Showing papers in "International Journal of Cardiovascular Imaging in 2002"

Determination of coronary calcium with multi-slice spiral computed tomography: a comparative study with electron-beam CT.

Abstract: Electron-beam Computed Tomography (EBCT) has been used for years to quantify coronary artery calcification as a marker of coronary atherosclerosis. The aim of this study was to determine the diagnostic accuracy of a new scanner, the Multi-slice Spiral CT (MSCT), for the assessment of coronary calcification and to compare this new technique to EBCT. The study population consisted of 99 male patients, aged 60 ± 10 years with suspected or known coronary artery disease. With EBCT 40 axial slices, ECG-triggered (scan time = 100 ms, slice thickness = 3 mm), were acquired in one breath-hold (35 ± 5 s). For MSCT simultaneous acquisition of four axial slices (scan time = 250 ms, slice thickness = 2.5 mm), allowed the entire heart (48 slices) to be covered in one breath-hold of 25 ± 5 s. For quantification of coronary calcium the Volumetric Calcium Score (VCS) was calculated. There was an excellent correlation for the VCS (r = 0.994, p = 0.01, mean difference = 97 ± 115) between both scanners. Comparison of low (1–100), moderate (101–400), high (401–1000) and very high score values (>1000) showed no significant differences. The number of calcified lesions and densities were statistically not different. Mean variability of the two scans was 17%. The MSCT scanner is equivalent to EBCT for the determination and quantification of coronary calcium and can therefore be used for calcium screening. With application of the spiral mode technique further improvement in variability can be expected, thus allowing for follow-up studies to determine progression or regression of atherosclerosis with high accuracy.

Three-dimensional echocardiographic measurement of left and right ventricular mass and volume: in vitro validation.

Abstract: Introduction: Three-dimensional (3D) echocardiography has been shown to offer highly accurate measurements of left ventricular (LV) volume and mass. The present study evaluated the accuracy of 3D surface reconstruction by the piecewise smooth subdivision method in measuring volume and mass not only in the LV but also in the more complexly shaped right ventricle (RV). Methods: 3D echo scans were obtained of in vitro LV's (n = 15) and RVs (n = 10). From digitized images, ventricular borders were traced and used in surface reconstructions. Mass and volume determined from the reconstructions were compared to true volume and mass determined prior to imaging. Additionally casts of two RVs were made and laser-scanned. Distances between the laser-identified points on the RV surface and the corresponding 3D echo reconstructions were measured. Results: 3D LV volume agreed well with the true volume (y = 0.99x + 1.73, r = 0.99, SEE = 3.35 ml, p < 0.0001), as did 3D LV mass (y = 0.99x − 4.71, r = 0.99, SEE = 9.85 g, p < 0.0001). 3D RV volume overestimated true volume (y = 1.11x + 1.77, r = 0.99, SEE = 3.36 ml, p < 0.001) by 6.23 ± 3.70 ml (p < 0.0001). 3D mass agreed well with RV mass (y = 0.78x + 17.32, r2 = 0.93, SEE = 3.54 g, p < 0.0001). 3D echo reconstructions matched the laser-scanned RV closely with residual distances of 1.1 ± 0.9 and 1.4 ± 1.2 mm, respectively. Conclusions: 3D echo using freehand scanning combined with surface reconstruction by the piecewise smooth subdivision surface method enables accurate determination of LV mass and volume, of RV mass and volume, and of the RV's complex shape.

Advanced contour detection for three-dimensional intracoronary ultrasound: a validation--in vitro and in vivo.

Abstract: Intracoronary ultrasound (ICUS) provides high-resolution transmural images of the arterial wall. By performing a pullback of the ICUS transducer and three-dimensional reconstruction of the images, an advanced assessment of the lumen and vessel wall morphology can be obtained. To reduce the analysis time and the subjectivity of boundary tracing, automated segmentation of the image sequence must be performed. The Quantitative Coronary Ultrasound-Clinical Measurement Solutions (QCU-CMS) (semi)automated analytical software package uses a combination of transversal and longitudinal model- and knowledge-guided contour detection techniques. On multiple longitudinal sections through the pullback stack, the external vessel contours are detected simultaneously, allowing mutual guidance of the detection in difficult areas. Subsequently, luminal contours are detected on these longitudinal sections. Vessel and luminal contour points are transformed to the individual cross-sections, where they guide the vessel and lumen contour detection on these transversal images. The performance of the software was validated stepwise. A set of phantoms was used to determine the systematic and random errors of the contour detection of external vessel and lumen boundaries. Subsequently, the results of the contour detection as obtained in in vivo image sets were compared with expert manual tracing, and finally the contour detection in in vivo image sequences was compared with results obtained from another previously validated ICUS quantification system. The phantom lumen diameters were underestimated by 0.1 mm, equally by the QCU-CMS software and by manual tracing. Comparison of automatically detected contours and expert manual contours, showed that lumen contours correspond very well (systematic and random radius difference: -0.025 +/- 0.067 mm), while automatically detected vessel contours slightly overestimated the expert manual contours (radius difference: 0.061 +/- 0.037 mm). The cross-sectional vessel and lumen areas as detected with our system and with the second computerized system showed a high correlation (r = 0.995 and 0.978, respectively). Thus, use of the new QCU-CMS analytical software is feasible and the validation data suggest its application for the analysis of clinical research.

Assessment of left ventricular diastolic function with Doppler tissue imaging: Effects of preload and place of measurements

Abstract: Mitral inflow velocities are widely used for the evaluation of left ventricular (LV) diastolic function. However, they are closely affected by other factors such as preload. The purpose of this study was to evaluate the usefulness of tissue Doppler velocities obtained from the mitral annulus for the evaluation of ventricular relaxation in patients under different loading conditions. We also evaluated the effect of preload at different sides on the mitral annulus. The study population consisted of 62 consecutive patients (38 male, 24 female with a mean age of 42 ± 13 years) who have undergone hemodialysis. Both mitral inflow velocities (E wave, A wave, E wave deceleration time and isovolumetric relaxation time) and mitral annulus tissue Doppler velocities (E′, A′) from the septal, lateral, anterior, posterolateral and inferior sides of the mitral annulus were measured immediately before and after hemodialysis. Mitral inflow E and A wave velocities and E/A ratio decreased significantly (p 0.05 for all) after hemodialysis. The decrease in E wave and E/A ratio in mitral inflow measurements and E′ velocities and E′/A′ ratios in tissue Doppler measurements were correlated with the amount of fluid extracted (for mitral inflow E wave, r = 0.392, p = 0.002 and E/A ratio, r = 0.280 and p = 0.027; for lateral side E′, r = 0.329, p = 0.009 and E′/A′ ratio, r = 0.286, p = 0.04; for septal side E′, r = 0.376, p = 0.003 and E′/A′ ratio, r = 0.297, p = 0.019; for anterior side E′, r = 0.342, p = 0.007 and E′/A′ ratio, r = 0.268, p = 0.035; for posterolateral side E′, r = 0.423, p = 0.001 and E′/A′ ratio, r = 0.343, p = 0.007; and for inferior side E′, r = 0.326, p = 0.01 and E′/A′ ratio, r = 0.278, p = 0.029). We conclude that mitral annular velocities obtained by tissue Doppler are preload dependent parameters for the evaluation of LV diastolic function.

Standardized myocardial segmentation and nomenclature for tomographic imaging of the heart. A statement for healthcare professionals from the Cardiac Imaging Committee of the Council on Clinical Cardiology of the American Heart Association.

Abstract: Nuclear cardiology, echocardiography, cardiovascular magnetic resonance (CMR), cardiac computed tomography (CT), positron emission computed tomography (PET), and coronary angiography are imaging modalities that have been used to measure myocardial perfusion, left ventricular function, and coronary anatomy for clinical management and research. Although there are technical differences between these modalities, all of them image the myocardium and the adjacent cavity. However, the orientation of the heart, angle selection for cardiac planes, number of segments, slice display and thickness, nomenclature for segments, and assignment of segments to coronary arterial territories have evolved independently within each field. This evolution has been based on the inherent strengths and weaknesses of the technique and the practical clinical application of these modalities as they are used for patient management. This independent evolution has resulted in a lack of standardization and has made accurate intra- and cross-modality comparisons for clinical patient management and research very difficult, if not, at times, impossible. Attempts to standardize these options for all cardiac imaging modalities should be based on the sound principles that have evolved from cardiac anatomy and clinical needs.1–3⇓⇓ Selection of standardized methods must be based on the following criteria: An earlier special report from the American Heart Association, American College of Cardiology, and Society of Nuclear Medicine4 defined standards for plane selection and display orientation for serial …

Quantification of shunt volumes in congenital heart diseases using a breath-hold MR phase contrast technique--comparison with oximetry.

Abstract: Aims: Comparison of breath-hold MR phase contrast technique in the estimation of cardiac shunt volumes with the invasive oximetric technique. Methods and Results: Seventeen patients with various cardiac shunts (10 ASD, 3 VSD, 1 PDA, 3 PFO) and five healthy volunteers were investigated using a 1.5 Tesla system. The mean flow velocity, the mean volume flow and the transverse area in the ascending aorta and the left and right pulmonary artery were measured using the MR phase contrast breath-hold technique (through plane, FLASH 2D-sequence, TR/TE 11/5 ms, phase length 106 ms, VENC 250 cm/s). The ratio of mean flow in the pulmonary (Q p: sum of mean flows in the left and right pulmonary arteries) and the systemic circulation (Q s: mean flow in the ascending aorta) was calculated and compared with invasively measured Q p:Q s ratios. Oximetry was performed within 24 h of the MR investigation. The non-invasive shunt measurement in the 17 patients showed a mean Q p:Q s ratio of 2.00 ± 0.86. Comparing the MR data with the invasively measured Q p:Q s showed a correlation coefficient of r = 0.91 (p < 0.001). Conclusion: Cardiac shunt volumes can be measured reliably using a shorter acquisition time with breath-hold MR phase contrast technique.

Congenital absence of pericardium revisited.

Abstract: Although much have been published regarding congenital absence of pericardium, it is essential that this anomaly, like an old friend, be revisited from time to time. Review of this anomaly with emphasis on its embryological process is discussed. Furthermore, with the advances in magnetic resonance imaging, absence of pericardium can now be diagnosed with ease and the radiological findings of this condition are reviewed as well.

Magnetic resonance perfusion imaging in patients with coronary artery disease: a qualitative approach.

Abstract: Although contrast-enhanced first pass magnetic resonance imaging (MRI) has potential to quantify blood flow through extensive image post-processing, clinical utility is likely to depend on rapid qualitative analysis. Aims: To investigate use of an on-line analytical approach for detection of coronary artery disease (CAD). Methods and results: Thirty subjects with CAD underwent contrast-enhanced rest/adenosine stress MRI with basal, mid-papillary and apical short-axis image acquisition. Each short axis was divided into eight regions of interest (ROI). Regional perfusion was visually classified as normal or impaired according to transmural distribution and defect reversibility. MRI and angiographic data were compared. Qualitative MRI reporting was possible for 98% ROI. Eighty-six coronary artery (CA) territories were assessed of which 71 (83%) had stenoses. Sensitivity and specificity for detection of stenoses were 93 and 60%, respectively. The proportion of hypoperfused ROI rose from 31% with <50% stenosis to 65% with occlusion. More transmural defects were seen in infarction-related territories (75 vs. 54%, p < 0.05). More ROI demonstrated defect reversibility in occluded rather than in stenosed infarction-related vessels (89 vs. 58%, p < 0.05). Occluded vessels with grade 2–3 collaterals contained a higher proportion of normal ROI (44 vs. 25%, p < 0.05). Conclusions: Qualitative MRI analysis had high sensitivity and moderate specificity for detecting CA stenoses. Additional information was obtained relating to lesion severity, previous infarction, myocardial viability and impact of collateral circulation. The technique has potential for de novo diagnosis of CAD and as a complementary modality to angiography to assess the significance of given angiographic lesions.

How good are experienced cardiologists at predicting the hemodynamic severity of coronary stenoses when taking fractional flow reserve as the gold standard.

Abstract: Background: Coronary angioplasty should be based on documented ischemia However, in daily clinical practice the indication for angioplasty is often based on eyeball assessment of the severity of the stenosis This study was performed to assess the accuracy of eyeball estimation of coronary stenosis when taking functional flow reserve (FFR) as gold standard Methods: Study lesions were where no mutual agreement on the severity of the stenosis was obtained The procedure consisted of a repeat control angiogram, FFR measurement and in case of FFR <75% percutaneous coronary intervention The eyeball assessment of the stenosis was written down before further execution of the procedure FFR was measured with a pressure monitoring guide Maximal myocardial hyperemia was induced by intravenous adenosine infusion Results: Fifty-two patients were studied Agreement between eyeball assessment and FFR existed in a total of 36 cases (692%) Over estimation of hemodynamic severity occurred in six cases (115%) and under estimation in 10 cases (192%) Consequently, the positive predictive value of eyeball assessment for pressure-derived FFR was 63% and the negative predictive value 76% Conclusion: The assessment of the hemodynamic severity of intermediate coronary stenosis should not be based on eyeball assessment even by experienced interventional cardiologists

Reproducibility of three different scoring systems for measurement of coronary calcium.

Abstract: Background: There is great interest in measuring and tracking atherosclerosis using electron beam tomography (EBT). We sought to assess the reproducibility of two new software systems, InSight and AccuImage, and the console workstation of an EBT scanner for measuring coronary calcification. Methods: Two sets of non-contrast EBT scans were obtained in 85 subjects. The calcium volume (CV) score and the Agatston score (AS) were analyzed and the relative differences were compared on three workstations. Results: The intra- and inter-observer variabilities by InSight and AccuImage were both significantly better than variabilities on the console workstation. Both intra- and inter-observer differences for the AS were significantly smaller than those for the CV on each workstation. However, inter-scan variability was lower for the volume method (13.3%) as compared to the AS (17%). Scores were divided into tertiles (T), and the relative inter-scan differences for the AS in T-I (scores 98%). There is minimal inter-scan variability for subjects with higher scores (>65) for both scoring methods.

A novel approach for the detection of pathlines in X-ray angiograms: the wavefront propagation algorithm

Abstract: This article presents a new pathline approach, based on the wavefront propagation principle, and developed in order to reduce the variability in the outcomes of the quantitative coronary artery analysis. This novel approach, called wavepath, reduces the influence of the user-defined start- and endpoints of the vessel segment and is therefore more robust and improves the reproducibility of the lesion quantification substantially. The validation study shows that the wavepath method is totally constant in the middle part of the pathline, even when using the method for constructing a bifurcation or sidebranch pathline. Furthermore, the number of corrections needed to guide the wavepath through the correct vessel is decreased from an average of 0.44 corrections per pathline to an average of 0.12 per pathline. Therefore, it can be concluded that the wavepath algorithm improves the overall analysis substantially.

Temporal heterogeneity of endothelium-dependent and -independent dilatation of brachial artery in patients with coronary artery disease

Abstract: Background: Endothelial function is routinely assessed with high frequency ultrasound of the brachial artery. Fixed time points (1′ post-occlusion and 3′ post-nitrate) are commonly used to assess dynamic changes in brachial artery diameter. The underlying assumption is the lack of variability in temporal response to both endothelium-dependent and -independent stimuli. Objective: To evaluate the temporal course of endothelium-dependent (flow-mediated) and endothelium-independent (nitrate-induced) vasodilation of the brachial artery in patients with coronary artery disease (CAD) using high resolution (10 MHz) ultrasound. Methods: Thirty-seven patients with angiographically assessed CAD were prospectively enrolled in the study. End-diastolic, two-dimensional, long axis ultrasonographic images of the brachial artery were digitally stored on-line every 10 s, from baseline up to 4′ during flow-mediated and up to 7′ during 300 μg sublingual nitrate-induced vasodilation of the brachial artery. Results: The mean percent endothelium-dependent flow-mediated maximal dilation (FMD) measured at 60 s was lower than the mean peak FMD (4.8 ± 4.1 vs. 6.6 ± 5.2%; p < 0.01). By 60 s only eight patients (35%) reached their maximum FMD response. The mean time to reach peak FMD was 87 ± 33 s. The mean time for the peak nitrate dilation was 291 ± 73 s. The peak nitrate-induced percent dilation was higher than that measured at 3 min (12.2 ± 6.7 vs. 5.4 ± 4.5%; p < 0.001). By 190 s, only four patients (11%) reached their maximum nitrate response. Conclusion: The routinely used measurement time points for evaluation of FMD and endothelium-independent vasodilation may not be adequate to detect the peak responses of individual patients with CAD.

Measurement of left ventricular volume after anterior myocardial infarction: comparison of magnetic resonance imaging, echocardiography, and radionuclide ventriculography.

Abstract: We have compared echocardiography (echo) and radionuclide ventriculography (RNV) with magnetic resonance imaging (MRI) for the measurement of left ventricular (LV) volume and ejection fraction. Seventy asymptomatic patients were studied up to 12 days after first Q wave anterior myocardial infarction and again after 6 months. Each patient had LV volume measured by all three techniques within 24 hours of each other on each occasion. LV end-systolic and end-diastolic volume index (LVESVI and LVEDVI) and LV ejection fraction (LVEF) were measured using the modified Simpson formula (echo), a counts-based method (RNV), and a multislice area summation method (MRI). Radionuclide volumes were measured both with and without correction for attenuation of isotope. Echocardiography overestimated LV volume compared with MRI. Mean (SD) differences (echo–MRI) were: LVEDVI + 10.6 ml/m2 (16.8), LVESVI + 13.7 ml/m2 (12.9), LVEF − 8.5% (11.2). RNV underestimated both volume and ejection fraction compared with MRI. Mean differences (RNV–MRI) were: LVEDVI −25.4 ml/m2 (23.8), LVESVI − 5.0 ml/m2 (18.6), LVEF − 13.8% (10.4). Variability in the difference between echo and MRI and between RNV and MRI was very similar for LVEF (coefficient of variation 23.9% echo, 22.2% RNV) but there was greater variability in the radionuclide than the echo measurements of absolute volume. Variability of the radionuclide measurements was reduced by not correcting for attenuation, and this finding may improve the radionuclide technique for serial measurements of percentage change in volume. Long-term inter-study reproducibility of MRI for LVEF (coefficient of reproducibility) was 10.9%, for echo it was 10.6%, and for RNV it was 14.6%. We conclude that measurements of LV volume depend on the method used and are not interchangeable. Echocardiography agrees more closely with MRI than RNV for the measurement of absolute volume, but the two techniques are similar for the measurement of LVEF.

Reproducibility of the ventricular synchronization parameters assessed by multiharmonic phase analysis of radionuclide angiography in the normal heart.

Abstract: Radionuclide angiography (RNA) permits analysis of contractility and conduction abnormalities. We determined the parameters of normal ventricular synchronization, assessed the reproducibility of the technique, and compared first harmonic (1H) and third harmonic (3H) analysis. Forty-four normal subjects (28 men and 16 women) were studied. RNA was performed in left anterior oblique (LAO) and left lateral (LL) projections. The onset (To), mean time (Tm), total contraction time (Tt) for right ventricle (RV) and left ventricle (LV), interventricular time (T(RV-LV) = Tm(LV - Tm(RV)) in LAO, and the apex-to-base time (T(a-b)) in LL were measured on the histograms of the time-activity curve. Reproducibility (R) was tested by studying 26 consecutive patients with two successive RNAs. RV starts contracting 25 ms before LV (To(RV) = 29 +/- 37 ms; To(LV) = 54 +/- 39 ms; mean +/- SD) with a 37 ms longer total contraction time. T(RV-LV) is 3 +/- 16 ms. In LL projection, apex and base contract synchronously: T(a-b) = 2 +/- 16 ms. 3H analysis enlarges all duration parameters (To, Tm and Tt), but does not alter synchronization (deltaT(a-b) and deltaT(RV-LV) between 1H and 3H <1%, p = NS). Reproducibility of the duration (T(tLV) and T(tRv)) and synchronization parameters (T(a-b) and T(RV-LV)) is high (R < or = 2.2%). In conclusion, the simultaneous contraction of right and left ventricles and of apex and base can be quantified by RNA phase analysis with high reproducibility. These results, consistent with published electrophysiological data, provide the basis for further non-invasive investigations of ventricular resynchronization in patients with basal electrical or mechanical asynchrony.

Tei-index in symptomatic patients with primary and secondary mitral regurgitation.

Abstract: Significant mitral regurgitation (MR) may result from primary valve dysfunction or develop secondary to ischemic or dilated cardiomyopathy. The index ‘isovolumic contraction time and isovolumic relaxation time divided by ejection time’ (ICT + IRT/ET, ‘Tei-index’) is a well established measure of global cardiac function in patients with dilated cardiomyopathy and cardiac amyloidosis. We sought to define the diagnostic value of the Tei-index in patients with significant MR of various origin. Sixteen asymptomatic control subjects (8 male (m)/8 female (f), age 62 ± 8 years, control group), 12 patients with primary MR (PMR) (mean grade 3.1 ± 0.3, due to rupture of the chordae tendineae (n = 2), flail leaflet (n = 1), valve prolaps (n = 6) or rheumatic degeneration (n = 3), 6 m/6 f, age 58 ± 18 years, NYHA class 2.5 ± 0.3, PMR group) and 25 patients with secondary MR (SMR) (mean grade 3.1 ± 0.3; due to ischemic (n = 14) or dilated cardiomyopathy (n = 10), 19 m/6 f, age 60 ± 11 years, NYHA class 3.1 ± 0.5, SMR group) underwent conventional two-dimensional (2D) and Doppler echocardiographic examination including measurement of the Tei-index. In the SMR group, left ventricular ejection fraction was reduced compared to the control and the PMR group (29 ± 13% vs. 59 ± 8% and 59 ± 8%, p < 0.001 for both comparisons). The E/A ratio was elevated in PMR and SMR groups in comparison to the control group (1.74 ± 0.44 and 1.70 ± 0.45 vs. 1.09 ± 0.28, p < 0.05). The Tei-index was easily and reproducibly measured in all study subjects. The mean value of the index was significantly elevated in the SMR group compared to control and PMR groups (0.87 ± 0.3 vs. 0.42 ± 0.07 and 0.38 ± 0.05, p < 0.001). The difference between the control group and the PMR group did not reach statistical significance. In MR patients, receiver operating characteristic curve analysis for the Tei-index yielded an area under the curve of 0.96 ± 0.03 for separating the PMR and the SMR group. Using a Tei-index ≥ 0.51 as a cutpoint, SMR was identified with a sensitivity of 92% and a specificity of 88%. In MR patients, a significant correlation between left ventricular end-systolic volume and the Tei-index was observed (r = 0.71, p < 0.01). The Tei-index is a feasible and sensitive indicator of overall cardiac dysfunction in severely symptomatic patients with significant MR secondary to ischemic or dilated cardiomyopathy. The index is in the normal range in symptomatic patients with PMR and preserved systolic function. The Tei-index differentiates between patients with SMR and PMR and may be useful in the work-up of such patients.

Imaging comparison of basic cardiac views between two- and three-dimensional ultrasound in normal fetuses in anterior spine positions

Abstract: Objective: When the fetal spine is in anterior position, it shadows the fetal heart, resulting in the difficult visualization using two-dimensional (2D) ultrasound. The purpose of this study was to compare the basic cardiac views of normal fetuses between 2D and 3D ultrasound to demonstrate whether 3D ultrasound improved the visualization of these views in fetuses in anterior spine positions. In addition, inter- and intra-observation reliabilities of basic cardiac views using 3D ultrasound were evaluated for their clinical applicability. Methods: Using a multiplanar technique, integrated 3D ultrasound was used to display the four-chamber view, aortic outflow tract and pulmonary outflow tract in fetuses in anterior spine positions for 23 uncomplicated singleton pregnant women. The imaging visualizations of these views for the 23 fetuses in 3D ultrasound were compared with those in 2D ultrasound using the McNemar test. We also evaluated the inter- and intra-observation differences of each basic cardiac view in 3D ultrasound using the κ statistic and McNemar test, respectively. Results: Only in the pulmonary outflow tract, 3D ultrasound had significantly better visualization than the 2D ultrasound in the fetuses in anterior spine positions (p < 0.05). There was good inter-observation reliability and no intra-observation differences for the technique were observed. Conclusions: Among the basic cardiac views in fetuses in anterior spine positions, 3D ultrasound improved the visualization of pulmonary outflow and provided reliable alternate technique for clinical use.

Left ventricular outflow tract presystolic flow velocity--another marker of left ventricular diastolic function.

Abstract: Left ventricular outflow tract (LVOT) presystolic flow velocities were studied using pulse doppler echocardiography in 30 normal persons. Thirty patients of mild hypertension with transmitral flow velocity pattern suggestive of impaired relaxation were also studied. Transmitral flow velocity pattern was correlated with LVOT presystolic flow velocities in the two groups. Hypertensive patients had significantly higher transmitral A wave velocity (p < 0.001) and significantly lower transmitral E wave/A wave velocity ratio (p < 0.001) as compared to normal group. LVOT presystolic flow velocities had significant direct correlation with transmitral A wave velocity (p < 0.01) and significant inverse relation with transmitral E wave/A wave velocity ratio (p < 0.05). Our observations suggest that increased LVOT presystolic flow peak velocity can also be used as another marker of impaired left ventricular compliance during atrial contraction. More work is needed to establish exact status of this preliminary observation.

Carotid turbulent flow observed by convergent color Doppler flowmetry in silent cerebral infarction.

Abstract: Aim: A newly developed convergent color Doppler (CCD) was used for evaluating the possible relationship of the flow dynamics of the internal carotid artery to silent cerebral infarction (SCI). Methods: In 108 patients (65 ± 8 years) with stroke risk factors, the CCD simultaneously images information, on both flow direction and Doppler signal energy. The relation between turbulent flow and the incidence of brain lesions of SCI as identified by magnetic resonance imaging was investigated in 212 vessels, excluding four occluded vessels. Percent area stenosis was measured as (vessel area − lumen area)/(vessel area) on cross-sectional echo image of stenotic site. Results: Incidence of turbulent flow in SCI patients with 50–70% or 70–90% stenosis was higher (76.5 or 59.1%) than that in non-SCI patients (17.4 or 33.3%, both p < 0.0001). Conclusion: Non-invasive assessment of flow dynamics by CCD imaging can be useful for proposing the early stages of brain damage even in patients free from neurological deficits.

Determination of left ventricular mass by three-dimensional echocardiography: in vitro validation of a novel quantification method using multiple equi-angular rotational planes for rapid measurements.

Abstract: Measuring left ventricular mass by m-mode echocardiography or two-dimensional echocardiography is limited by the fact that calculations are based on assumptions, which describe left ventricular shape by simple geometric figures. The ability of three-dimensional echocardiography (3-DE) to accurately assess left ventricular mass has been shown previously, but 3-DE approaches to quantitative analysis of ventricular mass required multiple tomographic sectioning, manual tracing in various cut planes and were time consuming and laborious. We investigated the accuracy of a novel, rapid method of 3-DE mass quantification using multiple rotational planes in left ventricles in vitro. Methods: Three-dimensional data sets of 10 fixed pig hearts were obtained using a TomTec 3-DE system. For 3-DE mass calculations, a rotational axis in the center of the ventricle (apical–basal orientation) was defined and 3, 6 and 12 equi-angular rotational planes were created. The endocardial and epicardial contour of the left ventricle was traced in each cut plane and the volume of the corresponding myocardial wedge was automatically calculated. Mass was calculated by multiplying the resulting myocardial volume by the specific weight of myocardial tissue. The measurements were performed by two investigators blinded to the anatomic true mass and were analyzed for interobserver and intraobserver variability. Results: The anatomic left ventricular mass was measured 73–219 (168 ± 50) g. 3-DE mass ranged from 88–247 (207 ± 51) g (three planes), 84–250 (205 ± 52) g (six planes) and 86–241 (202 ± 50) g (12 planes) respectively. The correlation between 3-DE mass and anatomic LV mass measurements (r = 0.92) and between two observers (r = 0.97–0.98) was good. True mass was slightly overestimated by 3-DE measurement (SEE = 22–23 g). The intraobserver and interobserver variabilities were ≤4 and ≤7% respectively for all measurements. Conclusion: This new 3-DE method of left ventricular mass quantification with rotational approach provides accurate and reproducible measurements. In normal shaped left ventricles even three planes were sufficient to provide accurate mass measurements in vitro.

Magnetic resonance imaging of coronary artery occlusions in the navigator technique.

Abstract: Non-invasive assessment of coronary arteries is possible with magnetic resonance imaging (MRI). Respiratory gated MR coronary angiography is a new imaging technique that permits reconstruction of the coronary arteries based on a three-dimensional (3D) data set obtained from the free-breathing patient. In this study, respiratory gated MR angiography (MRA) was performed to assess coronary artery occlusions. MRI was performed in 25 patients who had been referred for conventional coronary angiography because of suspected coronary artery disease. Coronary artery occlusion was evaluated in the proximal and middle vessel segments after multiplanar coronary reconstruction of the MR images. Five patients were excluded from the study; in the remaining 20 patients 120 coronary artery segments were analyzed. Good image quality could be obtained for 85% of the segments. Eighteen of the 24 occlusions were confirmed by MRI, the overall sensitivity was 75% and the specificity was 100%. The best results were found in the proximal left anterior descending (LAD) and descending parts of the right coronary artery (RCA), where all occlusions were confirmed. These results showed that coronary artery occlusions can be detected in the proximal and middle LAD and RCA using 3D respiratory gated MRA. Further technical improvements, especially in spatial resolution, are necessary before MRA can become a reliable diagnostic tool in the non-invasive evaluation of coronary arteries.

Elongation as a new shape index for the left ventricle.

Abstract: Objectives: This study was done to quantify the shape of the left ventricle (LV). It was proposed that the shape of the LV is intimately related to its performance and that its elongation (ELO) is a sensitive measure of this performance. The performance was tested against classical cardiovascular parameters. Methods: Using echocardiography and Simpson's rule, the endocardial surface area of the LV was calculated noninvasively with a simple experimental–mathematical model at enddiastole and endsystole. ELO as shape index was derived from the endocardial surface area of the LV with a simple formula. The endocardial surface area of the LV and ELO were determined in volunteers, in patients with mild heart failure and in patients with severe heart failure. Results: The normal value of endocardial surface area of LV at enddiastole is 138.3 cm2 while the normal value at endsystole is 99 cm2. The endocardial surface area of the LV is significantly bigger in patients with mild heart failure than in volunteers (p < 0.01) while the parameters ELO, ejection fraction and Doppler measurements are similar. The normal values of ELO at diastole and systole are 12 and 25 respectively. The value of ELO at endsystole is lower only in patients with severe heart failure. This means a more spherical shape and poor systolic function of the LV. Conclusion: ELO is usefull as quantitative and qualitative index of left ventricular shape. ELO could be integrated and applied with new diagnostic tools such three-dimensional and contrast echocardiography.

Echocardiographic assessment of left atrioventricular plane displacement as a complement to left ventricular regional wall motion evaluation in the detection of myocardial dysfunction.

Abstract: Aim: We aimed to find out if abnormal left atrioventricular plane displacement (AVPD) is a sign of myocardial dysfunction, even in patients with normal left ventricular (LV) regional wall motion (RWM). Methods: We prospectively performed echocardiography in 1350 consecutive patients referred to our echocardiography laboratory. Left AVPD and LV RWM were evaluated in all patients. We prospectively selected all patients with normal LV RWM but impaired left AVPD for further analysis of clinical parameters. Results: Eighty-eight of the 1350 patients had completely normal LV RWM but impaired left AVPD (≤10 mm) in at least one region (septal, lateral, posterior, anterior). Of these, 60.2% had prior and/or acute myocardial infarction, predominantly non-Q-wave, whereas 33.0% had angina without infarction and 2.3% had hypertension. In 49 (55.7%) patients coronary angiography was performed. All were abnormal. In 4.5% (n = 4) of the patients no obvious reason for the AVPD decrease was found, but was not precluded. Conclusion: Almost all patients with abnormal left AVPD and completely normal LV RWM had clinical cardiac disease. Thus, decreased AVPD despite normal LV RWM seems to be a true sign of myocardial dysfunction, predominantly indicating subendocardial dysfunction. In screening for patients with myocardial dysfunction assessment of left AVPD may be useful as a complement to LV RWM evaluation. The prognosis in such patients is currently being evaluated.

ECG-gated 18F-FDG positron emission tomography.

Abstract: Aim: 18F-fluorodeoxyglucose (18F-FDG)-positron emission tomography (PET) provides information about myocardial glucose metabolism to diagnose myocardial viability. Additional information about the functional status is necessary. Comparison of tomographic metabolic PET with data from other imaging techniques is always hampered by some transfer uncertainty and scatter. We wanted to evaluate a new Fourier-based ECG-gated PET technique using a high resolution scanner providing both metabolic and functional data with respect to feasibility in patients with diseased left ventricles. Methods: Forty-five patients with coronary artery disease and at least one left ventricular segment with severe hypokinesis or akinesis at biplane cineventriculography were included. A new Fourier-based ECG-gated metabolic 18F-FDG-PET was performed in these patients. Function at rest and 18F-FDG uptake were examined in the PET study using a 36-segment model. Results: Segmental comparison with ventriculography revealed a high reliability in identifying dysfunctional segments (>96%). 18F-FDG uptake of normokinetic/hypokinetic/akinetic segments was 75.4 ± 7.5, 65.3 ± 10.5, and 35.9 ± 15.2% (p < 0.001). In segments ≥70% 18F-FDG uptake no akinesia was observed. No residual function was found below 40% 18F-FDG uptake. An additional dobutamine test was performed and revealed inotropic reserve (viability) in 42 akinetic segments and 45 hypokinetic segments. Conclusion: ECG-gated metabolic PET with pixel-based Fourier smoothing provides reliable data on regional function. Assessment of metabolism and function makes complete judgement of segmental status feasible within a single study without any transfer artefacts or test-to-test variability. The results indicate the presence of considerable amounts of viable myocardium in regions with an uptake of 40–50% 18F-FDG.

Clinical application in routine practice of the proximal flow convergence method to calculate the mitral surface area in mitral valve stenosis.

Abstract: Background: Two-dimensional (2D) echocardiography planimetry, the Doppler pression half-time (PHT), and the continuity equation methods were used to estimate mitral valve area (MVA) in patients with mitral stenosis (MS). Recently, the proximal isovelocity surface area (PISA) method has been shown to be accurate for calculating MVA. The purpose of this study is (1) to compare in a large non-selected population the accuracy of the PISA and planimetry methods for echocardiographic estimation of MVA; (2) to determine the effect of atrial fibrillation (AF), Wilkins score, associated mitral regurgitation (MR), aortic regurgitation (AR), and of commissural calcifications on the accuracy of the PISA method. Methods: One hundred and eight consecutive patients with rheumatic MS were studied (76 females and 32 males; mean age: 36 ± 12 years); 64 were in sinus rhythm; 51 had associated MR and 46 had AR. By the PISA method, MVA was calculated assuming a uniform radius flow convergence region along a hemispherical surface. Results: The mean value of 2D MVA was 1.32 ± 0.59 cm2 (0.4–3.1 cm2) and that of PISA MVA 1.33 ± 0.62 cm2 (0.38–3 cm2). MVA calculated using the PISA method correlated well with 2D MVA (r = 0.93, y = 0.97x + 0.04, p 8 (r = 0.92, y = 0.96x + 0.06, p < 0.0001, SEE = 0.19 cm2), and in patients with commissural calcifications (r = 0.90, y = 0.88x + 0.009, p < 0.0001, SEE = 0.20 cm2). Conclusion:Our study shows that in routine practice, MVA calculated by the PISA method correlated well with the area obtained by planimetry even in the presence of commissural calcifications, associated MR, AR, AF and of high Wilkins score. Therefore, the PISA method provides a reliable measurement of the MVA in MS under different anatomic and clinical conditions and may be a useful alternative method for calculating MVA.

Strategies for cardiac CT imaging.

Abstract: We review the scanning techniques for cardiac CT imaging with single slice and multislice scanners. Combined with prospective triggering for transaxial scanning and retrospective gating for helical scanning the potential advantages and the basic limitations are discussed. Based on those theoretical considerations, the major conclusion is that high resolution data sets with isotropic spatial resolution can be acquired with quadslice, spiral scanning, only. First clinical results support this conclusion.

Widespread thrombosis associated with recurrent intracardiac masses in a patient with Behçet's disease.

Abstract: Behcet’s disease (BD) is a relapsing chronic inflammatory disease of unknown etiology. BD was initially characterized by a triad of recurrent oral aphtous ulcerations, genital ulcerations and uveitis, but it is now more commonly recognized to be a multi-system disease concomitant with vasculitis as its main pathological finding [1]. Although vascularmanifestations, particularly venous thrombosis, arteritis, and aneurysm formations, are not uncommon, a direct cardiac involvement is to be determined only rarely. We herein describe a patient with BD who developed recurrent operated intracardiac thrombi associated with inferior vena cava thrombosis, pulmonary arterial thrombosis, renal vein thrombosis and Budd–Chiari syndrome.

Ebstein's anomaly in siblings: an original observation.

Abstract: Siblings, a 26-year old male and a 31-year old female, were found do have Ebstein's anomaly Ebstein's anomaly is characterized by a downward displacement of the tricuspid valve into the right ventricle due to anomalous attachment of the tricuspid leaflets Echocardiography is the method of choice to diagnose Ebstein's anomaly on its own or in association with other heart defects Complications such as right ventricular failure, infective endocarditis, and paradoxical embolism can occur Ebstein's anomaly diagnosed in adult life is a benign and stable disease, particularly if the patient is asymptomatic These cases may represent a familial form of Ebstein's anomaly

Contrast agents provide a faster learning curve in dipyridamole stress echocardiography.

Abstract: Aim: Interobserver variability is an important limitation of the stress echocardiography and depends on the echocardiographer training. Our aim was to evaluate if the use of contrast agents during dipyridamole stress echocardiography would improve the agreement between an experienced and a non-experienced observer in stress echo and therefore if contrast would affect the learning period of dypyridamole stress echo. Methods and results: Two independent observers without knowledge of any patient data interpreted all stress studies. One observer was an experienced one and the other had experience in echocardiography but not in stress echo. Two observers analysed 87 non-selected and consecutive studies. Out of the 87 studies, 46 were performed without contrast administration, whereas i.v. contrast (2.5 g Levovist® by two bolus at rest and at peak stress) was administered in 41. In all cases, second harmonic imaging and stress digitalisation pack was used. The agreement between observers showed a κ index of 0.58 and 0.83 without and with contrast administration, respectively. Conclusions: The use of contrast agents provides a better agreement in the evaluation of stress echo between an experienced and a non-experienced observer in stress echo. Adding routinely contrast agents could probably reduce the number of exams required for the necessary learning curve in stress echocardiography.

Discordance between dipyridamole stress technetium-99m tetrofosmin single photon emission computed tomography and coronary angiography in patients with Kawasaki disease.

Abstract: Kawasaki disease (KD) is an acute vasculitis syndrome of unknown etiology that mainly affects the coronary arteries. The purpose of this study was to assess the agreement between dipyridamole stress technetium-99m tetrofosmin (Tc-TF) myocardial perfusion single photon emission computed tomography (SPECT) and coronary angiography in these patients. Twenty-nine children with KD were included in this study. All of the 29 children also received dipyridamole stress Tc-TF myocardial perfusion SPECT within 1 month of their coronary angiographic studies. The results showed that (1) 89.7% of children had negative coronary angiographic findings without significant coronary stenoses, and 10.3% of children had positive coronary angiographic findings with significant coronary stenosis; (2) 44.8% of children had negative Tc-TF myocardial perfusion SPECT findings without abnormal myocardial perfusion, and 55.2% of children had positive Tc-TF myocardial perfusion SPECT findings with abnormal myocardial perfusion; (3) 44.8% of children had both normal coronary angiographic and Tc-TF myocardial perfusion SPECT findings, and 10.3% of children had both abnormal coronary angiographic and Tc-TF myocardial perfusion SPECT findings; and (4) There was no significant agreement between coronary angiographic and Tc-TF myocardial perfusion SPECT findings. We concluded that poor agreement exists between coronary angiographic and Tc-TF myocardial perfusion SPECT findings with coronary stenoses and abnormal myocardial perfusion in children with KD.