89 research outputs found
Introduction to special issue on intelligent computing and adaptive systems
This special issue of Innovations in Systems and Software Engineering: A NASA Journal is devoted to selected contributions from the 4th International Conference on Advanced Computing, Networking and Informatics (ICACNI 2016
Computerized Analysis of Magnetic Resonance Images to Study Cerebral Anatomy in Developing Neonates
The study of cerebral anatomy in developing neonates is of great importance for
the understanding of brain development during the early period of life. This
dissertation therefore focuses on three challenges in the modelling of cerebral
anatomy in neonates during brain development. The methods that have been
developed all use Magnetic Resonance Images (MRI) as source data.
To facilitate study of vascular development in the neonatal period, a set of image
analysis algorithms are developed to automatically extract and model cerebral
vessel trees. The whole process consists of cerebral vessel tracking from
automatically placed seed points, vessel tree generation, and vasculature
registration and matching. These algorithms have been tested on clinical Time-of-
Flight (TOF) MR angiographic datasets.
To facilitate study of the neonatal cortex a complete cerebral cortex segmentation
and reconstruction pipeline has been developed. Segmentation of the neonatal
cortex is not effectively done by existing algorithms designed for the adult brain
because the contrast between grey and white matter is reversed. This causes pixels
containing tissue mixtures to be incorrectly labelled by conventional methods. The
neonatal cortical segmentation method that has been developed is based on a novel
expectation-maximization (EM) method with explicit correction for mislabelled
partial volume voxels. Based on the resulting cortical segmentation, an implicit
surface evolution technique is adopted for the reconstruction of the cortex in
neonates. The performance of the method is investigated by performing a detailed
landmark study.
To facilitate study of cortical development, a cortical surface registration algorithm
for aligning the cortical surface is developed. The method first inflates extracted
cortical surfaces and then performs a non-rigid surface registration using free-form
deformations (FFDs) to remove residual alignment. Validation experiments using
data labelled by an expert observer demonstrate that the method can capture local
changes and follow the growth of specific sulcus
Automated Quantification of Atherosclerosis in CTA of Carotid Arteries
How is the human body built and how does it function? What are the causes of
disease, and where is disease located? Throughout the history of mankind these
questions were answered by the use of invasive methods that included the
“opening” of the human body, mainly cadavers. Thanks to these invasive
techniques the first precise and complete anatomy works started to appear in
the 16th century. The most influential works were published by Leonardo da
Vinci and the anatomist and physician Andreas Vesalius.
The discovery of X-rays in 1895, and their use for medical applications,
introduced a new era, in which non-invasive imaging of the functioning human
body became feasible. Nowadays, medical imaging includes many different
imaging modalities, such as X-ray, computed tomography (CT), magnetic
resonance imaging (MRI), ultrasound (US), nuclear and optical imaging, and
has become an indispensable diagnostic tool for a wide range of applications.
Initially, the application of medical imaging focused on the visualization of
anatomy and on the detection and localization of disease. However, with the
development of different modalities it has evolved into a much more versatile
tool providing important information on e.g. physiology and organ function,
biochemistry and metabolism using nuclear imaging (mainly positron emission
tomography (PET) imaging), molecular and processes on the molecular
and cellular level using molecular imaging techniques
Vascular remodeling after endovascular treatment: quantitative analysis of medical images with a focus on aorta
In the last years, the convergence of advanced imaging techniques and endovascular procedures
has revolutionized the practice of vascular surgery. However, regardless the anatomical
district, several complications still occur after endovascular treatment and the impact of endovascular
repair on vessel morphology remains unclear. Starting from this background, the
aim of this thesis is to ll the gaps in the eld of vessel remodeling after endovascular procedure.
Main focus of the work will be the repair of the aorta and, in particular thoracic and
thoracoabdominal treatments. Furthermore an investigation of the impact of endovascular
repair on femoro-popliteal arterial segment will be reported in the present work. Analyses of
medical images will been conducted to extract anatomical geometric features and to compare
the changes in morphology before treatment and during follow-up.
After illustrating in detail the aims and the outline of the dissertation in Chapter 1, Chapter
2 will concern the anatomy and the physiology of the aorta along with the main aortic
pathologies and the related surgical treatments. Subsequently, an overview of the medical
image techniques for segmentation and vessel geometric quantication will be provided.
Chapter 3 will introduce the concept of remodeling of the aorta after endovascular procedure.
In particular, two types of aortic remodeling will be considered. On one side remodeling can
be seen as the shrinkage of the aneurysmal sac or false lumen thrombosis. On the other side,
aortic remodeling could be seen as the changes in the aortic morphology following endograft
placement which could lead to complications.
Chapter 4 will illustrate a study regarding the analysis of medical images to measure the geometrical
changes in the pathological aorta during follow-up in patients with thoracoabdominal
aortic aneurysms treated with endovascular procedure using a novel uncovered device, the Cardiatis
Multilayer Flow Modulator.
Chapter 5 will focus on the geometrical remodeling of the aortic arch and descending aorta in
patients who underwent hybrid arch treatment to treat thoracic aneurysms. The goal of the
work is to develop a pipeline for the processing of pre-operative and post-operative Computed
Tomography images in order to detect the changes in the aortic arch physiological curvature
due to endograft insertion.
Chapter 6 will focuse on the use of 3D printing technology as valuable tool to support patient's
follow-up. In particular, we report a case of a patient originally treated with endovascular
procedure for type B aortic dissection and which experimented several complications during
follow-up. 3D printing technology is used to show the remodeling of the aortic vasculature
during time.
Chapter 7 will concern patient-specic nite element simulations of aortic endovascular procedure.
In particular, starting from a clinical case where complication developed during followup,
the predictive value of computational simulations will be shown.
Chapter 8 will illustrate a study concerning the evaluation of morphological changes of the
femoro-popliteal arterial segment due to limb exion in patients undergoing endovascular
treatment of popliteal artery aneurysms
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