Y. Sun et al., DIRECTIONAL LOW-PASS FILTERING FOR IMPROVED ACCURACY AND REPRODUCIBILITY OF STENOSIS QUANTIFICATION IN CORONARY ARTERIOGRAMS, IEEE transactions on medical imaging, 14(2), 1995, pp. 242-248
Citations number
16
Categorie Soggetti
Engineering, Biomedical","Radiology,Nuclear Medicine & Medical Imaging
This Raper concerns the quantification of percent diameter stenosis in
digital coronary arteriograms of low spatial resolution. To improve a
ccuracy and reproducibility an edge-preserving smoothing method, calle
d the directional low-pass filter (DLF), was developed to suppress qua
ntum noise by averaging image intensity in a direction parallel to the
vessel border. Accuracy of stenosis quantification was assessed by us
ing stenosis phantoms. The standard error of the estimate (SEE) was 0.
76 pixel-length (p) without spatial filtering and further reduced to 0
.50 p by DLF; the average deviation as a measure of the regularity Of
border definition was also reduced by DLF from 1.00 to 0.68 p (n = 50,
P < 0.001). It was shown that the DLF outperformed the conventional m
oving average filter and median filter. Reproducibility in terms of in
traframe variability was assessed by using coronary arteriograms obtai
ned from 10 patients, intraframe variability of the percent stenosis m
easurements was reduced from 3.5% to 2.9% by DLF (n = 10, P < 0.005).
An analysis of variance showed, however, that the interframe variabili
ty cannot be reduced by any of the spatial filters under investigation
. The result of this study has provided a guideline for angiographical
ly based quantification of percent stenosis under limited imaging reso
lution and suggests a new method for improving accuracy and reproducib
ility by directional low-pass filtering.