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Federico Viel

Publications and source records attributed to Federico Viel.

2 recordsLinked to original sources

User attitudes in analyzing digital slides in a quality control test bed: a preliminary study.

The pathologist examines suitably stained glass slides through a bright field microscope in order to render histopathological or cytological diagnosis by looking at tissues and cells. Glass slides serve as a permanent record of the patient disease. Over the course of a patient's treatment slides may need to be reviewed at other institutions before treatment can commence. Due to their fragile nature a transportable permanent digital facsimile of the glass slide would be ideal. A digital slide is a set of digital images representing the whole slide normally used by the pathologist, or a significant part of it; it is usually made by a large amount of images, up to thousands, which makes its management difficult. The present paper provides a description of the requirements needed to reproduce glass slides and of the available technological equipment, then the features of the two systems we implemented on different hardware are described, together with those of the digital slide viewer. The viewer was evaluated in two experimental test phases, during which user behaviour and diagnostic reports were measured. Digital slides used in the two experiments were acquired with either system. Possible applications of digital slides are then discussed, including undergraduate and professional education, quality control, and image analysis on full samples as well as on tissue microarrays.

Attitude↗

A pixel-based autofocusing technique for digital histologic and cytologic slides.

The present paper describes a method for autofocusing specifically studied for the acquisition of digital slides, i.e. full histologic and cytologic slides, utilising low-cost equipment. At first, experimentations with some of the most used focus measures and algorithms have been made, in order to choose the most suitable for histologic and cytologic images. Then, a study of the specific features of digital slides has been preliminarily carried out in order to understand the constraints of the domain. These included the capability of autofocusing in an unattended way on thousands of microscope fields, while fast performance is not a strict requirement. Based on the findings, an algorithm based on a dynamic focus position space, with a variance-based focus measure has been adapted to the specific situation. A qualitative and quantitative evaluation of the proposed algorithm allowed us to show that the proposed algorithm is suitable for the acquisition of digital slides, and furthermore it can be implemented starting from a basic microscope with an inexpensive motorised stage. The algorithm is currently implemented into a complete digital slide acquisition system, which is in turn being used for a Quality Assurance Programme in cervicovaginal cytologic screening.

Algorithms↗