3D Planimetry Research Articles

Three‐Dimensional Echocardiography in Valvular Heart Disease

Two-dimensional echocardiography (2DE) with color Doppler has been the standard tool for assessing valvular heart disease. However, this requires conceptualizing three-dimensional (3D) valvular anatomy from individual 2D slices, which is inadequate for complex valvular abnormalities. Similarly, Doppler-based methods are inherently limited by several assumptions and are influenced by hemodynamics and concomitant valvular disease. 3DE has improved both morphological and functional assessment of valvular heart disease. It provides additional morphological information, which leads to better understanding of the mechanism of valvular dysfunction and surgical planning. 3D planimetry has proven to be accurate in the evaluation of valvular stenosis. This direct assessment eliminates measurement errors and could potentially serve as new gold standard. The continuity equation for aortic stenosis can be simplified by directly measuring left ventricular outflow tract area and stroke volume. In patients with valvular regurgitation, vena contracta area can be directly measured by using 3D color Doppler which is more accurate than the standard 2D methods. By applying hemi-elliptical formula or directly measuring isovelocity surface area, 3DE has significantly improved the accuracy in regurgitant severity assessment. This is particularly useful in patients with eccentric jets. 3DE has an advantage over 2DE in assessment of tricuspid valve due to its complex geometry. Direct planimetry of orifice area in tricuspid stenosis, or vena contracta area in tricuspid regurgitation are promising although validation studies are needed before they can be applied for clinical decision making. 3DE has not been widely studied in pulmonic valve disease but preliminary data indicate that it is feasible.

Real-time 3D transoesophageal measurement of the mitral valve area in patients with mitral stenosis

Planimetry measured by two-dimensional transthoracic echocardiography (TTE, MVA2D) is the reference method for the evaluation of the severity of mitral stenosis (MS) but requires experienced operators and good echocardiographic windows. Real-time three-dimensional transoesophageal echocardiography (3D-TEE, MVA3D) may overcome these limitations but its accuracy has never been evaluated. We prospectively enrolled 80 patients (58±15 years, 86% female) referred for MS evaluation who underwent, within 1 week, a clinically indicated TTE and TEE. MVA2D was measured by experienced operators (Level III), MVA3D by one experienced and one non-experienced (Level I) operators blinded of any clinical or TTE information. MVA3D measured by the experienced operator [1.11±0.32 cm2; median, 1.1 cm2; range (0.45-2.20)] did not differ from and correlated well with MVA2D [1.10±0.34 cm2; median, 1.05 cm2; range (0.45-2.30)], P=0.87; r=0.79, P<0.0001; ICC=0.79) and mean difference between methods was small (+0.004±0.21 cm2). MVA3D measured by the non-experienced operator [1.08±0.34 cm2; median 1.02 cm2; range (0.45-2.23)] also did not differ from and correlated well with MVA2D measured by experienced operators (P=0.25; r=0.86, P<0.0001; mean difference -0.02±0.18 cm2; ICC=0.86). Intra and interobserver variability were 0.02±0.25 and 0.01±0.33 cm2. 3D-TEE provides accurate and reproducible MVA measurements similar to 2D planimetry performed by experienced operators. Thus, 3D-TEE could be considered as a second-line alternative tool for the evaluation of MS severity in patients with poor echocardiographic windows or for team less accustomed to evaluate MS patients.

Real-Time 3D Transesophageal Echocardiography for the Evaluation of Rheumatic Mitral Stenosis

The aims of this study were: 1) to assess the feasibility and reliability of performing mitral valve area (MVA) measurements in patients with rheumatic mitral valve stenosis (RhMS) using real-time 3-dimensional transesophageal echocardiography (3DTEE) planimetry (MVA(3D)); 2) to compare MVA(3D) with conventional techniques: 2-dimensional (2D) planimetry (MVA(2D)), pressure half-time (MVA(PHT)), and continuity equation (MVA(CON)); and 3) to evaluate the degree of mitral commissural fusion. 3DTEE is a novel technique that provides excellent image quality of the mitral valve. Real-time 3DTEE is a relatively recent enhancement of this technique. To date, there have been no feasibility studies investigating the utility of real-time 3DTEE in the assessment of RhMS. Forty-three consecutive patients referred for echocardiographic evaluation of RhMS and suitability for percutaneous mitral valvuloplasty were assessed using 2D transthoracic echocardiography and real-time 3DTEE. MVA(3D), MVA(2D), MVA(PHT), MVA(CON), and the degree of commissural fusion were evaluated. MVA(3D) assessment was possible in 41 patients (95%). MVA(3D) measurements were significantly lower compared with MVA(2D) (mean difference: -0.16 ± 0.22; n=25, p<0.005) and MVA(PHT) (mean difference: -0.23 ± 0.28 cm(2); n=39, p<0.0001) but marginally greater than MVA(CON) (mean difference: 0.05 ± 0.22 cm(2); n=24, p=0.82). MVA(3D) demonstrated best agreement with MVA(CON) (intraclass correlation coefficient [ICC] 0.83), followed by MVA(2D) (ICC 0.79) and MVA(PHT) (ICC 0.58). Interobserver and intraobserver agreement was excellent for MVA(3D), with ICCs of 0.93 and 0.96, respectively. Excellent commissural evaluation was possible in all patients using 3DTEE. Compared with 3DTEE, underestimation of the degree of commissural fusion using 2D transthoracic echocardiography was observed in 19%, with weak agreement between methods (κ<0.4). MVA planimetry is feasible in the majority of patients with RhMS using 3DTEE, with excellent reproducibility, and compares favorably with established methods. Three-dimensional transesophageal echocardiography allows excellent assessment of commissural fusion.

P-53 Intraoperative determination of mitral valve area after mitral valve repair surgery: 3-D planimetry vs. pressure-half time

Introduction. Pressure-half time (PHT) of mitral inflow Doppler is not regarded as an accurate tool for measuring mitral valve area (MVA) in many clinical situations. We investigated the efficacy of PHT and 3 dimensional (3D) planimetry of intraoperative MVA determination during mitral valve repair surgery (MVP) using flexible posterior annuloplasty band in mitral stenosis (MS) patients. Method. In MVP patients due to MS (n 19), MVAs were determined by using 3D planimetry (MVA-3D TOE) and PHT (MVA-PHT) before and after cardiopulmonary-bypass (CPB). In 16/19 patients, MVA was also evaluated by planimetry of computed tomography scan (MVA-CT) on postoperative day 7. Three patients were excluded for analysis because of CT image loss. Results. No patients showed residual mitral regurgitation greater than mild. Mean pressure gradients during pre-CPB and post-CPB were 6 (5-7) mmHg and 4 (3-5) mmHg, respectively (P 0.001 by Wilcoxon’s signed rank test). In pre-CPB, MVA-3D and MVA-PHT were 1.17 0.47 cm2, 1.02 0.30 cm2, respectively, (P 0.327 by paired t-test). Post-CPB, MVA-3D (2.35 0.57 cm2) was significantly greater than MVA-PHT (2.00 0.61 cm2) (P 0.001). MVA-CT (2.35 0.35 cm2) was significantly different from MVA-PHT (2.00 0.61 cm2) (P 0.032), MVA-3D was not significantly different from MVA-CT.

117 Real-time 3D transoesophageal echocardiography evaluation of the mitral valve area in patients with mitral stenosis

Planimetry measured by two-dimensional transthoracic echocardiography (TTE, MVA2D) is the reference method for the evaluation of the severity of mitral stenosis (MS) but is significantly less reliable when performed by non-experienced operators and when transthoracic echogenicity is poor. Real-time three-dimensional transoesophageal echocardiography (RT3DTEE, MVA3D) may overcome those limitations but its accuracy has never been evaluated. We prospectively enrolled 43 patients (59 ± 15 years, 86% female) referred for MS evaluation who underwent the same day a TTE and a RT3DTEE. MVA2D was assessed by experienced operators, MVA3D was measured by one experienced (Level III) and one non-experienced operator (Level I) blinded of any clinical and TTE information. RT3DTEE images were digitally stored and analysed offline on a workstation using dedicated software (QLab, Philips) in a random order. MVA3D was measured at the best cross section of the mitral valve defined as the most perpendicular and smallest orifice. MVA3D measured by the experienced operator (1.07 ± 0.31 cm2 [range 0.45–1.85]) did not differ from and correlated well with MVA2D (1.08 ± 0.32 cm2 [range 0.54–2.00], p = 0.84, r = 0.71, p < 0.001), and mean difference was small (−0.01 ± 0.24 cm2). Similarly, the MVA3D measured by the non-experienced operator (1.03 ± 0.31 cm2 [range 0.45–1.69]) did not differ from and correlated well with MVA2D (p = 0.27, r = 0.66, p < 0.001; mean difference −0.05 ± 0.26 cm2). RT3DTEE intra and interobserver (between experienced and non-experienced operators) variability were respectively 0.13 ± 0.10 cm2 and 0.19 ± 0.14 cm2. RT3DTEE provides accurate and reproducible MVA measurements similar to 2D planimetry performed by experienced operators. Thus, RT3DTEE should be considered as an alternative tool for the evaluation of MS severity, especially in patients with poor echocardiographic windows or for team less accustomed to evaluate patients with MS.

Determination of stenotic mitral valve area: new, old, and gold standards

Two-dimensional (2D) echocardiographic mitral valve orifice area (2D) and invasively calculated area (Gorlin) are the standard reference methods to measure stenotic mitral valve area. These two methods have been compared with the ‘ultimate’ gold standard, visual direct valve area assessment, and in particular 2D has been impressively shown to be a reliable measure of valve area more than 30 years ago as well as recently.1,2 The authors of the recent thought-provoking article in this field,3 have in the past carefully and convincingly shown4,5 that mitral valve orifice area determined by 3D echo planimetry (3D) agreed better with Gorlin …

Automated Threshold-Based 3D Segmentation Versus Short-Axis Planimetry for Assessment of Global Left Ventricular Function with Dual-Source MDCT

The purpose of this study was to evaluate software for threshold-based 3D segmentation of the left ventricle in comparison with traditional 2D short axis-based planimetry (Simpson method) for measurement of left ventricular (LV) volume and global function with state-of-the-art dual-source CT. Fifty patients with known or suspected coronary artery disease underwent coronary CT angiography. LV end-diastolic, end-systolic, and stroke volumes and ejection fraction were determined from axial images to which 3D segmentation had been applied and from short-axis reformations from 2D planimetry. Interobserver variability was assessed for both approaches. Threshold-based 3D LV segmentation had excellent correlation with 2D short-axis results (end-diastolic volume, R = 0.99; end-systolic volume, R = 0.99; stroke volume, R = 0.90; ejection fraction, R = 0.97; p < 0.0001). Bland-Altman analyses revealed systematic underestimation of LV end-diastolic volume (-7.4 +/- 8.9 mL) and LV end-systolic volume (-7.0 +/- 4.4 mL) with the 3D segmentation approach and 2.8 +/- 3.3% overestimation of LV ejection fraction. Interobserver variation with 3D segmentation analysis was significantly (p < 0.001) less (e.g., LV ejection fraction, 0.1 +/- 1.7%) than with the 2D technique, and mean analysis time was significantly shorter (172 +/- 20 vs 248 +/- 29 seconds; p < 0.05). Automated threshold-based 3D segmentation enables accurate and reproducible dual-source CT assessment of LV volume and function with excellent correlation with results of 2D short-axis analysis. Exclusion of papillary muscles from LV volume results in small systematic differences in quantitative values.

67 Pulmonary artery systolic pressure is an independent predictor of N-terminal pro-B-type natriuretic peptide in systolic heart failure

Purpose: NT-pro B-type natriuretic peptide (NT-proBNP) has predominantly ventricular origin, produced and released in response to increases in ventricular wall stress. It has been related both to systolic and diastolic left ventricular (LV) dysfunction. The purpose of this study was to investigate the correlations of NT-proBNP levels with echocardiographic measurements in patients with systolic heart failure. Methods: We prospectively investigated patients with symptoms/signs of CHF class II-IV and LV biplane ejection fraction (EF)<45%. After clinical evaluation an echocardiogram was done including M mode, 2D (ventricular dimensions and LV ejection fraction (EF)), conventional Doppler (LV inflow E wave, pulmonary artery systolic pressure (PASP), LV dP/dT). Early and late peak systolic myocardial velocity (Sm1 and Sm2), velocity time integral of Sm(SmVTI), early(Em) and late (Am) peak diastolic myocardial velocities were assessed by pulsed tissue Doppler of septal and lateral mitral annulus and tricuspid annulus. Blood was collected for NT-proBNP measurement. Results: Twenty patients were included 85% male, 71±9,5 years. Mean LV EF was 30±8%, dP/dT 557±164mmHg/s, NT-proBNP 7052±6314pg/mL. There was a trend toward higher NT-proBNP levels in those patients with lower inferior vena cava (IVC) colapse index (p=0,09) and a nonsignificant higher expiratory IVC diameter (p=0,15). Right ventricular end-diastolic dimension by 2D planimetry of four-chamber apical view showed a significant direct correlation to NT-pro-BNP levels (r2=0,24; p=0,03) as did PSAP (r2=0,37; p=0,009). No significant correlation was found with tissue Doppler measurements of tricuspid annulus. There was a trend to lower mitral E-wave deceleration time (r2=0,15; p=0,09) in patients with higher NT-pro BNP. No correlation was found to dP/dT and there was a nonsignificant trend to lower LV EF (p=0,07) in those with higher natriuretic peptides. Sm VTI of septal mitral annulus inversely correlated to NT-proBNP (r2=0,20; p=0,049). No other tissue Doppler measurements showed a signicant relation. PSAP was the only independent predictor of NT-proBNP in multiple regression analysis (p=0,029). Conclusion: NT-proBNP level relates to right ventricular dimention and PSAP in systolic heart failure patients. This relation sugests that right ventricular secretion of NT-proBNP may be an important contributor to serum levels of this natriuretic peptide in patients with systolic heart failure. Septal mitral annulus Sm VTI may be a more accurate estimate of global systolic function since it may be under influence of both the right and left ventricle.

Which method should be the reference method to evaluate the severity of rheumatic mitral stenosis? Gorlin's method versus 3D-echo

Several studies have shown a wide variability among different methods to determine the valve area in patients with rheumatic mitral stenosis. Our aim was to evaluate if 3D-echo planimetry is more accurate than the Gorlin method to measure the valve area. Twenty-six patients with mitral stenosis underwent 2D and 3D-echo echocardiographic examinations and catheterization. Valve area was estimated by different methods. A median value of the mitral valve area, obtained from the measurements of three classical non-invasive methods (2D planimetry, pressure half-time and PISA method), was used as the reference method and it was compared with 3D-echo planimetry and Gorlin's method. Our results showed that the accuracy of 3D-echo planimetry is superior to the accuracy of the Gorlin method for the assessment of mitral valve area. We should keep in mind the fact that 3D-echo planimetry may be a better reference method than the Gorlin method to assess the severity of rheumatic mitral stenosis.

Three-dimensional evaluation of the mitral valve area and commissural opening before and after percutaneous mitral commissurotomy in patients with mitral stenosis

Management of patients with mitral stenosis (MS) relies on accurate evaluation of the mitral valve area (MVA). Planimetry (MVA(2D)) is considered as the reference method but must be performed at the tips of the leaflets with the correct plane orientation and therefore requires experienced operators. Real-time three-dimensional echocardiography (RT3DE) may overcome this limitation but its usefulness for experienced when compared with less experienced operators has not been evaluated. In addition, superiority of RT3DE for the evaluation of commissural splitting after percutaneous mitral commissurotomy (PMC) is unknown. 60 patients were prospectively evaluated by 2D and RT3DE before and after PMC by experienced operators. Before PMC, MVA(3D) was slightly higher than MVA(2D) (1.15 +/- 0.25 vs. 1.06 +/- 0.22 cm2, P = 0.0001) but correlation between methods was excellent (r = 0.73, P < 0.0001), mean difference was small (0.09 +/- 0.18 cm2) and clinically meaningless (three patients misclassified, two of whom had borderline MS severity). After PMC, MVA(3D) did not differ from and correlated well with MVA(2D) (1.87 +/- 0.37 vs. 1.85 +/- 0.32 cm2, P = 0.36; r = 0.76, P < 0.0001; mean difference 0.03 +/- 0.24 cm2). Twenty-five additional patients were also evaluated both by an experienced and a less experienced operators. Bland-Altman analysis showed the better agreement between MVA(3D) measured by the less experienced operator and MVA(2D) measured by the experienced operator than between MVA(2D) measured by the less experienced and the experienced operators (mean difference 0.03 +/- 0.34 vs. - 0.13 +/- 0.46 cm2, P = 0.03). When compared with RT3DE, 2DE underestimated the degree of commissural opening in 33% of patients and agreement between methods was weak (kappa = 0.41). RT3DE provides accurate MVA measurements similar to 2D planimetry performed by experienced operators. Thus, it does not provide a real advantage for experienced operators, whereas it seems particularly helpful for less experienced operators. In addition, RT3DE improves the description of valvular anatomy.

Comparison of Proximal Isovelocity Surface Area Method and Pressure Half Time Method for Evaluation of Mitral Valve Area in Patients Undergoing Balloon Mitral Valvotomy

The pressure half time (PHT) method is unreliable for measurement of mitral valve area (MVA) immediately after valvotomy. The proximal isovelocity surface area (PISA) method has been used to derive mitral valve area in patients with mitral stenosis. The aim of our study was to compare PISA method and PHT method in patients undergoing percutaneous balloon mitral valvotomy (BMV). The PISA was recorded from the apex and MVA was calculated using continuity equation by the formula 2pir(2) Vr/Vm, where 2pir(2) is the hemispheric isovelocity area, Vr is the velocity at the radial distance "r" from the orifice, and Vm is the peak velocity. A plain angle correction factor (theta)/180 was used to correct the inlet angle subtended by leaflet tunnel as a result of leaflet doming. MVA calculated using PISA method (r = 0.5217, P < 0.0001, SE = 0.016) and PHT (r = 0.6652, P < 0.0001, SE = 0.017) correlated well with 2D method in patients with mitral stenosis before BMV. After BMV, MVA by PISA method correlated well with 2D planimetry (r = 0.5803, P < 0.0001, SE = 0.053) but PHT showed poor correlation (r = 0.1334, P = 0.199, SE = 0.036). The variability of measurement of MVA was most marked with PHT method in the post-BMV period. The PISA method correlates well with 2D planimetry in patients with mitral stenosis before and after BMV and is superior to the PHT method in the post-BMV period where the latter may be unreliable.

Po‐Poster ‐ 25: Robust 3D prostate model reconstruction from a sparse collection of non‐parallel 2D TRUS biopsy images

Biopsy of the prostate using 2D transrectal ultrasound (TRUS) guidance is the current gold standard for diagnosis of prostate cancer. Physicians' procedural accuracy and precision is limited by working within the current 2D biopsy environment that is susceptible to uncertainties when targeting 3D biopsy locations. We propose a technique for the reconstruction of a patient‐specific 3D prostate volume from a sparse collection of 2D US biopsy images that may be utilized for accurate prostate volume calculation. 2D TRUS biopsy images, with known 3D coordinates, were simulated from 3D US prostate image volumes acquired from biopsy patients. The prostate boundaries were manually outlined from each simulated biopsy image and radial basis functions were used to estimate the 3D prostate capsule from collections of 2D prostate outlines varying from 6–16 contours. Each reconstructed prostate model was compared to a manually segmented, 3D planimetry model for volume and surface boundary accuracy as well as the clinical‐standard prolate ellipsoid volume estimation technique. Prostate models reconstructed from one patient's simulated biopsy images demonstrated a consistent volume error range of 1.1%–0.4%, which was less than the clinical standard calculation that produced a 1.44% error. The mean prostate surface boundary error for all generated models was consistently &lt; 1 mm with a RMS ≅ 1.1 mm. We have demonstrated a reconstruction technique capable of generating a 3D prostate model from a small sample of 2D TRUS biopsy images. This reconstruction technique has the potential to be incorporated into biopsy protocol for accurate volume measurements and needle guidance.

TH-C-I-609-03: 3D Prostate Model Reconstruction From 2D Transrectal Ultrasound Biopsy Images

Purpose: Biopsy of the prostate using 2D transrectal ultrasound (TRUS) guidance is the current gold standard for diagnosis of prostate cancer. Physicians' procedural accuracy and precision is limited by working within the current 2D biopsy environment that is susceptible to uncertainties when targeting 3D biopsy locations, which can ultimately result in false patient diagnoses. We propose a technique for the reconstruction of a patient-specific 3D prostate volume from a sparse collection of 2D US biopsy images that may be utilized for intra-biopsy needle guidance and accurate prostate volume calculation. Method and Materials: 2D TRUS axial and sagittal biopsy images, with known 3D coordinates, were simulated from 3D US prostate image volumes acquired from biopsy patients. The prostate boundaries were manually outlined from each simulated biopsy image and radial basis functions were used to estimate the 3D prostate capsule from collections of 2D boundary outlines varying from 6–16 contours. Each reconstructed prostate model was compared to a manually segmented, 3D planimetry model for volume and surface boundary accuracy as well as the clinical-standard prolate ellipsoid volume estimation technique. Results: Prostate models reconstructed from simulated biopsy images ranging from 8 – 16 contours demonstrated a consistent volume error range of 1.3% – 0.38%, which was less than the clinical standard calculation that produced a 1.44% error. The mean prostate surface boundary error for all generated models was consistently < 1 mm with a RMS ∼= 1.1 mm. Conclusion: We have demonstrated a reconstruction technique capable of generating a 3D prostate model from a small sample of 2D TRUS biopsy images. Initial results suggest the fidelity of this reconstruction technique for generation of prostate models with accurate capsule surface contours and volume measurements, making it a potential tool for 3D intra-biopsy needle guidance and more accurate prostate volume calculations.

Quantifizierung der Aortenklappen�ffnungsfl�che und der linksventrikul�ren Muskelmasse bei gesunden Probanden und bei Patienten mit symptomatischer Aortenklappenstenose mittels MRT

MRI allows visualization and planimetry of the aortic valve orifice and accurate determination of left ventricular muscle mass, which are important parameters in aortic stenosis. In contrast to invasive methods, MRI planimetry of the aortic valve area (AVA) is flow independent. AVA is usually indexed to body surface area. Left ventricular muscle mass is dependent on weight and height in healthy individuals. We studied AVA, left ventricular muscle mass (LMM) and ejection fraction (EF) in 100 healthy individuals and in patients with symptomatic aortic valve stenosis (AS). All were examined by MRI (1.5 Tesla Siemens Sonate) and the AVA was visualized in segmented 2D flash sequences and planimetry of the performed AVA was manually. The aortic valve area in healthy individuals was 3.9+/-0.7 cm(2), and the LMM was 99+/-27 g. In a correlation analysis, the strongest correlation of AVA was to height (r=0.75, p<0.001) and for LMM to weight (r=0.64, p<0.001). In a multiple regression analysis, the expected AVA for healthy subjects can be predicted using body height: AVA=-2.64+0.04 x(height in cm) -0.47 x w (w=0 for man, w=1 for female).In patients with aortic valve stenosis, AVA was 1.0+/-0.35 cm(2), in correlation to cath lab r=0.72, and LMM was 172+/-56 g. We compared the AS patients results with the data of the healthy subjects, where the reduction of the AVA was 28+/-10% of the expected normal value, while LMM was 42% higher in patients with AS. There was no correlation to height, weight or BSA in patients with AS. With cardiac MRI, planimetry of AVA for normal subjects and patients with AS offered a simple, fast and non-invasive method to quantify AVA. In addition LMM and EF could be determined. The strong correlation between height and AVA documented in normal subjects offered the opportunity to integrate this relation between expected valve area and definitive orifice in determining the disease of the aortic valve for the individual patient. With diagnostic MRI in patients with AS, invasive measurements of the systolic transvalvular gradient does not seem to be necessary.

Accuracy of mitral valve area measurements using transthoracic rapid freehand 3-dimensional scanning: comparison with noninvasive and invasive methods

Objective The feasibility and accuracy of direct transthoracic 3-dimensional (3D) mitral valve area (MVA) measurements obtained using freehand scanning was investigated in patients with mitral stenosis. Methods A total of 30 patients (26 women, 4 men; aged 55 ± 13 years) underwent a 2-dimensional (2D) and Doppler study 1 hour before percutaneous balloon mitral valvuloplasty. Transthoracic freehand data were acquired using a magnetic receiver attached to a broadband transducer, gated to electrocardiography and respiration. Volumetric MVA measurements from the left ventricle and left atrium were obtained and compared with MVA measurements derived from 2D planimetry, pressure half-time, and proximal isovelocity surface area. Invasive Gorlin MVA measurements were the gold standard for comparison. Results In all, 29 patients (97%) had 3D data allowing MVA measurements. Direct 3D measurements from the left ventricle had the least bias (0.06 ± 0.19 cm 2) and tightest limits of agreement (−0.44 to 0.32) compared with left atrium measurements (0.17 ± 0.25 cm 2 and −0.67 to 0.33, respectively). The proximal isovelocity surface area method (bias: 0.09 ± 0.34 cm 2) was the most accurate of all 2D methods followed by pressure half-time (0.17 ± 0.36 cm 2) and planimetry (0.21 ± 0.29 cm 2). Conclusion Direct 3D MVA measurements from the left ventricle using transthoracic freehand scanning are more accurate than traditional 2D methods.

Quantitative assessment of mechanical prosthetic valve area by 3-dimensional transesophageal echocardiography

Objective: The goal of this study was to assess the geometric orifice area of mechanical valve prostheses by transesophageal 3-dimensional echocardiographic planimetry. Methods and Results: Currently used Doppler methods for prosthetic assessment (orifice area-Doppler) were compared with 3D planimetry for orifice area (orifice area-3D) and with manufacturer's values (orifice area-manufacturer) for the corresponding prosthesis types and sizes and with historical controls provided by Doppler literature (orifice area-literature). Twenty-four mechanical valve prostheses (in 22 patients) were studied: 13 in mitral position and 11 in aortic position. Orifice area-manufacturer, orifice area-Doppler, orifice area-literature, and orifice area-3D were 3.6 ± 1.1 cm 2, 2.3 ± 0.9 cm 2, 2.4 ± 0.9 cm 2, and 2.6 ± 0.7 cm 2, respectively. Orifice area-manufacturer values were significantly larger. Correlation coefficients between orifice area-3D and orifice area-manufacturer, and between orifice area-3D and orifice area-Doppler and orifice area-literature were 0.83, 0.90, and 0.73, respectively (all P < .0001). Conclusion: Three-dimensional transesophageal echocardiography is feasible and has good correlation with orifice area-Doppler (in aortic position) and good correlation with orifice area-manufacturer (in aortic and mitral positions) methods. (J Am Soc Echocardiogr 2001;14:723-31.)

Noninvasive calculation of left heart compliance by echocardiography and its clinical significance in mitral stenosis.

Background:Although the net atrioventricular compliance can be obtained by invasive catheterization (Ccath) in mitral stenosis (MS), feasibility of noninvasive echocardiographic calculation of the compliance (Cecho) and its hemodynamic significance were not tested. Methods:Using valve area by 2D planimetry (A2D) and deceleration slope (dv/dt) of transmitral velocity decay in continuous wave Doppler echocardiographic tracing, Cecho was defined as -A2D/(ρ dv/dt), which was compared with Ccath obtained directly during the catheterization in 30 MS patients with sinus rhythm. Exercise Doppler echocardiography with symptom-limited treadmill was performed in 66 patients with moderate to tight MS;mean mitral gradient (MG)and peak pressure gradient of tricuspid regurgitation (PGTR) at baseline and immediately after exercise were obtained using continuous wave Doppler echocardiographic tracing. Hemodynamic variables including Cecho, MG, PGTR and mitral valve area were analyzed to determine the association with patients’ exercise tolerance. Results:Cecho in 30 patients with tight MS (valve area 0.9±0.2 cm) was 4±1 ml/mmHg (2-7 mmHg), which showed a significant correlation with Ccath (r=0.48, p=0.01). Exercise time in 66 patients with moderate to tight MS showed significant negative correlation with resting MG, resting and postexercise PGTR, and positive correlation with Cecho;exercise time in those patients did not show any significant correlation with resting valve area. In multivariate analysis, Cecho and postexercise PGTR were independent factors determining exercise time in MS. Conclusions:The net atrioventricular compliance in MS can be calculated by noninvasive echocardiography, and it is an important hemodynamic factor determining exercise tolerance in MS. (Korean Circulation J 2000;30(3):303-309)

Accuracy of mitral valve area in patients with mitral stenosis measured by echocardiography : Compared with operative mitral valve area

Background:Measurement of echocardiographic mitral valve area(MVA) is a useful non-invasive method of estimating the stenotic mitral valve area. This study was undertaken to evaluate the accuracy of echocardiographic MVA measurements by comparing MVAs measured by the planimetric and the pressure half-time method versus direct MVA measurement by using a cone shaped device specifically made for direct measurement of MVA. Methods and Results:The study population consisted of 22 consecutive patients from August 1993 to February 1996. All the patients underwent 2D planimetry and Doppler echocardiographic MVA measurements before and after valve replacement surgery;direct measurement also was performed after surgery. Five patients(22.7%) had normal sinus rhythm, and the rest of the patients had atrial fibrillation. Two-dimensional echocardiographic examinations were attempted in 22 patients, and adequate measurements were obtained in 21 of the patients studied. Mean mitral valve area were 0.99±0.32cm ranged from 0.42 to 1.68cm on 2D planimetry method, 0.93±0.32cm ranged from 0.42 to 1.68cm on Doppler pressure half-time method, 1.17±0.20cm ranged from 0.93 to 1.68cm on direct measurement of mitral valve area after surgery. 2D planimetry method(r=0.621, p=0.003, SE=0.165), pressure half-time method(r=0.454, p=0.003 SE=0.187), and transmitral peak velocity (r=-0.480, p=0.026, SE=0.189) was relatively well correlate with operative mitral valve area. There was relatively good agreement between direct and 2D planimetric measurements and between

The acutely burned hand: Management and outcome based on a ten-year experience with 1047 acute hand burns

The aim of this study was to compare the accuracy of burn size estimation using the computer-assisted software BurnCase 3D (RISC Software GmbH, Hagenberg, Austria) with that using a 2D scan, considered to be the actual burn size.Thirty artificial burn areas were pre planned and prepared on three mannequins (one child, one female, and one male). Five trained physicians (raters) were asked to assess the size of all wound areas using BurnCase 3D software. The results were then compared with the real wound areas, as determined by 2D planimetry imaging. To examine inter-rater reliability, we performed an intraclass correlation analysis with a 95% confidence interval.The mean wound area estimations of the five raters using BurnCase 3D were in total 20.7 ± 0.9% for the child, 27.2 ± 1.5% for the female and 16.5 ± 0.1% for the male mannequin. Our analysis showed relative overestimations of 0.4%, 2.8% and 1.5% for the child, female and male mannequins respectively, compared to the 2D scan. The intraclass correlation between the single raters for mean percentage of the artificial burn areas was 98.6%. There was also a high intraclass correlation between the single raters and the 2D Scan visible.BurnCase 3D is a valid and reliable tool for the determination of total body surface area burned in standard models. Further clinical studies including different pediatric and overweight adult mannequins are warranted.

Non-invasive assessment of mitral stenosis before and after percutaneous balloon mitral valvotomy by Doppler continuity equation.

The continuity equation was used to estimate non-invasively the stenotic mitral valve area by comparison with two other echocardiographic methods (planimetry and pressure half-time) and with Gorlin's formula as the gold standard. The accuracy of the equation of continuity was determined before and 24 h after valvuloplasty in a study group of 21 patients with severe mitral stenosis. According to the equation of continuity, mitral valve area was calculated by the product of the cross-sectional area and the aortic or pulmonary annulus and the ratio of the time velocity integral of the aortic or pulmonary flow to that of the mitral stenotic jet. In pre-valvotomy basal conditions, the Doppler continuity equation demonstrated significant correlations with 2D planimetry (r = 0.72, P less than 0.01), with the pressure half-time method (r = 0.62, P less than 0.01) and with the Gorlin formula (r = 0.66, P less than 0.01). There was no significant difference between the haemodynamic data and the echocardiographic measurements. Twenty-four hours after valvotomy, the Doppler continuity equation also demonstrated significant correlations with 2D planimetry (r = 0.83, P less than 0.01), with pressure half-time (r = 0.82, P less than 0.01) and with the Gorlin formula (r = 0.69, P less than 0.01). However, the haemodynamic measurements significantly overestimated (P less than 0.01) the echographic measurements. Thus, we conclude that the continuity equation provides an accurate estimation of mitral valve area in mitral stenosis before and after balloon valvotomy.