Surgery – Diagnostic testing – Cardiovascular
Reexamination Certificate
2000-03-02
2002-05-14
Layno, Carl (Department: 3762)
Surgery
Diagnostic testing
Cardiovascular
C600S509000
Reexamination Certificate
active
06389310
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates to a computer program storage medium suitable for treating data obtained from an synchronized electrocardiogram tomoscintigraphy, as well as a method and an apparatus for executing in a computing system the treatment of said data.
STATE OF THE ART
Reference is made to various publications for disclosing specific analysis or techniques used in the program and method of the invention.
These publications are:
“Ischemic heart disease and regional left ventricular wall motion: a study comparing radial, centerline and a video intensity based slope technique”, International Journal of Cardiac Imaging 6:85-96, 1990/91, Sunnerhagen et al;
“effect of myocardial wall thickness on Spect quantification”, IEEE Transactions on Medicakl imaging, vol 9, No 2, June 1990, pages 144 to 150, James Galt ety al;
“an efficient uniform cost algorithm applied to distance transforms”, Verwer et al, IEEE transactions on pattern analysis and machine intelligence, vol 11, No 4, April 1989, description of distance transform;
“Watersheds in Digital spaces: an efficient algorithm based on immersion simulations”, Vincent et al, IEEE transactions on pattern analysis and machine intelligence, vol 13, No 6, June 1991, (description of the watershed);
“Towards automated analysis in 3D cardiac MR imaging”, Bister et al, lecture notes in Computer Science, Springer-Verlag 1991, IMPI 91, 12th International Conference on Information Medical imaging, Wye, UK, pp 205-217 (description of the PDM and the egmentation);
“Digital Image Processing”, Gonzales et al, Addison-Wesley Publishing Company, 1992, page 81 to 92 and pages 119 to 128, (the FFT method);
“Digital Picture Processing”, Rosenfeld et al, Academic Press, 1982, pages 42-46 (the matched filter);
“use of watersheds in contour detection”, Beucher et al, International Workshop on Image processing, real time edge and motion detection/estimation, Rennes, France, September 1979;
“Distance transformations in digital images”, Borgefors, Journal CVGIP(34), No 3, June 1986, pages 244-371 (description of distance transform).
The content of these publications is incorporated in the present specification by reference for the disclosure of specific methods, algorithms, etc.
The majority of the cardiac pathologies cause an abnormal function or working of one or more cavities of the heart, and/or an abnormal volume for these cavities. For example, a lack of heart perfusion could lead to ischemia and/or infarct: these muscular fiber lesions don't allow a correct contraction of a portion of the heart. Also, pericardium problems, (for example a hardening or thickening of the heart envelope) will cause an abnormal expansion of one or more cavities. An abnormal working of the heart valves will modify the normal transit of the blood into the cavities, reducing the blood output. So, severe abnormal working or volume of one or more cavities of the heart will cause major problem in the blood flow and thus in the vascularisation of the body. These pathologies can also be associated with severe troubles in the cardiac rhythm, conducting to sudden deaths by stop or anarchic contraction of the cardiac walls.
Therefore, there is a need for having a correct analysis or view of one or more cavities of the heart.
Cardiac scintigraphy synchronized with ECG is a known technique for studying the heart. Before the acquisition really starts, the mean duration of a cardiac cycle is calculated and time interval are defined (the “time bins”) . By said technique, it is possible to visualize, by means of gamma rays, the distribution and the concentration of a radioisotope present in the heart during the cardiac cycle. There are roughly two approaches: the analysis of the myocardium and the analysis of the cavities themselves. There are also 2 major techniques: the planar and the tomographic scintigraphies:
a) the analysis of the myocardium: using an perfusion myocardial tracer (a product staying in the myocardial cell proportionally to the local flow and labeled with an radioactive agent) allows a good visualization of lack of vascularisation into the walls of mainly the left ventricle (LV). The topography technique allows a visualization in 3 dimensions (3D) of the heart, which is not possible with the planar (1 or 2 incidences) technique. This analysis has the drawback that the variation of maximal activity in the wall, which is correlated to the thickening of said wall, is influenced by a partial volume effect (Galt, 1990), and therefore based on a data which is not only correlated to the number of registered photons, but also to due to a lack of resolution. Moreover, the maximum variation is also correlated to the attenuation of the rays between the emitting heart portion and the detecting means, said attenuation of the rays being variable from patient to patient and, for the same patient, from place to place inside the thorax.
Furthermore, this analysis does not give a correct and precise view of the basal portion of the left ventricle, nor in the right ventricle and in the pathologies relating to local perfusion. Therefore, the analysis given many uncertainties about the exact shape and volume of said ventricles. Walls of the auricles or portion thereof arc also not visible.
Furthermore, the known myocardial scintigraphy technology is not adapted for correcting the image due to the movement of the heart. These movements could be due to motion of the heart in the thorax and/or due to the movement of the thorax (caused for example by the breath) and/or due to a movement of the patient during his examination. There is no place defined by the said technology in the heart, which can be used as a reference: a correction of the general cardiac motion is not possible.
b) the analysis of the cavities themselves: it has been proposed to study directly the heart cavities by labeling the red blood cells by means of a radioactive element, such as a gamma emitter or a positron emitter. This method gives only a substantially correct view of the inner wall of the heart, but give a goof imaging of all the cavities of the heart. The major problem of the planar imaging technology is that there is an overlapping, in the different views, of the cavities, whereby the limits and, a fortiori, the wall motions and the volume of one cavity are difficult to appreciate and to quantify.
In the known apparatus the data are treated so as to give a 2-dimension or 3-dimensions (time +2 spatial dimensions) analysis. In the treatment of the data, the cardiac activity is not really corrected in function of the position of the heart or a portion thereof: the proposed 2D correction use the centroid of the (ventricular) cavity as the reference point for the evaluation of the segmental wall motion, but this centroid can be falsely displaced during the cycle if the wall contraction is not synchronous and/or symmetrical (which is even physiologically generally not the case).
It has finally also been proposed to make a tomographic analysis of the heart, said analysis studying the different volumes in function of the time. Said analysis gives many data's to the operator or user, said data's being as such quite complicated to be analyzed. The analysis gives a series of images, each image being defined by a matrix, classically of 64×64×64 pixels and 8 time bins, each time bin corresponding to a part of the heart cycle.
The present invention aims, in a tomographic analysis of the cardiac chambers synchronized with ECG, to normalize the cardiac time bin activity, to correct for the global motion of the heart inside the considered matrix, to label the different cardiac cavities, to extract from these data the meaningful parameters and to display them in a 2D way appropriated, when necessary, to compare with normal data bases, so as to enable in preferred embodiments, at least a automated preprocessing of a four or five -dimensional analysis of one or more chambers of the heart, which could be afterwards easily controlled and corrected by the user.
BRIEF DESCRIPTIO
Bister Michel
Demonceau Georges
Van Hove Chris
Altera Law Group
Layno Carl
LandOfFree
Method and apparatus for analyzing heart function using 4D... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Method and apparatus for analyzing heart function using 4D..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method and apparatus for analyzing heart function using 4D... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2910544