Aug 20, 2012
Real-Time 3D Echocardiographic Quantification of Left Atrial Volume Multicenter Study for Validation With CMR
O B J E C T I V E S: We studied in a multicenter setting the accuracy and reproducibility of 3-dimensional echocardiography (3DE)–derived measurements of left atrial volume (LAV) using new, dedicated volumetric software, side by side with 2-dimensional echocardiography (2DE), using cardiac magnetic resonance (CMR) imaging as a reference.
B A C K G R O U N D: Increased LAV is associated with adverse cardiovascular outcomes. Although LAV measurements are routinely performed using 2DE, this methodology is limited because it is view dependent and relies on geometric assumptions regarding left atrial shape. Real-time 3DE is free of these limitations and accordingly is an attractive alternative for the evaluation of LAV. However, few studies have validated 3DE-derived LAV measurements against an accepted independent reference standard, such as CMR imaging.
M E T H O D S: We studied 92 patients with a wide range of LAV who underwent CMR (1.5-T) and echocardiographic imaging on the same day. Images were analyzed to obtain maximal and minimal LAV: CMR images using standard commercial tools, 2DE images using a biplane area-length technique, and 3DE images using Tomtec LA Function software. Intertechnique comparisons included linear regression and Bland-Altman analyses. Reproducibility of all 3 techniques was assessed by calculating the percentage of absolute differences in blinded repeated measurements. Kappa statistics were used to compare 2DE and 3DE classification of normal/enlarged against the CMR reference.
R E S U L T S: 3DE-derived LAV values showed higher correlation with CMR than 2DE measurements (r:0.93 vs. r: 0.74 for maximal LAV; r:0.88 vs. r: 0.82 for minimal LAV). Although 2DE underestimated maximal LAV by 31/ 25 ml and minimal LAV by 16/32 ml, 3DE resulted in a minimal bias of 1-14 ml for maximal LAV and 0-21 ml for minimal LAV. Interobserver and intraobserver variability of 2DE and 3DE measurements of maximal LAV were similar (7% to 12%) and approximately 2 times higher than CMR (4% to 5%). 3DE classified enlarged atria more accurately than 2DE (kappa: 0.88 vs. 0.71).
C O N C L U S I O N S: Compared with CMR reference, 3DE-derived LAV measurements are more accurate than 2DE-based analysis, resulting in fewer patients with undetected atrial enlargement. (J Am Coll Cardiol Img 2012;5:769–77) © 2012 by the American College of Cardiology Foundation
Jun 27, 2012
PAPER OF THE WEEK
J Cardiovasc Magn Reson. 2012 Jun 21;14(1):42
Non-contrast T1-mapping detects acute myocardial edema with high diagnostic accuracy: a comparison to T2-weighted cardiovascular magnetic resonance.
Dr. Ferreira and cols investigated 21 controls (55 +/- 13 years) and 21 patients (61 +/- 10
years) with Takotsubo cardiomyopathy or acute regional myocardial edema
without infarction. They hypothesized that
T1-mapping would have a higher diagnostic performance in detecting acute
edema than dark-blood and bright-blood T2w-CMR. Their conclusion was that non-contrast T1-mapping using ShMOLLI is a
novel method for objectively detecting myocardial edema with a high
diagnostic performance. T1-mapping may serve as a complementary
technique to T2-weighted imaging for assessing myocardial edema in
ischemic and non-ischemic heart disease, such as quantifying
area-at-risk and diagnosing myocarditis.
Jun 24, 2012
Jun 23, 2012
Diagnostic accuracy of cardiovascular magnetic resonance of right ventricular morphology and function in the assessment of suspected pulmonary hypertension
Andrew J Swift, Smitha Rajaram, Robin Condliffe, Dave Capener, Judith Hurdman, Charlie A Elliot, Jim M Wild and David G Kiely
Background Cardiovascular Magnetic Resonance (CMR) is accurate and reproducible for the assessment of right ventricular (RV) morphology and function. However, the diagnostic accuracy of CMR derived RV measurements for the detection of pulmonary hypertension (PH) in the assessment of patients with suspected PH in the clinic setting is not well described. Methods We retrospectively studied 233 consecutive treatment naive patients with suspected PH including 39 patients with no PH who underwent CMR and right heart catheterisation (RHC) within 48hours. The diagnostic accuracy of multiple CMR measurements for the detection of mPAP [greater than or equal to] 25 mmHg was assessed using Fisher's exact test and receiver operating characteristic (ROC) analysis. Results Ventricular mass index (VMI) was the CMR measurement with the strongest correlation with mPAP (r = 0.78) and the highest diagnostic accuracy for the detection of PH (area under the ROC curve of 0.91) compared to an ROC of 0.88 for echocardiography calculated mPAP. Late gadolinium enhancement, VMI [greater than or equal to] 0.4, retrograde flow [greater than or equal to] 0.3 L/min/m2 and PA relative area change [less than or equal to] 15% predicted the presence of PH with a high degree of diagnostic certainty with a positive predictive value of 98%, 97%, 95% and 94% respectively. No single CMR parameter could confidently exclude the presence of PH. Conclusion CMR is a useful alternative to echocardiography in the evaluation of suspected PH. This study supports a role for the routine measurement of ventricular mass index, late gadolinium enhancement and the use of phase contrast imaging in addition to right heart functional indices in patients undergoing diagnostic CMR evaluation for suspected pulmonary hypertension. Journal of Cardiovascular Magnetic Resonance 2012, 14:40
Andrew J Swift, Smitha Rajaram, Robin Condliffe, Dave Capener, Judith Hurdman, Charlie A Elliot, Jim M Wild and David G Kiely
Background Cardiovascular Magnetic Resonance (CMR) is accurate and reproducible for the assessment of right ventricular (RV) morphology and function. However, the diagnostic accuracy of CMR derived RV measurements for the detection of pulmonary hypertension (PH) in the assessment of patients with suspected PH in the clinic setting is not well described. Methods We retrospectively studied 233 consecutive treatment naive patients with suspected PH including 39 patients with no PH who underwent CMR and right heart catheterisation (RHC) within 48hours. The diagnostic accuracy of multiple CMR measurements for the detection of mPAP [greater than or equal to] 25 mmHg was assessed using Fisher's exact test and receiver operating characteristic (ROC) analysis. Results Ventricular mass index (VMI) was the CMR measurement with the strongest correlation with mPAP (r = 0.78) and the highest diagnostic accuracy for the detection of PH (area under the ROC curve of 0.91) compared to an ROC of 0.88 for echocardiography calculated mPAP. Late gadolinium enhancement, VMI [greater than or equal to] 0.4, retrograde flow [greater than or equal to] 0.3 L/min/m2 and PA relative area change [less than or equal to] 15% predicted the presence of PH with a high degree of diagnostic certainty with a positive predictive value of 98%, 97%, 95% and 94% respectively. No single CMR parameter could confidently exclude the presence of PH. Conclusion CMR is a useful alternative to echocardiography in the evaluation of suspected PH. This study supports a role for the routine measurement of ventricular mass index, late gadolinium enhancement and the use of phase contrast imaging in addition to right heart functional indices in patients undergoing diagnostic CMR evaluation for suspected pulmonary hypertension. Journal of Cardiovascular Magnetic Resonance 2012, 14:40
Velocity encoded cardiovascular magnetic resonance to assess left atrial appendage emptying
Kai Muellerleile, Arian Sultan, Michael Groth, Daniel Steven, Boris Hoffmann, Gerhard Adam, Gunnar Lund, Thomas Rostock and Stephan Willems Background
The presence of impaired left atrial appendage (LAA) function identifies patients who are prone to thrombus formation in the LAA and therefore being at high risk for subsequent cardioembolic stroke. LAA function is typically assessed by measurements of LAA emptying velocities using transesophageal echocardiography (TEE) in clinical routine. This study aimed at evaluating the feasibility of assessing LAA emptying by velocity encoded (VENC) cardiovascular magnetic resonance (CMR). Methods This study included 30 patients with sinus rhythm (n = 18) or atrial fibrillation (n = 12). VENC-CMR velocity measurements were performed perpendicular to the orifice of the LAA. Peak velocities were measured of passive diastolic LAA emptying (e-wave) in all patients. Peak velocities of active, late-diastolic LAA emptying (a-wave) were assessed in patients with sinus rhythm. Correlation and agreement was analyzed between VENC-CMR and TEE measurements of e- and a-wave peak velocities. Results A significant correlation and good agreement was found between VENC-CMR and TEE measurements of maximal e-wave velocities (r = 0.61, P<0.001; mean difference 0+/-10 cm/s). The a-wave was detectable by VENC-CMR in all patients with sinus rhythm. Correlation was also significant for measurements of peak a-wave velocities between VENC-CMR and TEE (r=0.69, P<0.01). There was no significant correlation of LAA emptying velocities with clinical characteristics and only a modest negative correlation of passive LAA emptying with LA function. Conclusions The assessment of active and passive LAA emptying by VENC-CMR is feasible. Further evaluation is required of potential future clinical applications such as risk stratification for cardioembolic stroke.
Journal of Cardiovascular Magnetic Resonance 2012, 14:39
Kai Muellerleile, Arian Sultan, Michael Groth, Daniel Steven, Boris Hoffmann, Gerhard Adam, Gunnar Lund, Thomas Rostock and Stephan Willems Background
The presence of impaired left atrial appendage (LAA) function identifies patients who are prone to thrombus formation in the LAA and therefore being at high risk for subsequent cardioembolic stroke. LAA function is typically assessed by measurements of LAA emptying velocities using transesophageal echocardiography (TEE) in clinical routine. This study aimed at evaluating the feasibility of assessing LAA emptying by velocity encoded (VENC) cardiovascular magnetic resonance (CMR). Methods This study included 30 patients with sinus rhythm (n = 18) or atrial fibrillation (n = 12). VENC-CMR velocity measurements were performed perpendicular to the orifice of the LAA. Peak velocities were measured of passive diastolic LAA emptying (e-wave) in all patients. Peak velocities of active, late-diastolic LAA emptying (a-wave) were assessed in patients with sinus rhythm. Correlation and agreement was analyzed between VENC-CMR and TEE measurements of e- and a-wave peak velocities. Results A significant correlation and good agreement was found between VENC-CMR and TEE measurements of maximal e-wave velocities (r = 0.61, P<0.001; mean difference 0+/-10 cm/s). The a-wave was detectable by VENC-CMR in all patients with sinus rhythm. Correlation was also significant for measurements of peak a-wave velocities between VENC-CMR and TEE (r=0.69, P<0.01). There was no significant correlation of LAA emptying velocities with clinical characteristics and only a modest negative correlation of passive LAA emptying with LA function. Conclusions The assessment of active and passive LAA emptying by VENC-CMR is feasible. Further evaluation is required of potential future clinical applications such as risk stratification for cardioembolic stroke.
Journal of Cardiovascular Magnetic Resonance 2012, 14:39
Jun 21, 2012
Non-US Cardiology SCMR Position
SCMR will elect a new Non-US Cardiology member for its board. This year Dr Carlos Rochitte from University of Sao Paulo, Brazil, is being a candidate. As a LatAm member, we wish to support his candidacy and hope he can be elected as member of the Board.
Juliano
Juliano
Jun 14, 2012
PAPER OF THE WEEK
Magn Reson Med. 2012 May 30. doi: 10.1002/mrm.24346. [Epub ahead of print]
Free-breathing multiphase whole-heart coronary MR angiography using image-based navigators and three-dimensional cones imaging.
In Dr Wu and Cols work, a new free-breathing coronary MR angiography technique that reduces scan time and improves robustness to motion is developed. Data acquisition is accomplished using a three-dimensional cones non-Cartesian trajectory, which can reduce the number of readouts 3-fold or more compared to conventional three-dimensional Cartesian encoding and provides greater robustness to motion/flow effects. Experimental results demonstrate that whole-heart coronary angiograms can be obtained rapidly and robustly with this proposed technique.May 22, 2012
Apr 21, 2012
Apr 9, 2012
PAPER OF THE WEEK
Cardiovascular magnetic resonance and single-photon emission computed tomography for diagnosis of coronary heart disease (CE-MARC): a prospective trial (Lancet 2012.4;379(9814):453-60)
Dr. Greenwood JP and cols studied 752 patients, with the purpose to establish the diagnostic accuracy of a multiparametric cardiovascular magnetic resonance (CMR) protocol with x-ray coronary
angiography as the reference standard, and to compare CMR with SPECT, in patients with suspected coronary
heart disease. They established CMR’s high diagnostic accuracy in coronary heart disease and CMR’s superiority over SPECT and concluded that it should be adopted more widely
than at present for the investigation of coronary heart disease.
Mar 26, 2012
PAPER OF THE WEEK
The diagnosis of hypertrophic cardiomyopathy (HCM) by cardiovascular magnetic resonance
J Cardiovasc Magn Reson 2012;14:17.
Dr. Noureldin, our dear Brazilian friend Marcelo Nacif and cols in their review, provide an overview of the clinical, pathological and imaging features relevant to understanding the diagnosis of HCM. They concluded that CMR appears to be highly relevant in the clinical as well as research evaluation of patients with overt as well as pre-clinical HCM. Late enhancement after gadolinium administration allows tissue characterization of myocardial fibrosis. The method may potentially identify HCM patients at greatest risk for adverse cardiac events. CMR evaluation of HCM mutation carriers in an early stage of disease has yet to be extensively evaluated, but represents a promising method for exploring the inter-relationship between functional, morphologic and tissue abnormalities in HCM.
Mar 20, 2012
Feb 26, 2012
4D cardiovascular magnetic resonance velocity mapping of alterations of right heart flow patterns and main pulmonary artery hemodynamics in tetralogy
Background
To assess changes in right heart flow and pulmonary artery hemodynamics in patients with repaired Tetralogy of Fallot (rTOF) we used whole heart, four dimensional (4D) velocity mapping (VM) cardiovascular magnetic resonance (CMR).
Methods
CMR studies were performed in 11 subjects with rTOF (5M/6F; 20.1+/-12.4 years) and 10 normal volunteers (6M/4F; 34.2+/-13.4 years) on clinical 1.5T and 3.0T MR scanners. 4D VM-CMR was performed using PC VIPR (Phase Contrast Vastly undersampled Isotropic Projection Reconstruction). Interactive streamline and particle trace visualizations of the superior and inferior vena cava (IVC and SVC, respectively), right atrium (RA), right ventricle (RV), and pulmonary artery (PA) were generated and reviewed by three experienced readers. Main PA net flow, retrograde flow, peak flow, time-to-peak flow, peak acceleration, resistance index and mean wall shear stress were quantified. Differences in flow patterns between the two groups were tested using Fisher's exact test. Differences in quantitative parameters were analyzed with the Kruskal-Wallis rank sum test.
Results
4D VM-CMR was successfully performed in all volunteers and subjects with TOF. Right heart flow patterns in rTOF subjects were characterized by (a) greater SVC/IVC flow during diastole than systole, (b) increased vortical flow patterns in the RA and in the RV during diastole, and (c) increased helical or vortical flow features in the PA's. Differences in main PA retrograde flow, resistance index, peak flow, time-to-peak flow, peak acceleration and mean wall shear stress were statistically significant.
Conclusions
Whole heart 4D VM-CMR with PC VIPR enables detection of both normal and abnormal right heart flow patterns, which may allow for comprehensive studies to evaluate interdependencies of post-surgically altered geometries and hemodynamics.
Journal of Cardiovascular Magnetic Resonance 2012, 14:16
To assess changes in right heart flow and pulmonary artery hemodynamics in patients with repaired Tetralogy of Fallot (rTOF) we used whole heart, four dimensional (4D) velocity mapping (VM) cardiovascular magnetic resonance (CMR).
Methods
CMR studies were performed in 11 subjects with rTOF (5M/6F; 20.1+/-12.4 years) and 10 normal volunteers (6M/4F; 34.2+/-13.4 years) on clinical 1.5T and 3.0T MR scanners. 4D VM-CMR was performed using PC VIPR (Phase Contrast Vastly undersampled Isotropic Projection Reconstruction). Interactive streamline and particle trace visualizations of the superior and inferior vena cava (IVC and SVC, respectively), right atrium (RA), right ventricle (RV), and pulmonary artery (PA) were generated and reviewed by three experienced readers. Main PA net flow, retrograde flow, peak flow, time-to-peak flow, peak acceleration, resistance index and mean wall shear stress were quantified. Differences in flow patterns between the two groups were tested using Fisher's exact test. Differences in quantitative parameters were analyzed with the Kruskal-Wallis rank sum test.
Results
4D VM-CMR was successfully performed in all volunteers and subjects with TOF. Right heart flow patterns in rTOF subjects were characterized by (a) greater SVC/IVC flow during diastole than systole, (b) increased vortical flow patterns in the RA and in the RV during diastole, and (c) increased helical or vortical flow features in the PA's. Differences in main PA retrograde flow, resistance index, peak flow, time-to-peak flow, peak acceleration and mean wall shear stress were statistically significant.
Conclusions
Whole heart 4D VM-CMR with PC VIPR enables detection of both normal and abnormal right heart flow patterns, which may allow for comprehensive studies to evaluate interdependencies of post-surgically altered geometries and hemodynamics.
Journal of Cardiovascular Magnetic Resonance 2012, 14:16
Pulmonary Hypertension: How the Radiologist Can Help
Abstract
Pulmonary hypertension is defined as an abnormal elevation of pressure in pulmonary circulation, with a mean pulmonary arterial pressure higher than 25 mmHg, regardless of the underlying mechanism. The clinical classification system for pulmonary hypertension was updated at the fourth World Symposium on Pulmonary Hypertension in Dana Point, California, in 2008. In patients with suspected pulmonary hypertension, the diagnostic approach includes four stages: suspicion, detection, classification, and functional evaluation. It is crucial to understand the advantages and disadvantages of the different imaging tools available for the diagnostic work-up and follow-up of patients with pulmonary hypertension. Many conditions that cause pulmonary hypertension have suggestive findings at multidetector computed tomography or magnetic resonance imaging; some causes may be surgically treatable, whereas others may demonstrate adverse reactions to vasodilator therapies used during the course of treatment. Therefore, the radiologist plays an important role in evaluating patients with this disease. Supplemental material available at http://radiographics.rsna.org/lookup/suppl/doi:10.1148/rg.321105232/-/DC1.
© RSNA, 2012
Pulmonary hypertension is defined as an abnormal elevation of pressure in pulmonary circulation, with a mean pulmonary arterial pressure higher than 25 mmHg, regardless of the underlying mechanism. The clinical classification system for pulmonary hypertension was updated at the fourth World Symposium on Pulmonary Hypertension in Dana Point, California, in 2008. In patients with suspected pulmonary hypertension, the diagnostic approach includes four stages: suspicion, detection, classification, and functional evaluation. It is crucial to understand the advantages and disadvantages of the different imaging tools available for the diagnostic work-up and follow-up of patients with pulmonary hypertension. Many conditions that cause pulmonary hypertension have suggestive findings at multidetector computed tomography or magnetic resonance imaging; some causes may be surgically treatable, whereas others may demonstrate adverse reactions to vasodilator therapies used during the course of treatment. Therefore, the radiologist plays an important role in evaluating patients with this disease. Supplemental material available at http://radiographics.rsna.org/lookup/suppl/doi:10.1148/rg.321105232/-/DC1.
© RSNA, 2012
Feb 20, 2012
Jan 23, 2012
Latin American Working Group meeting in SCMR Annual Session
The meeting will take place Saturday, Feb 4, at 07:00AM on the Crystal Salon Q.
For those in Orlando, do attend as important topics will be covered.
The meeting will be led by Dr de La Pena, chairman of the group.
Juliano
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