-
Akhil Narang,
Nicole M Bhave,
Chattanong Yodwut,
Giacomo Tarroni,
Benjamin H Freed,
Emily Estep,
Kristen M Turner, Cristiana Corsi,
Michael Davidson,
Tamar Polonsky,
Roberto Lang,
Victor Mor-Avi,
Amit R Patel
Journal of Cardiovascular Magnetic Resonance 01/2013; 15. · 3.72 Impact Factor
-
Giacomo Tarroni, Cristiana Corsi,
Patrick F Antkowiak,
Federico Veronesi,
Christopher M Kramer,
Frederick H Epstein,
James Walter,
Claudio Lamberti,
Roberto M Lang,
Victor Mor-Avi,
Amit R Patel
[show abstract]
[hide abstract]
ABSTRACT: Purpose: To develop and validate a technique for near-automated definition of myocardial regions of interest suitable for perfusion evaluation during vasodilator stress cardiac magnetic resonance (MR) imaging. Materials and Methods: The institutional review board approved the study protocol, and all patients provided informed consent. Image noise density distribution was used as a basis for endocardial and epicardial border detection combined with nonrigid registration. This method was tested in 42 patients undergoing contrast material-enhanced cardiac MR imaging (at 1.5 T) at rest and during vasodilator (adenosine or regadenoson) stress, including 15 subjects with normal myocardial perfusion and 27 patients referred for coronary angiography. Contrast enhancement-time curves were near-automatically generated and were used to calculate perfusion indexes. The results were compared with results of conventional manual analysis, using quantitative coronary angiography results as a reference for stenosis greater than 50%. Statistical analyses included the Student t test, linear regression, Bland-Altman analysis, and κ statistics. Results: Analysis of one sequence required less than 1 minute and resulted in high-quality contrast enhancement curves both at rest and stress (mean signal-to-noise ratios, 17 ± 7 [standard deviation] and 22 ± 8, respectively), showing expected patterns of first-pass perfusion. Perfusion indexes accurately depicted stress-induced hyperemia (increased upslope, from 6.7 sec(-1) ± 2.3 to 15.6 sec(-1) ± 5.9; P < .0001). Measured segmental pixel intensities correlated highly with results of manual analysis (r = 0.95). The derived perfusion indexes also correlated highly with (r up to 0.94) and showed the same diagnostic accuracy as manual analysis (area under the receiver operating characteristic curve, up to 0.72 vs 0.73). Conclusion: Despite the dynamic nature of contrast-enhanced image sequences and respiratory motion, fast near-automated detection of myocardial segments and accurate quantification of tissue contrast is feasible at rest and during vasodilator stress. This technique, shown to be as accurate as conventional manual analysis, allows detection of stress-induced perfusion abnormalities. © RSNA, 2012 Supplemental material: http://radiology.rsna.org/lookup/suppl/doi:10.1148/radiol.12112475/-/DC1.
Radiology 08/2012; 265(2):576-83. · 5.73 Impact Factor
-
Akhil Narang,
Chattanong Yodwut,
Giacomo Tarroni,
Emily Estep,
Kristen M Turner,
Benjamin H Freed,
Nicole M Bhave, Cristiana Corsi,
Michael H Davidson,
Roberto Lang,
Victor Mor-Avi,
Amit R Patel
Journal of Cardiovascular Magnetic Resonance 02/2012; 14 Suppl 1:P70. · 3.72 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Maintenance of normal potassium homeostasis is increasingly an important limiting factor in the therapy of several diseases including patients with heart failure. Nowadays, quantification of potassium concentration in the blood ([K + ]) is invasive and laboratory-based. The aims of the study were to develop a method quantifying [K + ] from the electrocardiogram (ECG) and validate it on 13 hemodialysis (HD) and 7 congenital long-QT type 2 (LQT2) patients. Reference values were obtained from blood samples. An ECG-based potassium estimator (K ECG) was defined and compared to the reference values. Data from 33/39 HD sessions gave consistent results. In 6 sessions, the presence of a systematic error inhibited reliable estimates. Patient specific calibration allowed good agreement in all HD patients (error: -0.04±0.61mM). As expected, [K + ] was significantly underestimated in LQT2 patients (error: 1.24±0.75mM, p<0.01). Preliminary results show K ECG estimates can be an effective tool for hyper/hypokalemic risk patient monitoring at home.
Lecture Notes in Computer Science 01/2012; 7251:116-123.
-
[show abstract]
[hide abstract]
ABSTRACT: Although cardiac resynchronization therapy (CRT) is an effective treatment for chronic systolic heart failure with dyssynchrony, about one-third of patients do not respond favorably. The interaction between the pacing lead and the coronary sinus (CS) branches is of paramount importance for an effective resynchronization. Minor changes in lead position overtime could interfere with CRT mechanics, without affecting even biophysical parameters or ECG morphology. Although late post-implant CS lead dislodgement rate is consistent, lead movements have been little investigated and only with bi-dimensional methods. The aim of this study was (1) to develop a method for quantifying CS lead position in the 3D domain throughout the cardiac cycle and (2) to test it by comparing the CS lead position at implant and at follow-up, using chest fluoroscopy. Method performance, its accuracy and reproducibility were qualitatively and quantitatively assessed. Intra- and inter-observer percent discordance between trajectories were also computed. The accuracy of the procedure resulted in 0.3 ± 0.1 mm and its resolution was 0.5 mm. Intra- and inter-observer discordances were 2.2 ± 1.5 and 5.5 ± 3.6 mm, respectively. The proposed method for measuring the CS lead dynamic placement in 3D space seems accurate and reproducible. Investigating CS lead 3D dynamics could provide further insights into CRT mechanics.
Medical & Biological Engineering 06/2011; 49(8):901-8. · 1.76 Impact Factor
-
Enrico G Caiani,
Laura Fusini,
Federico Veronesi,
Gloria Tamborini,
Francesco Maffessanti,
Paola Gripari, Cristiana Corsi,
Moreno Naliato,
Marco Zanobini,
Francesco Alamanni,
Mauro Pepi
[show abstract]
[hide abstract]
ABSTRACT: Mitral valve (MV) repair is the preferred treatment for mitral regurgitation associated with organic MV prolapse (MVP). Our goals were to describe by transthoracic real-time 3D echocardiography (RT3D TTE) the pre-operative changes in mitral annulus (MA) dynamic morphology related to MVP, compared with a normal population, and to evaluate the differential long-term effects induced by annuloplasty, using either an incomplete flexible band or a complete semi-rigid ring.
Forty-four patients (62 ± 11 years) with organic MVP and ejection fraction >55% were studied by RT3D TTE the day before MV repair, and 3 and 6 months after (23 patients received a complete rigid ring-CAR, 21 an incomplete flexible band-COS). An age-matched group of 20 normal subjects (57 ± 9 years) was studied as control. After initialization, the MA was tracked frame-by-frame in 3D, and several parameters computed. Differences in MVP vs. controls, vs. pre-surgery, and between rings were tested (P < 0.05). MVP showed enlarged MA resulting in greater area and height during the cardiac cycle, with reduced planarity compared with controls. Annuloplasty resulted in reduced MA area in both CAR and COS, with minimal area change, and planar shape (more evident in CAR than COS).
The main factor affecting MA function after annuloplasty appears to be the undersizing of the MA dimensions, and not the choice of the ring. This methodology could represent the basis for further evaluation of implanted rings, to provide the surgeon with additional information to be used in the pre-surgical planning and ring selection.
European Heart Journal – Cardiovascular Imaging 03/2011; 12(5):375-83. · 2.32 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Total renal volume (TRV) is an important index to evaluate the progression of autosomal-dominant polycystic kidney disease (ADPKD). TRV has been assessed by manually tracing renal contours from CT or MR scans, often employing contrast medium (CM). We developed a fast and nearly automated technique based on the analysis of MR images acquired without CM injection for TRV quantification.
30 ADPKD patients underwent MRI. After the selection of one point inside each kidney for the entire volume, the automatic extraction of kidney contours was performed on each acquired slice; the segmentation procedure was based on region growing and on the application of morphological operators and curvature-based motion. The area inside each contour was calculated and TRV was derived. Volume measurements were validated by comparison with measurements obtained by stereology.
TRV estimated in patients was 768 ± 545 ml (range 161-3,111 ml). The automatic measurements were in excellent correlation with the manual ones (r = 0.99, y = x - 0.7), with a small bias and narrow limits of agreement in both absolute (-5 ± 37 ml) and percentage (-0.6 ± 9.6%) terms.
This preliminary study showed the feasibility of a fast and nearly automated method for determining TRV; importantly it does not require the use of potentially nephrotoxic CM.
American Journal of Nephrology 02/2011; 33(2):176-84. · 2.54 Impact Factor
-
Journal of Cardiovascular Magnetic Resonance. 01/2011;
-
Journal of Cardiovascular Magnetic Resonance. 01/2010;
-
[show abstract]
[hide abstract]
ABSTRACT: Despite the potential ability of left ventricular (LV) shape analysis to provide independent information complementary to ventricular size and function, in clinical practice only ejection fraction (EF) is currently assessed while LV shape is not routinely quantified. Moreover, geometric assumptions in the computation of EF from multiple two-dimensional (2-D) cut-planes by disc summation or area-length methods, introduce inaccuracies in the estimates. Also, previous approaches for the quantification of LV shape were based on geometric modeling and, as a result, proved inaccurate. Our aims were (1) to develop and test a three-dimensional (3-D) technique for direct quantification of LV shape from real-time 3-D echocardiographic (RT3DE) images without the need for geometric modeling using a new class of LV shape indices; and (2) to study the relationship between these indices and ventricular size and function in normal and abnormal ventricles. Spherical (S), ellipsoidal (E) and conical (C) shape indices were calculated using custom software for analysis of transthoracic RT3DE images on both global and regional levels and initially tested on computer simulated objects of different shapes. The feasibility of using these indices to differentiate between normal and abnormal ventricles was tested in three groups of patients: normal volunteers (NL, n=9), dilated cardiomyopathy (DCM, n=9) and coronary artery disease with apical regional wall motion abnormalities (RWMA, n=9). Computer simulation demonstrated that these shape indices are size-independent and can correctly classify the simulated objects. In human ventricles, both S and C but not E correlated well with LV volumes and EF. Also, S and C changed throughout the cardiac cycle while E remained almost constant. In addition, both regional and global S and C were able to identify differences between NL and abnormal ventricles: normal ventricles were less spherical and more conical than those of patients with DCM at both end-systole and end-diastole (p<0.05) both globally and regionally. In contrast, in patients with RWMA, similar differences were noted only at end-systole, both on a global level and in the apical region. In this study, we demonstrated the feasibility of quantifying LV shape from transthoracic RT3DE images at both global and regional levels. Potentially, such 3-D shape analysis could be combined with conventional evaluation of LV volume and function to provide a more comprehensive assessment of left ventricular performance.
Ultrasound in medicine & biology 10/2009; 35(12):1953-62. · 2.02 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Although the ability of multi-detector computed tomography (MDCT) to detect perfusion abnormalities associated with acute and chronic myocardial infarction (MI) has been demonstrated, this methodology is based on visual interpretation of selected 2D slices.
We sought to develop a new technique for quantitative volumetric analysis of myocardial perfusion from 3D datasets and test it against resting nuclear myocardial perfusion imaging (NMPI) reference.
We studied 44 patients undergoing CTCA: a control group of 15 patients and a study group of 29 patients. MDCT datasets acquired for CTCA were analyzed using custom software designed to: (1) generate bull's eye display of myocardial perfusion and (2) calculate a quantitative index of extent and severity of perfusion abnormality, Q(H), for 16 volumetric myocardial segments. Visual interpretation of MDCT-derived bull's eyes was compared with rest NMPI scores using kappa statistics of agreement on a coronary territory and patient basis. Quantitative MDCT perfusion data were correlated with rest NMPI summed scores and used for objective detection of perfusion defects.
Visual analysis of MDCT-derived bull's eyes accurately detected perfusion defects in agreement with NMPI (kappa = 0.70 by territory; 0.79 by patient). Quantitative data were in good agreement with NMPI, as reflected by: (1) correlation of 0.87 (territory) and 0.84 (patient) between summed Q(H) and NMPI scores, (2) area under ROC curve 0.87 with sensitivity of 0.79-0.92, specificity 0.83-0.91, and accuracy 0.83-0.89 for objective detection of abnormalities.
Our new technique for volumetric analysis of 3D MDCT images allows accurate objective detection of perfusion defects. This perfusion information can be obtained without additional radiation or contrast load, and may aid in elucidating the significance of coronary lesions.
European Radiology 09/2009; 20(2):337-47. · 3.22 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: In spite of its potential impact on simulation results, the problem of setting the appropriate Ca(2+) concentration ([Ca(2+)](o)) in computational cardiac models has not yet been properly considered. Usually [Ca(2+)](o) values are derived from in vitro electrophysiology. Unfortunately, [Ca(2+)](o) in the experiments is set significantly far (1.8 or 2 mM) from the physiological [Ca(2+)] in blood (1.0-1.3 mM). We analysed the inconsistency of [Ca(2+)](o) among in vivo, in vitro and in silico studies and the dependence of cardiac action potential (AP) duration (APD) on [Ca(2+)](o). Laboratory measurements confirmed the difference between standard extracellular solutions and normal blood [Ca(2+)]. Experimental data on human atrial cardiomyocytes confirmed literature data, demonstrating an inverse relationship between APD and [Ca(2+)](o). Sensitivity analysis of APD on [Ca(2+)](o) for five of the most used cardiac cell models was performed. Most of the models responded with AP prolongation to increases in [Ca(2+)](o), i.e. opposite to the AP shortening observed in vitro and in vivo. Modifications to the Ten Tusscher-Panfilov model were implemented to demonstrate that qualitative consistency among in vivo, in vitro and in silico studies can be achieved. The Courtemanche atrial model was used to test the effect of changing [Ca(2+)](o) on quantitative predictions about the effect of K(+) current blockade. The present analysis suggests that (i) [Ca(2+)](o) in cardiac AP models should be changed from 1.8 to 2 mM to approximately 1.15 mM in order to reproduce in vivo conditions, (ii) the sensitivity to [Ca(2+)](o) of ventricular AP models should be improved in order to simulate real conditions, (iii) modifications to the formulation of Ca(2+)-dependent I(CaL) inactivation can make models more suitable to analyse AP when [Ca(2+)](o) is set to lower physiological values, and (iv) it could be misleading to use non-physiological high [Ca(2+)](o) when the quantitative analysis of in vivo pathophysiological mechanisms is the ultimate aim of simulation.
Philosophical Transactions of The Royal Society A Mathematical Physical and Engineering Sciences 07/2009; 367(1896):2203-23. · 2.77 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Detailed understanding of I(Ks) gating complexity may provide clues regarding the mechanisms of repolarization instability and the resulting arrhythmias. We developed and tested a kinetic model to interpret physiologically relevant I(Ks) properties, including pause-dependence and modulation by beta-adrenergic receptors (beta-AR). I(Ks) gating was evaluated in guinea-pig ventricular myocytes at 36 degrees C in control and during beta-AR stimulation (0.1 micromol/L isoprenaline (ISO)). We tested voltage dependence of steady-state conductance (Gss), voltage dependence of activation and deactivation time constants (tau(act), tau(deact)), and pause-dependence of tau(act) during repetitive activations (tau(react)). The I(Ks) model was developed from the Silva and Rudy formulation. Parameters were optimized on control and ISO experimental data, respectively. ISO strongly increased Gss and its voltage dependence, changed the voltage dependence of tau(act) and tau(deact), and modified the pause-dependence of tau(react). A single set of model parameters reproduced all experimental data in control. Modification of only three transition rates led to a second set of parameters suitable to fit all ISO data. Channel unitary conductance and density were unchanged in the model, thus implying increased open probability as the mechanism of ISO-induced Gss enhancement. The new I(Ks) model was applied to analyze ISO effect on repolarization rate-dependence. I(Ks) kinetics and its beta-AR modulation were entirely reproduced by a single Markov chain of transitions (for each channel monomer). Model-based analysis suggests that complete opening of I(Ks) channels within a physiological range of potentials requires concomitant beta-AR stimulation. Transient redistribution of state occupancy, in addition to direct modulation of transition rates, may underlie beta-AR modulation of I(Ks) time dependence.
Biophysical Journal 06/2009; 96(9):3862-72. · 3.65 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: To develop a technique based on image noise distribution for automated endocardial border detection from cardiac magnetic resonance (CMR) images throughout the cardiac cycle, validate it, and test its clinical utility.
Images obtained in 36 patients were analyzed using custom software to obtain left ventricular (LV) volume throughout the cardiac cycle, end-systolic and end-diastolic LV volumes, and ejection fraction (EF). Validation against manually-traced endocardial boundaries included intertechnique comparisons of LV volumes, slice areas, and border positions. Then, the clinical feasibility of the dynamic automated analysis of LV function was tested in 14 patients with normal LV function, 12 patients with systolic dysfunction, and 10 patients with diastolic dysfunction.
Analysis time for one cardiac cycle was <15 minutes. Intertechnique comparisons resulted in high correlation (r>0.96), small biases (volumes: -6 mL; EF: 4.6%) and narrow limits of agreement (volumes: 17.6 mL; EF: 9.2%). We found significant intergroup differences in multiple quantitative indices of systolic and diastolic function.
Fast, automated, dynamic detection of LV endocardial boundaries is feasible and allows accurate quantification of LV size and function, which is potentially clinically useful for objective assessment of systolic and diastolic dysfunction.
Journal of Magnetic Resonance Imaging 03/2009; 29(3):560-8. · 2.70 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Reduction in [Ca2+]o prolongs the AP in ventricular cardiomyocytes and the QTc interval in patients. Although this phenomenon is relevant to arrhythmogenesis in the clinical setting, its mechanisms are counterintuitive and incompletely understood. To evaluate in silico the mechanisms of APD modulation by [Ca2+]o in human cardiomyocytes. We implemented the Ten Tusscher-Noble-Noble-Panfilov model of the human ventricular myocyte and modified the formulations of the rapidly and slowly activating delayed rectifier K+ currents (IKr and IKs) and L-type Ca2+ current (ICaL) to incorporate their known sensitivity to intra- or extracellular Ca2+. Simulations were run with the original and modified models at variable [Ca2+]o in the clinically relevant 1 to 3 mM range. The original model responds with APD shortening to decrease in [Ca2+]o, i.e. opposite to the experimental observations. Incorporation of Ca2+ dependency of K+ currents cannot reproduce the inverse relation between APD and [Ca2+]o. Only when ICaL inactivation process was modified, by enhancing its dependency on Ca2+, simulations predict APD prolongation at lower [Ca2+]o. Although Ca2+-dependent ICaL inactivation is the primary mechanism, secondary changes in electrogenic Ca2+ transport (by Na+/Ca2+ exchanger and plasmalemmal Ca2+-ATPase) contribute to the reversal of APD dependency on [Ca2+]o. This theoretical investigation points to Ca2+-dependent inactivation of ICaL as a mechanism primarily responsible for the dependency of APD on [Ca2+]o. The modifications implemented here make the model more suitable to analyze repolarization mechanisms when Ca2+ levels are altered.
Journal of Molecular and Cellular Cardiology 01/2009; 46(3):332-42. · 5.17 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Mitral and aortic valves are known to be coupled via fibrous tissue connecting the two annuli. Previous studies evaluating this coupling have been limited to experimental animals using invasive techniques. The new matrix array transesophageal transducer provides high-resolution real-time 3D images of both valves simultaneously. We sought to develop and test a technique for quantitative assessment of mitral and aortic valve dynamics and coupling.
Matrix array transesophageal (Philips iE33) imaging was performed in 24 patients with normal valves who underwent clinically indicated transesophageal echocardiography. Custom software was used to detect and track the mitral and aortic annuli in 3D space throughout the cardiac cycle, allowing automated measurement of changes in mitral and aortic valve morphology. Mitral annulus surface area and aortic annulus projected area changed reciprocally over time. Mitral annulus surface area was 8.0+/-2.1 cm(2) at end-diastole and decreased to 7.7+/-2.1 cm(2) in systole, reaching its maximum (10.0+/-2.2 cm(2)) at mitral valve opening. Aortic annulus projected area was 4.1+/-1.2 cm(2) at end-diastole, then increased during isovolumic contraction reaching its maximum (4.8+/-1.3 cm(2)) in the first third of systole and its minimum (3.6+/-1.0 cm(2)) during isovolumic relaxation. The angle between the mitral and aortic annuli was maximum (136+/-13 degrees ) at end-diastole and decreased to its minimum value (129+/-11 degrees ) during systole.
This is the first study to report quantitative 3D assessment of the mitral and aortic valve dynamics from matrix array transesophageal images and describe the mitral-aortic coupling in a beating human heart. This ability may have impact on patient evaluation for valvular surgical interventions and prosthesis design.
Circulation Cardiovascular Imaging 01/2009; 2(1):24-31. · 5.94 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: AIMS: Despite the potential of real-time three-dimensional (3D) echocardiography (RT3DE) to assess myocardial perfusion, there is no quantification method available for perfusion analysis from RT3DE images. Such method would require 3D regions of interest (ROI) to be defined and adjusted frame-by-frame to compensate for cardiac translation and deformation. Our aims were to develop and test a technique for automated identification of 3D myocardial ROI suitable for translation-free quantification of myocardial videointensity over time, MVI(t), from contrast-enhanced RT3DE images. METHODS AND RESULTS: Twelve transthoracic RT3DE (Philips) data sets obtained in pigs during transition from no contrast to steady-state enhancement (Definity) were analysed using custom software. Analysis included: (i) semi-automated detection of left ventricular endo- and epicardial surfaces using level-set techniques in one frame to define a 3D myocardial ROI, (ii) rigid 3D registration to reduce translation and rotation, (iii) elastic 3D registration to compensate for deformation, and (iv) quantification of MVI(t) in the 3D ROI from the registered and non-registered data sets to assess the effectiveness of registration. For each MVI(t) curve we computed % variability during steady-state enhancement (100 x SD/mean) and goodness of fit (r(2)) to the indicator dilution equation MVI(t) = A[1-exp(-betat)]. Analysis of myocardial contrast throughout contrast inflow was feasible in all data sets. Three-dimensional registration improved MVI(t) curves in terms of both % variability (2.8 +/- 1.8 to 1.5 +/- 0.9%; P < 0.05) and goodness of fit (r(2) from 0.79 +/- 0.2 to 0.90 +/- 0.1; P < 0.05). CONCLUSION: This is the first study to describe a new technique for semi-automated volumetric quantification of myocardial contrast from RT3DE images that includes registration and thus provides the basis for 3D measurement of myocardial perfusion.
European Heart Journal – Cardiovascular Imaging 09/2008; · 2.32 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Mitral regurgitation (MR) in dilated cardiomyopathy (DCM-MR) and MR in ischemic cardiomyopathy (ISC-MR) usually occurs as a result of mitral annulus (MA) dilatation and papillary muscle displacement secondary to global left ventricle remodelling. We propose a method to determine MA area and motion throughout the cardiac cycle and to define papillary muscle position in 3-dimensional space using real-time 3-dimensional echocardiography. Real-time 3-dimensional echocardiography was performed in 24 healthy individuals, and in 30 patients with DCM-MR (n = 15) or ISC-MR (n = 15). Significant intergroup differences were noted in MA surface area (control: 6.4 +/- 1.7 cm(2); DCM-MR: 11.1 +/- 2.6 cm(2); ISC-MR: 9.0 +/- 2.0 cm(2)) and in peak MA motion (control: 8.7 +/- 3.0 mm; DCM-MR: 3.4 +/- 1.7 mm; ISC-MR: 4.9 +/- 1.5 mm). In patients with DCM-MR, papillary muscle symmetry was preserved, whereas in patients with ISC-MR, papillary tethering lengths were unequal as a result of wall-motion abnormalities. Our methodology for dynamic volumetric measurements of the mitral apparatus allows better understanding of MR mechanisms.
Journal of the American Society of Echocardiography: official publication of the American Society of Echocardiography 05/2008; 21(4):347-54. · 2.98 Impact Factor
-
Journal of Cardiovascular Magnetic Resonance. 01/2008;
-
Hans Jaochim Nesser,
Lissa Sugeng, Cristiana Corsi,
Lynn Weinert,
Johannes Niel,
Christian Ebner,
Regina Steringer-Mascherbauer,
Frank Schmidt,
Georg Schummers,
Roberto M Lang,
Victor Mor-Avi
[show abstract]
[hide abstract]
ABSTRACT: Quantitative information on regional left ventricular volumes from real-time three-dimensional echocardiographic (RT3DE) images has significant clinical potential but needs validation.
To validate these measurements against cardiac magnetic resonance (CMR) and test the feasibility of automated detection of regional wall motion (RWM) abnormalities from RT3DE data.
RT3DE (Philips) and CMR (Siemens) images were obtained from 31 patients and analysed by using prototype software to semiautomatically calculate indices of regional left ventricular function, which were compared between RT3DE and CMR (linear regression, Bland-Altman). Additionally, CMR images were reviewed by an expert, whose RWM grades were used as a reference for automated classification of segments as normal or abnormal from RT3DE and from CMR images. For each modality, normal regional ejection fraction (REF) values were obtained from 15 patients with normal wall motion. In the remaining 16 patients, REFs were compared with thresholds that were derived from patients with normal wall motion and optimised using receiver operating characteristic analysis.
RT3DE measurements resulted in good agreement with CMR. Regional indices calculated in patients with normal wall motion varied between segments, but overall were similar between modalities. In patients with abnormal wall motion, RWM was graded as abnormal in 74% segments. CMR and RT3DE thresholds were similar (16-segment average 55 (10)% and 56 (7)%, respectively). Automated interpretation resulted in good agreement with expert interpretation, similar for CMR and RT3DE (sensitivity 0.85, 0.84; specificity 0.81, 0.78; accuracy 0.84, 0.84, respectively).
Analysis of RT3DE data provides accurate quantification of regional left ventricular function and allows semiautomated detection of RWM abnormalities, which is as accurate as the same algorithm applied to CMR images.
Heart (British Cardiac Society) 06/2007; 93(5):572-8. · 4.22 Impact Factor
