In silico simulation of hepatic arteries: An open‐source algorithm for efficient synthetic data generation

Abstract

BackgroundIn silico testing of novel image reconstruction and quantitative algorithms designed for interventional imaging requires realistic high‐resolution modeling of arterial trees with contrast dynamics. Furthermore, data synthesis for training of deep learning algorithms requires that an arterial tree generation algorithm be computationally efficient and sufficiently random.PurposeThe purpose of this paper is to provide a method for anatomically and physiologically motivated, computationally efficient, random hepatic arterial tree generation.MethodsThe vessel generation algorithm uses a constrained constructive optimization approach with a volume minimization‐based cost function. The optimization is constrained by the Couinaud liver classification system to assure a main feeding artery to each Couinaud segment. An intersection check is included to guarantee non‐intersecting vasculature and cubic polynomial fits are used to optimize bifurcation angles and to generate smoothly curved segments. Furthermore, an approach to simulate contrast dynamics and respiratory and cardiac motion is also presented.Results: The proposed algorithm can generate a synthetic hepatic arterial tree with 40 000 branches in 11 s. The high‐resolution arterial trees have realistic morphological features such as branching angles (MAD with Murray's law ), radii (median Murray deviation ), and smoothly curved, non‐intersecting vessels. Furthermore, the algorithm assures a main feeding artery to each Couinaud segment and is random (variability = 0.98 ± 0.01).ConclusionsThis method facilitates the generation of large datasets of high‐resolution, unique hepatic angiograms for the training of deep learning algorithms and initial testing of novel 3D reconstruction and quantitative algorithms designed for interventional imaging.

Motion-compensation approach for quantitative digital subtraction angiography and its effect on in-vivo blood velocity measurement

“…Network training was performed on synthetic hepatic angiograms. 37 Angiograms were generated by combining random synthetic hepatic arterial trees with existing virtual phantoms, 38 and subsequent forward projection using an x-ray image simulator. 37 Training was performed using the weighted cross-entropy loss, 39 where each class was weighted by the inverse of the class frequency and the known vessel locations were used as ground truth.…”