Kuan-Yu Lin, Presenter: Nothing to Disclose

Tzu-Ching Shih, Abstract Co-Author: Nothing to Disclose

We can provide a non-invasive method that cardiac surgeon could use for CFD analysis to evaluate the pressure drop alteration in the coronary artery based on patient CT images. 

Coronary artery disease (CAD) is the most common type of heart disease and cause of heart attacks. The Doppler echocardiography was used to measure the averaged blood flow velocity in the left ventricular outflow tract. The aim of this study was to simulate the blood flow in the stenosis of a coronary artery and to calculate the pressure gradient in the artery using the patient-specific computed tomography (CT) images and the measured blood flow velocity by a Doppler echocardiography.

The patient CT images was acquired by a helical CT scanner. The thickness of the image slice was 3 mm and the pixel size was 0.62*0.62 mm. A 3D surface reconstruction was created on the workstation. The three-dimensional geometry of the coronary artery was created by the Amira and volume mesh was generated by the ANSYS ICEM-CFD. The blood velocity of the left ventricular outflow tract was measured by the Doppler ultrasound echocardiography machine. The measured blood velocity was about 62 cm/s in the coronary artery diagnosed with 50% stenosis. The inlet velocities were 62 cm/s (LVOT) and 80 cm/s.

In numerical simulation, the two blood velocities (62 cm/s and 80 cm/s) were used to simulate the blood flow in the coronary artery and to calculate the pressure drop across the stenosis of the artery. Computer simulation results showed that for the inlet blood velocity of 62 cm/s, the pressure drop over the stenosis of the coronary artery was 1.189 kPa. Meanwhile, the maximum velocity in the stenosis of the artery was about 153.063 cm/s. For a higher inlet velocity of 80 cm/s, the pressure drop in the artery was 2.054 kPa and the maximum velocity was 192.154 cm/s. The increment ratio of the pressure drop was about 72% when the inlet velocity form 62 to 80 cm/s. Furthermore, the increment ratio of maximum velocity in the stenosis was around 25%. It shows that higher blood flow velocity results in larger pressure drop in the stenosis of the coronary artery.

Lin, K, Shih, T, Computational Fluid Dynamics Analysis of Pressure Drop Alteration in the Coronary Artery Stenosis Based on Patient-specific Computed Tomographic Images.  Radiological Society of North America 2014 Scientific Assembly and Annual Meeting, - ,Chicago IL. http://archive.rsna.org/2014/14017882.html