Contrast echocardiography clarifies uninterpretable wall motion in intensive care unit patients

OBJECTIVES: The study examined the value of contrast echocardiography in the assessment of left ventricular (LV) wall motion in intensive care unit (ICU) patients. BACKGROUND: Echocardiograms done in the ICU are often suboptimal. The most common indication is the evaluation of LV wall motion and ejection fraction (EF). METHODS: Transthoracic echocardiograms were done in 70 unselected ICU patients. Wall motion was evaluated on standard echocardiography (SE), harmonic echocardiography (HE), and after intravenous (IV) contrast echocardiography (CE) using a score for each of 16 segments. A confidence score was also given for each segment with each technique (unable to judge; not sure; sure). The EF was estimated visually for each technique, and a confidence score was applied to the EF. RESULTS: Uninterpretable wall motion was present in 5.4 segments/patient on SE, 4.4 on HE (p = 0.2), and 1.1 on CE (p < 0.0001). An average of 7.8 segments were read with surety on SE, 9.2 on HE (p = 0.1), and 13.7 on CE (p < 0.0001). Ejection fraction was uninterpretable in 23% on SE, 13% on HE (p = 0.14), and 0% on CE (p = 0.002 vs. HE; p < 0.0001 vs. SE). The EF was read with surety in 56% of patients on SE, 62% on HE (p = 0.47), and 91% on CE (p < 0.0001). Thus, wall motion was seen with more confidence on CE. More importantly, the actual readings of segmental wall motion and EF significantly differed using CE. CONCLUSIONS: CE should be used in all ICU patients with suboptimal transthoracic echocardiograms.     

Contrast harmonic imaging improves the evaluation of left ventricular function in ventilated patients: comparison with transesophageal echocardiography.

AIMS: The study examined the value of contrast echocardiography (CE) in the assessment of left ventricular (LV) wall motion in ventilated patients in comparison with transesophageal (TOE) and standard fundamental transthoracic imaging (SE). METHODS: Transthoracic echocardiograms were done in 40 ventilated patients. Wall motion was evaluated using the recommendations of the American Society of Echocardiography on SE, CE and TOE. A visualization score was assigned on a scale of 2-0 for each of 16 segments. The segment was assigned a value of 2 if the segment was seen in both systole and diastole, 1 if seen only in systole or diastole, and 0 if not seen at all. A confidence score was also given for each segment with each technique (unable to evaluate; not sure; sure). The ejection fraction (EF) was estimated visually for each technique, and a confidence score was also applied to the EF. RESULTS: Visualization score 0 was present in 6.2 segments/patient on SE, 1.2 on CE (P<0.0001) and 1.1 on TOE (P<0.0001). An average of 6.5 segments were read with surety on SE, 11.5 on CE (P<0.0001) and 12.3 on TOE ( P<0.0001 ). There was no significant difference for CE vs TOE. EF was uninterpretable in 32% on SE, 0% on CE (P<0.001 and 0% on TOE (P<0.001). The EF was read with surety in 53% of patients on SE, 88% on CE (P < 0.0001) and 93% with TOE (P<0.0001) with no difference for CE vs TOE. Thus, wall motion was seen with more confidence on CE and TOE. CONCLUSIONS: In the ventilated patients with suboptimal transthoracic echocardiograms for the evaluation of the LV function, CE provides image quality of regional and global LV function similar to that achieved with TOE echocardiography.     

Quantitative measurement of infarct size by contrast-enhanced magnetic resonance imaging early after acute myocardial infarction: comparison with single-photon emission tomography using Tc99m-sestamibi

OBJECTIVES: The aim of this research was to evaluate kinetics and extent of myocardial contrast enhancement (CE) in comparison with single-photon emission computed tomography (SPECT) early after acute myocardial infarction (AMI). BACKGROUND: Quantification of infarct size serves as a surrogate end point in evaluating new therapies of AMI. Contrast-enhanced magnetic resonance imaging (CeMRI) of the myocardium is a promising new method for identification of irreversible tissue injury. METHODS: A total of 33 patients were examined by CeMRI and SPECT 7 +/- 2 days after AMI and successful coronary intervention. After gadolinium-diethylenetraimine pentaacetic acid injection (0.2 mmol/kg), continuous short-axis slices of the left ventricle (LV) were acquired every 7 min up to 42 min using different inversion times (TI). Myocardial CE at each imaging time point was quantified and compared with corresponding SPECT perfusion defect. RESULTS: All patients showed myocardial CE in the infarct region. A constant TI for CeMRI resulted in a decrease of signal intensity and extent of CE on late acquisitions. With TI adjustment, infarct image intensity peaked at 21 min with a contrast of 478% of remote myocardium and remained at this level up to 42 min after contrast injection (437%); CE extent was stable over time and agreed well with SPECT within an average difference of 3% of the LV myocardium, yielding the best correlation at 28 min (r = 0.86). CONCLUSIONS: In patients after AMI and successful reperfusion, CE is stable over time and matches well with SPECT perfusion defect; CeMRI under standardized conditions can accurately assess myocardial infarct size in vivo and may be attractive for serving as a surrogate end point early after AMI.     

Differential diagnosis of cardiac masses using contrast echocardiographic perfusion imaging

OBJECTIVES: We investigated the usefulness of echocardiographic contrast perfusion imaging in differentiating cardiac masses. BACKGROUND: Two-dimensional echocardiography is the primary diagnostic modality for cardiac masses. However, differentiation between the different types of cardiac masses may be difficult at times. We hypothesized that echocardiographic contrast perfusion imaging would differentiate the neo-vascularization of malignancies from the avascularity of thrombi and the sparse vascularity of stromal tumors. METHODS: Sixteen patients with cardiac masses underwent power-modulation imaging after echocardiographic intravenous contrast administration. Pixel intensities in the mass and an adjacent section of myocardium were analyzed visually and by dedicated software. All masses had a pathologic diagnosis or resolved after anticoagulation. In a subset of patients, video-intensity curves of contrast replenishment in the mass and myocardium over time were generated. The post-impulse steady-state pixel intensity (A) and initial rate of contrast replenishment after impulse (beta) were compared with an index of blood vessel area on pathology. RESULTS: In seven of 16 patients, contrast enhancement resulted in greater pixel intensity in the mass than in the adjacent myocardium. All of these masses were classified pathologically as malignant (n = 6) or benign and vascular (n = 1). Nine masses demonstrated decreased pixel intensity, compared with the myocardium, and were diagnosed pathologically as myxomas (n = 2) or thrombi (n = 5), or they resolved with anticoagulation (n = 2). For the subset of patients, beta correlated with the vessel area index (r = 0.60). CONCLUSIONS: Echocardiographic contrast perfusion imaging aids in the differentiation of cardiac masses. Compared with the adjacent myocardium, malignant and vascular tumors hyper-enhanced, whereas stromal tumors and thrombi hypo-enhanced.     

Recognition of endoscopic diagnosis in differentiated-type early gastric cancer by flexible spectral imaging color enhancement with indigo carmine

Background/Aims: To evaluate the usefulness of flexible spectral imaging color enhancement with indigo carmine (I-FICE) in early gastric cancer (EGC) demarcation. Methods: The study participants were 29 patients with differentiated-type EGC. The endoscope was fixed and images of the same area of EGC demarcations in each lesion were obtained using four different methods (WLE, flexible spectral imaging color enhancement (FICE), CE, and I-FICE). FICE mode at R 550 nm (Gain: 2), G 500 nm (Gain: 4), and B 470 nm (Gain: 4) was used. Four endoscopists ranked the images obtained by each method on the basis of the ease of recognition of demarcation using a 4-point system. We calculated the standard deviation of pixel values based on L*, a*, and b* color spaces in the demarcation region (Lab-SD score). Results: The median ranking score for I-FICE images was significantly higher than that obtained from the other methods. Further, the average Lab-SD score was significantly higher for I-FICE images than for images obtained by the other methods. There was a good correlation between the ranking score and Lab-SD score. Conclusion: EGC demarcations were most easily recognized both subjectively and objectively using I-FICE image, followed by CE, FICE and WLE images.     

Differentiation of focal liver lesions using three-dimensional ultrasonography: Retrospective and prospective studies

AIM: To differentiate focal liver lesions based on enhancement patterns using three-dimensional ultrasonography (3D US) with perflubutane-based contrast agent.METHODS: Two hundred and eighty two patients with focal liver lesions,including 168 hepatocellular carcinomas (HCCs),63 metastases,40 hemangiomas and 11 focal nodular hyperplasias (FNHs),were examined by 3D US with perflubutane-based contrast agent.Tomographic ultrasound images and sonographic angiograms were reconstructed.Among 282 lesions,enhancemen...     

MR characteristics of progressive massive fibrosis

This study was performed to evaluate the static and dynamic magnetic resonance imaging (MRI) contrast enhancement pattern of progressive massive fibrosis (PMF) in coal workers' pneumoconiosis. Eighteen lesions in 12 patients were evaluated using a 1.5-T MR unit. T1-weighted FLASH images were obtained before and 0.5, 1, 2, 3, 4, 5, 7.5, 10, 12.5, and 15 minutes after injection of gadolinium diethylenetriamine penta-acetic acid (Gd-DTPA; 0.1 mmol/kg). Imaging findings, the contrast enhancing pattern, enhancement time curve, and the contrast uptake equivalent (CE; mmol/L) were evaluated. On T1-weighted images, 14 lesions showed high signal intensity, and four showed low signal intensity. On T2-weighted images, all lesions were of low signal intensity and were indistinguishable from aerated lung parenchyma. After contrast infusion, all lesions except two enhanced markedly. The time enhancement curve showed a marked, gradual increase in signal intensity up to 3 minutes, a subtle increase in signal intensity up to 7.5 minutes, and then a plateau until 15 minutes after Gd-DTPA injection. Characteristic MR findings of PMF in coal workers' pneumoconiosis include T1 high signal intensity, T2 low signal intensity, and marked postinfusion enhancement. The time enhancement curve shows a marked, gradual increase of signal intensity up to 3 minutes and plateau up to 15 minutes.     

Long-term outcome in patients with obscure gastrointestinal bleeding after negative capsule endoscopy

AIM:To investigate long-term outcome in obscure gastrointestinal bleeding(OGIB) after negative capsule endoscopy(CE) and identify risk factors for rebleeding.METHODS:A total of 113 consecutive patients underwent CE for OGIB from May 2003 to June 2010 at Seoul National University Hospital.Ninety-five patients(84.1%) with a subsequent follow-up after CE of at least 6 mo were enrolled in this study.Follow-up data were obtained from the patients’ medical records.The CE images were reviewed by two board-certified gastroenterologists and consensus diagnosis was used in all cases.The primary outcome measure was the detection of rebleeding after CE,and factors associated with rebleeding were evaluated using multivariate analysis.RESULTS:Of the 95 enrolled patients(median age 61 years,range 17-85 years),62 patients(65.3%) were male.The median duration of follow-up was 23.7 mo(range 6.0-89.4 mo).Seventy-three patients(76.8%) underwent CE for obscure-overt bleeding.Complete examination of the small bowel was achieved in 77 cases(81.1%).Significant lesions were found in 38 patients(40.0%).The overall rebleeding rate was 28.4%.The rebleeding rate was higher in patients with positive CE(36.8%) than in those with negative CE(22.8%).However,there was no significant difference in cumulative rebleeding rates between the two groups(log rank test;P = 0.205).Anticoagulation after CE examination was an independent risk factor for rebleeding(hazard ratio,5.019;95%CI,1.560-16.145;P = 0.007),regardless of CE results.CONCLUSION:Patients with OGIB and negative CE have a potential risk of rebleeding.Therefore,close observation is required and alternative modalities should be considered in suspicious cases.     

Single center experience of capsule endoscopy in patients with obscure gastrointestinal bleeding

AIM:To identify optimum timing to maximize diagnostic yield by capsule endoscopy (CE) in patients with obscure gastrointestinal bleeding (OGIB).METHODS:We identified patients who underwent CE at our institution from August 2003 to December 2009.Patient medical records were reviewed to determine type of OGIB (occult,overt),CE results and complications,and timing of CE with respect to onset of bleeding.RESULTS:Out of 385 patients investigated for OGIB,284 (74%) had some lesion detected by CE.In 222 patients (...     

Differentiation between acute and healed myocardial infarction by signal averaging and color encoding two-dimensional echocardiography

To evaluate the ability of a system developed in our laboratory to differentiate between acute and healed myocardial infarction (MI), gated 2-dimensional echocardiography was performed in 10 patients with recent MI (within 48 hours) and 10 patients with healed MI (later than 4 weeks). The 2-dimensional echocardiographic images were digitized using a Datacube VG-120 videoframe digitizer and each digitized videoframe (320 X 240 matrix) was transmitted using a high-speed serial data link to a second computer and stored on floppy disc. Five gated video frames of each patient were time-averaged to give a smoothed digitized image. This image was displayed on high-resolution color monitor connected to a color graphic subsystem. Sixty-four colors indicated pixel intensity. The exact pixel value at any given location was determined using a high-resolution light pen. Color or pixel values were not significantly different between the area of acute MI (pixel intensity 23 +/- 3, mean +/- standard deviation) identified by a regional wall motion abnormality, and the adjacent normal muscle (23 +/- 4). In each patient with healed MI, an increase in color intensity and pixel value (43 +/- 6) was seen in the area of MI (i.e., area of regional wall motion abnormality) compared with adjacent normal muscle (23 +/- 2) (p less than 0.001). These preliminary data in selected patients indicate that this technique enables differentiation between acute and healed MI. It could be of value in management of patients with suspected MI.     

Immunohistochemical staining for megakaryocyte c-mpl may complement morphologic distinction between polycythemia vera and secondary erythrocytosis

Recent studies have shown decreased megakaryocyte expression of the thrombopoietin receptor (c-mpl) in patients with polycythemia vera (PV) but not in those with reactive erythrocytosis. We examined the diagnostic utility of this observation in 22 patients with PV, 7 patients with secondary erythrocytosis (SE), and 10 normal controls. Commercial antibodies against c-mpl were used with standard immunoperoxidase methods. Megakaryocyte c-mpl staining intensity was uniformly moderate-to-strong in the healthy controls and in all the patients with SE. In contrast, staining intensity in 9 patients with PV (41%) was uniformly weak. Furthermore, in 12 of the remaining 13 patients with PV, the c-mpl staining pattern in each case was heterogeneous and was associated with weak staining intensity in more than 20% of the megakaryocyte population. These preliminary data suggest that c-mpl immunostains may complement bone marrow histopathology in distinguishing PV from nonclonal causes of erythrocytosis. (Blood. 2000;96:771-772)     

Harmonic imaging: echocardiographic enhanced contrast intensity and duration

The intensity and duration of contrast effect within the left ventricular cavity after an intravenous bolus of Levovist Injection were observed with both harmonic and fundamental imaging in nine patients with known or suspected coronary artery disease. Contrast intensity was assessed by a qualitative grading system (0, none; 1, weak; 2, moderate; 3, good) and by videodensitometric analysis of pixel intensity. Duration of left ventricular contrast effect was determined by measuring time from the initial visual appearance of contrast agent to its disappearance. The mean increase in pixel intensity within the left ventricular cavity from precontrast to peak contrast was significantly greater for second harmonic than for fundamental imaging (25.5 vs 7.1; P < 0.012). The mean contrast intensity qualitative score with harmonic imaging was higher (2.6 ± 0.73 vs 1.2 ± 0.44; P < 0.01) and the duration of contrast effect was longer (242 ± 131 s vs 53 ± 33 s; P < 0.004). Second harmonic imaging significantly enhanced contrast intensity and prolonged visible duration of contrast effect after a peripheral venous injection of Levovist.     

Contrast administration reduces interobserver variability in determination of left ventricular ejection fraction in patients with left ventricular dysfunction and good baseline endocardial border delineation

Echocardiographic contrast agents improve endocardial border delineation in patients with technically difficult baseline studies. With medical and device therapy for heart failure increasingly based on left ventricular (LV) ejection fraction (EF) partition values, the accurate and reproducible assessment of LV function is necessary. It was hypothesized that routine contrast enhancement would significantly reduce interobserver variability in the determination of LVEFs in a cohort of patients with LV dysfunction and good baseline endocardial delineation. All patients underwent baseline noncontrast studies followed by contrast-enhanced imaging using Definity. Two experienced echocardiographers, blinded to the clinical data, determined LVEFs using 4 different techniques: noncontrast estimated (NCE), noncontrast calculated (NCC), contrast estimated (CE), and contrast calculated (CC). Using a mixed-model procedure that allows for fixed and random events, the variance due to error and that due to the patient was obtained (interclass correlation). The proportion of variation due to the reader was calculated as 1--interclass correlation. Mean standardized percentage differences ([reader 1 EF--reader 2 EF]/mean EF) were also calculated for each method. The proportion of variation due to the reader was smallest in the CC group and largest in the NCC group (NCE = 0.21, NCC = 0.33, CE = 0.25, CC = 0.11). The results were similar when only patients with NCE EFs >or=20% and or=20% and or=20% and 相似文献   

Cluster dynamics transcending chemical dynamics toward nuclear fusion

Ultrafast cluster dynamics encompasses femtosecond nuclear dynamics, attosecond electron dynamics, and electron-nuclear dynamics in ultraintense laser fields (peak intensities 10(15)-10(20) W.cm(-2)). Extreme cluster multielectron ionization produces highly charged cluster ions, e.g., (C(4+)(D(+))(4))(n) and (D(+)I(22+))(n) at I(M) = 10(18) W.cm(-2), that undergo Coulomb explosion (CE) with the production of high-energy (5 keV to 1 MeV) ions, which can trigger nuclear reactions in an assembly of exploding clusters. The laser intensity and the cluster size dependence of the dynamics and energetics of CE of (D(2))(n), (HT)(n), (CD(4))(n), (DI)(n), (CD(3)I)(n), and (CH(3)I)(n) clusters were explored by electrostatic models and molecular dynamics simulations, quantifying energetic driving effects, and kinematic run-over effects. The optimization of table-top dd nuclear fusion driven by CE of deuterium containing heteroclusters is realized for light-heavy heteroclusters of the largest size, which allows for the prevalence of cluster vertical ionization at the highest intensity of the laser field. We demonstrate a 7-orders-of-magnitude enhancement of the yield of dd nuclear fusion driven by CE of light-heavy heteroclusters as compared with (D(2))(n) clusters of the same size. Prospective applications for the attainment of table-top nucleosynthesis reactions, e.g., (12)C(P,gamma)(13)N driven by CE of (CH(3)I)(n) clusters, were explored.     

Vascularization and perfusion of hepatocellular carcinoma: assessment with contrast-enhanced ultrasound using perflutren protein-type A microspheres

PURPOSE: To assess the vascularization and the perfusion within hepatocellular carcinoma (HCC) including treatment-related changes with contrast-enhanced (CE) ultrasound (US). MATERIALS AND METHODS: Twenty-six biopsy-verified HCC lesions (size between 2.5-8 cm, median 3.8 cm) in 20 patients were examined with unenhanced and CE vascular US techniques immediately before selective angiography for transarterial chemoembolization (TACE) as well as immediately after TACE using all of the following modalities: color-coded Doppler sonography (CCDS), power Doppler imaging (PDI), CE pulse inversion harmonic imaging with PDI (PIHI+PDI), and CE coded harmonic angiography (CHA). In CE US studies, perflutren protein-type A microspheres were administered as contrast agent in a single 0.5 ml i.v. bolus diluted in 20 ml 0.9% NaCl. Selective arteriograms and CE computed tomographies were taken for reference purposes. The Wilcoxon test was used for statistical analysis. RESULTS: Intratumoral vessels could be visualized before TACE in 11/26 lesions (42%) with CCDS; in 15/26 (58%) with PDI; in 23/26 (88%) with CE CHA; in 26/26 (100%) with CE PIHI+PDI. Following TACE, the sensitivities were calculated as follows: CCDS 33%; PDI 55%; CE CHA 77%; and CE PIHI+PDI 100%. The corresponding negative predictive values were 74% for CCDS; 81% for PDI; 89% for CE CHA and 100% for CE PIHI+PDI. During the capillary phase, contrast enhancement could be observed in the CHA mode only. CONCLUSION: CE US by means of PIHI+PDI and CHA enables reliable visualization of residual tumor following TACE equivalent to that which is attained with angiography and Contrast Harmonic Imaging with Power Doppler, if perflutren microspheres are used as contrast agent in a single low-dose bolus.     

Intravenous contrast echocardiography with use of sonicated albumin in humans: systolic disappearance of left ventricular contrast after transpulmonary transmission

The transmission of echocardiographic contrast medium and the cyclic changes in left ventricular videodensity during transpulmonary contrast echocardiography were investigated in nine adult volunteers with the use of intravenous injections of sonicated albumin (microbubble size 5.2 +/- 2.6 microns). Right and left ventricular and myocardial contrast were quantitated by videodensitometric analysis. The injections caused no symptoms, and no hemodynamic or electrocardiographic changes were observed. All injections resulted in right ventricular contrast. Mean peak right ventricular videodensity was 75 +/- 48 at end-diastole and 61 +/- 36 gray scale U/pixel at end-systole (p less than 0.05). Seventy-eight percent of injections resulted in left ventricular contrast with a mean peak videodensity of 21 +/- 33 gray scale U/pixel. Early systole was associated with a rapid decrease in left ventricular contrast intensity with near total disappearance of contrast by end-systole (from 23 +/- 33 and 17 +/- 23 U/pixel at end-diastole to 6 +/- 10 and 3 +/- 2 at end-systole at the left ventricular base and apex, respectively; p less than 0.05). None of the injections resulted in myocardial contrast enhancement by visual or quantitative analysis. Thus, left ventricular contrast echocardiography can be achieved after intravenous injections of sonicated albumin. Transpulmonary left ventricular contrast echocardiography is associated with near total disappearance of contrast during systole. This may be secondary to the destruction of microbubbles by the high left ventricular systolic pressure. These findings may help explain the limited success of this technique thus far for myocardial perfusion imaging.     

Computerized analysis of myocardial echocardiographic enhancement during coronary revascularization by high-speed rotational atherectomy.

A previous report demonstrated transient myocardial echocardiographic contrast (MEC) enhancement following high-speed rotational atherectomy (HSRA). This phenomenon was found to be correlated to the speed and duration of rotation and related to creation of cavitations. To determine other correlations and the significance of MEC, continuous echocardiographic recording was performed in 10 patients undergoing HSRA. Images were digitized and videointensity-time curves generated. Curve parameters were calculated and correlated with procedural variables, plaque mass, and side effects. Twenty-nine ablation passes in 10 patients were analyzed. Videointensity peaked 9-44 sec from initiation of ablation and decayed to a higher baseline level after each consecutive ablation. Increase in peak contrast intensity (PCI) from baseline and the percentage of the left ventricle undergoing enhancement were highest (33 +/- 31 gray level/pixel and 32% +/- 8%, mean +/- SD, respectively) after the second rotation and were not influenced by the duration of rotation. PCI, side effects, and transient left ventricular wall motion abnormalities were positively correlated with plaque mass, defined by the product of lesion length, diameter, and percent stenosis. HSRA resulted in significant myocardial echocardiographic contrast. PCI is related to ablation sequence and plaque mass. Plaque debris embolization is probably responsible for myocardial echocardiographic contrast and transient wall motion abnormalities. Cathet. Cardiovasc. Intervent. 49:39-44, 2000.     

Detection of early myocardial tissue changes in acute canine myocardial infarction by ultrasonic tissue characterization methods

To determine the time after left anterior descending (LAD) artery occlusion in which myocardial texture changes first occur, two-dimensional echocardiograms on five sham operated dogs and eight dogs before and after proximal LAD occlusion were performed. Serial two-dimensional echocardiograms were performed every 15 mins by placing a 5 MHz transducer directly on the chest wall. The dogs were sacrificed at the end of the study and the area of myocardial infarction was confirmed by triphenyltetrazolium chloride staining. The two-dimensional echocardiogram images were digitized. The mean pixel intensity +/- SD in the area of myocardial infarction (region of asynergy) and a normally moving area (control region) equidistant from the transducer were calculated; thus, each dog served as its own control. In sham operated dogs, no significant changes in mean pixel intensity, skewness or kurtosis were observed. There was a significant increase (P less than 0.01) in mean pixel intensity in the infarcted regions (anteroseptal) compared to values obtained in the normally moving (lateral) regions at 30 mins (mean pixel intensity 25.2 +/- 2.1 versus 23.0 +/- 0.7, P less than 0.05); this difference persisted at 45 mins (mean pixel intensity 25.8 +/- 0.9 versus 22.6 +/- 0.5, P less than 0.01), 60 mins (mean pixel intensity 27.2 +/- 1.4 versus 22.8 +/- 0.8, P less than 0.01), 90 mins (mean pixel intensity 28.6 +/- 1.6 versus 22.5 +/- 0.9, P less than 0.01) and 180 mins (mean pixel intensity 28.7 +/- 1.8 versus 21.3 +/- 1.4, P less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)     

Contrast echocardiography in Canada: Canadian Cardiovascular Society/Canadian Society of Echocardiography position paper

As an adjunct to transthoracic, transesophageal and stress echocardiography, contrast echocardiography (CE) improves the diagnostic accuracy of technically suboptimal studies when used in conjunction with harmonic imaging. Intravenous ultrasound contrast agents are indicated for left ventricular (LV) opacification and improvement of LV endocardial border delineation in patients with suboptimal acoustic windows. Demonstrated benefits of CE include improvement in the accuracy of LV measurements, regional wall motion assessment, evaluation of noncompaction cardiomyopathy, thrombus detection, Doppler signal enhancement and conjunctive use with stress echocardiography. Studies have shown the value of CE in the assessment and quantification of myocardial perfusion, and recent clinical trials have suggested a role for contrast perfusion imaging in the stratification of patients with suspected coronary artery disease. While it adds some time and cost to the echocardiographic study, CE frequently obviates the need for additional specialized, expensive and less accessible cardiac investigations, and allows for prompt and optimal subsequent patient management. Despite its proven advantages, CE is presently underused in Canada, and this situation will, unfortunately, not improve until several barriers to its use are overcome. Resolving these important hurdles is vital to the future of CE and to its eventual implementation into clinical practice of promising contrast-based diagnostic and therapeutic applications, including the assessment of perfusion by myocardial CE.