Biomedical subjects
C Boulay
Publications and source records attributed to C Boulay.
An experimental study in electrical impedance tomography using backprojection reconstruction.
This paper reports on experiments designed to evaluate the performance of the equipotentials backprojection method under conditions modeling those of proposed applications of electrical impedance tomography. Small spherical targets were placed inside a saline-filled tank with dimensions similar to a human torso. Data were acquired with a computer-based instrument that applies current to pairs of electrodes located on two horizontal planes and records potential differences between electrodes of a third plane. The relative contrast produced by nonconducting spheres in a uniform saline background was measured on the reconstructed images and used to determine system sensitivity to target volume and to the radial and vertical positions of single spheres. Results show that for radial positions within a critical radius sensitivity is always maximum when the spheres center is on the recording plane and decreases gradually when the target is moved outside this plane. Localization of simple targets in 3-D, with data acquired from multiple recording planes, appears feasible. The results provide guidelines for the interpretation of images with complex 3-D conductivity distributions.
[Pallido-pyramidal syndrome: an unrecognized entity].
A female teenager, without familial history, presented, since the age of 13 years, with gradually worsening pyramidal signs and a parkinsonian syndrome controlled by L-Dopa in small doses. The clinical complex was suggestive of the pallido-pyramidal syndrome, an entity which was individualized in 1954 by Davison on the basis of 5 young patients who had pyramidal signs and a parkinsonian syndrome. In only one of these patients a pathological study was carried out, disclosing a non specific degeneration without inclusions, involving the pallidum, substantia nigra and pyramidal tract. We hope that this report will encourage other authors to report similar cases, since only the study of new cases will determine whether the pallido-pyramidal syndrome is a true entity.