BIOIMAGING 2014 Abstracts

Full Papers Short Papers
Full Papers
Paper Nr: 7
Title:

Evaluation of the Effects of Dose on Lung Ventilation Calculated from 4D-CT using Deformable Image Registration - An Application of a Ventilation Calculation Algorithm based on 4D-CT
Authors:

Kujtim Latifi, Thomas J. Dilling, Craig W. Stevens, Vladimir Feygelman, Eduardo G. Moros and Geoffrey G. Zhang
Abstract: Ventilation derived from 4D-CT using deformable image registration (DIR) has been found correlate to the result from a conventional modality very well. How radiation affects ventilation in lungs is still not clearly studied. In this paper, ventilation versus radiation dose is investigated using ΔV method, a ventilation calculation algorithm based on 4D-CT and DIR. Diffeomorphic morphons was used as the DIR tool. Tidal volume normalized ventilation was used in this study. A total of 20 SBRT lung cancer patients’ 4D-CT and planning dose data were retrospectively analysed. All the patients had two sets of 4D-CT, one at pre-treatment and one post treatment. Ventilation distributions were calculated based on the two sets of 4D-CT for each case. The two ventilation data sets were aligned using DIR. Radiation dose distributions were resampled to match the resolution of CT images. A ventilation (or ventilation change) and dose values were thus associated to each voxel of the CT images. A function (ventilation change) – dose – volume surface was generated for each case. Average ventilation was found degraded in higher than 20 Gy dose regions for 16 out of the 20 cases. This result can be applied in treatment planning to spare functional lung volumes.
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Paper Nr: 22
Title:

Finding Coherent Regions in PET Images for the Diagnosis of Alzheimer’s Disease
Authors:

Helena Aidos, João Duarte and Ana Fred
Abstract: Alzheimer's disease is a type of dementia that mainly affects elderly people, with unknown causes and no effective treatment up to date. The diagnosis of this disease in an earlier stage is crucial to improve patients' life quality. Current techniques focus on the analysis of neuroimages, like FDG-PET or MRI, to find changes in the brain activity. While high accuracies can be obtained by combining the analysis of several types of neuroimages, they are expensive and not always available for medical analysis. Achieving similar results using only 3-D FDG-PET scans is therefore of huge importance. While directly applying classifiers to the FDG-PET scan voxel intensities can lead to good prediction accuracies, it results in a problem that suffers from the curse of dimensionality. This paper thus proposes a methodology to identify regions of interest by segmenting 3-D FDG-PET scans and extracting features that represent each of those regions of interest, reducing the dimensionality of the space. Experimental results show that the proposed methodology outperforms the one using voxel intensities despite only a small number of features is needed to achieve that result.
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Paper Nr: 24
Title:

Model-based Approach to Tissue Characterization using Optical Coherence Tomography
Authors:

Cecília Lantos, Rafik Borji, Stéphane Douady, Karolos Grigoriadis, Kirill Larin and Matthew A. Franchek
Abstract: Structural property of the tissue can be quantified by its optical scattering properties. Since a tumor is differentiated from healthy tissue based on morphological analysis, model-based approach to cancer diagnosis is developed. The scattering property is measured using Optical Coherence Tomography. The structural subsurface images from the measurements are described quantitatively. A parametric model is developed to classify tissue as healthy or cancerous. A statistical model-based imaging method is created to distinguish healthy vs. cancerous soft tissue using the example of human Normal Fat vs. Well-Differentiated- (WD-), and De-Differentiated Liposarcoma (DDLS).
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Short Papers
Paper Nr: 15
Title:

Mapping Membrane Topology Label Free and Corrected for Changes in the Refractive Index of the Membrane on a Nanometer Scale
Authors:

Joachim Walter, Natalia Schiefermeier, Nina Hobi, Benjamin Grau, Christine E. Bandtlow, Lukas A. Huber, Rainer Uhl and Sebastian Munck
Abstract: The plasma membrane is the outer limit of the animal cell. As such, it is both a border separating inside from outside and a signaling platform for interactions with the surroundings. Among these interactions are extracellular matrix contacts and adhesion sites. The membrane and its contact sites together with the underlying cytoskeleton undergo constant remodeling, which leads to changes of the cell shape. In addition to spatial information micro-topographical maps provide, information about the z-dimension and describe the position of the plasma membrane with respect to the distance to a given substrate. Here we address how to measure height differences in the plasma membrane and how to create topographical maps of the plasma membrane with nanometer resolution. We address the currently used methodologies along with their advantages and drawbacks. Moreover, we delineate a label-free method to obtain topographic maps of the plasma membrane that are corrected for differences in the refractive index of the membrane utilizing an interferometric approach with multiple wavelengths and a normalization procedure to account for changes in the refractive index in the membrane.
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Paper Nr: 21
Title:

A Prostate Cancer Computer Aided Diagnosis Software including Malignancy Tumor Probabilistic Classification
Authors:

Alessandro Savino, Alfredo Benso, Stefano Di Carlo, Valentina Giannini, Anna Vignati, Gianfranco Politano, Simone Mazzetti and Daniele Regge
Abstract: Prostate Cancer (PCa) is the most common solid neoplasm in males and a major cause of cancer-related death. Screening based on Prostate Specific Antigen (PSA) reduces the rate of death by 31%, but it is associated with a high risk of over-diagnosis and over-treatment. Prostate Magnetic Resonance Imaging (MRI) has the potential to improve the specificity of PSA-based screening scenarios as a non-invasive detection tool. Research community effort focused on classification techniques based on MRI in order to produce a malignancy likelihood map. The paper describes the prototyping design, the implemented work-flow and the software architecture of a Computer Aided Diagnosis (CAD) software which aims at providing a comprehensive diagnostic tool, including an integrated classification stack, from a preliminary registration of images to the classification process. This software can improve the diagnostic accuracy of the radiologist, reduce reader variability and speed up the whole diagnostic work-up.
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Paper Nr: 27
Title:

Laser Speckle Contrast Images - Processing of Data to Analyze Microvascular Variations in Hand Skin of Healthy Subjects
Authors:

Anne Humeau-Heurtier, Jérémy Dexet, Pierre Abraham and Guillaume Mahé
Abstract: Diseases such as frostbite, Raynaud’s phenomenon, carpal tunnel syndrome, systemic sclerosis, hand burns, hand flaps or hand wounds lead to microvascular dysfunctions. These diseases can affect only one hand and even sometimes only some fingers. Therefore, in order to quantify the microvascular alterations, it can be useful to compare microvascular perfusion of both hands (altered versus healthy hand). However, skin microvasculature presents spatial variations and the possibility to directly compare perfusion values of the two hands has not been studied yet. We therefore propose to quantify these spatial variations. For this purpose, perfusion values from laser speckle contrast images (LSCI) of the two hands (dorsal faces) from seven young healthy subjects are acquired simultaneously and then processed. The results show that the dorsal faces of the two hands in our young healthy subjects present close perfusion values (average coefficient of variation less than 9% for our subjects). These findings are preliminary observations to quantify the microvascular alterations in the above-mentioned diseases. The coefficient of variation in diseased states remains to be studied in order to see whether LSCI could be of interest to improve the diagnosis of hand skin pathologies.
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Paper Nr: 28
Title:

Infrared Spectral Microimaging - A New Tool to Characterise the Tissue Features in Skin Cancers of Melanoma Type
Authors:

David Sebiskveradze, Cyril Gobinet, Nathalie Cardot-Leccia, Michel Manfait, Pierre Jeannesson, Vincent Vuiblet and Olivier Piot
Abstract: Infrared (IR) spectral microimaging is a label-free optical technique that permits to probe the intrinsic chemical composition of biological samples. This technique appears more informative than conventional histology and could be developed as a non-destructive and objective diagnostic tool for in routine use in pathology departments. The discrimination between tumoral and neighbouring tissues relies on highlighting subtle spectral differences by means of advanced statistical multivariate data processing. In this way, we applied an innovative algorithm based on fuzzy clustering to take into account the notion of nuance into the clustering of IR image pixels. IR spectral imaging of human cutaneous melanomas was performed on paraffin-embedded tissue sections, without previous chemical dewaxing. Reconstructed colour-coded images allow recovering automatically different histological structures, by distinguishing tumour from the connective tissue. This approach gives also access to information about the tissue structures. Indeed, it permits to highlight the interconnection between neighbouring structures. In this work in progress study, the analysis was focussed on the interconnection between the tumoral and peritumoral structures and between the tumoral areas in case of a heterogeneous lesion. These first encouraging results pave the way to access new diagnostic and prognostic criteria associated to the tumour aggressiveness in cutaneous melanomas.
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Paper Nr: 30
Title:

Principal Component Analysis based Colour Scheme Optimisation in Eye Fundus Images - Contrast Enhancement for Detection and Evaluation of Drusen in Age Related Macular Degeneration Patients' Follow up
Authors:

Algimantas Kriščiukaitis, Robertas Petrolis, Daiva Stanislovaitienė and Dalia Žaliunienė
Abstract: Efficiency of the patient status monitoring in Age Related Macular Degeneration cases, based on evaluation of morphological properties eye fundus images, can be significantly increased by specific contrast enhancement in the images. Objects of interest - drusen (focal deposits of extracellular debris located between the basal lamina of the retinal pigment epithelium and the inner collagenous layer of Bruch membrane) usually are represented by various intensity but the same unique color in the image. Construction of the optimal color scheme to increase the contrast of drusen can be realized by means of Principal Component Analysis, which transforms original RGB color representation into principal components space. The study demonstrates that proposed method can increase contrast-to-noise ratio of the drusen areas 10-fold or more.
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Paper Nr: 32
Title:

Customised 3D Tooth Modeling by Minimally Invasive Imaging Modalities
Authors:

Sandro Barone, Alessandro Paoli and Armando Viviano Razionale
Abstract: Dental panoramic tomography represents a standard imaging modality in dentistry since it provides a convenient and inexpensive method to visualize anatomic structures and pathologic conditions with low radiation doses. However, this technique does not provide comprehensive 3D geometries of dental shapes which are conventionally demanded to computerised tomography (CT) techniques. In this paper, a tooth reconstruction process is presented by integrating patient-specific information with general dental templates. A 2D panoramic radiograph and the digitised patient plaster cast are used to customise both shape and orientation of teeth templates thus allowing a consistent 3D tooth reconstruction with minimally invasive imaging modalities. The proposed methodology does not make any assumption about the tomographic device used to collect the panoramic radiograph.
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Paper Nr: 33
Title:

Content-guided Navigation in Multimeric Molecular Complexes
Authors:

Mikael Trellet, Nicolas Ferey, Marc Baaden and Patrick Bourdot
Abstract: In the field of structural biology, molecular visualization is a critical step to study and understand 3D structures generated by experimental and theoretical technics. Numerous programs are dedicated to the exploration and analysis of structures in 3 dimensions. However, very few of them offer navigation algorithms that deal in an intelligent way with the content they display and the task to perform. This observation is emphasized in the case of navigation in immersive environments where users are immersed in their molecular systems, without any spatial landmark to guide their exploration. Starting from this observation, we propose to take into account some geometrical features found in multimeric molecular complexes to provide navigation guides to the users during the exploration process. It is possible thanks to the common symmetrical layout molecular complexes present. Beyond the biological meaning and importance that symmetric layouts have in proteins, they allow us to orient and guide the exploration of molecular complexes in an intelligent and meaningful manner. We present then a current work on the design of navigation paradigms based on the content and the task for the molecular visualization.
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Paper Nr: 16
Title:

Automated Analysis of Collagen Histology in Ageing Skin
Authors:

Osman S. Osman, Joanne L. Selway, Parvathy E. Harikumar, Sabah Jassim and Kenneth Langlands
Abstract: Traditionally, expert analysis is required to evaluate pathological changes manifested in tissue biopsies. This is a highly-skilled process, notwithstanding issues of limited throughput and inter-operator variability, thus the application of image analysis algorithms to this domain may drive innovation in disease diagnostics. There are a number of problems facing the development of objective, unsupervised methods in morphometry that must be overcome. In the first instance, we decided to focus on one aspect of skin histopathology, that of collagen structure, as changes in collagen organisation have myriad pathological sequelae, including delayed wound healing and fibrosis. Methods to quantify incremental loss in structure are desirable, particularly as subclinical changes may be difficult to assess using existing criteria. For example, collagen structure is known to change with age, and through the calculation of foci distances in ellipses derived from the Fourier scatter, we were able to measure a decrease in collagen bundle thickness in picrosirius stained skin with age. Another key indicator of skin physiology is new collagen synthesis, which is necessary to maintain a healthy integument. To investigate this phenomenon, we developed a colour-based image segmentation method to discriminate newly-synthesised from established collagen revealed by Herovici’s polychrome staining. Our scheme is adaptive to variations in hue and intensity, and our use of K-means clustering and intensity-based colour filtering informed the segmentation and quantification of red (indicating old fibres) and blue pixels (indicating new fibres). This allowed the determination of the ratio of young to mature collagen fibres in the dermis, revealing an age-related reduction in new collagen synthesis. These automated colour and frequency domain methods are tractable to high-throughput analysis and are independent of operator variability.
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