Integration of digital angiography and gamma-camera diagnostic modalities to a generalized hospital information system.

Within the framework of the NIKA project for the development of a "Generalized System for Processing and Management of Medical Images", we have integrated a Digital Subtraction Angiography (DSA) station and a gamma-camera diagnostic modality to the newly developed generalized hospital-wide information system. The integration consists of acquiring, digitizing, converting and filing the information from the above diagnostic modalities to the hospital's Picture Archiving and Communication System (PACS). The PACS, which is installed in the Onasio Cardiosurgery Centre of Athens, Greece, is responsible for archival, cataloging, retrieval and viewing of the large volume of patient examination data accumulated during his/her stay in the Centre. The ultimate goal is for all patient data, from all different examinations, to be viewed on dedicated client workstations. Information from different modalities can then be simultaneously presented to the attending physician, for a complete picture of the patient history and condition.

Nonparametric two-dimensional point spread function estimation for biomedical imaging.

The problem of identifying optical system point spread functions (PSFs) arises frequently in the area of image processing and restoration. The paper presents a method for determining two-dimensional PSFs from input/output image signals. The PSF of the system is determined from a set of linear equations involving elements of the input autocorrelation function and the input/output cross-correlation function. The resulting PSF is the one that minimises the sum of squares difference between the actual output image and the predicted one.