Retinal fundus photographs are employed as standard diagnostic tools in ophthalmology. Serial photographs of the flow of fluorescein and indocyanine green (ICG) dye are used to determine the areas of the retinal lesions. For objective measurements of features, the registration of the images is a necessity. In this paper, we employ optimization techniques for registration with the help of 2-parameter translational motion model of retinal angiograms, based on non-linear pre-processing (Wiener filtering and morphological gradient) and computation of the similarity criteria for the alignment of the two gradient images for any given rigid transformation. The optimization methods are effectively employed to minimize the similarity criterion.
The presence of noise, the variations in the background and the temporal variation of the fluorescence level pose serious problems in obtaining a robust registration of the retinal images. Moreover, local search strategies are not robust in the case of ICG angiograms, even if one uses a multiresolution approach.
The present work makes a systematic comparison of different optimization techniques, namely the minimization method derived from the optical flow formulation, the Nelder-Mead local search and the HCIAC ant colony metaheuristic, each optimizing a similarity criterion for the gradient images. The impact of the resolution and median filtering of gradient image is studied and the robustness of the approaches is tested through experimental studies, performed on macular fluorescein and ICG angiographies.
Our proposed optimization techniques have shown interesting results especially for high resolution difficult registration problems. Moreover, this approach seems promising for affine (6-parameter motion model) or elastical registrations. 相似文献
Recently, the digital imaging and communications in medicine (DICOM) standard introduced rules for the encoding, transmission,
and storage of the imaging diagnostic report. This medical document can be stored and communicated with the images in picture
archiving and communication system (PACS). It is a structured document that contains text with links to other data such as
images, waveforms, and spatial or temporal coordinates. Its structure, along with its wide use of coded information, enables
the semantic understanding of the data that is essential for the Electronic Healthcare Record deployment. In this article,
we present DICOM Structured Report (SR) and discuss its benefits. We show how SR enables efficient radiology workflow, improves
patient care, optimizes reimbursement, and enhances the radiology ergonomic working conditions. As structured input significantly
alters the interpretation process, understanding all its benefits is necessary to support the change.
Biography Rita Noumeir is a professor at the Department of Electrical Engineering of the University of Quebec, école de Technologie Superieure in
Montreal. A founding member of the Imaging, Vision, and Artificial Intelligence Laboratory (LIVIA), her main research interest
is the Healthcare Information Technology, specifically, Interoperability, Electronic Patient Record, Security, Information
Confidentiality, and Image Processing.
As a member of both Technical and Planning International IHE Radiology Committees, Dr. Noumeir took part over the last 5 years
in developing many Integrating the Healthcare Enterprise (IHE) Integration Profiles in Radiology and in organizing several
Integration Demonstrations. She is a cofounder of IHE Canada.
Dr. Noumeir contributed to many research and development projects in collaboration with several Canadian and international
companies in medical imaging and healthcare information. Currently, she collaborates with the Diagnostic Imaging Team of Canada
Health Infoway to define the principles and architecture for sharing imaging information between multiple healthcare institutions.
She plays a leading role in the development of this solution that is published as an IHE Integration Profile for which she
is the editor.
Rita Noumeir holds a Ph.D. and a Masters degree in Biomedical Engineering from école Polytechnique of Montreal specializing
in Medical Imaging. She is a professional engineer, and a member of the Ordre des ingénieurs du Québec. 相似文献