Abstract W P72: Quantitative Analysis of The Blood Flow Reduction In Brain Aneurysms Treated By Flow Diverter Stents
Purpose: This pilot study demonstrates an approach to quantitatively analyze the blood flow reduction in intracranial aneurysms treated by flow diverter stents (FDS).
Method: 2D digital subtraction angiography (DSA) images from 13 aneurysm patients were analyzed with the model. Each patient had 2 sets of consecutive DSA images (3 frames/sec and 6 ml/sec contrast injection rate) acquired before and after FDS treatment. The mean age of the patients was 55, ranging from 5 to 86 years old. The model extracted contrast-agent concentration profiles from each DSA image’s ROIs (inlet, aneurysm, and outlet regions) to calculate the blood contrast-agent mixture ratio, which reflected the percentage of blood not being diverted into aneurysm. To evaluate image quality, signal-to-noise ratio (SNR) and the relative-standard-deviation (RSD, a measure of results’ dispersion), 10 additional sets of ROIs were randomly generated for each DSA image set and also analyzed.
Result: The model showed that the 13 patients’ blood contrast-agent mixture ratios increased by 48% on average after FDS treatment. This demonstrates that the blood flow into the aneurysms was significantly (p< 0.0006) reduced after FDS treatment. The study also found an inverse relationship between the input image SNR and the RSD of output results. The correlation coefficient of image SNR and mixture ratio RSD was -0.6257 for pre-FDS treatment image sets, and -0.4512 for post-FDS treatment image sets. To control the dispersion of results for future studies, images with SNR > 11.2487 were recommended in order to yield results with RSD < 0.15 for 95% C.I.
Conclusion: Blood flow reduction due to FDS treatment in patients with brain aneurysms can be measured directly by 2D DSA. This study also verified the impact of input image quality on flow reduction estimation.
Author Disclosures: A. Chien: None. Q. Yu: None. D. Zosso: None.
- © 2015 by American Heart Association, Inc.