{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,1,2]],"date-time":"2026-01-02T17:18:06Z","timestamp":1767374286673,"version":"build-2065373602"},"reference-count":28,"publisher":"MDPI AG","issue":"7","license":[{"start":{"date-parts":[[2021,6,24]],"date-time":"2021-06-24T00:00:00Z","timestamp":1624492800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["JPM"],"abstract":"<jats:p>Currently, an echocardiography expert is needed to identify calcium in the aortic valve, and a cardiac CT-Scan image is needed for calcium quantification. When performing a CT-scan, the patient is subject to radiation, and therefore the number of CT-scans that can be performed should be limited, restricting the patient\u2019s monitoring. Computer Vision (CV) has opened new opportunities for improved efficiency when extracting knowledge from an image. Applying CV techniques on echocardiography imaging may reduce the medical workload for identifying the calcium and quantifying it, helping doctors to maintain a better tracking of their patients. In our approach, a simple technique to identify and extract the calcium pixel count from echocardiography imaging, was developed by using CV. Based on anonymized real patient echocardiographic images, this approach enables semi-automatic calcium identification. As the brightness of echocardiography images (with the highest intensity corresponding to calcium) vary depending on the acquisition settings, echocardiographic adaptive image binarization has been performed. Given that blood maintains the same intensity on echocardiographic images\u2014being always the darker region\u2014blood areas in the image were used to create an adaptive threshold for binarization. After binarization, the region of interest (ROI) with calcium, was interactively selected by an echocardiography expert and extracted, allowing us to compute a calcium pixel count, corresponding to the spatial amount of calcium. The results obtained from these experiments are encouraging. With this technique, from echocardiographic images collected for the same patient with different acquisition settings and different brightness, obtaining a calcium pixel count, where pixel values show an absolute pixel value margin of error of 3 (on a scale from 0 to 255), achieving a Pearson Correlation of 0.92 indicating a strong correlation with the human expert assessment of calcium area for the same images.<\/jats:p>","DOI":"10.3390\/jpm11070598","type":"journal-article","created":{"date-parts":[[2021,6,24]],"date-time":"2021-06-24T11:01:38Z","timestamp":1624532498000},"page":"598","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":11,"title":["Calcium Identification and Scoring Based on Echocardiography. An Exploratory Study on Aortic Valve Stenosis"],"prefix":"10.3390","volume":"11","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-7489-4380","authenticated-orcid":false,"given":"Luis B.","family":"Elvas","sequence":"first","affiliation":[{"name":"Inov Inesc Inova\u00e7\u00e3o\u2014Instituto de Novas Tecnologias, 1000-029 Lisbon, Portugal"},{"name":"Instituto Universit\u00e1rio de Lisboa (ISCTE-IUL), ISTAR, 1649-026 Lisboa, Portugal"}]},{"given":"Ana G.","family":"Almeida","sequence":"additional","affiliation":[{"name":"Faculty of Medicine, Lisbon University, Hospital Santa Maria\/CHULN, CCUL, 1649-028 Lisbon, Portugal"}]},{"given":"Lu\u00eds","family":"Rosario","sequence":"additional","affiliation":[{"name":"Faculty of Medicine, Lisbon University, Hospital Santa Maria\/CHULN, CCUL, 1649-028 Lisbon, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-1445-2695","authenticated-orcid":false,"given":"Miguel Sales","family":"Dias","sequence":"additional","affiliation":[{"name":"Instituto Universit\u00e1rio de Lisboa (ISCTE-IUL), ISTAR, 1649-026 Lisboa, Portugal"}]},{"given":"Jo\u00e3o C.","family":"Ferreira","sequence":"additional","affiliation":[{"name":"Inov Inesc Inova\u00e7\u00e3o\u2014Instituto de Novas Tecnologias, 1000-029 Lisbon, Portugal"},{"name":"Instituto Universit\u00e1rio de Lisboa (ISCTE-IUL), ISTAR, 1649-026 Lisboa, Portugal"}]}],"member":"1968","published-online":{"date-parts":[[2021,6,24]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"7","DOI":"10.1016\/j.ahj.2003.11.027","article-title":"Coronary artery disease in the developing world","volume":"148","author":"Okrainec","year":"2004","journal-title":"Am. 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