shu-508 and Arterial-Occlusive-Diseases

Colour Doppler US is well established for imaging of hepatic vessels in the assessment of pre- and post-liver transplant patients. Unfortunately, a full colour Doppler US examination of the portal or hepatic venous and hepatic arterial systems is frequently precluded by technical factors. Ultrasound contrast agents are useful in enhancing vascular Doppler signal and play an important role in liver transplantation assessment. A series of patients with vascular problems illustrates the role of US contrast in the pre-transplant candidate, where portal vein patency and direction of flow is assessed, presence of portal vein thrombus is confirmed and cavernous transformation demonstrated. Occlusion of hepatic veins in Budd-Chiari syndrome is confidently confirmed. Following liver transplantation, US contrast allows a comprehensive assessment of hepatic artery thrombosis, hepatic artery stenosis and pseudoaneurysm formation. The need for further imaging is reduced or confidently deferred in many instances. Ultrasound contrast agents play an important role in the liver transplant candidate.

Topics: Arterial Occlusive Diseases; Contrast Media; Hepatic Artery; Hepatic Veins; Humans; Liver Transplantation; Polysaccharides; Portal Vein; Postoperative Care; Postoperative Complications; Preoperative Care; Ultrasonography, Doppler, Color; Vena Cava, Inferior

Contrast angiography is widely regarded as the gold standard investigation in peripheral artery disease (PAD). It produces images that are diagnostically valuable, but is limited by its inability to image the vessel walls or the dynamics of blood flow in the lumen. Color duplex sonography is increasingly used in PAD to replace or pre-empt angiography. It is a simple non-invasive technique that gives information about both structural and dynamic anomalies in the peripheral arteries, with an accuracy close to that of angiography. Certain situations are difficult to visualize using this technique. Arteries that are deep-lying, calcified, obscured by fat or bowel gas, or that contain low-velocity blood flow, will generate sub-optimal scans due to inadequate returning signal strength. This can be corrected by the use of microbubble echo-enhancing agents, which increase the strength of the returning signal, generating a clear image from which a diagnosis can be made. Results of multicenter studies of echo-enhanced color duplex sonography in PAD are reviewed and the impact of the technique on the diagnostic work-up of PAD is assessed.

Topics: Algorithms; Angiography; Arterial Occlusive Diseases; Blood Flow Velocity; Contrast Media; Humans; Image Enhancement; Polysaccharides; Ultrasonography, Doppler, Color

To estimate the dosage needed for continuous infusion and to investigate whether continuous infusion of the ultrasound contrast-enhancing agent Levovist (SH U 508A) can improve duplex scanning of crural arteries in patients with peripheral arterial obstructive disease (PAOD) eligible for distal bypass graft surgery.. The study design consisted of two parts. Part 1 investigated the color and spectral Doppler scan enhancement of three different Levovist dosages (200, 300, and 400 mg/mL) in one arterial segment of a patent lumen of a crural artery in seven patients with PAOD. Part 2 investigated the value of the optimum Levovist dosage in the assessment of 10 crural arteries in 10 consecutive patients with PAOD. Angiography was the reference standard.. Part 1: Levovist significantly enhanced color and spectral Doppler scan as compared with baseline ultrasound scan, but no differences were found between the Levovist dosages. Thus, the lowest Levovist dosage sufficed for application in part 2, because of its infusion volume and prolonged enhancement time. Part 2: The agreement between contrast-enhanced duplex scanning and angiography was moderate (kappa = 0.50; 95% confidence interval [CI], 0.03-0.97). Five (50%) of 10 crural arteries that could not adequately be visualized with routine duplex scanning could be visualized with contrast-enhanced duplex scanning.. Contrast-enhanced duplex scanning by means of continuous infusion of Levovist in patients with PAOD improves the ultrasound scan investigation of crural arteries in case routine duplex scanning is inconclusive and might reduce the need for angiography.

Topics: Aged; Aged, 80 and over; Angiography; Arterial Occlusive Diseases; Arteries; Blood Vessel Prosthesis Implantation; Contrast Media; Dose-Response Relationship, Drug; Female; Humans; Infusions, Intravenous; Leg; Male; Middle Aged; Peripheral Vascular Diseases; Polysaccharides; Ultrasonography, Doppler, Duplex; Vascular Patency

We sought to evaluate the diagnostic value of echo-enhanced transcranial color-coded duplex sonography (TCCD) and the clinical relevance of vascular pathology assessed by sonography for early clinical outcome in acute ischemic stroke.. We present 23 consecutive patients with an anterior circulation stroke in whom clinical examination, CT, and ultrasonography were performed within 5 hours after the onset of symptoms. Transcranial Doppler sonography (TCD) and unenhanced and contrast-enhanced TCCD (Levovist, 4 g, 300 mg/mL) were compared for their ability to detect middle cerebral artery (MCA) occlusion and flow velocity reduction suggesting hemodynamic impairment in the MCA distribution pathway. Sonographic examination times were registered. Baseline clinical characteristics and CT findings were assessed. Neurological deficit was quantified according to the National Institutes of Health Stroke Scale score, with an early clinical improvement defined as decrease of the score by 4 or more points or a complete resolution of the deficit on day 4.. Contrast-enhanced TCCD enabled diagnosis of intracranial vascular pathology in 20 affected hemispheres, whereas unenhanced TCCD and TCD were conclusive in 7 and 14 hemispheres, respectively (P=0.0001). Contrast-enhanced TCCD was superior in evaluating distal carotid (carotid-T) occlusion and differentiating major vessel occlusions from patent arteries with flow velocity diminution. Mean examination time for enhanced TCCD ranged from 5 to 7 minutes, depending on the number of investigated vessels (without or with MCA branches). Logistic regression selected a patent MCA without reduced blood flow velocity as the only independent predictor for an early clinical improvement (P<0.01).. Contrast-enhanced TCCD is a promising tool for early prognosis in anterior circulation stroke. It is considered superior to unenhanced TCCD and TCD.

Topics: Acute Disease; Aged; Aged, 80 and over; Arterial Occlusive Diseases; Cerebral Arteries; Cerebrovascular Disorders; Contrast Media; Diagnostic Imaging; Female; Humans; Image Enhancement; Male; Middle Aged; Polysaccharides; Prognosis; Reproducibility of Results; Sensitivity and Specificity; Time Factors; Ultrasonography, Doppler, Color; Ultrasonography, Doppler, Transcranial

to evaluate if ultrasound contrast-agent infusion could improve duplex-ultrasound imaging of peripheral arterial disease (PAD) and increase the agreement with digital subtraction arteriography (DSA).. prospective and consecutive study.. of 60 consecutive PAD patients, 15 were found to have an inconclusive duplex-ultrasound scan of the trifurcation and were included in the study. All 15 patients (53% male) were scheduled for DSA, all being candidates for vascular surgery due to claudication (n = 3, 20%), rest pain (n = 5, 33%) and tissue loss (n = 7, 47%).. on the day before DSA, a duplex-ultrasound scan of the trifurcation was performed. If the duplex-ultrasound scan was found inconclusive, it was repeated during continuous ultrasound contrast-agent infusion. DSA was performed unaware of the duplex-ultrasound results and served as the gold standard.. after contrast-agent administration, the number of inconclusively diagnosed segments was significantly reduced by 26 (70%), from 37 to 11(p < 0.001). In 19 segments (73%) contrast-agent infusion changed the diagnosis in accordance with the DSA (p < 0.05). Values of sensitivity and positive predictive value were improved from 0.20 (0.04-0.62) to 0.47 (0.26-0.69) and 0.50 (0.10-0.91) to 0.80 (0.49-0.93), respectively. Specificity and negative predictive value were unchanged. Agreement between duplex-ultrasound and DSA were improved from poor (kappa = 0.18 (95% CI: 0-0.82)) to moderate (kappa = 0.45 (0.17-0.74)) (p = 0.44).. ultrasound contrast-agents improve the diagnostic ability of duplex-ultrasound when scanning difficult arterial segments in patients suffering from PAD.

Topics: Adult; Aged; Aged, 80 and over; Angiography, Digital Subtraction; Arterial Occlusive Diseases; Contrast Media; Female; Humans; Lower Extremity; Male; Middle Aged; Peripheral Vascular Diseases; Polysaccharides; Predictive Value of Tests; Prospective Studies; Tibial Arteries; Ultrasonography, Doppler, Color

To evaluate the role of microbubble ultrasound contrast media in detecting stenosis of the post-liver transplant extrahepatic hepatic artery (HA) in the presence of the tardus parvus spectral Doppler waveform of the intrahepatic HA.. All post-liver transplant patients with a prolonged systolic acceleration time (SAT>0.08s) and/or a reduced resistant index (RI<0.50) of the HA (the tardus parvus waveform) on colour Doppler ultrasound (CDUS), were assessed with microbubble contrast medium for a focal arterial stenosis. Following microbubble contrast-enhanced CDUS, patients underwent arteriography or follow-up CDUS.. A total of 2038 examinations were performed in 529 liver transplant recipients; 16 (3.02%) tardus parvus waveforms were identified. The median SAT of the intrahepatic HA was 0.18s (range 0.11-0.38s) and the RI 0.47 (range 0.22-0.58). No extrahepatic elevated peak systolic velocity (PSV), defined as above 1.00m/s, was detected on the baseline examinations. Following the administration of microbubble contrast, medium, PSV in the extrahepatic HA was elevated in 14 of 16 patients, (median=2.15m/s, range=1.44-3.10m/s); flow was not identified in two patients. Arteriography was performed in 10 patients and confirmed stenosis in eight (median grade of stenosis 93%, range 60-99%) and occlusion in two. The measured median PSV at contrast-enhanced CDUS in the stenosis group was 2.03m/sec (range 1.44-2.71m/sec). Repeat CDUS in six patients not undergoing arteriography showed resolution in four; one underwent re-transplantation before arteriography and one patient maintains a tardus parvus waveform. In transplant recipients undergoing arteriography during the study period (n=55), no hepatic artery stenosis without a tardus parvus waveform was seen.. The tardus parvus waveform pattern is an excellent screening test for the presence of post-liver transplantation hepatic artery stenosis. There is only a limited role for microbubble ultrasound contrast agent in the presence of a tardus parvus waveform. It could be used following equivocal colour Doppler ultrasound, but arteriography will still be necessary.

Topics: Adolescent; Adult; Arterial Occlusive Diseases; Contrast Media; Female; Hepatic Artery; Humans; Liver Transplantation; Male; Middle Aged; Polysaccharides; Postoperative Complications; Prospective Studies; Radiography; Ultrasonography, Doppler, Color

The purpose of this study was to evaluate the use of an echo-enhancing agent in patients with carotid artery occlusion to improve the sensitivity and specificity of carotid color flow ultrasonography.. Between January 1997 and December 1998, a prospective study involving 85 cases of carotid artery occlusion in 84 patients was carried out. After a baseline duplex ultrasonography (DU) diagnosis, a second (DU) along with an echo-enhancement agent (SHU-508-A [Levovist]) study was carried out (echo enhancement ultrasonography diagnosis [DUEE]). In 82 cases, a contrast angiography was performed to confirm the diagnosis, whereas in the other three cases the diagnoses were confirmed with surgery.. From the 85 internal carotid artery occlusions diagnosed at the initial DU examination, seven came out to be false occlusions in the DUEE examination (8,2%). There was a 100% correlation of the cases between the DUEE examination and the contrast angiography in the 82 cases in which this had been done. In three of the cases, the diagnosis was confirmed surgically because these displayed severe stenoses according to the DUEE studies in symptomatic patients, and so they required urgent treatment.. The DUEE study is a potent diagnosis tool that allows the differentiation between true carotid artery occlusions and pseudo-occlusions.

Topics: Aged; Angiography; Arterial Occlusive Diseases; Carotid Artery Diseases; Carotid Artery, Internal; Carotid Stenosis; Confidence Intervals; Contrast Media; Evaluation Studies as Topic; False Positive Reactions; Female; Humans; Image Enhancement; Male; Polysaccharides; Predictive Value of Tests; Prospective Studies; Radiographic Image Enhancement; Reproducibility of Results; Sensitivity and Specificity; Ultrasonography, Doppler, Color; Ultrasonography, Doppler, Duplex

Transcranial color-coded real-time sonography (TCCS) is an emerging diagnostic technique that allows noninvasive imaging of intracranial vessels within parenchymal structures. However, in some patients, transcranial ultrasound is particularly hindered by insufficient ultrasound penetration through the temporal bone. The present study evaluates whether or not application of an echo-contrast agent in ultrasound-refractory patients with middle cerebral artery (MCA) trunk occlusion enhances image acquisition enough to yield accurate diagnoses. Contrast-enhanced (CE) TCCS examinations, computed tomography scans and angiographic studies were performed in 20 patients with clinical symptoms suggestive of MCA occlusion within 12 h of the onset of symptoms. For comparison, 20 control persons without history or clinical signs for cerebrovascular diseases were examined using CE-TCCS. In none of the patients or control subjects did unenhanced TCCS investigations depict any color-coded vascular signal of an intracranial vessel. After application of 9 mL of 400 mg/mL galactose-based microbubbles, CE-TCCS was performed. In subjects with MCA occlusion, CE-TCCS examinations were repeated within 24 h, 48 h and 5 days after stroke. In stroke patients (n = 20), CE-TCCS showed an occluded MCA main stem in 11 patients, and this vessel was clearly demonstrable on the unaffected side. On the affected side, the posterior cerebral artery (PCA) and anterior cerebral artery (ACA) could be visualized in 8 of 11 subjects; in 3 patients, at least 1 of these vessels was detectable. Angiographic studies confirmed the diagnosis of MCA trunk occlusion in all 11 individuals. In follow-up investigations, 3 stroke patients had angiographic and CE-TCCS examinations consistent with vessel reperfusion. Nine stroke patients had a patent MCA shown in angiographic and CE-TCCS examinations. In the control group, the MCA trunk could be visualized in all subjects by CE-TCCS. CE-TCCS is a sensitive and specific ultrasound method for the diagnosis of MCA trunk occlusion that overcomes the anatomical hindrance of inadequate acoustic bone window. This technique may help to identify patients suitable for thrombolytic therapies and monitor their response.

Topics: Aged; Aged, 80 and over; Angiography, Digital Subtraction; Arterial Occlusive Diseases; Brain Ischemia; Cerebral Arterial Diseases; Contrast Media; Female; Follow-Up Studies; Humans; Image Enhancement; Infusions, Intravenous; Magnetic Resonance Angiography; Male; Middle Aged; Polysaccharides; Temporal Bone; Tomography, X-Ray Computed; Ultrasonography, Doppler, Transcranial

Transcranial color Doppler sonography permits the accurate assessment of intracranial arteries. The latest Doppler units, using the color and power techniques, can show even very small flow volumes (1 x 1 mm). Low frequency (2-2.5 MHz) and very focused transducers are used in transcranial color Doppler. The skull is a very strong barrier for ultrasounds, which requires the use of some acoustic windows like some thin portions of the skull bone or some natural skull foramina. The use of echocontrast agents in color Doppler seems to increase the applications of transcranial studies.. (1) To report on transcranial color Doppler technique and findings. (2) To assess the role of contrast agents in the visualization of intracranial vessels. (3) To define the main indications of this technique.. The temporal, the orbital and the suboccipital are the main acoustic windows used for transcranial color Doppler studies. We use phased-array transducers (2-2.5 MHz) and, preferrably, the echocontrast agent. We examined 15 patients with severe internal carotid artery stenoses after the infusion of Levovist (Schering AG, Berlin, Germany) suspension (8 ml at 300 mg Galactose/ml, infused at 0.5 ml/s).. Levovist infusion permitted to depict the main intracranial vessels in all cases. The middle and the anterior cerebral arteries are shown through the temporal window. The former is the main cerebral artery, it is the easiest to identify and presents the highest peak systolic velocity. The orbital window can be used to visualize the ophthalmic artery and the internal carotid artery siphon, while the vertebral and the basilar arteries are demonstrated through the suboccipital window.. We report the most important findings and discuss the main indications of transcranial color Doppler studies. In addition to flow presence and direction, the main indices of arterial flow can be measured thanks to contrast agent administration, namely the peak systolic velocity, the end diastolic velocity, the resistance index and the pulsatility index. A morphological assessment of the Willis circle can also be carried out with color and power Doppler. Functional studies can be performed to assess the residual autoregulatory function of the cerebral circle in the patients with internal carotid artery stenosis or occlusion. The development of intracranial collateral circles can also be studied in these patients. Moreover, the M1 segment of the middle cerebral artery and the internal carotid artery siphon can be demonstrated directly. Transcranial color Doppler is also a useful tool to detect vasospasm after subarachnoid hemorrhage and to monitor blood flow velocity in the middle cerebral artery during carotid endarterectomy. The assessment of blood supply to arteriovenous malformations and to intracranial neoplasms is another application.. With reference to internal carotid stenoses, the main applications of transcranial color Doppler are the study of intracranial vessels, of intracranial arterial stenosis, of arteriovenous malformations and of Willis circle aneurysms, as well as the monitoring of blood flow velocity during carotid endarterectomy. Echocontrast agents play an important role in the visualization of intracranial vessels.

Topics: Arterial Occlusive Diseases; Blood Flow Velocity; Brain; Carotid Stenosis; Contrast Media; Humans; Polysaccharides; Reference Values; Sensitivity and Specificity; Subarachnoid Hemorrhage; Ultrasonography, Doppler, Color; Ultrasonography, Doppler, Transcranial

Levovist, a new echo-enhancing agent, is proclaimed to give more information about blood flow and therefore might be supposed to show the true intravascular lumen. Thus, it has to be shown whether such an echo-enhancing agent influences the sonographic estimation of vascular stenosis. We investigated 32 patients with PAOD and a single stenosis in the iliacal or femoral arteries (mean age 54+/-13 years) using a color Doppler sonographic equipment with a 5.4 or 7.3 MHz linear transducer. Levovist was given in a concentration of 200 mg/ml i.v with a total dose of 4 g. We did two measurements before the application of Levovist. Peak systolic velocity ratio (PSVR) was 6.5+/-3.6 and 6.4+/-3.8 before and 6.3+/-4.2 after application of Levovist. Sonographic diameter reduction was 59+/-15 and 62+/-16% before, and 60+/-16% after application. Diameter reduction in angiography was 65+/-13%. Reduction of the cross section area was 81+/-14 and 83+/-15% before, and 83+/-16% after application. The use of the echo-enhancing agent Levovist does not influence the calculation of the peak systolic velocity ratio, diameter reduction or cross section area reduction. The degree of the stenosis calculated from the sonographic reduction in diameter tended to be smaller than in angiography either with or without Levovist.

Topics: Angiography; Arterial Occlusive Diseases; Blood Flow Velocity; Blood Pressure; Contrast Media; Female; Femoral Artery; Humans; Iliac Artery; Image Enhancement; Infusions, Intravenous; Male; Middle Aged; Polysaccharides; Reproducibility of Results; Severity of Illness Index; Ultrasonography, Doppler, Color

The effect of continuous infusion of a signal enhancer on the diagnostic efficacy of Doppler ultrasound in peripheral artery disease was evaluated.. 35 patients with peripheral artery disease were investigated by Doppler ultrasound before and during infusion of a signal enhancer (Levovist). Femoral and popliteal arteries were examined. Angiographic diagnoses included occlusions (24) and stenoses (22). They were compared to plain and enhanced Doppler findings. Artefacts and effects on signal intensity were evaluated.. An increased Doppler signal was observed starting 1 min 35 s (mean) after begin of the infusion. It persisted for 11 min 46 s (mean). Signal enhanced studies provided less over- (0/1) and underestimation (3/5) of the findings and evaluation in the adductor channel was less compromised. Signal enhanced studies highlighted collaterals.. Doppler ultrasound in patients with peripheral arterial disease is improved by continuous application of a signal enhancer.

Topics: Adult; Aged; Arterial Occlusive Diseases; Artifacts; Contrast Media; Female; Femoral Artery; Humans; Infusions, Intravenous; Male; Middle Aged; Polysaccharides; Popliteal Artery; Radiography; Reproducibility of Results; Sensitivity and Specificity; Ultrasonography, Doppler, Color

Ultrasound contrast agents (US-CA) amplify reflected sound waves. Most substances used as contrast agents are destroyed when passing the lungs. SH U 508 is a new US-CA that can pass the lungs without impairment after peripheral intravenous application. In a clinical trial of this US-CA, we investigated its effect on the visualization of blood movement in peripheral arteries by color-coded Duplex sonography (CCDS). The leg arteries of 20 patients with severe chronic arterial occlusion were examined by CCDS (QAD I and Platinum) after i.v. application of the US-CA. After passage of the pulmonary capillaries, the US-CA amplified blood flow signals in the arterial system in a dose-dependent manner with both systems used. Undesired side-effects were not observed. The amplification produced by appropriate concentrations of the US-CA markedly improved the visualization of blood movement. Further studies are required to determine the optimal dosage and application technique as well as the indication for using this US-CA.

Topics: Adult; Aged; Aged, 80 and over; Arterial Occlusive Diseases; Blood Flow Velocity; Contrast Media; Female; Humans; Image Processing, Computer-Assisted; Male; Middle Aged; Polysaccharides; Ultrasonography