Original ContributionsDetermination of normal regional left ventricular function from cine-MR images using a semi-automated edge detection method
Introduction
Detailed information on cardiac dimensions and function is of great interest for cardiac diagnosis1, 2 and treatment monitoring,3 as well as for basic physiological4 and biomechanical5, 6 studies of cardiac wall motion. MRI has the capability of providing an accurate and precise determination of cardiac geometry. Several attempts have been made to use MRI as a non-invasive technique for the assessment of cardiac function, specifically, the determination of left ventricular (LV) volumes, ejection fractions7, 8, 9, 10 and myocardial wall thickness, and thickening and motion,11, 12, 13, 14 in patients with congenital or acquired heart disease. These prior studies used manual tracing of epicardial and endocardial borders and manual segmentation of the myocardium in multiple, parallel images for subsequent determination of functional parameters.
Manual tracing and segmentation, although reasonably accurate, is time consuming and subjective, potentially leading to substantial inter- and intra-observer variability. To reduce the variability and time constraints inherent in observer tracing of biomedical images, digital image processing methods have been widely used in other imaging modalities. Those methods published rely on complicated techniques such as closed loop B-spline curve fitting,15 segmentation by region growing,16 graph searching,17 deformable contour models18 and others.19, 20 We have developed a method that relies on first derivative edge detection and weighted polynomial fitting, both of which are elementary mathematical techniques, to determine the epicardial and endocardial borders. The epicardial and endocardial borders were then used to determine the LV end diastolic and end systolic volumes, and to calculate segmental wall motion and thickening.
Section snippets
Imaging techniques
After giving informed consent, ten healthy male volunteers, aged 24 to 30 years, (mean 27 years) with normal physical examination results and no history of heart or lung disease underwent MR imaging using a 0.95 Tesla Siemens (Erlangen, Germany) Impact imager, with a standard body transmit and receive RF coil. Multiple temporal cine-MR images were obtained in the short axis, positioned using the end-systolic long axis view as the frame of reference, using a FISP pulse sequence with gradient
Results
Evaluation of the wall thickening, wall motion, and ejection fraction from the ED and ES images of the four SA slices took less than 3 min, including manual positioning of the initial circles. Figure 5 shows an example of both the endo- and epicardial borders obtained automatically superimposed onto four original end systolic images. The automatic software successfully detected the LV borders in all of the images where good contrast was present. In the cases where cardiac activity was too
Discussion
Cine-MR imaging has been proved to be highly accurate in assessment of cardiac volumes and function. In the present study we used a cardiac gated cine-MR imaging technique with non-contiguous slices and a semi-automated edge detection method. The use of these two techniques allows the endo- and epicardial borders of the LV to be delineated in a time efficient manner.
Evaluation of left ventricular function is of great importance in the diagnosis and management of patients with known or suspected
References (39)
- et al.
Low-dosage dobutamine magnetic resonance imaging as an alternative to echocardiography in the detection of viable myocardium after acute infarction
Am Heart J
(1995) MRI of myocardial functionmotion tracking techniques
Magn Reson Imag
(1996)- et al.
Regional left ventricular wall thickening by magnetic resonance imaging: Evaluation in normal persons and patients with global and regional dysfunction
Am J Cardiol
(1987) - et al.
Detection of regional left ventricular asynchrony in obstructive hypertrophic cardiomyopathy by magnetic resonance imaging
Am Heart J
(1994) - et al.
Automated myocardial edge detection from breath-hold cine-MR images: Evaluation of left ventricular volumes and mass
Magn. Reson. Imag.
(1994) - et al.
Multimodality cardiovascular image segmentation using a deformable contour model
Comp Medic Imag Graph
(1997) - et al.
Accuracy of biplane long-axis left ventricular volume determination by cine magnetic resonance imaging in patients with regional and global dysfunction
Am J Cardiol
(1996) - et al.
Sectional and segmental variability of left ventricular function: Experimental and clinical studies using ultrafast computed tomography
J Am Coll Cardiol
(1988) - et al.
Reproducibility of left ventricular volumes by two-dimensional echocardiography
J Am Coll Cardiol
(1983) - et al.
Left ventricular mass volumes determined by two-dimensional echocardiography in a normal human population
J Am Coll Cardiol
(1983)
Estimation of left ventricular volumes in man from biplane cineangiograms filmed in oblique projections
Am J Cardiol
Wall stress in the normal and hypertrophied left ventricle
Am J Cardiol
Effect of interventions in salvaging left ventricular function in acute myocardial infarction: A study of intracoronary streptokinase
Am J Cardiol
Assessment of regional myocardial performance from biplane coronary cineangiograms
Am J Cardiol
Mortality and morbidity after coronary artery bypass surgery related to pre-operative left ventricular ejection fraction: A follow up study
Eur Heart J
Editorial. Left ventricular ejection fraction: An important but incomplete determinant of long-term outcome after coronary bypass surgery
Eur Heart J
MR of the heart: Anatomy, physiology and metabolism
AJR
Three-dimensional left ventricular deformation in hypertrophic cardiomyopathy
Circulation
Normal left ventricular dimensions and function: interstudy reproducibility of measurements with cine-MR imaging
Radiology
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2011, Medical Image AnalysisCitation Excerpt :Contours in each individual image are then recovered using minimum surface segmentation. Several solutions are proposed, in order not to include papillary muscles: computation of the convex hull of the contour (van der Geest et al., 1994; Lin et al., 2006), applications of mathematical morphology (MM) operations such as opening and closing on the contour (Nachtomy et al., 1998; Cousty et al., 2010), or fitting a parametric curve to the contour, allowing it to be smooth (Waiter et al., 1999). The epicardium is found during a second step, often relying on the endocardial contour, that makes use of a spatial model incorporating myocardial thickness or MM operators, applied on the endocardial contour.
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2007, European Journal of Internal MedicineCitation Excerpt :Using the standard two-dimensional (2D) Fourier transformation algorithm, the raw data was reconstructed to 256 × 256 pixel images. MR images were transferred to an offline workstation and processed using a home-written package [16]. In each patient, two short-axis tomograms from mid-LV with 16 segments each, corresponding to SPECT slices showing areas of reversible ischemia, were analysed for signal change on BOLD MRI.
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2007, International Journal of CardiologyCitation Excerpt :In each patient, two short axis tomograms from mid LV were analysed for signal change on BOLD MRI. The myocardium in each of the slices was masked out, from the rest of the image, using semi-automated edge detection method [18]. These slices, in turn, were then aligned with the corresponding short axis tomographic images of myocardial 13NH3 images from the PET study.
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Present address of Roger J. Trent: Medical Cardiology, Western Infirmary, Glasgow, UK.