Design of a Patient-Specific Respiratory-Motion-Simulating Platform for In Vitro 4D Flow MRI

• Published in: Annals of biomedical engineering Vol. 51; no. 5; pp. 1028 - 1039
• Main Authors: Li, Ning, Tous, Cyril, Dimov, Ivan P., Fei, Phillip, Zhang, Quan, Lessard, Simon, Moran, Gerald, Jin, Ning, Kadoury, Samuel, Tang, An, Martel, Sylvain, Soulez, Gilles
• Format: Journal Article
• Language: English
• Published: Cham Springer International Publishing 01.05.2023; Springer Nature B.V
• Subjects: Abdomen; Actuators; Animals; Arteries; Biochemistry; Biological and Medical Physics; Biomedical and Life Sciences; Biomedical Engineering and Bioengineering; Biomedicine; Biophysics; Classical Mechanics; Flow velocity; Gating; Hepatic artery; Human motion; Humans; Imaging techniques; Imaging, Three-Dimensional - methods; In vivo methods and tests; Liver; Magnetic resonance imaging; Magnetic Resonance Imaging - methods; Motion; Original Article; Phantoms, Imaging; Signal to noise ratio; Simulation; Swine; Signal-to-noise ratio; 4D flow MRI; Liver motion; and; Respiratory-motion-simulating platform; In vitro and in vivo
• ISSN: 0090-6964; 1573-9686
• DOI: 10.1007/s10439-022-03117-6

Four-dimensional (4D) flow magnetic resonance imaging (MRI) is a leading-edge imaging technique and has numerous medicinal applications. In vitro 4D flow MRI can offer some advantages over in vivo ones, especially in accurately controlling flow rate (gold standard), removing patient and user-specific variations, and minimizing animal testing. Here, a complete testing method and a respiratory-motion-simulating platform are proposed for in vitro validation of 4D flow MRI. A silicon phantom based on the hepatic arteries of a living pig is made. Under the free-breathing, a human volunteer's liver motion (inferior–superior direction) is tracked using a pencil-beam MRI navigator and is extracted and converted into velocity–distance pairs to program the respiratory-motion-simulating platform. With the magnitude displacement of about 1.3 cm, the difference between the motions obtained from the volunteer and our platform is ≤ 1 mm which is within the positioning error of the MRI navigator. The influence of the platform on the MRI signal-to-noise ratio can be eliminated even if the actuator is placed in the MRI room. The 4D flow measurement errors are respectively 0.4% (stationary phantom), 9.4% (gating window = 3 mm), 27.3% (gating window = 4 mm) and 33.1% (gating window = 7 mm). The vessel resolutions decreased with the increase of the gating window. The low-cost simulation system, assembled from commercially available components, is easy to be duplicated.