Medical Imaging

Integrated Support for Neuroscience Research: from Study Design to Publication

by Shayan Shahand

S. Shahand, M.W.A. Caan, A.H.C. van Kampen, S.D. Olabarriaga. In Proceedings of HealthGrid 2012 (HealthGrid Applications and Technologies Meet Science Gateways for Life Sciences).

Computational neuroscience is a new field of research in which neurodegenerative diseases are studied with the aid of... more Computational neuroscience is a new field of research in which neurodegenerative diseases are studied with the aid of new imaging techniques and computation facilities. Researchers with different expertise collaborate in these studies. A study requires scalable computational and storage capacity and information management facilities to succeed. Many virtual laboratories are proposed and developed to facilitate these studies, however most of them cover only the parts related to the computational data processing. In this paper we describe and analyse the phases of the computational neuroscience studies including the actors, the tasks they perform, and the characteristics of each phase. Based on these we identify the required properties and functionalities of a virtual laboratory that supports the actors and their tasks throughout the complete study.

Evolution of grid-based services for Diffusion Tensor Image analysis

by Shayan Shahand

M.W.A. Caan, S. Shahand, F.M. Vos, A.H.C. van Kampen, S.D. Olabarriaga. In Journal of Future Generation Computer Systems, 2012.

Analyzing Diffusion Tensor Image data of the human brain of large study groups is complex and demands new,... more Analyzing Diffusion Tensor Image data of the human brain of large study groups is complex and demands new, sophisticated and computationally intensive pipelines that can efficiently be executed. We present our progress over the past five years in the development and porting of the DTI analysis pipeline to a grid infrastructure. Starting with simple jobs submitted from the command-line, we moved towards a workflow-based implementation and finally into the e-BioInfra Gateway, which offers a web interface for the execution of selected biomedical data analysis software on the Dutch Grid. This gateway is currently being actively used by neuroscientists and for educational purposes.

Improving the sensitivity of high-frequency subharmonic imaging with coded excitation: A feasibility study

by Himanshu Shekhar

Himanshu Shekhar and Marvin M. Doyley
Medical Physics / Volume 39 / Issue 4 / ULTRASOUND PHYSICS

Purpose: Subharmonic intravascular ultrasound imaging (S-IVUS) could visualize the adventitial vasa vasorum, but the... more Purpose: Subharmonic intravascular ultrasound imaging (S-IVUS) could visualize the adventitial vasa vasorum, but the high pressure threshold required to incite subharmonic behavior in an ultrasound contrast agent will compromise sensitivity—a trait that has hampered the clinical use of S-IVUS. The purpose of this study was to assess the feasibility of using coded-chirp excitations to improve the sensitivity and axial resolution of S-IVUS.
Methods: The subharmonic response of Targestar-pTM, a commercial microbubble ultrasound contrast agent (UCA), to coded-chirp (5%–20% fractional bandwidth) pulses and narrowband sine-burst (4% fractional bandwidth) pulses was assessed, first using computer simulations and then experimentally. Rectangular windowed excitation pulses with pulse durations ranging from 0.25 to 3 μs were used in all studies. All experimental studies were performed with a pair of transducers (20 MHz/10 MHz), both with diameter of 6.35 mm and focal length of 50 mm. The size distribution of the UCA was measured with a CasyTM Cell counter.
Results: The simulation predicted a pressure threshold that was an order of magnitude higher than that determined experimentally. However, all other predictions were consistent with the experimental observations. It was predicted that: (1) exciting the agent with chirps would produce stronger subharmonic response relative to those produced by sine-bursts; (2) increasing the fractional bandwidth of coded-chirp excitation would increase the sensitivity of subharmonic imaging; and (3) coded-chirp would increase axial resolution. The experimental results revealed that subharmonic-to-fundamental ratios obtained with chirps were 5.7 dB higher than those produced with sine-bursts of similar duration. The axial resolution achieved with 20% fractional bandwidth chirps was approximately twice that achieved with 4% fractional bandwidth sine-bursts.
Conclusions: The coded-chirp method is a suitable excitation strategy for subharmonic IVUS imaging. At the 20 MHz transmission frequency and 20% fractional bandwidth, coded-chirp excitation appears to represent the ideal tradeoff between subharmonic strength and axial resolution.

Nonrigid free-form registration using landmark-based statistical deformation models

by Stefan Pszczolkowski Parraguez

In this paper, we propose an image registration algorithm named statistically-based FFD registration (SFFD). This... more In this paper, we propose an image registration algorithm named statistically-based FFD registration (SFFD). This registration method is a modification of a well-known free-form deformations (FFD) approach. Our framework dramatically reduces the number of parameters to optimise and only needs to perform a single-resolution optimisation to account for coarse and fine local displacements, in contrast to the multi-resolution strategy employed by the FFD-based registration. The proposed registration uses statistical deformation models (SDMs) as a priori knowledge to guide the alignment of a new subject to a common reference template. These SDMs account for the anatomical mean and variability across a population of subjects. We also propose that available anatomical landmark information can be encoded within the proposed SDM framework to enforce the alignment of certain anatomical structures. We present results in terms of fiducial localisation error, which illustrate the ability of the SDMs to encode landmark position information. We also show that our statistical registration algorithm can provide registration results comparable to the standard FFD-based approach at a much lower computational cost.

Computed tomography and magnetic resonance imaging studies of Latimeria chalumnae

by Richard Cloutier

Authors: Schultze, H.-P. & R. Cloutier
Year: 1991
Reference: Environmental Biology of Fishes, 32: 159-181.

Recent radiologic imaging techniques (CT[Computed Tomography] and MRI[Magnetic Resonance Imaging]) were used to... more Recent radiologic imaging techniques (CT[Computed Tomography] and MRI[Magnetic Resonance Imaging]) were used to investigate the cranial anatomy of the coelacanth Latimeria chalumnae. The non-invasive CT and MRI techniques were performed successfully on a 1.45 m female specimen. This specimen had been frozen a year earlier for future research; the CT was conducted on the frozen animal, whereas the MRI method was performed immediately after thawing. The CT technique provides information about differential density of the organism (especially informative with respect to hard tissues, bone and cartilage), whereas three different types of MRI (proton resonance T,, T, and ‘flash’) distinguish cartilage, muscles, and different connective tissues. A total of 381 CT cross sections (2 mm thick with 1 mm of overlap) through the head region were used in a computerized three-dimensional reconstruction program to address questions concerning cranial morphology. The results obtained from these radiologic imaging techniques confirmed most of the basic anatomy known from traditional dissections. However, the morphology of complex structures, such as the cartilaginous processes of the neurocranium, and the integration of the branchial arches and palate can only now be described more accurately

A coded excitation technique for the functional imaging of coronary atherosclerosis using ultrasound contrast agents.

by Himanshu Shekhar

Acute coronary syndromes may occur when life‐threatening atherosclerotic plaques rupture in the advanced stages of... more Acute coronary syndromes may occur when life‐threatening atherosclerotic plaques rupture in the advanced stages of cardiovascular disease. There is increasing evidence that plaque neovascularization accelerates the progression and disruption of atherosclerotic plaque. Plaque neovessels may be detected by subharmonic intravascular ultrasound (IVUS) imaging with ultrasound contrast agents (UCAs). The assessment of plaque neovascularity and perfusion at high spatial and contrast resolution may help identify those most at risk of acute coronary syndromes. While theoretical considerations dictate the use of high peak pressures and long excitation pulses for obtaining high contrast subharmonic IVUS images, microbubble disruption and the risk of hemorrhage limit the peak pressures practicable. Moreover, the use of long pulses degrades the axial resolution of achievable. In this paper, we report a novel excitation strategy using preemphasized chirps for microbubble insonation, which significantly enhances subharmonic signal from UCA. Therefore, low peak pressures can be employed to obtain high contrast resolution and the axial resolution can be restored by pulse compression. This technique was validated by numerical simulations and flow studies at high transmit frequencies (20 MHz). High spatial and contrast resolution achievable by this technique may significantly enhance the clinical potential for functional imaging of coronary atherosclerosis.

Imaging Services on the Grid as a Product Line: Requirements and Architecture

by Mathieu Acher

Issues in managing variability of medical imaging grid services

by Mathieu Acher

AUTOMATING MEDICAL DIAGNOSIS IN RENAL SCINTIGRAMS USING RBF NETWORKS

by George Siogkas

Co-authored with E.S. Dermatas
Presented in 1st International Conference “From Scientific Computing to Computational Engineering”
1st IC-SCCE
Athens, 8-10 September, 2004

In this paper we present a novel method for automatic detection of the Renals ROI, automatc detection of the dynamic... more In this paper we present a novel method for automatic detection of the Renals ROI, automatc detection of the dynamic Renograms excluding the pelv area, and the pathological Renograms are detected using RBFneural networks. The proposed diagnostc system was evaluated using 485 scingraphic files. The experimenal results gve classification error less than 4.2%, with 96.9% sensitivity and 95.5% specificity rates.

3D thermography imaging standardization technique for inflammation diagnosis

by Jean-Christophe Nebel

We develop a 3D thermography imaging standardization technique to allow quantitative data analysis. Medical Digital... more We develop a 3D thermography imaging standardization technique to allow quantitative data analysis. Medical Digital
Infrared Thermal Imaging is very sensitive and reliable mean of graphically mapping and display skin surface temperature. It allows doctors to visualise in colour and quantify temperature changes in skin surface. The spectrum of colours indicates both hot and cold responses which may co-exist if the pain associate with an inflammatory focus excites an increase in sympathetic activity. However, due to thermograph provides only qualitative diagnosis information, it has not gained acceptance in the medical and veterinary communities as a necessary or effective tool in inflammation and tumor detection. Here, our technique is based on the combination of visual 3D imaging technique and
thermal imaging technique, which maps the 2D thermography images on to 3D anatomical model. Then we rectify the 3D thermogram into a view independent thermogram and conform it a standard shape template. The combination of these imaging facilities allows the generation of combined 3D and thermal data from which thermal signatures can be quantified.

3D CT segmentation for clinical evaluation of knee prosthesis operations

by Sebastiano Battiato

Simulazione strutturale di un sistema osso-protesi del ginocchio

by Sebastiano Battiato

The strange space of the Body: Two dialogues

by Michael Sappol

co-authored with Eva Åhrén, in A, Jansson & A. Lagerkvist, eds., Strange spaces: Explorations into mediated obscurity (Ashgate, 2009), 73-100.

A meditation on the strange space and spaces of the human body, in two dialogues on: (1) an illustration, "The... more A meditation on the strange space and spaces of the human body, in two dialogues on: (1) an illustration, "The oxygen cycle: What goes on in you when you see this picture?" in Fritz Kahn's Das Leben des Menschen (1926); (2) the anatomical-pathological-medical Mütter Museum (Philadelphia). We think about divided spaces within the human body, relationships between corporeal/spatial embodiment and the representational space of the page, the representational space of representations, the space of the museum, spaces in the museum (galleries, vitrines, jars, etc.). At the same time, the paper is a conversation between phenomenology and Bakhtinian dialogics.

Adaptive techniques for microarray image analysis with related quality assessment

by Sebastiano Battiato

Structural simulation of a bone-prosthesis system of the knee joint

by Sebastiano Battiato

Cortical bone classification by local context analysis

by Sebastiano Battiato

Internet experiments: methods, guidelines, metadata

by Ulf-Dietrich Reips

published 2009 in Human Vision and Electronic Imaging XIV 7240(1), 724008. (Invited paper by the SPIE-IS&T Science and Technology Electronic Imaging societies)

The Internet experiment is now a well-established and widely used method. The present paper describes guidelines for... more The Internet experiment is now a well-established and widely used method. The present paper describes guidelines for the proper conduct of Internet experiments, e.g. handling of dropout, unobtrusive naming of materials, and pre-testing. Several methods are presented that further increase the quality of Internet experiments and help to avoid frequent errors. These methods include the "seriousness check", "warm-up," "high hurdle," and "multiple site entry" techniques, control of multiple submissions, and control of motivational confounding. Finally, metadata from sites like WEXTOR (http://wextor.org) and the web experiment list (http://wexlist.net/) are reported that show the current state of Internet-based research in terms of the distribution of fields, topics, and research designs used.

Rediscovering Radiology: New Technologies and Remedial Action at the Worksite

by Jonas Ivarsson

Rystedt, H., Ivarsson, J., Asplund, S., Johnsson, Å. A., & Båth, M. (2011). Social studies of science, 41(6), 101-125.

This study contributes to social studies of imaging and visualization practices within scientific and medical... more This study contributes to social studies of imaging and visualization practices within scientific and medical settings. The focus is on practices in radiology, which are bound up with visual records known as radiographs. The study addresses work following the introduction of a new imaging technology, tomosynthesis. Since it was a novel technology, there was limited knowledge of how to correctly analyse tomosynthesis images. To address this problem, a collective review session was arranged. The purpose of the present study was to uncover the practical work that took place during that session and to show how, and on what basis, new methods, interpretations and understandings were being generated. The analysis displays how the diagnostic work on patients’ bodies was grounded in two sets of technologically produced renderings. This shows how expertise is not simply a matter of providing correct explanations, but also involves discovery work in which visual renderings are made transparent. Furthermore, the results point to how the disciplinary knowledge is intertwined with timely actions, which in turn, partly rely on established practices of manipulating and comparing images. The embodied and situated reasoning that enabled radiologists to discern objects in the images thus display expertise as inherently practical and domain-specific.

Robust diffusion of structural flows for volumetric image interpolation

by Ashish Doshi

Multifunctional human serum albumin nanoparticles for biomedical imaging and targeted drug delivery

by Bharat Kumar Reddy Karumuri

David K. Bwambok1, Kristen E. Schexnayder1, James McNamara2, Bharat Karumuri2, Mark A. DeCoster2,Leszek Malkinski1 and Matthew A. Tarr1*
1Department of Chemistry and AMRI, University of New Orleans, New Orleans, LA 70148
2Institute of Micromanufacturing, Louisiana Tech University, Ruston, LA 71270

The use of magnetic and fluorescent nanoparticles as drug delivery agents has received considerable attention due to... more The use of magnetic and fluorescent nanoparticles as drug delivery agents has received considerable attention due to the prospect of simultaneous magnetic and fluorescence imaging as well as magnetic drug release. We report the synthesis and characterization of multifunctional human serum albumin magnetic nanoparticles for potential drug delivery, biomedical imaging, and therapeutic applications. Well dispersed, spherical albumin nanoparticles with average diameter in the range of 150-250 nm were obtained as characterized using dynamic light scattering and transmission electron microscopy. We have demonstrated the incorporation of magnetic nanoparticles, fluorescent drug analogs and drugs into these human serum albumin nanoparticles. Enhanced release of the fluorescent molecules and drugs from the nanoparticles after treatment with enzymes or upon exposure to radiofrequency magnetic field have been demonstrated. The presence of magnetic nanoparticles provides the possibility of magnetic resonance tissue imaging, magnetic triggered drug release, and magnetic hyperthermia therapy. In addition, fluorescent molecules enable the use of fluorescence imaging providing for a bimodal imaging system for biomedical applications.