Automated Interventricular Septum Segmentation for Black-Blood Myocardial T2*Measurement in Thalassemia

作者:Zheng, Qian; Feng, Yanqiu*; Wei, Xiaping; Feng, Meiyan; Chen, Wufan; Lu, Zhentai; Xu, Yikai; Chen, Hongwen; He, Taigang
来源:Journal of Magnetic Resonance Imaging, 2015, 41(5): 1242-1250.
DOI:10.1002/jmri.24662

摘要

PurposeTo develop and validate an automated segmentation method that extracts the interventricular septum (IS) from myocardial black-blood images for the T2* measurement in thalassemia patients. @@@ Materials and MethodsA total of 144 thalassemia major patients (age range, 11-51 years; 73 males) were scanned with a black-blood multi-echo gradient-echo sequence using a 1.5 Tesla Siemens Sonata system (flip angle 20 degrees, sampling bandwidth 810 Hz/pixel, voxel size 1.56x1.56x10 mm(3) and variable fields of view (20-30)x40 cm(2) depending on patient size). The improved Chan-Vese model with an automated initialization by the circular Hough transformation was implemented to segment the endocardial and epicardial margins of the left ventricle (LV). Consequently, the IS was extracted by analyzing the anatomical relation between the LV and the blood pool of the right ventricle, identified by intensity thresholding. The proposed automated IS segmentation (AISS) method was compared with the conventional manual method by using the Bland-Altman analysis and the coefficient of variation (CoV). @@@ ResultsThe T2* measurements using the AISS method were in good agreement with those manually measured by experienced observers with a mean difference of 1.71% and a CoV of 4.15% (P<0.001). @@@ ConclusionBlack-blood myocardial T2* measurement can be fully automated with the proposed AISS method. J. Magn. Reson. Imaging 2015;41:1242-1250.