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Dive into the research topics where John I. Jackson is active.

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Featured researches published by John I. Jackson.


Journal of the Acoustical Society of America | 2003

Medical diagnostic ultrasound system and method for mapping surface data for three dimensional imaging

Thilaka S. Sumanaweera; John I. Jackson; Michael G. Curley; Randall L. Schlesinger; John A. Hossack; Linyong Pang

A method and system for mapping surface data onto a geometrical representation of a structure for 3D imaging is provided. A boundary of a structure is determined from one type of data, such as Doppler energy data. Another type of data, such as B-mode data, representing the boundary or an area adjacent the boundary is extracted or identified. The B-mode data is then rendered as a function of the boundary, such as by texture mapping the B-mode data onto or adjacent the boundary. As the user examines the structure representation, the texture mapped data may provide texture details based on an optimally determined representation. The boundary may alternatively be used to select data for volume rendering.


Journal of the Acoustical Society of America | 2004

Medical diagnostic ultrasound catheter and method for position determination

John A. Hossack; Michael G. Curley; Thilaka S. Sumanaweera; John I. Jackson

A catheter and method for determining a position of the catheter within the cardiovascular system is provided. Local bending and twisting is measured at multiple locations along the catheter. By integrating the measurements, the position and orientation of the catheter is determined. Based on the catheter position information, the location and orientation of an ultrasound transducer array connected with the catheter is known. The imaging array position and orientation information may be used to assist a physician in determining the tissue structure or fluid being scanned and/or assist in the accurate generation of three-dimensional representations.


Echocardiography-a Journal of Cardiovascular Ultrasound and Allied Techniques | 2005

Effect of cardiac resynchronization therapy on longitudinal and circumferential left ventricular mechanics by velocity vector imaging: description and initial clinical application of a novel method using high-frame rate B-mode echocardiographic images.

Mani A. Vannan; Gianni Pedrizzetti; Peng Li; Swaminathan Gurudevan; Helene Houle; Joan Main; John I. Jackson; Navin C. Nanda

Cardiac resynchronization therapy (CRT) has emerged as an important method to treat patient with symptomatic heart failure with evidence of intraventricular dyssynchrony. Tissue Doppler imaging by echocardiography has been shown to be an excellent tool for the assessment of mechanical left ventricular dyssynchrony and the selection of patients for CRT. However, there are some patients who do not show symptomatic improvement following CRT. One possible explanation for this is the need to optimize not only longitudinal synchrony, but also improve the circumferential and radial dynamics of the left ventricle. Doppler imaging does not allow reliable assessment of the latter because of the angle‐dependency of the technique. Velocity Vector Imaging (VVI) is a newer technique which is angle‐independent and thus provides an avenue to evaluate short‐axis mechanics of the left ventricle. We describe a case in which VVI was used to assess the left ventricular dynamics in a patient with heart failure who did not respond to CRT. (ECHOCARDIOGRAPHY, Volume 22, November 2005)


Journal of the Acoustical Society of America | 2003

Medical diagnostic ultrasound-aided drug delivery system and method

John I. Jackson; Edward A. Gardner

A method and system is provided for delivering drugs carried by microspheres. A medical diagnostic ultrasound system destroys microspheres in a specific localized area or at a specific time. A region of interest that is a subset of an imaged area is identified for destroying drug-carrying microspheres. The transmit beamformer is configured to transmit acoustic energy for destroying microspheres within that area while minimizing the destruction of microspheres outside of the region of interest. A multidimensional transducer array may provide focusing in three-dimensions for accurately destroying microspheres in the specific region while minimizing the destruction of microspheres outside that region. A trigger responsive to a heart or breathing cycle may control when microspheres are destroyed, providing delivery of drugs at the most opportune time in the cycle.


Journal of the Acoustical Society of America | 2003

Methods and apparatus for ultrasound imaging with automatic color image positioning

Ismayil M. Guracar; John I. Jackson

A method and apparatus for quantifying and displaying ultrasound signals in an ultrasonic system are provided. A first signal value for each of at least one spatial location in a region of interest is acquired at a first time, and the signal values are summed to obtain a first surface integral value. A second signal value for each of said at least one spatial location in said region of interest is acquired at a second time, and the second signal values are summed to obtain a second surface integral value. The first surface integral value is summed with the second surface integral value to obtain a time based integral. The time based integral is displayed. Other quantities based on any of various ultrasound parameters, such as Doppler energy, Doppler velocity and B-mode intensity, are calculated and displayed as quantities or as waveforms as a function of time. Furthermore, various comparisons of quantities and waveforms are provided. Image plane data or other ultrasound data are used in the calculations. Finally, a histogram data structure is provided to aid calculation of the various quantities.


Echocardiography-a Journal of Cardiovascular Ultrasound and Allied Techniques | 2008

Assessment of Systolic and Diastolic Left Ventricular and Left Atrial Function Using Vector Velocity Imaging in Takotsubo Cardiomyopathy

Manjula V. Burri; Navin C. Nanda; Steven G. Lloyd; Ming Chon Hsiung; Harvinder S. Dod; Robert J. Beto; Ravinda Bhardwaj; Abnash C. Jain; John I. Jackson; Amrish Agarwal; Preeti Chaurasia; A.N. Ravi Prasad; Jayaprakash Manda; Koteswara R. Pothineni

Five adult patients with Takotsubo cardiomyopathy (TC) diagnosed by usual criteria were studied with velocity vector imaging (VVI) on admission and at follow‐up, when their LV function had improved, as assessed by 2D TTE wall‐motion score (WMS) index. Averaged peak segmental longitudinal strain (S) in systole, and velocity (V) and strain rate (SR) in both systole and diastole were measured from apical 4‐ (A4C) and 2‐chamber views (A2C) in all patients. The data obtained by VVI were analyzed separately for involved and uninvolved segments, which were independently assessed by WMS. In the involved segments, systolic S, V, SR, and diastolic SR improved (P‐value < 0.05) on follow‐up. Diastolic V showed a trend toward improvement but did not reach statistical significance. In the uninvolved segments, none of the parameters improved significantly either during systole or diastole. In three of these five patients, left atrial (LA) walls were also studied by placing region of interest (ROI) points in the middle of each wall. Peak segmental LA systolic and diastolic V and SR as well as systolic S were obtained for both involved and uninvolved LA walls which were assessed independently using WMS similar to LV. In the involved LA walls, none of the atrial systolic and diastolic parameters changed significantly but all parameters with the exception of systolic V showed a tendency toward improvement during follow‐up. Among the uninvolved LA walls, none changed significantly but atrial systolic SR and, diastolic V and SR tended to increase during follow‐up. Our retrospective study using VVI demonstrates that TC patients also have LV systolic and diastolic longitudinal dysfunction, not just systolic radial dysfunction as assessed by traditional 2D TTE indices. Longitudinal LA dysfunction may also be present.


Journal of the Acoustical Society of America | 1981

Ultrasonic imaging system

John I. Jackson; Lewis J. Thomas; Constantine Simopoulos

Disclosed are a system and method of selecting one or more operational parameters of an ultrasonic imaging system. In particular, methods and means are disclosed for automatically or semi-automatically determining a best operating frequency, or for determining whether a system should operate in a fundamental imaging mode or a harmonic imaging mode.


Journal of the Acoustical Society of America | 2003

System and method for the display of ultrasound data

John I. Jackson; Joan Main; Janice L. Marshall

A system and method for converting 2-D ultrasound data into a 2-D display image. The system and method input a 2-D ultrasound data set, transform the 2-D ultrasound data set into a mathematical 3-D data set, and transform the mathematical 3-D data set into an altered 2-D data set. Another preferred embodiment of the invention involves generating a mathematical surface, such that the height of the mathematical surface is based on a first component of an ultrasound signal in a 2-D ultrasound data set; mapping the mathematical surface to points on a 2-D plane; assigning a color value to each point based on a second component of the ultrasound signal; and displaying the mapped mathematical surface with the assigned color values on a 2-D display device.


international conference on computer vision | 2007

A probabilistic, hierarchical, and discriminant framework for rapid and accurate detection of deformable anatomic structure

S. Kevin Zhou; F. Guo; J.H. Park; Gustavo Carneiro; John I. Jackson; M. Brendel; Costas Simopoulos; Joanne Otsuki; Dorin Comaniciu

We propose a probabilistic, hierarchical, and discriminant (PHD) framework for fast and accurate detection of deformable anatomic structures from medical images. The PHD framework has three characteristics. First, it integrates distinctive primitives of the anatomic structures at global, segmental, and landmark levels in a probabilistic manner. Second, since the configuration of the anatomic structures lies in a high-dimensional parameter space, it seeks the best configuration via a hierarchical evaluation of the detection probability that quickly prunes the search space. Finally, to separate the primitive from the background, it adopts a discriminative boosting learning implementation. We apply the PHD framework for accurately detecting various deformable anatomic structures from M- mode and Doppler echocardiograms in about a second.


medical image computing and computer assisted intervention | 2008

Automatic Mitral Valve Inflow Measurements from Doppler Echocardiography

JinHyeong Park; S. Kevin Zhou; John I. Jackson; Dorin Comaniciu

Doppler echocardiography is widely used for functional assessment of heart valves such as mitral valve. In current clinical work flow, to extract Doppler measurements, the envelopes of acquired Doppler spectra are manually traced. We propose a robust algorithm for automatically tracing the envelopes of mitral valve inflow Doppler spectra, which exhibit a large amount of variations in envelope shape and image appearance due to various disease conditions, patient/sonographer/instrument differences, etc. The algorithm is learning-based and capable of fully automatic detection and segmentation of the mitral inflow structures. Experiments show that the algorithm, running within one second, yields comparable performance to experts.

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