| Records |
| Author |
Aura Hernandez-Sabate |
| Title |
Exploring Arterial Dynamics and Structures in IntraVascular Ultrasound Sequences |
Type |
Book Whole |
| Year |
2009 |
Publication |
PhD Thesis, Universitat Autonoma de Barcelona-CVC |
Abbreviated Journal |
|
Volume  |
|
Issue |
|
Pages |
|
| Keywords |
|
| Abstract |
Cardiovascular diseases are a leading cause of death in developed countries. Most of them are caused by arterial (specially coronary) diseases, mainly caused by plaque accumulation. Such pathology narrows blood flow (stenosis) and affects artery bio- mechanical elastic properties (atherosclerosis). In the last decades, IntraVascular UltraSound (IVUS) has become a usual imaging technique for the diagnosis and follow up of arterial diseases. IVUS is a catheter-based imaging technique which shows a sequence of cross sections of the artery under study. Inspection of a single image gives information about the percentage of stenosis. Meanwhile, inspection of longitudinal views provides information about artery bio-mechanical properties, which can prevent a fatal outcome of the cardiovascular disease. On one hand, dynamics of arteries (due to heart pumping among others) is a major artifact for exploring tissue bio-mechanical properties. On the other one, manual stenosis measurements require a manual tracing of vessel borders, which is a time-consuming task and might suffer from inter-observer variations. This PhD thesis proposes several image processing tools for exploring vessel dy- namics and structures. We present a physics-based model to extract, analyze and correct vessel in-plane rigid dynamics and to retrieve cardiac phase. Furthermore, we introduce a deterministic-statistical method for automatic vessel borders detection. In particular, we address adventitia layer segmentation. An accurate validation pro- tocol to ensure reliable clinical applicability of the methods is a crucial step in any proposal of an algorithm. In this thesis we take special care in designing a valida- tion protocol for each approach proposed and we contribute to the in vivo dynamics validation with a quantitative and objective score to measure the amount of motion suppressed. |
| Address |
|
| Corporate Author |
|
Thesis |
Ph.D. thesis |
| Publisher |
Ediciones Graficas Rey |
Place of Publication |
|
Editor |
Debora Gil |
| Language |
|
Summary Language |
|
Original Title |
|
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
|
ISBN |
978-84-937261-6-4 |
Medium |
|
| Area |
|
Expedition |
|
Conference |
|
| Notes |
IAM; |
Approved |
no |
| Call Number |
IAM @ iam @ Her2009 |
Serial |
1543 |
| Permanent link to this record |
| |
|
| |
| Author |
Aura Hernandez-Sabate |
| Title |
Automatic adventitia segmentation in IntraVascular UltraSound images |
Type |
Report |
| Year |
2005 |
Publication |
CVC Technical Report |
Abbreviated Journal |
|
| Volume |
|
Issue |
85 |
Pages |
|
| Keywords |
|
| Abstract |
A usual tool in cardiac disease diagnosis is vessel plaque assessment by analysis of IVUS sequences. Manual detection of lumen-intima, intima-media and media-adventitia vessel borders is the main activity of physicians in the process of plaque quantification. Large variety in vessel border descriptors, as well as, shades, artifacts and blurred response due to ultrasound physical properties troubles automated media-adventitia segmentation. This experimental work presents a solution to such a complex problem. The process blends advanced anisotropic filtering operators and statistic classification techniques, achieving an efficient vessel border modelling strategy. First of all, we introduce the theoretic base of the method. After that, we show the steps of the algorithm, validating the method with statistics that show that the media-adventitia border detection achieves an accuracy in the range of inter-observer variability regardless of plaque nature, vessel geometry and incomplete vessel borders. Finally, we present a little Matlab application to the automatic media-adventitia border. |
| Address |
|
| Corporate Author |
|
Thesis |
Master's thesis |
| Publisher |
|
Place of Publication |
08193 Bellaterra, Barcelona (Spain) |
Editor |
|
| Language |
|
Summary Language |
|
Original Title |
|
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
|
ISBN |
|
Medium |
|
| Area |
|
Expedition |
|
Conference |
|
| Notes |
IAM; |
Approved |
no |
| Call Number |
IAM @ iam @ Her2005 |
Serial |
1544 |
| Permanent link to this record |
| |
|
| |
| Author |
Aura Hernandez-Sabate; Debora Gil; Petia Radeva |
| Title |
A Deterministic-Statistical Strategy for Adventitia Segmentation in IVUS images |
Type |
Report |
| Year |
2005 |
Publication |
CVC Technical Report |
Abbreviated Journal |
|
| Volume |
|
Issue |
89 |
Pages |
|
| Keywords |
|
| Abstract |
A useful tool for some specific studies in cardiac disease diagnosis is vessel plaque assessment by analysis of IVUS sequences. Manual detection of luminal (inner) and media-adventitia (external) vessel borders is the main activity of physicians in the process of lumen narrowing (plaque) quantification. Difficult definition of vessel border descriptors, as well as, shades, artifacts and blurred signal response due to ultrasound physical properties troubles automated adventitia segmentation. In order to efficiently approach such a complex problem, we propose blending advanced anisotropic filtering operators and statistical classification techniques into a vessel border modelling strategy. Our systematic statistical analysis shows that the reported adventitia detection achieves an accuracy in the range of inter-observer variability regardless of plaque nature, vessel geometry and incomplete vessel borders. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
|
Editor |
|
| Language |
|
Summary Language |
|
Original Title |
|
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
|
ISBN |
|
Medium |
|
| Area |
|
Expedition |
|
Conference |
|
| Notes |
IAM; MILAB |
Approved |
no |
| Call Number |
IAM @ iam @ HGR2005a |
Serial |
1548 |
| Permanent link to this record |
| |
|
| |
| Author |
Aura Hernandez-Sabate; Debora Gil; Petia Radeva |
| Title |
On the usefulness of supervised learning for vessel border detection in IntraVascular Imaging |
Type |
Conference Article |
| Year |
2005 |
Publication |
Proceeding of the 2005 conference on Artificial Intelligence Research and Development |
Abbreviated Journal |
|
| Volume |
|
Issue |
|
Pages |
67-74 |
| Keywords |
classification; vessel border modelling; IVUS |
| Abstract |
IntraVascular UltraSound (IVUS) imaging is a useful tool in diagnosis of cardiac diseases since sequences completely show the morphology of coronary vessels. Vessel borders detection, especially the external adventitia layer, plays a central role in morphological measures and, thus, their segmentation feeds development of medical imaging techniques. Deterministic approaches fail to yield optimal results due to the large amount of IVUS artifacts and vessel borders descriptors. We propose using classification techniques to learn the set of descriptors and parameters that best detect vessel borders. Statistical hypothesis test on the error between automated detections and manually traced borders by 4 experts show that our detections keep within inter-observer variability. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
IOS Press |
Place of Publication |
Amsterdam, The Netherlands |
Editor |
|
| Language |
|
Summary Language |
|
Original Title |
|
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
|
ISBN |
|
Medium |
|
| Area |
|
Expedition |
|
Conference |
|
| Notes |
IAM;MILAB |
Approved |
no |
| Call Number |
IAM @ iam @ HGR2005c |
Serial |
1549 |
| Permanent link to this record |
| |
|
| |
| Author |
Aura Hernandez-Sabate; Debora Gil; Albert Teis |
| Title |
How Do Conservation Laws Define a Motion Suppression Score in In-Vivo Ivus Sequences? |
Type |
Conference Article |
| Year |
2007 |
Publication |
Proc. IEEE Ultrasonics Symp |
Abbreviated Journal |
|
| Volume |
|
Issue |
|
Pages |
2231-2234 |
| Keywords |
validation standards; IVUS motion compensation; conservation laws. |
| Abstract |
Evaluation of arterial tissue biomechanics for diagnosis and treatment of cardiovascular diseases is an active research field in the biomedical imaging processing area. IntraVascular UltraSound (IVUS) is a unique tool for such assessment since it reflects tissue morphology and deformation. A proper quantification and visualization of both properties is hindered by vessel structures misalignments introduced by cardiac dynamics. This has encouraged development of IVUS motion compensation techniques. However, there is a lack of an objective evaluation of motion reduction ensuring a reliable clinical application This work reports a novel score, the Conservation of Density Rate (CDR), for validation of motion compensation in in-vivo pullbacks. Synthetic experiments validate the proposed score as measure of motion parameters accuracy; while results in in vivo pullbacks show its reliability in clinical cases. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
|
Editor |
|
| Language |
|
Summary Language |
|
Original Title |
|
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
|
ISBN |
|
Medium |
|
| Area |
|
Expedition |
|
Conference |
|
| Notes |
IAM |
Approved |
no |
| Call Number |
IAM @ iam @ HTG2007 |
Serial |
1550 |
| Permanent link to this record |
| |
|
| |
| Author |
Aura Hernandez-Sabate; Petia Radeva; Antonio Tovar; Debora Gil |
| Title |
Vessel structures alignment by spectral analysis of ivus sequences |
Type |
Conference Article |
| Year |
2006 |
Publication |
Proc. of CVII, MICCAI Workshop |
Abbreviated Journal |
|
| Volume |
|
Issue |
|
Pages |
39-36 |
| Keywords |
|
| Abstract |
Three-dimensional intravascular ultrasound (IVUS) allows to visualize and obtain volumetric measurements of coronary lesions through an exploration of the cross sections and longitudinal views of arteries. However, the visualization and subsequent morpho-geometric measurements in IVUS longitudinal cuts are subject to distortion caused by periodic image/vessel motion around the IVUS catheter. Usually, to overcome the image motion artifact ECG-gating and image-gated approaches are proposed, leading to slowing the pullback acquisition or disregarding part of IVUS data. In this paper, we argue that the image motion is due to 3-D vessel geometry as well as cardiac dynamics, and propose a dynamic model based on the tracking of an elliptical vessel approximation to recover the rigid transformation and align IVUS images without loosing any IVUS data. We report an extensive validation with synthetic simulated data and in vivo IVUS sequences of 30 patients achieving an average reduction of the image artifact of 97% in synthetic data and 79% in real-data. Our study shows that IVUS alignment improves longitudinal analysis of the IVUS data and is a necessary step towards accurate reconstruction and volumetric measurements of 3-D IVUS. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
Copenhaguen (Denmark), |
Editor |
|
| Language |
|
Summary Language |
|
Original Title |
|
| Series Editor |
|
Series Title |
1st International Wokshop on Computer Vision for Intravascular and Intracardiac Imaging (CVII’06) |
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
|
ISBN |
|
Medium |
|
| Area |
|
Expedition |
|
Conference |
|
| Notes |
IAM; MILAB |
Approved |
no |
| Call Number |
IAM @ iam @ HRT2006 |
Serial |
1552 |
| Permanent link to this record |
| |
|
| |
| Author |
Aura Hernandez-Sabate; David Rotger; Debora Gil |
| Title |
Image-based ECG sampling of IVUS sequences |
Type |
Conference Article |
| Year |
2008 |
Publication |
Proc. IEEE Ultrasonics Symp. IUS 2008 |
Abbreviated Journal |
|
| Volume |
|
Issue |
|
Pages |
1330-1333 |
| Keywords |
Longitudinal Motion; Image-based ECG-gating; Fourier analysis |
| Abstract |
Longitudinal motion artifacts in IntraVascular UltraSound (IVUS) sequences hinders a properly 3D reconstruction and vessel measurements. Most of current techniques base on the ECG signal to obtain a gated pullback without the longitudinal artifact by using a specific hardware or the ECG signal itself. The potential of IVUS images processing for phase retrieval still remains little explored. In this paper, we present a fast forward image-based algorithm to approach ECG sampling. Inspired on the fact that maximum and minimum lumen areas are related to end-systole and end-diastole, our cardiac phase retrieval is based on the analysis of tissue density of mass along the sequence. The comparison between automatic and manual phase retrieval (0.07 ± 0.07 mm. of error) encourages a deep validation contrasting with ECG signals. |
| Address |
Beijing (China) |
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
|
Editor |
|
| Language |
|
Summary Language |
|
Original Title |
|
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
|
ISBN |
|
Medium |
|
| Area |
|
Expedition |
|
Conference |
|
| Notes |
IAM;MILAB |
Approved |
no |
| Call Number |
IAM @ iam @ HRG2008 |
Serial |
1553 |
| Permanent link to this record |
| |
|
| |
| Author |
Ole Larsen; Petia Radeva; Enric Marti |
| Title |
Bounds on the optimal elasticity parameters for a snake |
Type |
Journal Article |
| Year |
1995 |
Publication |
Image Analysis and Processing |
Abbreviated Journal |
|
| Volume |
|
Issue |
|
Pages |
37-42 |
| Keywords |
|
| Abstract |
This paper develops a formalism by which an estimate for the upper and lower bounds for the elasticity parameters for a snake can be obtained. Objects different in size and shape give rise to different bounds. The bounds can be obtained based on an analysis of the shape of the object of interest. Experiments on synthetic images show a good correlation between the estimated behaviour of the snake and the one actually observed. Experiments on real X-ray images show that the parameters for optimal segmentation lie within the estimated bounds. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
|
Editor |
|
| Language |
|
Summary Language |
|
Original Title |
|
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
|
ISBN |
|
Medium |
|
| Area |
|
Expedition |
|
Conference |
|
| Notes |
MILAB;IAM |
Approved |
no |
| Call Number |
IAM @ iam @ LRM1995a |
Serial |
1559 |
| Permanent link to this record |
| |
|
| |
| Author |
Ole Larsen; Petia Radeva; Enric Marti |
| Title |
Calculating the Bounds on the Optimal Parameters of Elasticity for a Snake |
Type |
Report |
| Year |
1994 |
Publication |
Technical Report |
Abbreviated Journal |
|
| Volume |
|
Issue |
|
Pages |
|
| Keywords |
|
| Abstract |
|
| Address |
Aalborg University |
| Corporate Author |
|
Thesis |
|
| Publisher |
Aalborg University, Laboratory of image Analysis. |
Place of Publication |
Denmark |
Editor |
|
| Language |
|
Summary Language |
|
Original Title |
|
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
|
ISBN |
|
Medium |
|
| Area |
Aalborg University, Laboratory of image Analysis. |
Expedition |
|
Conference |
|
| Notes |
MILAB;IAM |
Approved |
no |
| Call Number |
IAM @ iam @ LRM1994 |
Serial |
1560 |
| Permanent link to this record |
| |
|
| |
| Author |
Jaime Lopez-Krahe; Josep Llados; Enric Marti |
| Title |
Architectural Floor Plan Analysis |
Type |
Report |
| Year |
2000 |
Publication |
CVonline |
Abbreviated Journal |
|
| Volume |
|
Issue |
|
Pages |
|
| Keywords |
|
| Abstract |
|
| Address |
Edimburg, UK |
| Corporate Author |
|
Thesis |
|
| Publisher |
University of Edinburgh |
Place of Publication |
|
Editor |
Robert B. Fisher |
| Language |
|
Summary Language |
|
Original Title |
|
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
|
ISBN |
|
Medium |
online pdf |
| Area |
|
Expedition |
|
Conference |
|
| Notes |
DAG;IAM |
Approved |
no |
| Call Number |
IAM @ iam @ LLM2000 |
Serial |
1561 |
| Permanent link to this record |
| |
|
| |
| Author |
Josep Llados;Horst Bunke; Enric Marti |
| Title |
Using Cyclic String Matching to Find Rotational and Reflectional Symmetries in Shapes |
Type |
Conference Article |
| Year |
1997 |
Publication |
Intelligent Robots: Sensing, Modeling and Planning |
Abbreviated Journal |
|
| Volume |
|
Issue |
|
Pages |
164-179 |
| Keywords |
|
| Abstract |
Dagstuhl Workshop |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
World Scientific Press |
Place of Publication |
|
Editor |
|
| Language |
|
Summary Language |
|
Original Title |
|
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
|
ISBN |
9810231857 |
Medium |
|
| Area |
|
Expedition |
|
Conference |
|
| Notes |
DAG;IAM; |
Approved |
no |
| Call Number |
IAM @ iam @ LBM1997b |
Serial |
1563 |
| Permanent link to this record |
| |
|
| |
| Author |
Josep Llados; Horst Bunke; Enric Marti |
| Title |
Using cyclic string matching to find rotational and reflectional symmetric shapes |
Type |
Conference Article |
| Year |
1996 |
Publication |
Dagstuhl Seminar on Modelling and Planning for Sensor–based Intelligent Robot Systems |
Abbreviated Journal |
|
| Volume |
|
Issue |
|
Pages |
|
| Keywords |
|
| Abstract |
|
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
World Scientific |
Place of Publication |
Saarbrucken (Germany). |
Editor |
R.C. Bolles, H.B.H.N. |
| Language |
|
Summary Language |
|
Original Title |
|
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
|
ISBN |
|
Medium |
|
| Area |
|
Expedition |
|
Conference |
|
| Notes |
DAG;IAM |
Approved |
no |
| Call Number |
IAM @ iam @ LBM1996 |
Serial |
1564 |
| Permanent link to this record |
| |
|
| |
| Author |
Josep Llados; Horst Bunke; Enric Marti |
| Title |
Structural Recognition of hand drawn floor plans |
Type |
Conference Article |
| Year |
1996 |
Publication |
VI National Symposium on Pattern Recognition and Image Analysis |
Abbreviated Journal |
|
| Volume |
|
Issue |
|
Pages |
|
| Keywords |
Rotational Symmetry; Reflectional Symmetry; String Matching. |
| Abstract |
A system to recognize hand drawn architectural drawings in a CAD environment has been deve- loped. In this paper we focus on its high level interpretation module. To interpret a floor plan, the system must identify several building elements, whose description is stored in a library of pat- terns, as well as their spatial relationships. We propose a structural approach based on subgraph isomorphism techniques to obtain a high-level interpretation of the document. The vectorized input document and the patterns to be recognized are represented by attributed graphs. Discrete relaxation techniques (AC4 algorithm) have been applied to develop the matching algorithm. The process has been divided in three steps: node labeling, local consistency and global consistency verification. The hand drawn creation causes disturbed line drawings with several accuracy errors, which must be taken into account. Here we have identified them and the AC4 algorithm has been adapted to manage them. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
Cordoba |
Editor |
|
| Language |
|
Summary Language |
|
Original Title |
|
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
|
ISBN |
|
Medium |
|
| Area |
|
Expedition |
|
Conference |
|
| Notes |
DAG;IAM; |
Approved |
no |
| Call Number |
IAM @ iam @ LIM1995 |
Serial |
1565 |
| Permanent link to this record |
| |
|
| |
| Author |
Josep Llados; Enric Marti |
| Title |
Graph-edit algorithms for hand-drawn graphical document recognition and their automatic introduction |
Type |
Journal Article |
| Year |
1999 |
Publication |
Machine Graphics & Vision journal, special issue on Graph transformation |
Abbreviated Journal |
|
| Volume |
|
Issue |
|
Pages |
|
| Keywords |
|
| Abstract |
|
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
|
Editor |
|
| Language |
|
Summary Language |
|
Original Title |
|
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
|
ISBN |
|
Medium |
|
| Area |
|
Expedition |
|
Conference |
|
| Notes |
DAG;IAM |
Approved |
no |
| Call Number |
IAM @ iam @ LIM1999c |
Serial |
1569 |
| Permanent link to this record |
| |
|
| |
| Author |
Josep Llados; Enric Marti |
| Title |
Playing with error-tolerant subgraph isomorphism in line drawings |
Type |
Conference Article |
| Year |
1997 |
Publication |
VII National Symposium on Pattern Recognition and image Analysis |
Abbreviated Journal |
|
| Volume |
|
Issue |
|
Pages |
|
| Keywords |
|
| Abstract |
|
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
|
Editor |
|
| Language |
|
Summary Language |
|
Original Title |
|
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
|
ISBN |
|
Medium |
|
| Area |
|
Expedition |
|
Conference |
|
| Notes |
DAG;IAM; |
Approved |
no |
| Call Number |
IAM @ iam @ LlM1997 |
Serial |
1570 |
| Permanent link to this record |
