Shape-based approach for coronary calcium lesion volume measurement on intravascular ultrasound imaging and its association with carotid intima-media thickness

Tadashi Araki; Nobutaka Ikeda; Nilanjan Dey; Suvojit Acharjee; Filippo Molinari; Luca Saba; Elisa Cuadrado Godia; Andrew Nicolaides; Jasjit S Suri

doi:10.7863/ultra.34.3.469

Shape-based approach for coronary calcium lesion volume measurement on intravascular ultrasound imaging and its association with carotid intima-media thickness

J Ultrasound Med. 2015 Mar;34(3):469-82. doi: 10.7863/ultra.34.3.469.

Authors

Tadashi Araki¹, Nobutaka Ikeda¹, Nilanjan Dey¹, Suvojit Acharjee¹, Filippo Molinari¹, Luca Saba¹, Elisa Cuadrado Godia¹, Andrew Nicolaides¹, Jasjit S Suri²

Affiliations

¹ Division of Cardiovascular Medicine, Toho University Ohashi Medical Center, Tokyo, Japan (T.A.); Division of Cardiovascular Medicine, National Center for Global Health and Medicine, Tokyo, Japan (N.I.); Point of Care Devices, Global Biomedical Technologies, Inc, Roseville, California USA (N.D., S.A., J.S.S.); Biolab, Department of Electronics, Politecnico di Torino, Torino, Italy (F.M.); Azienda Ospedaliero Universitaria di Cagliari-Polo di Monserrato, Università di Cagliari, Cagliari, Italy (L.S.); Institut Hospital del Mar d'Investigacions Mèdiques, Hospital del Mar, Barcelona, Spain (E.C.G.); Vascular Screening and Diagnostic Center, London, England (A.N.); Department of Biological Sciences, University of Cyprus, Nicosia, Cyprus (A.N.); Diagnostic and Monitoring Division, AtheroPoint, LLC, Roseville, California USA (J.S.S.); and Department of Electrical Engineering (Affiliate), Idaho State University, Pocatello, Idaho USA (J.S.S.).
² Division of Cardiovascular Medicine, Toho University Ohashi Medical Center, Tokyo, Japan (T.A.); Division of Cardiovascular Medicine, National Center for Global Health and Medicine, Tokyo, Japan (N.I.); Point of Care Devices, Global Biomedical Technologies, Inc, Roseville, California USA (N.D., S.A., J.S.S.); Biolab, Department of Electronics, Politecnico di Torino, Torino, Italy (F.M.); Azienda Ospedaliero Universitaria di Cagliari-Polo di Monserrato, Università di Cagliari, Cagliari, Italy (L.S.); Institut Hospital del Mar d'Investigacions Mèdiques, Hospital del Mar, Barcelona, Spain (E.C.G.); Vascular Screening and Diagnostic Center, London, England (A.N.); Department of Biological Sciences, University of Cyprus, Nicosia, Cyprus (A.N.); Diagnostic and Monitoring Division, AtheroPoint, LLC, Roseville, California USA (J.S.S.); and Department of Electrical Engineering (Affiliate), Idaho State University, Pocatello, Idaho USA (J.S.S.). jasjit.suri@atheropoint.com.

PMID: 25715368
DOI: 10.7863/ultra.34.3.469

Abstract

Objectives: Coronary calcification plays an important role in diagnostic classification of lesion subsets. According to histopathologic studies, vulnerable atherosclerotic plaque contains calcified deposits, and there can be considerable variation in the extent and degree of calcification. Intravascular ultrasound (IVUS) has demonstrated its role in imaging coronary arteries, thereby displaying calcium lesions. The aim of this work was to develop a fully automated system for detection, area and volume measurement, and characterization of the largest calcium deposits in coronary arteries. Furthermore, we demonstrate the correlation between the coronary calcium IVUS volume and the neurologic risk biomarker B-mode carotid intima-media thickness (IMT).

Methods: Our system automatically detects the frames with calcium, identifies the largest calcium region, and performs shape-based volume measurements. The carotid IMT is measured by using AtheroEdge software (AtheroPoint, LLC) on B-mode ultrasound imaging.

Results: Our database consists of low-contrast IVUS videos and corresponding B-mode images from 100 patients. Our experiments showed that the correlation between calcium volumes and carotid IMT was higher for the left carotid artery compared to the right carotid artery (r = 0.066 for the left carotid artery and 0.121 for the right carotid artery). We obtained 97% accuracy for automated calcium detection compared against the scoring given by our expert radiologists. Furthermore, we benchmarked shape-based volume measurement against the conventional method, which used integration of regions and showed a correlation of 84%.

Conclusions: Since carotid IMT is an independent prognostic factor for myocardial infarction, and calcium lesions are correlated with stroke risk, we believe that this automated system for calcium volume measurement could be useful for assessing patients' cardiovascular risk.

Keywords: carotid intima-media thickness; coronary calcium; shape-based volume measurement; vascular ultrasound.

MeSH terms

Artificial Intelligence
Calcinosis / diagnostic imaging*
Carotid Arteries / diagnostic imaging*
Carotid Intima-Media Thickness*
Coronary Artery Disease / diagnostic imaging*
Humans
Imaging, Three-Dimensional / methods
Pattern Recognition, Automated / methods*
Reproducibility of Results
Sensitivity and Specificity
Ultrasonography, Interventional / methods*