1
|
Abstract
Gas-filled microbubbles are currently in clinical use as blood pool contrast agents for ultrasound imaging. The goal of this review is to discuss the trends and issues related to these relatively unusual intravascular materials, which are not small molecules per se, not polymers, not even nanoparticles, but larger micrometer size structures, compressible, flexible, elastic, and deformable. The intent is to connect current research and initial studies from 2 to 3 decades ago, tied to gas exchange between the bubbles and surrounding biological medium, in the following areas of focus: (1) parameters of microbubble movement in relation to vasculature specifics; (2) gas uptake and loss from the bubbles in the vasculature; (3) adhesion of microbubbles to target receptors in the vasculature; and (4) microbubble interaction with the surrounding vessels and tissues during insonation.Microbubbles are generally safe and require orders of magnitude lower material doses than x-ray and magnetic resonance imaging contrast agents. Application of microbubbles will soon extend beyond blood pool contrast and tissue perfusion imaging. Microbubbles can probe molecular and cellular biomarkers of disease by targeted contrast ultrasound imaging. This approach is now in clinical trials, for example, with the aim to detect and delineate tumor nodes in prostate, breast, and ovarian cancer. Imaging of inflammation, ischemia-reperfusion injury, and ischemic memory is also feasible. More importantly, intravascular microbubbles can be used for local deposition of focused ultrasound energy to enhance drug and gene delivery to cells and tissues, across endothelial barrier, especially blood-brain barrier.Overall, microbubble behavior, stability and in vivo lifetime, bioeffects upon the action of ultrasound and resulting enhancement of drug and gene delivery, as well as targeted imaging are critically dependent on the events of gas exchange between the bubbles and surrounding media, as outlined in this review.
Collapse
Affiliation(s)
- Alexander L Klibanov
- From the Cardiovascular Division, Department of Medicine and Robert M. Berne Cardiovascular Research Center, University of Virginia School of Medicine; and Departments of Biomedical Engineering, and Radiology, University of Virginia, Charlottesville, VA
| |
Collapse
|
2
|
Diebold B. Contrast echocardiography, tumors and thrombus: a new episode in a 50-year history. Arch Cardiovasc Dis 2009; 102:163-4. [PMID: 19375668 DOI: 10.1016/j.acvd.2009.02.004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/20/2009] [Accepted: 02/20/2009] [Indexed: 12/18/2022]
|
3
|
Bierig SM, Mikolajczak P, Herrmann SC, Elmore N, Kern M, Labovitz AJ. Comparison of myocardial contrast echocardiography derived myocardial perfusion reserve with invasive determination of coronary flow reserve. EUROPEAN JOURNAL OF ECHOCARDIOGRAPHY 2008; 10:250-5. [DOI: 10.1093/ejechocard/jen217] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
|
4
|
van der Heide J, Mannaerts H, Yang L, Sieswerda G, Visser† C, Kamp O. Contrast-enhanced versus non-enhanced three-dimensional echocardiography of left ventricular volumes. Neth Heart J 2008; 16:47-52. [PMID: 18335021 PMCID: PMC2245811 DOI: 10.1007/bf03086117] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
BACKGROUND In three-dimensional echocardiography (3DE), individual endocardial trabeculae are not clearly visible necessitating left ventricular (LV) volumes to be measured by tracing the innermost endocardial contour. Ultrasound contrast agents aim to improve endocardial definition, but may delineate the outermost endocardial contour by filling up intertrabecular space. Although measurement reproducibility may benefit, there may be a significant influence on absolute LV volume measurements. METHODS Twenty patients with a recent myocardial infarction and good ultrasound image quality underwent 3DE using the TomTec Freehand method before and during continuous intravenous contrast infusion. LV volumes were measured offline using TomTec Echo-Scan software. RESULTS The use of contrast enhancement increased end-diastolic (110+/-35 vs. 144+/-53 ml; p<0.01) and end-systolic volume measurements (68+/-31 vs. 87+/-45 ml; p<0.01) significantly compared with non-contrast; the ejection fraction remained unchanged (40+/-13 vs. 41+/-14%, p=NS). Measurement reproducibility did not improve significantly, however. CONCLUSION Volumes measured by 3DE are significantly larger when ultrasound contrast is used. Possibly, intertrabecular space comprises a substantial part of the LV cavity. In the presence of an adequate apical acoustic window, ultrasound contrast does not improve LV volume measurement reproducibility. (Neth Heart J 2008;16:47-52.).
Collapse
Affiliation(s)
- J.A. van der Heide
- Department of Cardiology, VU University Medical Centre, Amsterdam, the Netherlands
| | - H.F.J. Mannaerts
- Department of Cardiology, VU University Medical Centre, Amsterdam, the Netherlands
| | - L. Yang
- Department of Cardiology, the Second Affiliated Hospital, Sun Yat-Sen University, Ghangzou, People’s Republic of China
| | - G.T. Sieswerda
- Department of Cardiology, VU University Medical Centre, Amsterdam, the Netherlands
| | - C.A. Visser†
- Department of Cardiology, VU University Medical Centre, Amsterdam, the Netherlands
| | - O. Kamp
- Department of Cardiology, VU University Medical Centre, Amsterdam, the Netherlands
| |
Collapse
|
5
|
Zachary JF, Blue JP, Miller RJ, O'Brien WD. Vascular lesions and s-thrombomodulin concentrations from auricular arteries of rabbits infused with microbubble contrast agent and exposed to pulsed ultrasound. ULTRASOUND IN MEDICINE & BIOLOGY 2006; 32:1781-91. [PMID: 17112964 PMCID: PMC1885542 DOI: 10.1016/j.ultrasmedbio.2005.11.013] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/28/2005] [Revised: 11/04/2005] [Accepted: 11/17/2005] [Indexed: 05/12/2023]
Abstract
Arterial injury resulting from the interaction of contrast agent (CA) with ultrasound (US) was studied in rabbit auricular arteries and assessed by histopathologic evaluation and s-thrombomodulin concentrations. Three sites on each artery were exposed (2.8 MHz, 5-min exposure duration, 10-Hz pulse repetition frequency, 1.4-mus pulse duration) using one of three in situ peak rarefactional pressures (0.85, 3.9 or 9.5 MPa). Saline, saline/CA, and saline/US infusion groups (n = 28) did not have histopathologic damage. The saline/CA/US infusion group (n = 10) at exposure conditions below the FDA mechanical index limit of 1.9 did not have histopathologic damage, whereas the saline/CA/US infusion group (n = 9) at exposure conditions above the FDA limit did have damage (5 of 9 arteries). Lesions were characteristic of acute coagulative necrosis. Mean s-thrombomodulin concentrations, a marker for endothelial cell injury, were highest in rabbits exposed to US at 0.85 and 3.9 MPa, suggesting that vascular injury may be physiological and not accompanied by irreversible cellular injury.
Collapse
Affiliation(s)
- James F Zachary
- Department of Pathobiology, College of Veterinary Medicine, University of Illinois at Urbana-Champaign, Urbana, IL 61802, USA.
| | | | | | | |
Collapse
|
6
|
Lohmaier S, Ghanem A, Veltmann C, Sommer T, Bruce M, Tiemann K. In vitro and in vivo studies on continuous echo-contrast application strategies using SonoVue in a newly developed rotating pump setup. ULTRASOUND IN MEDICINE & BIOLOGY 2004; 30:1145-1151. [PMID: 15550318 DOI: 10.1016/j.ultrasmedbio.2004.07.019] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/31/2003] [Revised: 07/20/2004] [Accepted: 07/29/2004] [Indexed: 05/24/2023]
Abstract
With emerging imaging strategies for contrast sonography (CS), there is a rising demand for the precise control of ultrasound (US) contrast agent delivery. Constant delivery minimizes artefacts and improves efficacy. The aim of this study was to evaluate the physical properties of the new contrast agent SonoVue and to evaluate the feasibility and accuracy of a new infusion approach using an automated infusion system for contrast agitation and delivery of echo-contrast agents. In vitro testing of infusion properties of SonoVue were performed in a capillary phantom mimicking tissue perfusion. Nonagitated standard infusion setups were compared with hand agitation and the new pump system with respect to possible artefacts, constancy of contrast effect and efficacy. In three volunteers, the new pump system was tested for constancy of contrast in large vessels. Without continuous agitation, continuous infusion of SonoVue resulted in bolus-like signal-intensity curves, along with substantial imaging artefacts. Additionally, homogenization of SonoVue significantly improved efficacy (p < 0.0001). No significant differences were found between hand agitation and homogenization by the new pump. In clinical settings, constant agitation using the new pump resulted in constant signal conditions in the carotid artery 3.72 +/- 0.46 units (U) after 5 min. Continuous agitation of SonoVue is mandatory for quantitative approaches. By the new infusion technique, CS could be performed for a reasonably long time period and efficacy is significantly improved (p < 0.0001). The new infusion technique might thereby allow routine application of constant infusion scenarios in clinical CS.
Collapse
|
7
|
Bransford TL, Bierig SM, Habermehl K, Labovitz AJ. Instantaneous quantitative video intensity heterogeneity: evaluation with low mechanical index contrast echocardiography. Echocardiography 2004; 21:509-15. [PMID: 15298686 DOI: 10.1111/j.0742-2822.2004.03053.x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Abstract
BACKGROUND Instantaneous video intensity of myocardium has been poorly characterized. Myocardial video intensity is usually displayed in the fitted curve from the exponential equation, y = a(1 - e (-bt)). However, information from the fitted curve will be as accurate as the original video intensity data from the perfusion image. Therefore, we sought to characterize the intramyocardial instantaneous video intensity from low mechanical index (MI) contrast echo imaging for variation. METHOD Low-MI imaging using a nonlinear cancellation technique was performed on 10 subjects with normal myocardium. Quantitative video intensity was analyzed in five segments in the epicardium and subendocardium, as well as in systole and diastole. RESULTS Video intensity varied between the epicardium and endocardium in each of the region that was analyzed, with the greatest variation in the inferior region (P < 0.0001). Diastolic and systolic differences were also present. CONCLUSION Instantaneous video intensity is heterogeneous within the myocardium. Differences can result from attenuation, myocardial fiber structure, and even isotropic effects of the contrast agent, and should be taken into account when data are fitted into an exponential function.
Collapse
|
8
|
Li P, Cao LQ, Dou CY, Armstrong WF, Miller D. Impact of myocardial contrast echocardiography on vascular permeability: an in vivo dose response study of delivery mode, pressure amplitude and contrast dose. ULTRASOUND IN MEDICINE & BIOLOGY 2003; 29:1341-9. [PMID: 14553812 DOI: 10.1016/s0301-5629(03)00988-8] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
An in vivo rat model of myocardial contrast echocardiography (MCE) was defined and used to examine the dose range response of microvascular permeabilization and premature ventricular contractions (PVCs) with respect to method of imaging, peak rarefactional pressure amplitude (PRPA) and agent dose. A left ventricular short axis view was obtained on anesthetized rats at 1.7 MHz using a diagnostic ultrasound system with simultaneous ECG recording. Evans blue dye, a marker for microvascular leakage, and a bolus of Optison were injected i.v. Counts of PVCs were made from video tape during the 3 min of MCE. Hearts were excised 5 min after imaging and petechial hemorrhages, Evans blue colored area and Evans blue content were determined. No PVCs or microvascular leakage were seen in rats imaged without contrast agent followed by contrast agent injection without imaging. When PVCs were detected during MCE, petechial hemorrhages and Evans blue leakage were also found in the myocardium. Triggering 1:4 at end-systole produced the most PVCs per frame and most microvascular leakage, followed by end-systole 1:1, continuous scanning and end-diastole triggering 1:1. All effects increased with increasing Optison dosage in the range 25 to 500 microL kg(-1). Ultrasound PRPA was important, with apparent thresholds for PVCs at 1.0 MPa and for petechiae at 0.54 MPa. PVCs, petechial hemorrhages and microvascular leakage in the myocardium occur as a result of MCE in rats.
Collapse
Affiliation(s)
- Peng Li
- Department of Cardiology, University of Michigan, Ann Arbor, MI 48109-0553, USA
| | | | | | | | | |
Collapse
|
9
|
Kontos MC, Hinchman D, Cunningham M, Miller JJ, Cherif J, Nixon JV. Comparison of contrast echocardiography with single-photon emission computed tomographic myocardial perfusion imaging in the evaluation of patients with possible acute coronary syndromes in the emergency department. Am J Cardiol 2003; 91:1099-102. [PMID: 12714154 DOI: 10.1016/s0002-9149(03)00156-5] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Affiliation(s)
- Michael C Kontos
- Medical College of Virginia, Virginia Commonwealth University, Richmond, Virginia 23298, USA
| | | | | | | | | | | |
Collapse
|
10
|
Ishikura F, Beppu S, Ueda H, Kayano H, Asanuma T, Otani K. Delayed Opacification of the Coronary Bypass Region Detected by Intravenous Myocardial Contrast Echocardiography. J Echocardiogr 2003. [DOI: 10.2303/jecho.1.1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
|
11
|
Zachary JF, Hartleben SA, Frizzell LA, O'Brien WD. Arrhythmias in rat hearts exposed to pulsed ultrasound after intravenous injection of a contrast agent. JOURNAL OF ULTRASOUND IN MEDICINE : OFFICIAL JOURNAL OF THE AMERICAN INSTITUTE OF ULTRASOUND IN MEDICINE 2002; 21:1347-1345. [PMID: 12494976 DOI: 10.7863/jum.2002.21.12.1347] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
OBJECTIVE To develop an animal model suitable for characterizing electrocardiographic arrhythmias in hearts exposed to ultrasound after injection of a microbubble contrast agent. METHODS Conduction complex and heart lesion data were recorded from 20 rats that received intravenous injections of 0.25 mL of a contrast agent and were exposed to pulsed ultrasound (frequency, 3.1 MHz; pulse duration, 1.3 microseconds; pulse repetition frequency, 1700 Hz; and in situ peak rarefactional pressure, 15.9 MPa). The volume of the contrast agent based on body weight and the mechanical index (ultrasonic pressure) exceeded those used in echocardiography by 14 to 345 and 3 to 29 times, respectively. RESULTS Premature atrial complexes, premature ventricular complexes, or polymorphic ventricular tachycardia occurred in 10 rats. When ultrasound exposure was halted, arrhythmias ceased but reoccurred in 4 of the 10 rats when exposure resumed. Myocardial degeneration identified by histochemical staining (hematoxylin-basic fuchsinpicric acid) was observed in 16 rats; however, only 10 rats had arrhythmias. There was no significant difference in the amount of histochemical staining in hearts from rats with arrhythmias when compared with rats without arrhythmias. CONCLUSIONS An animal model suitable for characterizing electrocardiographic arrhythmias in rat hearts exposed to ultrasound after injection of a microbubble contrast agent was developed. Because arrhythmias were induced principally when the contrast agent interacted with ultrasound during exposure, the presence of myocardial degeneration alone was not a sufficient explanation for ectopic electrical activity. Under these extreme exposure conditions, the data suggest that pulsed ultrasound through its biomechanical interactions with contrast agents has the potential to induce arrhythmias.
Collapse
Affiliation(s)
- James F Zachary
- Bioengineering Program, University of Illinois at Urbana-Champaign, 61802, USA
| | | | | | | |
Collapse
|
12
|
Kuersten B, Nahar T, Vannan MA. Methods of contrast administration for myocardial perfusion imaging: continuous infusion versus bolus injection. Am J Cardiol 2002; 90:35J-37J. [PMID: 12450589 DOI: 10.1016/s0002-9149(02)02946-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The debate over the optimal contrast administration method involves many issues. This article discusses bolus versus infusion administration pertaining to myocardial perfusion imaging. Continuous infusion ensures efficient and optimal data capture during contrast studies and is preferred over bolus injection for both theoretical and practical reasons. Although bolus administration is easier, its relative disadvantages outweigh its usefulness in myocardial perfusion imaging.
Collapse
Affiliation(s)
- Bettina Kuersten
- Division of Cardiology, Department of Medicine, MCP Hahnemann University, Philadelphia, Pennsylvania 19102, USA
| | | | | |
Collapse
|
13
|
Bierig SM, Dittrich T. Clinical Application and Technical Considerations for the Use of Contrast Agents in the Echocardiography Laboratory. JOURNAL OF DIAGNOSTIC MEDICAL SONOGRAPHY 2002. [DOI: 10.1177/87579302018003001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Contrast imaging represents a new and exciting application to the field of ultrasonography. As with the introduction of new imaging modes (i.e., color flow imaging) or examination (i.e., stress echocardiog-raphy), a learning phase will be necessary. For optimal contrast use, it is important to understand what microbubbles are designed to enhance, how to optimize the imaging system, and how to interpret the resulting images. Types of administration and use of the agents are also important to understand. This article will offer technical tips and helpful hints to shorten the sonographer's learning curve to successfully implement optimal contrast imaging for cardiac applications.
Collapse
Affiliation(s)
- S. Michelle Bierig
- Echocardiography Laboratory, Department of Cardiology, St. Louis University Health Science Center, 14th Floor,3635 Vista Avenue at Grand, St. Louis, MO 63110
| | - Teri Dittrich
- Echocardiography Laboratory, St. Louis University Health Science Center, St. Louis, Missouri
| |
Collapse
|
14
|
Bierig SM, Herrmann SC. Feasibility of Performing Real-Time Myocardial Contrast Echocardiography During Clinical Dobutamine Stress Echocardiography in Technically Difficult Patients. JOURNAL OF DIAGNOSTIC MEDICAL SONOGRAPHY 2002. [DOI: 10.1177/875647930201800104] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Myocardial contrast echocardiography (MCE) has emerged as an alternative to nuclear medicine perfusion imaging. The aim of this study was to evaluate the feasibility of performing and the interpretation of MCE for perfusion imaging in a clinical laboratory. The study population consisted of 150 consecutive patients referred for dobutamine stress echocardiography (DSE) to determine the presence of myocardial ischemia. Echocardiographic perfusion images were digitized at rest and at peak dobutamine infusion for later review. A total of 12 myocardial segments in the apical four and two chamber views were graded as no perfusion, minimal perfusion, definite perfusion, or not able to evaluate. Of 3600 possible segments, a total of 2926 (81%) were able to be graded at either rest or peak dobutamine. At rest, 79% of segments were graded for perfusion (1419 of 1800 segments). At peak dobutamine infusion, 84% of segments were graded for perfusion (1507 of 1800 segments). The results demonstrate that MCE is clinically feasible to perform and interpret during DSE on a routine daily basis.
Collapse
Affiliation(s)
- S. Michelle Bierig
- Echocardiography Laboratory, St. Louis University Health Science Center, Department of Cardiology, 14th Floor, 3635 Vista Avenue at Grand, St. Louis, MO 63110
| | - Steven C. Herrmann
- Echocardiography Laboratory, St. Louis University Health Science Center, St. Louis, Missouri
| |
Collapse
|
15
|
Belohlavek M, Asanuma T, Kinnick RR, Greenleaf JF. Vibro-acoustography: quantification of flow with highly-localized low-frequency acoustic force. ULTRASONIC IMAGING 2001; 23:249-256. [PMID: 12051277 DOI: 10.1177/016173460102300403] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
The intersection of two ultrasound beams with slightly different frequencies results in generation of a localized radiation force and stimulates emission of audio signals from targeted objects. Vibro-acoustography uses this phenomenon to probe elastic properties of objects. Vibro-acoustography of contrast microbubbles in degassed water produced quantitative flow measurements from analysis of their acoustic emission. We used a dual-beam transducer generating bursts of 40-kHz vibrations. The vibrations resulted from interference of 3.48-MHz and 3.52-MHz confocal beams intersecting at the center of a thin plastic conduit. We tested flows of 13,48, 85, and 120 mL/min of contrast microbubbles at concentrations from 1.2 x 10(5) to 6 x 10(9) bubbles/mL. The amplitude of the acoustic emission was linear with microbubble concentrations up to a value of 3.6 x 10(5) bubbles/mL. A replenishment method for microbubble contrast and flow rate analysis was used with radiation force bursts deployed at 0.05, 0.1, 0.2, (.5, 1, and 2-second pulsing intervals. The relation between the pulsing intervals and the peak amplitude was fitted by an exponential curve and a rate constant calculated for each tested flow rate. The rate constant values were linearly correlated with the tested flows. The vibro-acoustography method provides objective, quantitative, and highly-localized assessment of flow using contrast microbubbles.
Collapse
Affiliation(s)
- M Belohlavek
- Division of Cardiovascular Diseases and Internal Medicine, Mayo Clinic, Rochester, MN 55905, USA.
| | | | | | | |
Collapse
|
16
|
Handke M, Schäfer DM, Heinrichs G, Magosaki E, Lutter G, Dern P, Bode C, Geibel A. Improved 3-D-echocardiographic endocardial border delineation using the contrast agent FS069 (Optison) transesophageal studies in a porcine model. ULTRASOUND IN MEDICINE & BIOLOGY 2001; 27:1185-1190. [PMID: 11597358 DOI: 10.1016/s0301-5629(01)00415-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
3-D echocardiography has the potential for quantitative assessment of regional wall motion. However, the 3-D procedures used to date do not provide the same spatial and temporal resolution as 2-D echocardiography, which results in problems with border delineation of the endocardium. There are, as yet, few studies testing if the use of contrast agent can improve endocardial definition in the 3-D data set. FS069 (Optison) was used for the first time for this purpose in the present study. A total of 12 mechanically-ventilated pigs were examined by transesophageal 3-D echocardiography, 1. using fundamental imaging and 2. following left-atrial injection of FS069 (Optison). The left ventricle was analyzed using an 18-segment model. Score with the value 0 (not visible), 1 (moderately visible) and 2 (well defined) were used to rate endocardial definition. All segments were assessed both end-diastolic and end-systolic. Various LV regions were examined by grouping segments (anterior/lateral/inferior and basal/mid-ventricular/apical). Using the contrast agent, the proportion of nonvisible segments fell diastolic from 40 (18.5%) to 15 (6.9%), and systolic from 26 (12.0%) to 11 (5.1%). The proportion of well defined segments increased diastolic from 62 (28.7%) to 108 (50%) and systolic from 73 (33.8%) to 123 (56.9%). The mean visibility score increased diastolic from 1.10 +/- 0.68 to 1.43 +/- 0.62 (p < 0.001), systolic from 1.22 +/- 0.64 to 1.52 +/- 0.59 (p < 0.001). The benefit was greatest in regions where the visibility score was lowest without contrast: in the area of the lateral wall and systolic near the apex. In conclusion, the use of FS069 (Optison) results in significantly better endocardial delineation in the 3-D data set. This could be important in future for the 3-D echocardiographic assessment of regional wall motion.
Collapse
Affiliation(s)
- M Handke
- Department of Cardiology and Angiology, Albert Ludwigs University, Freiburg, Germany.
| | | | | | | | | | | | | | | |
Collapse
|
17
|
Kuntz-Hehner S, Goenechea J, Pohl C, Schlosser T, Veltmann C, Lentz C, Lohmaier S, Ehlgen A, Omran H, Becher H, Tiemann K. Continuous-infusion contrast-enhanced US: in vitro studies of infusion techniques with different contrast agents. Radiology 2001; 220:647-54. [PMID: 11526262 DOI: 10.1148/radiol.2203001628] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
PURPOSE To evaluate the infusion properties of three ultrasonographic (US) contrast agents and to compare different infusion techniques for achieving constant signals during harmonic power Doppler US. MATERIALS AND METHODS In vitro studies were performed in a flow phantom. SH U 508A, NC100100, or FS069 was continuously infused at clinically usable doses and infusion rates. To assess agent-specific physical properties, these agents were administered by using a vertically fixed infusion pump and varying infusion start times. The contrast agents were administered by also using a horizontally oriented infusion pump that was either fixed or continuously rotated to homogenize the agent in the syringe. RESULTS With SH U 508A and NC100100, constant signals were achieved, regardless of the infusion modality used. Compared with conventional infusion, the continuous homogenization of SH U 508A, although not necessary for signal constancy, increased the agent's usefulness (P <.05). With FS069, only continuous homogenization yielded constant signals (P <.001). CONCLUSION Continuous infusion of SH U 508A or NC100100 provided constant harmonic power Doppler US signals, regardless of the infusion modality used. Because of the special physical properties of FS069, only homogenization produced constant harmonic power Doppler US signals during continuous infusion of this agent.
Collapse
Affiliation(s)
- S Kuntz-Hehner
- Department of Cardiology, University of Bonn, Sigmund-Freud-Strasse 25, 53105 Bonn, Germany
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|