Deconvolution of in-Vivo Ultrasound B-Mode Images

An algorithm for deconvolution of medical ultrasound images is presented. The procedure involves estimation of the basic one-dimensional ultrasound pulse, determining the ratio of the covariance of the noise to the covariance of the reflection signal, and finally deconvolution of the rf signal from the transducer. Using pulse and covariance estimators makes the approach self-calibrating, as all parameters for the procedure are estimated from the patient under investigation. An example of use on a clinical, in-vivo image is given. A 2 × 2 cm region of the portal vein in a liver is deconvolved. An increase in axial resolution by a factor of 2.4 is obtained. The procedure can also be applied to whole images, when it is ensured that the rf signal is properly measured. A method for doing that is outlined.

Download Full-text

Noise robust one-dimensional blind deconvolution of medical ultrasound images

IEEE Transactions on Ultrasonics Ferroelectrics and Frequency Control ◽

10.1109/58.753017 ◽

1999 ◽

Vol 46 (2) ◽

pp. 291-299 ◽

Cited By ~ 42

Author(s):

T. Taxt ◽

G.V. Frolova

Keyword(s):

Blind Deconvolution ◽

Ultrasound Images ◽

Medical Ultrasound ◽

One Dimensional ◽

Noise Robust

Download Full-text

Estimation of in Vivo Pulses in Medical Ultrasound

Ultrasonic Imaging ◽

10.1177/016173469401600304 ◽

1994 ◽

Vol 16 (3) ◽

pp. 190-203 ◽

Cited By ~ 1

Author(s):

Jørgen Arendt Jensen

Keyword(s):

Local Minimum ◽

Three Dimensional ◽

Synthetic Data ◽

Medical Ultrasound ◽

One Dimensional ◽

Main Application ◽

Estimated Parameters ◽

Ultrasound Field ◽

The One

An algorithm for the estimation of one-dimensional in-vivo ultrasound pulses is derived. The routine estimates a set of ARMA parameters describing the pulse and uses data from a number of adjacent rf lines. Using multiple lines results in a decrease in variance on the estimated parameters and significantly reduces the risk of terminating the algorithm at a local minimum. Examples from use on synthetic data confirms the reduction in variance and increased chance of successful minimization termination. Simulations are also reported indicating the relation between the one-dimensional pulse and the three-dimensional, attenuated ultrasound field for a concave transducer. Pulses are estimated from in-vivo liver data showing good resemblance to a pulse measured as the response from a planar reflector and then properly attenuated. The main application for the algorithm is to function as a preprocessing stage for deconvolution algorithms using parametric pulses.

Download Full-text

Autologous transplantation of mesenchymal stem cells into the portal vein of the miniature pig; a preliminary experiment for NOTES approach

Perspectives in Surgery ◽

10.33699/pis.2019.98.9.350-355 ◽

2019 ◽

Vol 98 (9) ◽

pp. 350-355

Keyword(s):

Stem Cells ◽

Mesenchymal Stem Cells ◽

Cell Therapy ◽

Portal Vein ◽

Liver Parenchyma ◽

Miniature Pig ◽

Hepatic Diseases ◽

Study Results

Introduction: There is evidence that mesenchymal stem cells (MSCs) could trans-differentiate into the liver cells in vitro and in vivo and thus may be used as an unfailing source for stem cell therapy of liver disease. Combination of MSCs (with or without their differentiation in vitro) and minimally invasive procedures as laparoscopy or Natural Orifice Transluminal Endoscopic Surgery (NOTES) represents a chance for many patients waiting for liver transplantation in vain. Methods: Over 30 millions of autologous MSCs at passage 3 were transplanted via the portal vein in an eight months old miniature pig. The deposition of transplanted cells in liver parenchyma was evaluated histologically and the trans-differential potential of CM-DiI labeled cells was assessed by expression of pig albumin using immunofluorescence. Results: Three weeks after transplantation we detected the labeled cells (solitary, small clusters) in all 10 samples (2 samples from each lobe) but no diffuse distribution in the samples. The localization of CM-DiI+ cells was predominantly observed around the portal triads. We also detected the localization of albumin signal in CM-DiI labeled cells. Conclusion: The study results showed that the autologous MSCs (without additional hepatic differentiation in vitro) transplantation through the portal vein led to successful infiltration of intact miniature pig liver parenchyma with detectable in vivo trans-differentiation. NOTES as well as other newly developed surgical approaches in combination with cell therapy seem to be very promising for the treatment of hepatic diseases in near future.

Download Full-text

Development of a semi-automated segmentation tool for high frequency ultrasound image analysis of mouse echocardiograms

Scientific Reports ◽

10.1038/s41598-021-85971-3 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Kristi Powers ◽

Raymond Chang ◽

Justin Torello ◽

Rhonda Silva ◽

Yannick Cadoret ◽

...

Keyword(s):

Image Analysis ◽

Automated Analysis ◽

Structure And Function ◽

Ultrasound Images ◽

Cardiac Structure ◽

Short Axis ◽

Pixel Intensity ◽

Cardiac Structure And Function ◽

And Function

AbstractEchocardiography is a widely used and clinically translatable imaging modality for the evaluation of cardiac structure and function in preclinical drug discovery and development. Echocardiograms are among the first in vivo diagnostic tools utilized to evaluate the heart due to its relatively low cost, high throughput acquisition, and non-invasive nature; however lengthy manual image analysis, intra- and inter-operator variability, and subjective image analysis presents a challenge for reproducible data generation in preclinical research. To combat the image-processing bottleneck and address both variability and reproducibly challenges, we developed a semi-automated analysis algorithm workflow to analyze long- and short-axis murine left ventricle (LV) ultrasound images. The long-axis B-mode algorithm executes a script protocol that is trained using a reference library of 322 manually segmented LV ultrasound images. The short-axis script was engineered to analyze M-mode ultrasound images in a semi-automated fashion using a pixel intensity evaluation approach, allowing analysts to place two seed-points to triangulate the local maxima of LV wall boundary annotations. Blinded operator evaluation of the semi-automated analysis tool was performed and compared to the current manual segmentation methodology for testing inter- and intra-operator reproducibility at baseline and after a pharmacologic challenge. Comparisons between manual and semi-automatic derivation of LV ejection fraction resulted in a relative difference of 1% for long-axis (B-mode) images and 2.7% for short-axis (M-mode) images. Our semi-automatic workflow approach reduces image analysis time and subjective bias, as well as decreases inter- and intra-operator variability, thereby enhancing throughput and improving data quality for pre-clinical in vivo studies that incorporate cardiac structure and function endpoints.

Download Full-text

Novel High-Voltage Power Driver with an Active Floating Gate Bias for Medical Ultrasound Pulse Generators

2020 IEEE International Conference on Consumer Electronics - Taiwan (ICCE-Taiwan) ◽

10.1109/icce-taiwan49838.2020.9258188 ◽

2020 ◽

Author(s):

Li-Jie Huang ◽

Chin Hsia ◽

Deng-Fong Lu ◽

Yen-Chung Huang

Keyword(s):

High Voltage ◽

Floating Gate ◽

Medical Ultrasound ◽

Gate Bias ◽

Pulse Generators ◽

Ultrasound Pulse

Download Full-text

Motion blur invariant for estimating motion parameters of medical ultrasound images

Scientific Reports ◽

10.1038/s41598-021-93636-4 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Barmak Honarvar Shakibaei Asli ◽

Yifan Zhao ◽

John Ahmet Erkoyuncu

Keyword(s):

Image Quality Assessment ◽

Medical Image Analysis ◽

Main Idea ◽

Delta Function ◽

Motion Blur ◽

Ultrasound Images ◽

Medical Ultrasound ◽

Fetal Ultrasound ◽

Dirac Delta ◽

Motion Parameters

AbstractHigh-quality medical ultrasound imaging is definitely concerning motion blur, while medical image analysis requires motionless and accurate data acquired by sonographers. The main idea of this paper is to establish some motion blur invariant in both frequency and moment domain to estimate the motion parameters of ultrasound images. We propose a discrete model of point spread function of motion blur convolution based on the Dirac delta function to simplify the analysis of motion invariant in frequency and moment domain. This model paves the way for estimating the motion angle and length in terms of the proposed invariant features. In this research, the performance of the proposed schemes is compared with other state-of-the-art existing methods of image deblurring. The experimental study performs using fetal phantom images and clinical fetal ultrasound images as well as breast scans. Moreover, to validate the accuracy of the proposed experimental framework, we apply two image quality assessment methods as no-reference and full-reference to show the robustness of the proposed algorithms compared to the well-known approaches.

Download Full-text