Automatic determination of aortic compliance based on MRI and adapted curvilinear detector

Parameters of aortic elasticity, such as aortic compliance or aortic distensibility, can be estimated from cine-MRI through the knowledge of the aortic contour on each image. In this context, a completely automatic method for the measurement of aortic elasticity is proposed in this study, and compared with previously published methods which are not fully automatic. An adaptation of a curvilinear region detector was used for the aortic wall detection over the entire cardiac cycle, to completely automatically evaluate the aortic stiffness in a pilot study including 40 volunteers. Near circular regions were detected (ascending and descending aorta cross-sections) in each image of the sequence using robust scale-space based method with removing of false positives using probabilistic approach. Robustness against noise was studied and an evaluation of area estimation was performed. A comparison between manual segmentation by two experts is provided on whole images from the patient dataset. The global mean relative errors for the area are 2.83 ± 1.88% and 1.44 ± 1.52% for the ascending and descending aorta, respectively. The global means of the Dice's coefficient are 0.97 ± 0.01 for the ascending aorta and 0.97 ± 0.01 for the descending aorta. These values are high and very stable. Finally, the Bland-Altman plots for compliance and distensibility values show good agreements between our method and experts, with a mean of difference always close to zero, and a low standard deviation. Then the proposed tool allows a precise and accurate automatic measurement of aortic stiffness from cine-MRI and can be applied in clinical practice.