct recording of the internal carotid artery pressure (ICP) and indirect determination of the brachial artery pressure (BAP) demonstrated that OAP values assessed by the OMD device are highly correlated with simultaneous ipsilateral intraarterial systolic ICP measurements (r = 0.95, n = 10) and with simultaneous recordings of the BAP (r = 0.88, n = 15). In 50 patients presenting angiographically occlusions and 52 patients presenting angiographically stenoses (greater than 60%) of the carotid artery the measured Doppler ophthalmic pressure index (OPI = ratio of the ophthalmic to systemic blood pressure) was lower ipsilateral to an occlusion (0.46 +/- 0.08) than ipsilateral to a stenosis (0.54 +/- 0.08; p less than 0.001) of the carotid artery. In both it was clearly diminished compared to normal values (0.68 +/- 0.04; p less than 0.001). In carotid artery occlusions, the ipsilateral OPI was 0.46 +/- 0.06 for antegrade (n = 17) and 0.46 +/- 0.09 for retrograde (n = 28) ophthalmic artery flow. In carotid artery stenoses, the ipsilateral OPI was 0.55 +/- 0.07 for antegrade (n = 41) and 0.48 +/- 0.06 for retrograde (n = 9) ophthalmic artery flow (p less than 0.01). It is concluded that in carotid occlusions presenting a longer disease history extra-intracranial collateralisation via the ophthalmic artery are as efficient as a functional circle of Willis.     

Color-coded Doppler sonography in the diagnosis of carotid artery diseases

Color-flow Doppler is a new development of duplex sonography of the peripheral vessels. In this study 844 consecutive patients were evaluated (a) to assess the comparative value of these two methods, (b) to see if there is a correlation between the degree of stenosis and the incidence of neurological symptoms and (c) to find a possible relationship between the plaque structure and the incidence of neurological deficits. (a) In 89%, the color-flow assessment was in complete agreement with the duplex assessment. In the remaining 11%, important additional results were discovered in the color flow examination. (b) Non-stenotic plaques were seen more often (43%) in the wide carotic bulb, stenotic plaques and occlusion were found more often (66 and 82%) in the internal carotic artery. Vessel occlusion was found most often in patients with cerebral ischemia. Color-flow Doppler demonstrated a higher incidence of hemodynamic stenosis in patients with peripheral vascular disease, hypertension and bruits. (c) Patients with heterogeneous plaques demonstrated a significantly higher risk of neurological deficits than those with homogeneous plaques. The great advantage of color-flow Doppler is that it enables sonomorphological (plaques, stenoses, occlusion) and functional parameters (turbulences, flow enhancement) to be studied during the same procedure.     

Concurrent multivessel stenting in a patient with multifocal arterial disease.

PURPOSE: To report the concurrent endovascular treatment of multiple stenoses in different vascular territories. METHODS AND RESULTS: A 45-year-old male presented with an aortic arch syndrome, renovascular hypertension, and Leriche syndrome. Intra-arterial digital arteriography disclosed occlusion of the left subclavian artery and stenoses in the left common carotid artery (CCA), the right CCA at the bifurcation, the left renal artery, and both iliac arteries. In a single procedure, the patient received 5 stents in 2 carotid, 1 renal, and 2 iliac arteries. At 3-month follow-up, color flow duplex imaging confirmed continued patency of all stented arteries. CONCLUSIONS: This case illustrates the feasibility, safety, and cost effectiveness of treating multivessel stenoses using a single-session endovascular approach executed by experienced interventionists.     

Effects of atherosclerotic lesions on ultrasonic beam and cw doppler signals

Doppler ultrasound has been shown to be a useful clinical tool in the noninvasive detection of vascular stenoses, occlusion, or plaques. The presence of atherosclerotic lesions in blood vessel walls can distort the Doppler ultrasonic signal, producing inverted or biphasic tracings. This observation, in fact, has been used frequently as a criterion for the diagnosis of plaque formation and calcification of these lesions. To define the source of this distortion, we have examined the effects of various types of atherosclerotic lesions on the transmitted ultrasonic beam generated by a continuous wave (CW) Doppler ultrasonic probe. These results are compared to the Doppler flow tracings obtained by a CW ultrasonic Doppler flowmeter from blood vessels with overlaying lesions in a mock flow system. It is concluded that severe distortion in the form of beam refraction or diffraction can be produced by calcified lesions, resulting in biphasic or inverted flow signals.     

三维彩色多普勒超声成像在诊断颈动脉粥样硬化中的应用研究

目的：探讨颈动脉粥样硬化的三维超声成像特征及其价值。方法：健康志愿者32例；颈动脉粥样硬化患者30例，均经二维超声证有1处以上的粥样斑块形成，应用彩色多普勒超声诊断仪及三维彩色多普勒超成像系统，三维图像采集方法选用自由臂方式，扫描过程包括血管长轴扇形扫描和血管短轴平行扫描，脱机进行血管壁，管腔血流的三维重与显示。结果：正常颈动脉的三维重图像能够连续，完整地同颈总动脉，颈内动脉，颈外动脉的空间走行，可见其管壁内膜面光滑平整，管腔通畅，血流充填完满，粥样斑块形成的颈动脉三维重建图像可直观显示斑块的立体形状，表面特征，确切部位，血管腔大小及血流的空间走行情况，结论。三维彩色多普勒超声成像对于颈动脉粥样硬化的影像诊断具有 临床价值和应用潜力。     

Dodecafluoropentane ultrasonic contrast enhancement in carotid diagnosis: preliminary results.

To assess the efficacy in carotid diagnosis of an investigational dodecafluoropentane ultrasonic contrast enhancing agent, we compared B-mode, color flow, and duplex Doppler findings in 16 patients with common carotid artery bifurcation disease after dodecafluoropentane and saline injections. Dodecafluoropentane produced enhanced backscatter in all patients for 4 to 20 min (mean, 8.4+/-4.74 min) after intravenous injection. In six patients this enhancement improved the color flow and pulsed Doppler signal detection in areas of sonographic shadowing. The enhanced color flow information changed the diagnostic impression in one case. Dodecafluoropentane produced enhanced backscatter in the carotid artery in all patients, and for a mean duration longer than that reported for other agents. It has the potential to improve the efficacy of carotid ultrasonic evaluation.     

Current applications of duplex and color Doppler ultrasound imaging: carotid and peripheral vascular system

Recent advances in ultrasound technology have made possible the development of diagnostic instruments that combine cross-sectional imaging and Doppler analysis. These instruments have expanded the role of diagnostic ultrasonography to the assessment of carotid and peripheral vascular disease. The current applications of duplex Doppler and color Doppler imaging in evaluating the extracranial carotid arteries, vertebral artery, peripheral venous system, and peripheral arterial system are reviewed. The indications for and limitations of these examinations, as well as the potential future uses, are discussed.     

Determination of the hemodynamic factors which influence the carotid Doppler spectral broadening

In the diagnosis of extracranial carotid arterial disease, quantitative measurements from the continuous wave (CW) Doppler spectrum have the potential for detecting stenoses and occlusions. The measurement of maximum peak Doppler frequency at the site of stenosis has been shown to detect severe, but not minor or moderate, stenoses. Diagnosis of minor or moderate stenoses may be possible by assessing the degree of flow disturbance beyond the stenosis. Such flow disturbances cause the Doppler spectrum at peak systole to be broadened, and it has been suggested that the measurement of spectral broadening may be of diagnostic value. This paper describes the results of an in vitro study aimed at determining the hemodynamic factors that influence the severity of the Doppler spectral broadening. The spectral broadening index (SBI) at peak systole, defined as SBI = 1 - Fmean/Fmax, was used to quantify the instantaneous spectrum. In a pulsatile flow in vitro model that produced spectral waveforms virtually identical to those recorded in the human carotid, we observed a direct linear relationship between SBI and the severity of stenosis, at least for those stenoses having greater than 40% cross-sectional area (R = 0.82 to 0.93). The SBI was found to be maximum when recorded immediately beyond the stenosis and returned to normal 4-5 cm downstream from the stenosis. The SBI was higher for nonsymmetrically shaped stenoses than for symmetrical stenoses for lesions greater than 60%, but not for stenoses less than 60%. In this model, the SBI recorded from both normal or abnormal waveforms was not affected by the flow rate.(ABSTRACT TRUNCATED AT 250 WORDS)     

Duplex scanning with continuous wave Doppler for carotid disease

Duplex scanning with the use of continuous wave Doppler instrumentation was used for the evaluation of carotid disease and compared to angiography. In twenty such patients 100% accuracy for diagnosis of total occlusion by Duplex scanning with continuous wave Doppler, was obtained. The sensitivity for those patients with 50%-99% stenosis was 92% and for those patients with 20%-49% stenosis was 75%. The overall accuracy for this diagnostic test for all groups of stenosis was 85%. This compares favorably with other noninvasive vascular techniques and is felt to be an accurate and useful technique for the detection of carotid stenosis. Several advantages of this technique are pointed out.     

彩色多普勒在门静脉穿刺注药治疗肝癌中的应用

本文探讨了彩色多普勒在门静脉穿刺注药治疗肝癌中的应用价值。对15例原发性肝癌和1例继发性肝癌患者门静脉穿刺注药前后及注药过程中彩色多普勒的应用表明;注药前彩色多普勒对肝肿瘤病灶及门脉血流动力学的检查有助于本治疗适应证的选择;注药过程中的彩色多普勒应用,有助于提高静脉穿刺注药的准确性和观察药液在肝内的弥散;注药后彩色多普勒检查及其穿刺活检有助于对肝癌疗效的观察;超声引导下的门静脉穿刺导向化疗,作为肝癌综合治疗的方法之一,值得进一步探讨。     

Review of the assessment of single level and multilevel arterial occlusive disease in lower limbs by duplex ultrasound.

The purpose of this article is to review the performance of duplex ultrasound scanning in assessing lower limb arterial disease with emphasis on patients with multisegmental occlusive lesions. Several studies have reported that duplex scanning can be as accurate as angiography to localize arterial stenoses. In spite of these promising results, there still remain some difficulties and controversies. Among them, it has been reported that multisegmental disease may affect the accuracy of duplex scanning. Indeed, some studies have indicated a lower sensitivity for detecting significant stenoses distal to severe or total occlusions. It also was demonstrated that second-order stenoses were detected with lower sensitivity compared to first-order stenoses. The main reason proposed to explain this lower sensitivity is that the highly reduced flow distal to occluded or highly stenotic segments increases the difficulty of detecting significant Doppler velocity changes in the distal or secondary stenoses. The intrinsic limitations of the peak systolic velocity ratio used as a classification criterion are presented. Finally, new and promising developments in power Doppler imaging and ultrasound contrast agents are discussed, because they may allow expansion of the capabilities of current ultrasound scanning systems and provide more accurate diagnosis of patients with multiple disease.     

Carotid artery duplex scanning

Duplex scanning of the carotid arteries combines B-mode ultrasound and Doppler ultrasound within a single instrument, thus providing both anatomical imaging of the vessel and flow velocity information. Combining these two unique aspects of ultrasound overcomes many of the individual limitations of each and provides improved noninvasive diagnosis of cerebrovascular disease. The Doppler signal is analyzed using fast Fourier transform methods and displayed as a spectral waveform. Assessment of the presence and severity of vascular disease is based primarily on Doppler information and the B-mode image of the vessel serves mainly as a road map to guide the placement of the pulsed Doppler sample volume. The parameters used to classify severity of disease include peak systolic frequency, degree of spectral broadening, end diastolic velocity, and overall shape of the waveform. Using these features, stenosis at the carotid bifurcation is classified into six categories: (A) none, (B) 1%-15% diameter reduction, (C) 16%-49% diameter reduction, (D) 50%-79% diameter reduction, (D+) 80%-99% diameter reduction, and (E) complete occlusion. These methods have a sensitivity of 99% and a specificity of 84% when compared with angiography. The clinical applications of carotid artery duplex scanning are discussed with particular reference to (1) patients with cerebrovascular symptoms, (2) asymptomatic cerebrovascular disease, (3) follow-up of carotid endarterectomy, and (4) cerebrovascular research. Patterns of use of duplex scanning in current practice and potential future applications are discussed.     

Total occlusion of the common carotid artery with patent internal carotid artery. Identification with color flow Doppler imaging.

With common carotid artery occlusion there is usually no flow in the distal vessels. However, flow to the ipsilateral internal common carotid artery may be maintained by collateral vessels. Nine of 1100 patients referred for carotid duplex sonography were found to have occluded common carotid arteries. Five of these patients had collateral circulation with reconstitution of flow via the external carotid artery. The color Doppler sonograms of three representative patients are presented. There was antegrade flow in the internal carotid artery with retrograde flow in the external carotid artery.     

Contrast‐enhanced transoral carotid ultrasonography for the diagnosis and follow‐up of extracranial internal carotid artery dissection: A case report

A 56‐year‐old woman was admitted to our hospital because of amaurosis fugax. The carotid angiogram showed irregularly stenotic lesions of the left and right internal carotid arteries (ICAs), suggestive of dissection. Follow‐up evaluation was performed by transoral carotid ultrasonography (TOCU) with contrast enhancement (CE), which yielded better vessel lumen and intramural hematoma visualization than color Doppler imaging. CE‐TOCU is useful for evaluating ICA dissections that extends to the high cervical portion.