Showing papers on "Parametric Image published in 1984"
TL;DR: A new method for analyzing cardiac parametric images provides an efficient means of automatically classifying cardiac studies and ROC curves show a good agreement between the automated and visual methods.
Abstract: A new method for analyzing cardiac parametric images is introduced. Its orginal feature is the representation of local heart motion in a polar coordinate plane which makes the integration of the information contained in three parametric images possible. These images are calculated using first harmonic Fourier filtering and are the maximum volume image, the local ejection fraction image, and the phase image. The last two parametric images are considered as the complex ejection fraction parametric image which is described by a 2D distribution in the complex plane. This method is a generalized 2D version of the well-known phase histogram method. By segmenting the complex plane in which this representation is made, four indexes are defined called the index of hypokinesia, the index of asynergy, the mean phase shift in asynergic regions, and the mean ejection fraction in asynergic regions. The values of those indexes are used to assess the degree and extent of regional wall motion abnormalities. An automated classification as normal, hypokinetic, akinetic, slightly dyskinetic, and strongly dyskinetic made on the basis of the values of those indexes has been compared with a visual classification made by three observers in 219 studies. ROC curves show a good agreement between the automated and visual methods. This new method provides an efficient means of automatically classifying cardiac studies.
4 citations
01 Jan 1984
TL;DR: Fixed zonal areas and bands are established within the imaged organ, and the mean value for each zone is computed, and it is shown that in this way parametric images can be quantified and objectively compared.
Abstract: A new method is described that modifies the original concept of parametric or functional imaging. While the conventional parametric image replaces a temporal sequence of images with a single static image based upon a selected parameter, in the new approach fixed zonal areas and bands are established within the imaged organ, and the mean value for each zone is computed. It is shown that in this way parametric images can be quantified and objectively compared. Examples for various organs are given.
2 citations