Determination Of Ventricular Volume Research Articles

Tricuspid annular plane systolic excursion assessed using MRI for semi-quantification of right ventricular ejection fraction

Accurate determination of right ventricular volume and ejection fraction (RVEF) is established using MRI. Automatic contour detection of the right ventricular endocardial border is not established in clinical practice, resulting in considerable manual efforts to quantify RVEF. Using transthoracic echocardiography (TTE), the tricuspid annular plane systolic excursion (TAPSE) has proved its worth for quantification of RVEF and risk prediction. Therefore, the aim of this study was to clarify whether TAPSE assessed with MRI as a fast and easily obtainable parameter correlated with volumetric quantification of RVEF. Right ventricular volumes and RVEF were measured with the standardised slice-summation method at MRI. MRI-TAPSE was defined as maximum apical excursion of lateral tricuspid annular plane and measured in a four-chamber view using steady-state free precession sequences. Additionally, MRI-TAPSE was compared with TAPSE assessed using TTE. 76 consecutive patients (aged 58±17 years) were examined. At MRI, right end-diastolic volumes were 97±36 ml, right end-systolic volumes were 57±27 ml and the mean RVEF was 42±14%. MRI-TAPSE was determined with 19±6 mm and correlated well at linear regression analysis with volumetric RVEF (r=0.72, p<0.001). Furthermore, MRI-TAPSE discriminated sufficiently between patients with impaired and normal RVEF. Multiplying MRI-TAPSE by 2.5 led to values close to the RVEF by volumetry. Additionally, MRI-TAPSE correlated well with TAPSE determined using TTE. The inter- and intra-observer variabilities of MRI-TAPSE determination were low (3.1% and 1.8%). TAPSE assessed with MRI is a fast and easily obtainable parameter which correlates well with volumetric quantification of RVEF.

Three-Dimensional Mechanical Dyssynchrony and Myocardial Deformation of the Left Ventricle in Patients with Tricuspid Atresia after Fontan Procedure

The aim of this study was to test the hypothesis that dyssynchronous contraction of functional single ventricles occurs in Fontan patients and is related to indices of myocardial deformation and global ventricular function. Twenty patients with tricuspid atresia (mean age, 23.5 ± 7.1 years) were studied 17.8 ± 3.8 years after undergoing the Fontan procedure. Three-dimensional echocardiographic data were acquired for determination of left ventricular (LV) volumes and systolic dyssynchrony indices. LV myocardial deformation was determined using speckle-tracking echocardiography. Calibrated integrated backscatter intensity was measured as an index of myocardial fibrosis. The results were compared with those in 20 controls. Compared with controls, patients had significantly greater systolic dyssynchrony indices (6.13 ± 1.32% vs 4.06 ± 0.84%, P < .001). The prevalence of LV mechanical dyssynchrony (systolic dyssynchrony index > 5.74%) in patients was 55% (95% confidence interval, 32%-77%). LV global systolic longitudinal, radial, and circumferential strain (P < .001 for all), longitudinal systolic (P < .001) and early diastolic (P < .001) strain rate, and circumferential systolic (P < .001) and early diastolic (P= .009) strain rate were significantly lower in patients than in controls, while the average calibrated integrated backscatter was higher (P < .001). Patients with LV dyssynchrony (n= 11) had lower global LV longitudinal strain (P= .02), reduced LV ejection fractions (P= .002), and higher average calibrated integrated backscatter (P= .03) compared with those without LV dyssynchrony (n= 9). A high proportion of patients with tricuspid atresia after the Fontan operation exhibit LV mechanical dyssynchrony, which may in part be related to myocardial fibrosis and has implications for myocardial deformation and global ventricular function.

Three‐Dimensional Echocardiography in Evaluation of Left Ventricular Indices

Accurate determination of left ventricular mass, volume, ejection fraction, and wall motion is important for clinical decision making. Currently, M-mode and two-dimensional echocardiography (2DE) have been routinely used for this purpose. Although these 1D or 2D modalities provide excellent diagnostic and prognostic information, they have a number of technical limitations including the time required to perform the procedure and operator-dependent image acquisitions. In addition, they are inherently limited by geometric assumption of three-dimensional (3D) left ventricular structures based on 2D slices. With the improvement in transducer technology and software development, 3D echocardiography (3DE) has become widely available. Left ventricular quantitation by 3DE has been demonstrated to be accurate by multiple studies that compared 3DE with reference techniques. In addition, 3DE measurements were found to be more reproducible and less variable than 2DE. Real time 3DE imaging has potential advantages in stress echocardiography including rapid acquisition, unlimited number of planes, avoidance of foreshortening, and precise segment matching. This is a major step forward in our diagnostic armamentarium for the evaluation of ischemia. In this review, we summarized the current evidence of 3DE for left ventricular evaluation.

Prevalence and Significance of Alterations in Cardiac Structure and Function in Patients With Heart Failure and a Preserved Ejection Fraction

The purpose of this study was to examine the prevalence of abnormalities in cardiac structure and function present in patients with heart failure and a preserved ejection fraction (HFPEF) and to determine whether these alterations in structure and function were associated with cardiovascular morbidity and mortality. The Irbesartan in HFPEF trial (I-PRESERVE) enrolled 4128 patients; echocardiographic determination of left ventricular (LV) volume, mass, left atrial (LA) size, systolic function, and diastolic function were made at baseline in 745 patients. The primary end point was death or protocol-specific cardiovascular hospitalization. A secondary end point was the composite of heart failure death or heart failure hospitalization. Associations between baseline structure and function and patient outcomes were examined using univariate and multivariable Cox proportional hazard analyses. In this substudy, LV hypertrophy or concentric remodeling was present in 59%, LA enlargement was present in 66%, and diastolic dysfunction was present in 69% of the patients. Multivariable analyses controlling for 7 clinical variables (including log N-terminal pro-B-type natriuretic peptide) indicated that increased LV mass, mass/volume ratio, and LA size were independently associated with an increased risk of both primary and heart failure events (all P<0.05). Left ventricular hypertrophy or concentric remodeling, LA enlargement, and diastolic dysfunction were present in the majority of patients with HFPEF. Left ventricular mass and LA size were independently associated with an increased risk of morbidity and mortality. The presence of structural remodeling and diastolic dysfunction may be useful additions to diagnostic criteria and provide important prognostic insights in patients with HFPEF.

Non-Responders to Cardiac Resynchronization Therapy - The Magnitude of the Problem and the Issues -

A variable proportion of cardiac resynchronization therapy (CRT) patients do not benefit from treatment (termed `non-responders'). The problem of non-response to CRT might become increasingly important, because it is anticipated that larger groups of heart failure patients are indicated to the therapy. This article will discuss the definition of response to CRT, the parameters related to response to CRT, and finally whether response to CRT might be predicted. The effort to improve patient selection in order to maximize human and financial resource utilization has fallen short so far. It is, however, conceivable that rather than the identification of a `universally' applicable cut-off value, risk strata-in which inclusion of method for determination of left ventricular volumes, etiology, QRS duration and morphology, etc-might better serve the goal of defining non-responders. Potentially simple clinical scores might help in refining outcome and by doing so, allow to more precisely measure response to CRT in daily practice in the individual patient at the time of CRT implantation. Although sophisticated cardiac imaging modalities have been intensively utilized for improving patient outcome, it seems that many mechanical dyssynchrony measures suffer from technical limitations and from difficult interpretation of the complex signals, which lack reproducibility outside highly specialized laboratories.

Assessment of left ventricular function with magnetic resonance imaging vs. echocardiography, contrast echocardiography, and single-photon emission computed tomography in patients with recent ST-elevation myocardial infarction

Magnetic resonance imaging (MRI) is often considered to be the gold standard in measuring left ventricular function and volumes. The aim of this study was to assess the agreements between standard echocardiography (standard echo), contrast echocardiography (contrast echo), single-photon emission computed tomography (SPECT), and MRI in the determination of left ventricular ejection fraction (EF) and end-diastolic volumes (EDV) in patients treated for acute ST-elevation myocardial infarction (STEMI). Standard echo, contrast echo, SPECT and MRI were performed on the same day, 3 months after STEMI in 150 patients participating in the NORwegian Study on District Treatment of ST-Elevation Myocardial Infarction (NORDISTEMI). Bland-Altman analysis of EF measured by all four imaging modalities showed generally low mean differences but wide limits of agreement. The mean EDV difference, however, was consistently higher when MRI was compared with standard echo (54.9 mL), contrast echo (41.7 mL) and SPECT (54.6 mL), and the limits of agreement were wider. The mean EDV differences between contrast echo vs. standard echo, SPECT vs. standard echo and contrast echo vs. SPECT were small. Our data suggest that all four imaging modalities measured EF closely similar after STEMI as demonstrated by a very small bias. The limits of agreement were however wide. EDV measured by MRI was consistently higher when compared with the other methods which may be caused by different tracing-methods and imaging principles. As echocardiography is preferable from a cost-benefit point of view, further analysis would be needed to clarify the nature of such differences.

Dynamic Assessment of Right Ventricular Volumes and Function by Real-Time Three-Dimensional Echocardiography: A Comparison Study With Magnetic Resonance Imaging in 100 Adult Patients

The aim of this study was to validate a novel real-time three-dimensional echocardiographic (RT3DE) analysis tool for the determination of right ventricular volumes and function in unselected adult patients. A total of 100 consecutive adult patients with normal or pathologic right ventricles were enrolled in the study. A dynamic polyhedron model of the right ventricle was generated using dedicated RT3DE software. Volumes and ejection fractions were determined and compared with results obtained on magnetic resonance imaging (MRI) in 88 patients with adequate acquisitions. End-diastolic, end-systolic, and stroke volumes were slightly lower on RT3DE imaging than on MRI (124.0 +/- 34.4 vs 134.2 +/- 39.2 mL, P < .001; 65.2 +/- 23.5 vs 69.7 +/- 25.5 mL, P = .02; and 58.8 +/- 18.4 vs 64.5 +/- 24.1 mL, P < .01, respectively), while no significant difference was observed for ejection fraction (47.8 +/- 8.5% vs 48.2 +/- 10.8%, P = .57). Correlation coefficients on Bland-Altman analysis were r = 0.84 (mean difference, 10.2 mL; 95% confidence interval [CI], -31.3 to 51.7 mL) for end-diastolic volume, r = 0.83 (mean difference, 4.5 mL; 95% CI, -23.8 to 32.9 mL) for end-systolic volume, r = 0.77 (mean difference, 5.7 mL; 95% CI, -24.6 to 36.0 mL) for stroke volume, and r = 0.72 (mean difference, 0.4%; 95% CI, -14.2% to 15.1%) for ejection fraction. Right ventricular volumes and ejection fractions as assessed using RT3DE imaging compare well with MRI measurements. RT3DE imaging may become a time-saving and cost-saving alternative to MRI for the quantitative assessment of right ventricular size and function.

Impedance cardiography: Pulsatile blood flow and the biophysical and electrodynamic basis for the stroke volume equations

Abstract Impedance cardiography (ICG) is a branch of bioimpedance primarily concerned with the determination of left ventricular stroke volume (SV). As implemented, using the transthoracic approach, the technique involves applying a current field longitudinally across a segment of thorax by means of a constant magnitude, high frequency, low amplitude alternating current (AC). By Ohm’s Law, the voltage difference measured within the current field is proportional to the electrical impedance Z (Ω). Without ventilatory or cardiac activity, Z is known as the transthoracic, static base impedance Z0. Upon ventricular ejection, a characteristic time dependent cardiac-synchronous pulsatile impedance change is obtained, ΔZ(t), which, when placed electrically in parallel with Z0, constitutes the time-variable total transthoracic impedance Z(t). ΔZ(t) represents a dual-element composite waveform, which comprises both the radially-oriented volumetric expansion of and axially-directed forward blood flow within both great thoracic arteries. In its majority, however, ΔZ(t) is known to primarily emanate from the ascending aorta. Conceptually, commonly implemented methods assume a volumetric origin for the peak systolic upslope of ΔZ(t), (i.e. dZ/dtmax), with the presumed units of Ω·s–1. A recently introduced method assumes the rapid ejection of forward flowing blood in earliest systole causes significant changes in the velocity-induced blood resistivity variation (Δρb(t), Ωcm·s–1), and it is the peak rate of change of the blood resistivity variation dρb(t)/dtmax (Ωcm·s–2) that is the origin of dZ/dtmax. As a consequence of dZ/dtmax peaking in the time domain of peak aortic blood acceleration, dv/dtmax (cm·s–2), it is suggested that dZ/dtmax is an ohmic mean acceleration analog (Ω·s–2) and not a mean flow or velocity surrogate as generally assumed. As conceptualized, the normalized value, dZ/dtmax/Z0, is a dimensionless ohmic mean acceleration equivalent (s–2), and more precisely, the electrodynamic equivalent of peak aortic reduced average blood acceleration (PARABA, d&lt;v&gt;/dtmax/R, s–2). As necessary for stroke volume calculation, dZ/dtmax/Z0 must undergo square root transformation to yield an ohmic mean flow velocity equivalent. To compute SV, the square root of the dimensionless ohmic mean acceleration equivalent ([dZ/dtmax/Z0]0.5, s–1) is multiplied by a volume of electrically participating thoracic tissue (VEPT, mL) and left ventricular ejection time (TLVE, s). To find the bulk volume of the thoracic contents (i.e. VEPT), established methods implement exponential functions of measured thoracic length (L(cm)n) or height-based thoracic length equivalents (0.01×%H(cm)n). The new method conceptualizes VEPT as the intrathoracic blood volume (ITBV, mL), which is approximated through allometric equivalents of body mass (aMb). In contrast to the classical two-element parallel conduction model, the new method comprises a three-compartment model, which incorporates excess extra-vascular lung water (EVLW) as a component of both Z0 and VEPT. To fully appreciate the evolution and analytical justification for impedance-derived SV equations, a review of the basics of pulsatile blood flow is in order.

Abstract 4557: Validation of Three-Dimensional Echocardiographic Left Ventricular Volumes in Young Pediatric Patients with Complex Congenital Heart Disease: Comparison with Cardiac Magnetic Resonance Imaging

Determination of left ventricular volumes (LVV) is essential for management of infants and small children with complex congenital heart disease (CHD), in particular left heart obstructive lesions. We compared 3-D echo (3DE) LVV in this population to cardiac magnetic resonance (CMR). We prospectively studied children ≤4 y undergoing clinical CMR. Full-volume, subcostal, 3DE data sets were obtained immediately after CMR under similar anesthetic conditions with a 2– 4-MHz matrix-array probe. Endocardial and epicardial borders were manually traced in sequential cross-sectional planes across a minimum of 6 disks. LVVs, mass, and ejection fraction (EF) were subsequently measured on dedicated software using summation of disc methodology. 35 children were studied, including 11 pts with severe LV hypoplasia, median age 7 mo., median weight 7 Kg. Mean vols, mass and EF by 3DE and CMR are shown in the table . LV diastolic vols and mass by 3DE correlated well with good agreement with MRI. 3DE systolic vols correlated well but were higher than MRI (Table , Fig ). EF was thus lower by 3DE. 3DE compares well with CMR for evaluation of LV diastolic volumes and mass in young pediatric patients. This will provide essential information to guide clinical management of pts with CHD, especially those with left heart obstructive disease.

Right ventricular volume determination: not a matter for echocardiography

to the editor: Potkin and coworkers ([3][1]) recently reported in the Journal of Applied Physiology on an original investigation concerning the cardiovascular changes induced by glossopharyngeal insufflation in breath-hold divers. Authors obtained echocardiographic data suggesting an acute right

Reply from Potkin, Siegel, and Chen

LETTERS TO THE EDITORReply from Potkin, Siegel, and ChenRalph Potkin, Robert Siegel, and Victor ChengRalph Potkin, Robert Siegel, and Victor ChengPublished Online:01 May 2008https://doi.org/10.1152/japplphysiol.00101.2008MoreSectionsPDF (27 KB)Download PDF ToolsExport citationAdd to favoritesGet permissionsTrack citations ShareShare onFacebookTwitterLinkedInEmailWeChat to the editor: We thank Marabotti and colleagues (1) for their letter addressing the use of subcostal echocardiographic imaging to assess right ventricular systolic function in our recent work regarding glossopharyngeal insufflation. The major concerns raised in the letter were twofold: that radionuclide ventriculography, rather than echocardiography, is the most accurate assessment of right ventricular volume, and that the volumes obtained in our calculations were significantly discordant from those obtained in the left ventricle and much smaller than expected in healthy persons.We considered several factors before selecting echocardiography to evaluate ventricular function in the elite divers. First, our primary interest was the change of ventricular function induced by glossopharyngeal insufflation, rather than a true measure of ventricular size and volume. In this respect, each diver at rest acted as his/her own control, and ventricular volume calculations were strictly used to demonstrate the degree of change in ventricular function. Second, subcostal echocardiographic assessment of right ventricular function has shown good correlation with radionuclide angiography in the past (2). Third, echocardiography allowed rapid, real-time imaging of cardiac function before, during, and after glossopharyngeal insufflation. In our hypothesis-generating investigation, it was the only noninvasive modality that achieves appropriate temporal and visual resolution for the requisite analysis while sparing participating divers ionizing radiation. Despite the known shortcomings of subcostal echocardiographic imaging when studying the geometrically complex right ventricle, it was still a strong modality to detect marked changes in ventricular function, and we firmly believe in the validity of the observed decline in right and left ventricular function during glossopharyngeal insufflation.The principal message in our study was that, for the first time, decrease in biventricular function due to glossopharyngeal insufflation has been demonstrated by direct cardiac imaging. We agree with Marabotti and colleagues that pursuing confirmation of our findings with “gold-standard” evaluation of right ventricular function is worthwhile. Perhaps more importantly, we believe, are future investigations to clarify the underlying mechanisms by which glossopharyngeal insufflation compromises cardiac performance.REFERENCES1 Marabotti C, Bedini R, L'Abbate A. Right ventricular volume determination: not a matter for echocardiography. J Appl Physiol; doi:10.1152/japplphysiol.00065.2008.Link | ISI | Google Scholar2 Panidis IP, Ren JP, Kotler MN, Mintz G, Iskandrian A, Ross J, Kane S. Two-dimensional echocardiographic estimation of right ventricular ejection fraction in patients with coronary artery disease. J Am Coll Cardiol 2: 911–918, 1983.Crossref | ISI | Google ScholarAUTHOR NOTESAddress for reprint requests and other correspondence: R. Potkin, Beverly Hills Center for Hyperbaric Medicine, 1125 S. Beverly Dr., Los Angeles, CA 90035 (e-mail: [email protected]) Download PDF Previous Back to Top FiguresReferencesRelatedInformation More from this issue > Volume 104Issue 5May 2008Pages 1548-1548 Copyright & PermissionsCopyright © 2008 the American Physiological Societyhttps://doi.org/10.1152/japplphysiol.00101.2008History Published online 1 May 2008 Published in print 1 May 2008 Metrics

Accuracy of right and left ventricular heart volume and left ventricular muscle mass determination with cine MRI in breath holding technique

To assess the accuracy of right- (RV) and left-ventricular (LV) heart volume and muscle mass determinations by cine MR imaging. Ten subjects were examined twice by a segmented, ECG-triggered cine sequence in the short axis plane and breath-hold technique by two independent operators and again 4 weeks later by one of the operators. The contours were evaluated manually by two independent examiners and again four weeks later by one of the examiners. LV and RV end-diastolic and end-systolic volumes, stroke volume, cardiac output, ejection fraction (EF), and left-ventricular muscle mass were compared. The RV evaluation variations (RV-EF: 6.46%) were higher than the LV (LV-EF: 4.46%). The intra-examiner variations were smaller than the inter-examiner variations. The generally operators did not cause a significantly increased variation (LV-EF: 5.77%). In contrast, the repeat examinations at different times did lead to a significant increase in the variation (LV-EF: 10.15%). The rapid ECG-triggered cine MRI in breath-hold technique allows the simultaneous RV and LV, artefact-free determination of heart volumes and LV muscle mass. The LV volumes can be determined more accurately than the RV. The examiner has a distinct influence on the accuracy, the operator has a lesser effect. Physiological fluctuations of cardiac activity significantly influence the follow-up.

EANM/ESC guidelines for radionuclide imaging of cardiac function

Radionuclide imaging of cardiac function represents a number of well-validated techniques for accurate determination of right (RV) and left ventricular (LV) ejection fraction (EF) and LV volumes. These first European guidelines give recommendations for how and when to use first-pass and equilibrium radionuclide ventriculography, gated myocardial perfusion scintigraphy, gated PET, and studies with non-imaging devices for the evaluation of cardiac function. The items covered are presented in 11 sections: clinical indications, radiopharmaceuticals and dosimetry, study acquisition, RV EF, LV EF, LV volumes, LV regional function, LV diastolic function, reports and image display and reference values from the literature of RVEF, LVEF and LV volumes. If specific recommendations given cannot be based on evidence from original, scientific studies, referral is given to "prevailing or general consensus". The guidelines are designed to assist in the practice of referral to, performance, interpretation and reporting of nuclear cardiology studies for the evaluation of cardiac performance.

Towards comprehensive assessment of mitral regurgitation using cardiovascular magnetic resonance.

Cardiovascular magnetic resonance (CMR) is increasingly used to assess patients with mitral regurgitation. Its advantages include quantitative determination of ventricular volumes and function and the mitral regurgitant fraction, and in ischemic mitral regurgitation, regional myocardial function and viability. In addition to these, identification of leaflet prolapse or restriction is necessary when valve repair is contemplated. We describe a systematic approach to the evaluation of mitral regurgitation using CMR which we have used in 149 patients with varying etiologies and severity of regurgitation over a 15 month period.Following standard ventricular cine acquisitions, including 2, 3 and 4 chamber long axis views and a short axis stack for biventricular function, we image movements of all parts of the mitral leaflets using a contiguous stack of oblique long axis cines aligned orthogonal to the central part of the line of coaptation. The 8–10 slices in the stack, orientated approximately parallel to a 3-chamber view, are acquired sequentially from the superior (antero-lateral) mitral commissure to the inferior (postero-medial) commissure, visualising each apposing pair of anterior and posterior leaflet scallops in turn (A1-P1, A2-P2 and A3-P3). We use balanced steady state free precession imaging at 1.5 Tesla, slice thickness 5 mm, with no inter-slice gaps. Where the para-commissural coaptation lines curve relative to the central region, two further oblique cines are acquired orthogonal to the line of coaptation adjacent to each commissure. To quantify mitral regurgitation, we use phase contrast velocity mapping to measure aortic outflow, subtracting this from the left ventricular stroke volume to calculate the mitral regurgitant volume which, when divided by the left ventricular stroke volume, gives the mitral regurgitant fraction. In patients with ischemic mitral regurgitation, we further assess regional left ventricular function and, with late gadolinium enhancement, myocardial viability.Comprehensive assessment of mitral regurgitation using CMR is feasible and enables determination of mitral regurgitation severity, associated leaflet prolapse or restriction, ventricular function and viability in a single examination and is now routinely performed at our centre. The mitral valve stack of images is particularly useful and easy to acquire.

Can left ventricular function parameters be determined within half of the time with MRI?

Accurate determination of left ventricular mass and left ventricular systolic volume and function is important for assessment of prognosis and therapeutic options in patients with hypertensive heart disease, coronary heart disease and congestive heart failure [1, 2]. In patients with hypertension, left ventricular hypertrophy increases the relative risk of mortality by twofold in those patients who also have coronary artery disease and by fourfold in those patients with normal coronary arteries [3]. Because of the low cost, M-mode echocardiography is the most widely used method to determine left ventricular mass [4]. However, there is considerable variability for repeated measurements. Two-dimensional and 3-dimensional echocardiography is more used for determination of left ventricular volumes and left ventricular ejection fraction, with an excellent intra-observer variability but worse inter-observer variability [5]. Additionally, not in all patients high quality images can be obtained, which permit precise assessment of left ventricular volumes and function. Because of its high spatial and temporal resolution, MRI is the best technique for assessment of right and left ventricular function. For determination of left ventricular function one can either use the Simpson’s rule or the area-length method. With the Simpson’s rule left ventricular volumes are calculated by summing the endocardial area within multiple short axis slices from base to apex of the heart and multiplying each area by the slice thickness [6]. Left ventricular volumes and left ventricular mass using this technique have been validated with cast measurements and cadaver studies and show an excellent correlation. Intra- and inter-observer variability of the measurements of left ventricular volume, ejection fraction and left ventricular mass are very low [7, 8]. Because of this high reproducibility, in clinical trials, only limited number of patients are needed to detect a change of left ventricular volume, ejection fraction or left ventricular mass. Studies, that use MR, require sample sizes that are 80–90% smaller than other imaging methods [9]. For calculation left ventricular mass endocardial and epicardial contours have to be drawn from base to apex and multiplied by slice thickness [10]. Manually, tracing of all contours is cumbersome and time consuming. Also with automated contour detection using commercially available software correct analysis remains time consuming. In this issue of the International Journal of Cardiac Imaging, Lubbers et al. demonstrate, that by tracing every second slice decreases accuracy for left ventricular ejection fraction with only 1.7% and for left ventricular mass with 4.1%. For left ventricular volume one has to be aware, however that tracing half of the slices gives half the accuracy compared to true volume. In clinical studies, this could imply the need of more patients for comparison. For normal patient care the method suggested by Lubbers satisfies completely and could become the standard procedure for measurement of left ventricular mass, volume and function. However, in clinical studies one can better rely on the better accuracy of tracing all slices.

Comparison of gated blood pool SPECT and spiral multidetector computed tomography in the assessment of right ventricular functional parameters: validation with first-pass radionuclide angiography

The aim of this study was to compare gated blood pool single photon emission computed tomography (SPECT) (GBPS) and multidetector row computed tomography (MDCT) for the determination of right ventricular ejection fraction (RVEF) and right ventricular volumes (RVV) and to compare first-pass radionuclide angiography (FP-RNA) as the gold standard. Twenty consecutive patients (11 men, 9 women) referred for MDCT for the evaluation of the presence of coronary artery disease underwent FP-RNA and GBPS. The mean right ventricular end-diastolic volume (EDV) calculated with GBPS revealed a statistically significant lower value than that of MDCT. The mean right ventricular end-systolic volume (ESV) calculated with GBPS was also lower than that of MDCT. A comparison of right ventricular EDV from GBPS and MDCT yielded a correlation coefficient of 0.5972. Right ventricular ESV between GBPS and MDCT showed a correlation coefficient of 0.5650. The mean RVEFs calculated with FP-RNA (39.8% +/- 4.0%), GBPS (43.7% +/-6.9%0), and MDCT (40.4% + 7.7%) showed no statistical differences (Kruskal-Wallis statistics 4.538, P = 0.1034). A comparison of RVEFs from FP-RNA and GBPS yielded a correlation coefficient of 0.7251; RVEFs between FP-RNA and MDCT showed a correlation coefficient of 0.6166 and between GBPS and MDCT showed a correlation coefficient of 0.6367. The RVEF, EDV, and ESV calculated by GBPS had good correlation with those obtained with MDCT. In addition, there were no statistical differences of RVEF calculated from FP-RNA, GBPS, and MDCT. However, with regard to RVV, EDV and ESV from GBPS revealed statistically significantly lower values than those of MDCT. Although reasonable correlations among these modalities were obtained, the agreement among these three modalities was not good enough for interchangeable use in the clinical setting. Also, these results should be confirmed in patients with cardiac diseases in future larger population-based studies.

3D Echocardiography: A Review of the Current Status and Future Directions

Ultrasound technology has improved markedly in the past 10 to 15 years, prompting echocardiographers to extend its use in studying cardiac structure and function. New ultrasound equipment and techniques offer superior image quality, greater accuracy, and expanding capabilities. As a result, more and improved imaging modalities are available for evaluating cardiac anatomy, ventricular function, blood flow velocity, and valvular diseases. Threedimensional (3D) echocardiography offers the ability to improve and expand the diagnostic capabilities of cardiac ultrasound. However, as with any emerging technology, the enthusiasm to embrace a new technique must be tempered by a critical appraisal of the evidence supporting its use. It is essential to assess the limitations as well as the unique capabilities it provides. Cardiac imaging should be safe, accurate, versatile, comprehensive, and cost-effective, while providing important clinical information. Criteria for appropriate utilization should be based on current evidence and updated as new information becomes available. To justify the use of a new 3D modality, its unique contribution to clinical practice must be critically analyzed. In this article we review the status of 3D echocardiography, examine the evidence for its use in various clinical situations, and propose guidelines for appropriate application of this technique based on available evidence.

Contrast-enhanced echocardiography improves agreement on the assessment of ejection fraction and left ventricular function. A multicentre study

Analysis of global and regional left ventricular function has important therapeutic and prognostic implications 1–3. Several imaging modalities are used to define left ventricular function and left ventricular volumes as well as regional function, among them echocardiography, cineventriculography, radionuclide ventriculography and magnetic resonance imaging (MRI). Cardiac MRI has evolved in recent years as the gold standard for determination of left ventricular mass, volumes and left ventricular function owing to the high image quality allowing clear endocardial and epicardial border definition in volumetric data sets 4,5. Echocardiography is the most frequently used modality in clinical practice to define global and regional left ventricular function. Limited endocardial border definition with subsequent moderate reproducibility and accuracy are the major limitation of 2-D echocardiography. Contrast echocardiography in combination with recent innovations in ultrasound technology like Harmonic Imaging has been shown to significantly improve endocardial border delineation especially in patients with difficult imaging conditions which was unattainable before 6–8. The SonoVue LV Function Group evaluated in a European multicentre study consisting of two parts the utility of contrast-enhanced echocardiography for assessment of global and regional left

MDCT Determination of Volume and Function of the Left Ventricle: Are Short-Axis Image Reformations Necessary?

Determination of left ventricular (LV) volumes and global function parameters from MDCT data sets is usually based on short-axis reformations from primarily reconstructed axial images, which prolong postprocessing time. The aim of this study was to evaluate the feasibility of LV volumetry and global LV function assessment from axial images in comparison with short-axis image reformations. This study consisted of 20 patients with either coronary artery disease or dilated cardiomyopathy. We evaluated MDCT results using cine MRI as the reference technique. LV end-diastolic volume (LVEDV) and end-systolic volume (LVESV) were significantly overestimated by the axial MDCT approach in comparison with volume measurements from short-axis CT image reformations. The mean LV ejection fraction (LVEF) was not significantly different (41.2% vs 42.7%). Short-axis and axial MDCT determination of LVEF revealed a systematic underestimation by a mean +/- SD of -2.1% +/- 3.6% versus -3.6% +/- 8.2%, respectively, when compared with LVEF values based on cine MRI. The interobserver variability for volume and function measurements from axial images (LVEDV = 8.5%, LVESV = 10.8%, LVEF = 9.6%) was slightly higher than those measurements from short-axis reformations (LVEDV = 7.2%, LVESV = 9.5%, LVEF = 8.7%). The mean total evaluation time was significantly shorter using axial images (14.1 +/- 3.9 min) compared with short-axis reformations (16.9 +/- 5.2 min) (p < 0.05). Determination of LV volumes and assessment of global LV function from axial MDCT image reformations is feasible and time efficient. This approach might be a clinically useful alternative to established short-axis-based measurements in patients with normal or near-normal LV function. A progressive underestimation of LVEF with increasing LV volumes may limit the clinical applicability of the axial approach in patients with dilated cardiomyopathy.

Comparison of Gated Blood Pool SPECT and Multi-Detector Row Computed Tomography for Measurements of Left Ventricular Volumes and Ejection Fraction in Patients with Atypical Chest Pain: Validation with Radionuclide Ventriculography

Gated blood pool SPECT (GBPS) is an alternative to planar radionuclide ventriculography (PRNV) and offers potential advantages. The aim of this study was to compare GBPS, multi-row detector spiral computed tomography (MDCT), and PRNV for the determination of left ventricular ejection fraction (LVEF) and left ventricular volumes (LV) in subjects with atypical chest pain. Method: Twenty-three consecutive patients (14 men, 9 women; mean age 56.2 ± 9.5 years) referred for MDCT for evaluation of atypical chest pain. All patients underwent PRNV, GBPS, and MDCT at the same day. Results: The mean LVEFs calculated with PRNA (57.3 ± 8.6%), GBPS (55.2 ± 6.6%), and MDCT (56 ± 9.1%) were not statistically different (F value 0.3374, p = 0.715). Comparison of LVEFs from GBPS and MDCT yielded correlation coefficients of 0.5238 (p = 0.0178, 95% CI = 0.1057–0.7845). The correlation of LVEFs between GBPS and PRNV showed a correlation coefficient of 0.8073 (p < 0.0001, 95% CI = 0.5676–0.9209) and 0.6190 (p = 0.0036, 95% CI = 0.2431–0.8333) between MDCT and PRNV. The mean LV end-diastolic volume (EDV) calculated with GBPS (82.7 ± 17.5 ml) was significantly lower than MDCT (106.8 ± 18.5 ml) (p = 0.0001). The mean LV end-systolic volume (ESV) calculated with GBPS (37.2 ± 9.6 ml) was also significantly lower than MDCT (48.1 ± 15.8 ml) (p = 0.012). Comparison of EDV from GBPS and MDCT yielded a correlation coefficient of 0.5220 (p = 0.0182, 95% CI = 0.1033–0.7835). The correlation of ESV between GBPS and MDCT showed a correlation coefficient of 0.6642 (p = 0.0014, 95% CI = 0.3140–0.8553). Conclusion: In conclusion, the LVEF, EDV, and ESV calculated by GBPS correlated significantly with those of obtained with 16-MDCT. In addition, there were no statistical differences of LVEF calculated from PRNV, GBPS, and MDCT. However, with regard to LV, EDV and ESV from GBPS revealed statistically significantly lower than those of MDCT. Also, these results should be addressed whether similar results could also be found in patients with cardiac diseases by the consequent larger population-based study.