Sensitivity Of Duplex Scanning Research Articles

Echographic pattern features of dissections of the extracranial parts of the brachiocephalic arteries

Purpose: to determine the frequency of various ultrasound signs of dissections of the extracranial parts of the brachiocephalic arteries, as well as to compare the results of ultrasound and neuroimaging methods in the diagnostics of dissections.Materials and methods. The study included data on 108 patients, among them 44 (40.7%) women, 64 (59.3%) men, mean age was 56 ± 14 years. All patients underwent duplex scanning of the brachiocephalic arteries, 53 patients underwent CT-angiography, and 99 patients underwent MRI.Results. The sensitivity of duplex scanning in the primary diagnosis of dissections in our study was 97.2%. In 40 patients (37%) with dissections according to duplex scanning the presence of dissection was also confirmed on CT-angiography or MRI. Expansion of the vessel diameter and the presence of intramural hematoma (IMH), as well as their combination, were the most common ultrasound signs of dissections in our study. In cases where dissection was not confirmed by CT-angiography or MRI data moderate echogenicity of IMH was noted significantly more often (p = 0.018). Of all the ultrasound signs of dissections, the highest share of coincidence with the signs obtained with neuroimaging diagnostic methods occurred with IMG.Conclusion. The most frequently recorded ultrasound signs of dissections were the expansion of the vessel diameter and the presence of IMG, as well as their combination. The results of the study showed a high sensitivity of the ultrasound method in detecting dissections, especially in the subacute and chronic stages, as well as to determine the causes of ischemic stroke in the differential diagnosis of brachiocephalic artery pathologies.

Ultrasound Diagnostic compared with angiography of low extremity arteries in the diagnosis of multifocal atherosclerosis

In clinical practice the combined atherosclerotic lesions of several arterial regions are observed twice often in comparison with the isolated lesions. About 25 % of cases of multifocal stenoses are significant (> 50 %) and demand surgical correction. For the purpose of definition of surgical tactics (staging and sequence of revascularization of each region), and tracking of results of treatment, high-informative, available and, as possible, noninvasive diagnostic methods are necessary. Ultrasonic visualization of the arteries is one of such methods. However, so far an X-ray angiography (AG) remains the conventional method of «the gold standard». The screening part is traditionally assigned to the ultrasonic duplex scanning (USDS). Recently several authors report about a successful application of USDS, in a combination with magnetic resonance imaging and/or computed tomography or independently, as a decisive method before operation. The purpose of the current study was to compare the USDS and AG of low extremity arteries in terms of their sensitivity and specificity in patients with multifocal atherosclerosis (MFA). By means of screening of 565 men at the age of 45-59 years, 64 patients with multifocal lesion of coronary, carotid and low extremity arteries were identified. The degree of stenosis had been defined both by USDS and AG. USDS provided best results compared with angiography which failed in detection of smaller grades of stenoses and abdominal aorta aneurysms. Sensitivity of duplex scanning was 90 vs. 75 % for angiography. Application of functional tests can further extend the possibilities of USDS. Thus, ultrasound assessment may be considered a useful method for detecting different characteristics of multifocal athero-sclerotic lesion and planning surgical tactics.

Cost-effectiveness of identifying aortoiliac and femoropopliteal arterial disease with angiography or duplex scanning

Objectives Cost-effectiveness analysis of three diagnostic imaging strategies for the assessment of aortoiliac and femoropopliteal arteries in patients with peripheral arterial occlusive disease. The strategies were: angiography as the reference strategy, duplex scanning (DS) plus supplementary angiography (S1) and DS plus confirmative angiography (S2). Design, materials and methods A decision model was built with sensitivity and specificity data from literature, supplemented with prospective hospital cost data in Euro (€). The probability of correctly identifying the status of a lesion was taken as the primary outcome. We compared strategies by assessing the extra costs per additional correctly identified case. Results Assuming no false positive or false negative results, angiography is the most effective strategy if the prevalence of significant obstructive lesions in the aortoiliac and femoropopliteal tract exceeds 70%, or if the sensitivity of duplex scanning is lower than 83%. In case of lower prevalence, strategy S1 becomes equally or even more effective than angiography. At a prevalence of 75%, performing angiography costs €8443 per extra correctly identified case compared with strategy S1. Conclusions In most situations angiography is more effective than diagnostic strategy S1. However, if society is unwilling to pay more than €8443 for knowing a patient's disease status, diagnostic strategy S1 is a cost-effective alternative to angiography, especially at lower prevalence values.

The role of duplex scanning in the selection of patients with critical lower-limb ischemia for infrainguinal percutaneous transluminal angioplasty.

To investigate the role of duplex scanning in the selection of patients with critical lower-limb ischemia (CLI) for infrainguinal percutaneous transluminal angioplasty (PTA). One hundred and sixty-two limbs with CLI (150 patients) that underwent duplex scanning within 3 months prior to conventional diagnostic angiography (n = 88) or infrainguinal PTA (n = 74) were retrospectively studied. The findings obtained from duplex scanning and angiography were analyzed in a masked fashion by two different investigators. The accuracy, sensitivity, specificity, and negative and positive predictive values of duplex scanning in the selection of patients for infrainguinal PTA were 86%, 84%, 89%, 86%, and 87% respectively. Forty-two procedures (57%) were performed at multiple arterial segments. The accuracy of duplex scanning in the selection of femoropopliteal and crural lesions for PTA was over 85%. However, the sensitivity of duplex scanning in the selection of popliteal and crural lesions for PTA was 49% and 38% respectively, compared with 80% for superior femoral artery lesions. In 39% of patients who were correctly selected for PTA, duplex scanning misdiagnosed one of the multiple lesions treated by PTA. Duplex scanning can safely be used for the selection of patients for infrainguinal PTA. The sensitivity of duplex scanning in the selection of lesions for PTA was less satisfactory in the popliteal and crural arteries compared with the femoropopliteal arteries.

Doppler spectral characteristics of infrainguinal vein bypasses

With the aim of assessing the velocity profile of femoropopliteal and femorocrural vein bypasses, 128 patients undergoing infrainguinal vein bypass surgery entered a postoperative Duplex surveillance protocol, which included clinical assessment and Duplex scanning, using Doppler spectral analysis. Doppler spectra were obtained at three sites in each graft and the following waveform parameters recorded: maximum systolic velocity, minimum diastolic velocity and resistance index. In patent reconstructions systolic velocity decreased by 30% during the first 6 months after surgery. In the absence of arteriovenous fistulas the initially antegrade diastolic velocity was replaced by a retrograde flow within 3 months, whereas a forward flow in diastole was sustained in grafts with patent fistulas. Abnormal Duplex findings in 31 patients led to angiography and revision in 13 cases. Four revised grafts failed, while nine remained patent at follow-up 1-12 months later. Ten (56%) of 18 non-revised bypasses with abnormal Duplex findings failed within 9 months compared to 1 (1%) of 76 bypasses with a normal velocity profile (p < 0.00001). In conclusion, Ultrasound Duplex scanning with spectral analysis provides valuable information concerning haemodynamics of infrainguinal vein bypasses and identifies grafts at risk of thrombosis. Inclusion of low resistance index (< 0.75) as an additional criteria for detection of stenoses appears to improve the sensitivity of Duplex scanning.

Evaluation of the extracranial carotid arteries: Correlation of magnetic resonance angiography, duplex ultrasonography, and conventional angiography

We compared duplex scanning, “bright blood” and “black blood” magnetic resonance angiography, and conventional angiography for evaluation of the extracranial carotid arteries. All three methods were applied to 39 vessels in 20 patients. Duplex scanning was inaccurate when compared to conventional angiography in six instances. In three instances the degree of stenosis was overgraded by the scanner, and in three cases the stenosis was undergraded. Magnetic resonance angiography was inaccurate when compared to conventional angiography in three instances. In all cases magnetic resonance angiography overgraded the degree of stenosis. By use of a greater than 70% stenosis as a positive study, the sensitivity of magnetic resonance angiography was 100% and the specificity 92%. With use of the same criteria, the sensitivity of duplex scanning was 86%, and specificity was 84%. In those evaluations where the results of the magnetic resonance angiography and duplex scanning were in agreement, the correlation with conventional angiography was 100%. We conclude that magnetic resonance angiography is an alternative means to duplex scanning for noninvasive carotid imaging. A combination of bright and black blood magnetic resonance angiography is precise in delineating lesions of the extracranial carotid artery and may ultimately eliminate the need for conventional angiography in the evaluation of carotid stenosis.

Duplex Scanning for Noninvasive Assessment of Both Carotid Luminal Diameter and Atheromatous Plaque Morphology

The value of Duplex scanning in 50 consecutive patients with symptomatic carotid stenosis was evaluated. Compared with contrast arteriography, the sensitivity of Duplex scanning, for a greater than 50% internal carotid diameter reduction, was 90% (66/73) with a specificity of 96% (26/27). The overall agreement between Duplex and contrast arteriography as measured by the Kappa value was K = 0.561. One of the 13 arteries felt to be occluded on Duplex scanning was radiologically found to be patent. Excluding the six normal and 13 occluded arteries, 81 carotid plaques were defined as either heterogeneous, suggestive of intraplaque hemorrhage or as homogeneous. Twenty-four of the 32 asymptomatic cerebral hemispheres were associated with ipsilateral homogeneous plaques, while 30 of the 49 symptomatic hemispheres had heterogeneous plaques in the ipsilateral carotid, (p less than 0.001). This study confirms the accuracy of duplex scanning in detecting internal carotid stenosis as well as in identifying plaques which are morphologically heterogeneous and more likely to be associated with ipsilateral cerebral hemispheric symptoms.

Can carotid duplex scanning supplant arteriography in patients with focal carotid territory symptoms?

Previous reports have suggested that duplex ultrasonography might supplant arteriography as a guide to operative decision making in selected patients with cerebrovascular disease. This study was undertaken to test that tenet in patients with focal carotid territory symptoms. Seventy-two patients having independently interpreted arch and selective carotid arteriography and duplex scanning underwent 78 carotid endarterectomies. Operative specimens were analyzed in all cases and used as the standard in evaluating the accuracy of the preoperative studies. All patients had disease found at the time of operation. The sensitivity of duplex scanning was 99% vs. 91% for arteriography (p = 0.06). In seven cases the scan accurately predicted disease in patients which normal arteriograms and in a single case the scan was read as normal in a patient with a smooth minimally stenotic plaque read as an irregular 30% stenosis on arteriography. The accuracy of duplex scanning was markedly superior to arteriography in detecting intimal surface abnormalities (92% vs. 64%, p < 0.001) and ulceration (90% vs. 54%, p < 0.001). There was no difference between duplex scan and arteriography (p = 1.0) in predicting a greater or less than 50% stenosis (accuracy, 94% for arteriogram; 92% for duplex scanning). Of the patients with preoperative potentially reversible symptoms, 97% were free of symptoms at a mean follow-up of 9 months after operation. Eighty-nine percent (17 of 19 patients) of patients with concomitant, ipsilateral, intracranial, or intrathoracic cerebrovascular disease were free of symptoms after carotid endarterectomy.