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At least 145 records · Page 8Linked to original sources
PubMed1991

Hepatic focal nodular hyperplasia: specific findings at dynamic contrast-enhanced US with carbon dioxide microbubbles.

Dynamic contrast material-enhanced ultrasonography (US) with intraarterial infusion of carbon dioxide microbubbles was performed for four cases of histologically proved focal nodular hyperplasia (FNH) in four patients and for 167 cases of various hepatic nodules in 144 patients. No complications due to dynamic US were observed in any of the 148 patients. All FNH nodules were less than 3 cm in diameter. Consistent specific findings of FNH were not obtained with US, computed tomography, magnetic resonance imaging, radiocolloid scanning, or angiography in the four cases of FNH. In contrast, the characteristic vascular pattern (ie, early central hypervascular supply with centrifugal filling to the periphery at the arterial phase and a uniform or lobulated dense stain at the capillary phase) was observed in all four cases of FNH with dynamic US. This vascular pattern demonstrated in FNH with dynamic US was not seen in any of the 167 hepatic nodules, including 44 small hepatocellular carcinomas less than 3 cm in diameter. Therefore, the newly developed, dynamic contrast-enhanced US technique seems to be extremely sensitive and specific for diagnosing FNH and is useful in the differentiation of FNH from other hepatic tumors, especially hepatocellular carcinoma.

Adult↗
PubMed1992

Small hepatocellular carcinoma: diagnosis with US angiography with intraarterial CO2 microbubbles.

Ultrasonographic (US) angiography enhanced with intraarterial CO2 microbubbles, a contrast material used in US imaging, was performed of 103 histologically proved hepatocellular carcinomas (HCCs) smaller than 3 cm in diameter in 95 patients. The detection rate for hypervascular HCC with US angiography was compared with the rate of detection with conventional angiography, digital subtraction angiography (DSA), and computed tomography (CT) after intraarterial injection of iodized oil. Sensitivity in detection of hypervascular HCCs with US angiography was 86% (89 of 103 HCCs), compared with 63% (44 of 70 HCCs) detected with conventional angiography, 70% (23 of 33 HCCs) with DSA, and 82% (75 of 91 HCCs) with CT with iodized oil. US angiography depicted small hypervascular HCCs, especially those less than 1 cm in diameter, and helped clarify vascularity as isovascular or hypovascular in angiographically undetectable HCCs. Findings at US angiography assisted the choice of a therapeutic strategy for treatment of HCC, such as transarterial therapy, percutaneous ethanol injection therapy, or resection.

Angiography, Digital Subtraction↗
PubMed1993

Hepatocellular carcinoma in adenomatous hyperplasia: detection with contrast-enhanced US with carbon dioxide microbubbles.

Adenomatous hyperplasia (AH) of the liver is considered a precancerous lesion because hepatocellular carcinoma (HCC) has been found in nodules of AH at histologic examination. Contrast material-enhanced ultrasound (US) with intraarterial infusion of carbon dioxide microbubbles was performed in four patients with HCC in AH lesions. In all four patients, a "hyperechoic focus in an area of hypoechoic change" in relation to the adjacent liver was demonstrated, compatible with the minimal vascular change associated with neoplastic transformation and carcinoma development. Because early detection of the minute cancer foci that may develop in an AH nodule is clinically important, this contrast-enhanced US technique may be a useful tool for the detection of these associated lesions.

Adenoma↗
PubMed1996

Analysis of regional cerebral blood flow in dogs, with an experimental microbubble-based US contrast agent.

PURPOSE: To evaluate a perfluorochemical stabilized microbubble-based ultrasound (US) contrast agent (Imagent US, formulation AF0145) create regional cerebral blood flow (CBF) maps. MATERIALS AND METHODS: Intravenous injections of the contrast agent (0.16-0.20 mL/kg) were performed in four anesthetized dogs (9-14 kg). Serial coronal color-Doppler-amplitude and gray-scale US scans were obtained through a cranial window during injection of contrast material. Mean pixel intensity was analyzed on digitized images. Regional CBF was varied by modifying arterial partial pressure of carbon dioxide (PaCO2). Color-Doppler-amplitude and gray-scale mean pixel intensity and percentage change in mean pixel intensity after injection of contrast material were analyzed, by means of a bolus injection curve that plotted color mean pixel intensity per unit area versus time. RESULTS: Contrast material injection resulted in a statistically significant difference in color-Doppler-amplitude and gray-scale enhancement of brain. Color mean pixel intensity increased from 1.4 units +/- 1 (standard error) to 122 units +/- 6 in thalamus and from 9.7 units +/- 4.0 to 107 units +/- 9 in cortex (P < .0001). Gray-scale mean pixel intensity increased from 0.55 units +/- 0.20 to 33 units +/- 11 in thalamus and from 0.42 units +/- .06 to 10.5 units +/- 2.0 in cortex (P < .005). Correlation between the area under the color-Doppler-amplitude mean-pixelintensity curve and regional CBF in thalamus and cortex was significant (r = .815, P < .0001). CONCLUSION: Color-Doppler-amplitude US can be used to create regional CBF maps and shows potential for noninvasive evaluation of CBF in the critically ill newborn.

Animals↗
PubMed1978

Microbubble elimination during priming improves biocompatibility of membrane oxygenators.

We tested the hypothesis that platelet loss following blood contact with foreign materials is partly related to the presence of microbubbles of gas (gas nuclei) trapped in surface defects on the membrane material. Extracorporeal membrane oxygenator perfusions were conducted in two groups of sheep, with use of standard priming techniques for the oxygenator in one group and a new vacuum priming technique in the other group. The vacuum priming technique was developed to eliminate gas nuclei from the oxygenator surface. With denucleation priming, platelet loss during perfusion was markedly reduced, as was thrombus formation on the membrane surface. The platelet particle-size distribution curve showed a shift consistent with platelet aggregation with the standard priming technique but not with the vacuum priming technique. We conclude that the elimination of trapped gas nuclei from the membrane surface during priming reduces the initial interaction between blood elements and the foreign surface.

Animals↗
PubMed1996

Detection of hepatocellular carcinoma by intraarterially enhanced ultrasonography with CO2 microbubbles. Comparison with DSA, dynamic CT, and Lipiodol CT.

PURPOSE: To evaluate the diagnostic value of contrast-enhanced US with CO2 microbubbles (EU) for HCCs. Detectability was compared with DSA, dynamic CT, and Lipiodol CT. MATERIAL AND METHODS: Forty-seven histologically proven HCCs detected with US were evaluated with EU, DSA, and dynamic CT. In 23 patients (35 lesions), Lipiodol CT was also performed. The size of the tumors ranged from 8 to 71 mm (average 28.1 mm); 24 lesions were smaller than 20 mm and 23 lesions were larger than 20 mm. RESULTS: Overall detection was possible in 40 of 47 lesions (85%) by EU, in 32 of 47 (68%) by DSA, in 33 of 47 (74%) by dynamic CT, and in 27 of 35 (77%) by Lipiodol CT. In tumors smaller than 20 mm, detection was possible in 21 of 24 lesions (88%) by EU, 14 of 24 (58%) by DSA, 14 of 24 (58%) by dynamic CT, and 11 of 17 (65%) by Lipiodol CT. CONCLUSION: EU has significant diagnostic value for detection of HCCs, particularly tumors smaller than 20 mm.

Angiography, Digital Subtraction↗
PubMed1992

Sonography with intraarterial infusion of carbon dioxide microbubbles (sonographic angiography): value in differential diagnosis of hepatic tumors.

Differential diagnosis of small liver tumors is important, but is not always possible, even with angiography. To solve this problem, we introduced sonographic angiography, which combines sonography and angiography. The vascular pattern of a variety of hepatic nodules was evaluated with sonographic angiography, and the results were compared with those of conventional angiography. Sonographic angiography (sonography performed during intraarterial infusion of carbon dioxide microbubbles) was performed in 184 patients with a total of 222 hepatic nodules: 139 hepatocellular carcinomas, nine adenomatous hyperplasias, seven regenerative nodules, 21 hemangiomas, 33 metastases, seven lymphomas, one granuloma, and five focal nodular hyperplasias. Sonographic angiography detected a hypervascular pattern with peripheral blood supply in cases of hepatocellular carcinoma (sensitivity, 90%; specificity, 89%). Typical vascular patterns of adenomatous hyperplasia, hemangioma, metastasis, and focal nodular hyperplasia on sonographic angiography were hypovascularity (sensitivity, 100%; specificity, 91%), spotty pooling (sensitivity, 100%; specificity, 100%), peripheral hypervascularity (sensitivity, 64%; specificity, 100%), respectively. The detectability of hypervascularity was greater with sonographic angiography than with conventional angiography in hepatocellular carcinoma, metastasis, and hemangioma. Our experience indicates that sonographic angiography depicts characteristic vascular features that reflect the vascular anatomy of specific types of hepatic tumors, and thus is useful in the differential diagnosis of these lesions.

Carbon Dioxide↗
PubMed1985

[Prenatal assessment of fetal lung maturity by the stable microbubble method--fundamental and clinical study].

Diagnostic value of RDS was investigated by the Stable Microbubble Method. When this method was applied to the tracheal fluid of fetuses in rabbit (28 days of gestation), the PV curve and lung-thoracic compliance showed mature patterns in the test results for weak, medium, and strong as compared with those for zero and very weak in which they showed an immature pattern. Results by this method correlated with the DSPC level in human amniotic fluid, and were little affected by the contamination of meconium or fresh plasma. Amounts of DSPC were 0.69 +/- 0.05 (mg/dl, Mean +/- SE) in zero, 1.19 +/- 0.15 in very weak, 3.99 +/- 5.06 in weak, 6.58 +/- 2.01 in medium, and 7.70 +/- 1.15 in strong test results. The coefficient of correlation was 0.56 (p less than 0.01). In the clinical study, when the mature level was arbitrarily defined as weak, the diagnostic accuracy was 76.8%, false negative rate was 0%, and false positive rate was 27.5%. If the mature level was defined as very weak, the diagnostic accuracy was 94.2% and the false positive rate was 3.4%. But the false negative rate increased to 18.8%. The diagnostic accuracy of this method was higher than the double shake test (72.2%), and was as high as the measurement of the DSPC level (92.0%).

Amniotic Fluid↗
PubMed1985

A new method for assessing right-sided heart pressures using encapsulated microbubbles--a preliminary report.

A new noncatheter method for measuring pressures of the right side of the heart uses specially manufactured microbubbles of carbon dioxide injected into the peripheral venous system. Sudden expansion of these bubbles in the cardiac chambers causes bubble oscillations at a frequency that is primarily a function of surrounding pressure. The oscillations are recordable by a microphone on the chest wall. The preliminary experience has been in dogs and further development is needed before we can begin clinical testing of the method. In its current form, the potential for measuring higher systolic pressures seems better than that for lower diastolic pressures.

Animals↗
PubMedDate not supplied

Differential diagnosis of renal lesions with US-angiography using intra-arterial CO2 microbubbles.

To differentiate renal masses, 58 patients with renal masses (39 men and 19 women, aged 23-81 years [mean age 60 years]) underwent US-angiography with intra-arterial infusion of carbon dioxide (CO2) microbubbles during conventional angiography; 32 patients had renal cell carcinomas; nine, transitional cell carcinomas; nine, renal complicated cysts; four, angiomyolipomas; two, acute focal bacterial nephritis and hematomas. Renal masses were classified into six enhancement patterns of US-angiography. Thirty-one (97%) renal cell carcinomas were histologically alveolar type and demonstrated the well-enhancement pattern. All nine renal complicated cysts showed the non-enhancement pattern. Although transitional cell carcinomas did not show definite neovascularity on conventional angiography, they were classified as the well-enhancement pattern in 4/9 (44%) and poor-enhancement pattern in 5/9 (56%) on US-angiography. Four angiomyolipomas were homogeneously enhanced. Complicated cysts were clearly differentiated from renal cell carcinomas by the enhancement pattern on US-angiography. But the differentiation between renal cell carcinomas and angiomyolipomas was difficult. US-angiography is useful for detecting fine neovascularity of renal lesions and also for the differentiation or renal cell carcinomas from complicated cysts or transitional cell carcinomas during conventional angiography.

Angiomyolipoma↗
PubMed1997

Opacification of the thoracic aorta after venous injection of sonicated albumin microbubbles. Implications for aortic dissection.

This study was designed to assess the feasibility of thoracic aorta opacification after intravenous injection of sonicated albumin microbubbles in patients with and without aortic dissection. Twenty-one patients were studied by transesophageal echocardiography. In 11 patients without aortic dissection, the opacification of the left ventricular outflow tract, aortic root and descending aorta was evaluated. Ten patients with aortic dissection were studied to assess perfusion of the true and false lumen. The left ventricular outflow tract, aortic root and descending aorta were opacified in all patients, with a systolic increase in contrast at visual analysis and at videodensitometry. The differentiation between false and true lumen was improved and was crucial in 1 case of type A chronic dissection. The intimal tear was detected in 7/9 cases by color Doppler vs 9/9 cases by contrast echocardiography. The noninvasive ultrasound opacification of thoracic aorta is feasible and may improve the diagnosis of aortic dissection.

Adult↗
PubMed1997

[Percutaneous ethanol injection therapy by ethanol mixed with CO2 microbubble for hepatocellular carcinoma].

One of the shortcomings of percutaneous ethanol injection therapy (PEIT) for hepatocellular carcinoma (HCC) is that many sessions are necessary to accomplish the treatment. This may be caused by which the ultrasonography (US) image does not reflect correctly to the kinetics of injected ethanol into HCC nodule. It is considered that number of treatment sessions are able to be reduced if we just enough injected labelled ethanol under US into HCC nodule. Therefore, we tried PEIT by ethanol mixed with CO2 microbubble (CO2 ethanol). The injected CO2 ethanol was aquired as hyperechoic image without strong acoustic shadow to the end of injection. Consequently we could reduce the number of treatment sessions to almost 1 for lesions < or = 3 cm in diameter and markedly reduce total dose of injected ethanol. The detectable rate of CO2 ethanol leaked out HCC nodule was high. No serious complication occurred. There have been only 1 lesion of local recurrence and no case of intrahepatic and peritoneal dissemination for 11.5 months on average of observation after PEIT by CO2 ethanol (CO2PEIT). These findings suggest that CO2PEIT is useful method for reducing the number of treatment sessions and total dose of injected ethanol, moreover preventing complication by ethanol leakage.

Carbon Dioxide↗
PubMed1998

[Diagnosis of small hepatocellular carcinoma by US angiography with intraarterial CO2 microbubbles imaging].

US angiography, enhanced with intraarterial CO2 microbubbles imaging, documented 40 nodules of hepatocellular carcinoma (HCC) lesser than 20 mm in diameter in 34 patients, which were convinced histopathologically. As to the imaging acuity of arterial vascularity in nodules, US angiography was compared with DSA and US color angio. The detection of arterial vascularity was possible in 34 (85.0%) of 40 nodules by US angiography, 26 (65.0%) by DSA, and 28 (70.0 %) by US color angio. US angiography was available for detection of HCC, particularly with small HCC lesser than 20 mm in size.

Carbon Dioxide↗
PubMed1998

[Clinical diagnosis of pancreato-biliary lesions by ultrasound angiography with intra-arterial infusion of carbon dioxide microbubbles].

Ultrasound angiography (USAG), sonographic imaging of the blood flow with intra-arterial infusion of carbon dioxide (CO2) microbubbles, was applied to pancreato-biliary lesions. Hypervascular pattern was observed in all cases of gallbladder elevated lesions except for debris balls. However, the vascular pattern of CO2 inflow that many arterial vessels were branching off into the lesion was characteristic for gallbladder carcinomas. The hemodynamics of solid tumors of the pancreas with USAG were divided into three patterns. Most of hypovascular nodules were duct cell carcinomas, while inflammatory pancreatic masses always exhibited isovascular except for two cases of hypovascular pattern. Furthermore, islet cell tumors showed hypervascular. In cases of mucin-producing cystic tumors of the pancreas, excrescent nodules or thickened septa within the lesions were identified as hypervascular. Other cystic tumors of the pancreas also presented peculiar hemodynamics. Therefore USAG is potentially useful for detecting various vascular patterns of pancreato-biliary lesions, contributory as a diagnostic tool in this area.

Carbon Dioxide↗
PubMed1997

Transrectal ultrasound microbubble contrast angiography of the prostate.

BACKGROUND: Prostate cancer, suspected by serum prostate-specific antigen (PSA) elevation and/or digital abnormalities, is not always evident on gray-scale or color Doppler transrectal ultrasound (TRUS). EchoGen (Sonus Pharmaceuticals, Inc., Bothell, WA), a blood vessel image enhancer able to visualize smaller, low-flow vessels and thus possibly the microvascular angiogenesis often associated with cancer, was employed to see if it would improve prostate cancer detection, particularly in patients with a rising serum PSA and prior negative biopsies. METHODS: Color Doppler TRUS was performed before and after intravenous injection of 0.05 ml/kg of EchoGen. Random and/or specifically directed sextant TRUS biopsies were performed. RESULTS: Fifteen patients with serum PSA elevations were included in the study. Fourteen had a negative prior biopsy (1-3 x). Prostate cancer was detected in 5 patients. Microvascular patterns were judged abnormal in 8 patients, 2 of which proved malignant, 2 of which were benign, and 1 of which was diagnosed with prostatis. False-negative results were observed in 3 patients, whose positive biopsy sites were from the prostate apex. CONCLUSIONS: Following EchoGen administration, prostate blood vessel image enhancement was noted in all patients, and there were no adverse reactions during or after EchoGen administration with the dose employed.

Aged↗