Marco M. Voormolen

InPhase Solutions (Norway)

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Nico de Jong

Erasmus MC

Boudewijn J. Krenning

Erasmus MC

Charles T. Lancée

Erasmus MC

Johan G. Bosch

Erasmus MC

Folkert J. ten Cate

Erasmus MC

Marijn van Stralen

University Medical Center Utrecht

Johan H. C. Reiber

Centre for Medical Systems Biology

Antonius F.W. van der Steen

Erasmus MC

Jos R.T.C. Roelandt

Erasmus University Rotterdam

Gerard van Burken

Erasmus University Rotterdam

Cooperative Institutions

Erasmus MC

Erasmus University Rotterdam

Netherlands Heart Institute

Rotterdam University of Applied Sciences

Leiden University Medical Center

Delft University of Technology

Norwegian University of Science and Technology

University of Twente

University Medical Center Utrecht

Leiden University

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Comparison of fundamental, second harmonic, and superharmonic imaging: A simulation study

The Journal of the Acoustical Society of America (2011)

P.L.M.J. van Neer Mikhail G. Danilouchkine Martin D. Verweij Libertario Demi Marco M. Voormolen

In medical ultrasound, fundamental imaging (FI) uses the reflected echoes from the same spectral band as that of the emitted pulse. The transmission frequency determines the trade-off between penetration depth and spatial resolution. Tissue harmonic imaging (THI) employs the second harmonic of the emitted frequency band to construct images. Recently, superharmonic imaging (SHI) has been introduced, which uses the third to the fifth (super) harmonics. The harmonic level is determined by two competing phenomena: nonlinear propagation and frequency dependent attenuation. Thus, the transmission frequency yielding the optimal trade-off between the spatial resolution and the penetration depth differs for THI and SHI. This paper quantitatively compares the concepts of fundamental, second harmonic, and superharmonic echocardiography at their optimal transmission frequencies. Forward propagation is modeled using a 3D-KZK implementation and the iterative nonlinear contrast source (INCS) method. Backpropagation is assumed to be linear. Results show that the fundamental lateral beamwidth is the narrowest at focus, while the superharmonic one is narrower outside the focus. The lateral superharmonic roll-off exceeds the fundamental and second harmonic roll-off. Also, the axial resolution of SHI exceeds that of FI and THI. The far-field pulse-echo superharmonic pressure is lower than that of the fundamental and second harmonic. SHI appears suited for echocardiography and is expected to improve its image quality at the cost of a slight reduction in depth-of-field.

Subharmonic function

Fundamental frequency

Harmonic

Second-harmonic imaging microscopy

Distortion (music)

10.1121/1.3643815

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Citations (36)

Improving 3D active appearance model segmentation of the left ventricle with Jacobian tuning

Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE (2008)

K. Y. Esther Leung Marijn van Stralen Marco M. Voormolen Nico de Jong Antonius F.W. van der Steen

Automated image processing techniques may prove invaluable in the examination of real-time three-dimensional echocardiograms, by providing quantitative and objective measurements of functional parameters such as left ventricular (LV) volume and ejection fraction. In this study, we investigate the use of active appearance models (AAMs) for automatic detection of left ventricular endocardial contours. AAMs are especially useful in segmenting ultrasound images, due to their ability to model the typical LV appearance. However, since only a limited number of images is available for training, the model may be incapable of capturing the large variability in ultrasound image appearance. This may cause standard AAM matching procedures to fail if the model and image are significantly different. Recently, a Jacobian-tuning method for AAM matching was proposed, which allowed the model's training matrix to adapt to the new, unseen image. This may potentially result in a more robust matching. To compare both matching methods, AAMs were built with end-diastolic images from 54 patients. Larger capture ranges and higher accuracy were obtained when the new method was used. In conclusion, this method has great potential for segmentation in echocardiograms and will improve the assessment of LV functional parameters.

Active appearance model

10.1117/12.769436

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Citations (10)

Deep Learning for Automated Egg Maturation Prediction of Atlantic Salmon using Ultrasound Imaging

IEEE Access (2024)

Yasin Yari Ingun Næve Per Helge Bergtun Asle Hammerdal Svein‐Erik Måsøy

The Atlantic salmon maturation process has been studied for decades to increase the quantity and quality of the production in farming facilities. An important topic in this context is the salmon egg maturation process. Ultrasound imaging is considered an effective tool for monitoring the egg development stage of salmon, but manual inspection is time-consuming and dependent on operator experience. We propose a method for automated monitoring of the egg maturation stage in salmon using deep learning, providing complimentary decisions on egg morphology. A segmentation network was developed to solve the challenge of separating and measuring individual eggs in the ovary. The segmentation part was combined with a classification network to determine the maturation stage of the eggs. Our model was able to segment eggs and classify their development stage with over 88% accuracy, outperforming established methods designed for similar tasks. A real-time application was developed which provided an estimation of size and maturity stage while scanning. The egg state estimation showed potential for replacing manual evaluations and can enable fully automatic evaluation of maturation in Atlantic salmon.

10.1109/access.2024.3409360

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Citations (1)

Feasibility of 3D harmonic contrast imaging

Ultrasonics (2003)

Marco M. Voormolen Ayache Bouakaz Boudewijn J. Krenning Charles T. Lancée Folkert J. ten Cate

Second-harmonic imaging microscopy

Harmonic

10.1016/j.ultras.2003.12.012

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Citations (6)

Harmonic 3-D echocardiography with a fast-rotating ultrasound transducer

IEEE Transactions on Ultrasonics Ferroelectrics and Frequency Control (2006)

Marco M. Voormolen Boudewijn J. Krenning Charles T. Lancée Folkert J. ten Cate Jos R.T.C. Roelandt

Although the advantages of three-dimensional (3-D) echocardiography have been acknowledged, its application for routine diagnosis is still very limited. This is mainly due to the relatively long acquisition time. Only recently has this problem been addressed with the introduction of new real-time 3-D echo systems. This paper describes the design, characteristics, and capabilities of an alternative concept for rapid 3-D echocardiographic recordings. The presented fast-rotating ultrasound (FRU)-transducer is based on a 64-element phased array that rotates with a maximum speed of 8 Hz (480 rpm). The large bandwidth of the FRU-transducer makes it highly suitable for tissue and contrast harmonic imaging. The transducer presents itself as a conventional phased-array transducer; therefore, it is easily implemented on existing 2-D echo systems, without additional interfacing. The capabilities of the FRU-transducer are illustrated with in-vitro volume measurements, harmonic imaging in combination with a contrast agent, and a preliminary clinical study.

Second-harmonic imaging microscopy

Interfacing

Harmonic

Echo (communications protocol)

10.1109/tuffc.2006.107

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Citations (22)

Semi-automatic border detection method for left ventricular volume estimation in 4D ultrasound data

Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE (2005)

Marijn van Stralen Johan G. Bosch Marco M. Voormolen Gerard van Burken Boudewijn J. Krenning

We propose a semi-automatic endocardial border detection method for LV volume estimation in 3D time series of cardiac ultrasound data. It is based on pattern matching and dynamic programming techniques and operates on 2D slices of the 4D data requiring minimal user-interaction. We evaluated on data acquired with the Fast Rotating Ultrasound (FRU) transducer: a linear phased array transducer rotated at high speed around its image axis, generating high quality 2D images of the heart. We automatically select a subset of 2D images at typically 10 rotation angles and 16 cardiac phases. From four manually drawn contours a 4D shape model and a 4D edge pattern model is derived. For the selected images, contour shape and edge patterns are estimated using the models. Pattern matching and dynamic programming is applied to detect the contours automatically. The method allows easy corrections in the detected 2D contours, to iteratively achieve more accurate models and improved detections. An evaluation of this method on FRU data against MRI was done for full cycle LV volumes on 10 patients. Good correlations were found against MRI volumes [r=0.94, y=0.72x + 30.3, difference of 9.6 +/- 17.4 ml (Av +/- SD)] and a low interobserver variability for US (r=0.94, y=1.11x - 16.8, difference of 1.4 +/- 14.2 ml). On average only 2.8 corrections per patient were needed (in a total of 160 images). Although the method shows good correlations with MRI without corrections, applying these corrections can make significant improvements.

Cardiac cycle

Ventricular volume

10.1117/12.596876

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Citations (10)

Efficient Quantification of the Left Ventricular Volume Using 3-Dimensional Echocardiography: The Minimal Number of Equiangular Long-axis Images for Accurate Quantification of the Left Ventricular Volume

Journal of the American Society of Echocardiography (2007)

Marco M. Voormolen Boudewijn J. Krenning Robert-Jan van Geuns J. Borsboom Charles T. Lancée

Short axis

Equiangular polygon

Ventricular volume

10.1016/j.echo.2006.09.016