Pamukkale Univ Muh Bilim Derg, 27(2), 122-128, 2021 Pamukkale Üniversitesi Mühendislik Bilimleri Dergisi Pamukkale University Journal of Engineering Sciences 122 Model-Free automatic segmentation of the aortic valve in multislice computed tomography images Aort kapakçığının çok-kesitli bilgisayarlı tomografi görüntülerinden model-bağimsiz otomatik bölütlenmesi Devrim ÜNAY 1* , İbrahim HARMANKAYA 2 , İlkay ÖKSÜZ 3 , Rahmi ÇUBUK 4 , Levent ÇELİK 5 , Kamuran KADIPAŞAOĞLU 6 1 Electrical-Electronics Engineering, Faculty of Engineering, Izmir Democracy University, Izmir, Turkey. unaydevrim@gmail.com 2,3 Electrical and Electronics Engineering, Faculty of Engineering, Bahcesehir University, Istanbul, Turkey. i.harmankaya@yahoo.com, oksuzilkay@gmail.com 4 Department of Radiology, Faculty of Medicine, Maltepe University, Istanbul, Turkey. rahmicubuk@gmail.com 5 Radyoloji Online Medical Imaging Services Inc., Istanbul, Turkey. leventcelik@hotmail.com 6 Biomedical Engineering, Electrical-Electronics Faculty, Yıldız Technical University, Istanbul, Turkey. kamuran@yildiz.edu.tr Received/Geliş Tarihi: 11.12.2019 Accepted/Kabul Tarihi: 03.03.2020 Revision/Düzeltme Tarihi: 02.03.2020 doi: 10.5505/pajes.2020.26817 Research Article/Araştırma Makalesi Abstract Öz Valvular diseases may affect one or more of the cardiac valves, which may need to be replaced or restored for effective treatment. The surgical procedure can be guided by a patient-specific and dynamic model containing information complementary to the 2D/3D static images of the valves. To this end, in this study a novel automated model-free aortic valve segmentation method is presented, and its performance is evaluated against expert annotations over conventional contrast- enhanced ECG-gated multislice CT data of the aortic valve at its closed position. Detailed evaluation of the proposed method in 19 real cases revealed an encouraging performance of 3D region growing over Hessian based approach but also demonstrated the complexity of the problem. Bir veya birden fazla kalp kapakçığının etkilenebildiği kapakçık hastalıklarının etkin tedavisi için bu kapakçıkların onarılması ya da değiştirilmesini gereklidir. Kapakçıkların 2B/3B statik görüntülerinden elde edilecek bilgiyi tamamlayıcı bilgi içeren hastaya-özgü ve dinamik bir model bu girişimsel tedavi rehberlik edebilir. Bu amaçla bu çalışmada yeni bir otomatik model-bağımsız aort kapakçığı bölütleme yöntemi önerilmiş ve yöntemin doğruluğu aort kapakçığının kapalı anına ait geleneksel kontrastlı EKG-güdümlü çok-kesitli BT verisinden elde edilen uzman işaretlemeleri ile ölçülmüştür. Yöntemin başarısı 19 gerçek veride detaylı olarak değerlendirilmiş ve Hessian temelli sonucun üzerine bölge büyütme yaklaşımının performansının umut vadettiği ama bunun yanı sıra problemin zorluğunu göstermiştir. Keywords: Aortic valve, Segmentation, Model-Free, Region growing, Hessian, Supravalvular sinus detection, Ascending aorta, Computed tomography, Valvular heart diseases. Anahtar Kelimeler: Aort kapakçığı, Bölütleme, Model-Bağımsız, Bölge büyütme, Hessian, Supravalvüler sinüs tespiti, Çıkan aort, Bilgisayarlı tomografi, Kalp kapakçığı hastalıkları. 1 Introduction Heart disease is the leading cause of death in the Western world. Mortality is close to 2% in primary valvular disease, where one or more of the four cardiac valves (particularly the aortic and mitral) is affected. Roughly 2.5% of the world population acquires some form of symptomatic aortic valve diseases regardless of age [1]. Invasive interventional treatment of valvular disease consists of replacement or restoration of the affected valve(s) and, in either case, pre-operative planning and procedural outcome are greatly affected by the resolution and accuracy of the diagnostic information. However, capturing intricate anatomic detail of highly dynamic cardiac sub-structures, such as the valves and chordae, can be challenging, particularly when diagnostic images are processed with conventional techniques. Either 3-D topographic information is sacrificed when dynamic * Corresponding author/Yazışılan Yazar 2-D images are viewed, or functional detail is left out from high- resolution 3-D anatomic renderings. There is an evident need for a diagnostic tool, which can offer both 3-D and dynamic images of the heart, particularly of the intra-cardiac structures, in a patient-specific and real-time setting. Such a 4-D model (3 dimensions in space and an additional fourth in time) will provide the interventionalist the possibility to carry out a detailed and more accurate pre-operative planning of the subsequent surgical procedure. When the “first-in-line” ultrasound examination proves technically difficult due to patient anatomy and/or data it provides do not match the clinical picture, evaluations of diagnostic accuracy of multislice CT in valvular disorders (such as aortic valve stenosis) with respect to ultrasound is advocated [2],[3]. Accordingly cardiac image segmentation with CT has been a popular research area, where initial methods included mostly semi-automated solutions [4],[5]