4D Flow MR Imaging Reveals a Decrease of Left Atrial Blood Flow in a Patient with Cardioembolic Cerebral Infarction after Pulmonary Left Upper Lobectomy

Figures

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  Fig. 1. Contrast-enhanced chest CT on postoperative day 3. A thrombus is seen in the left superior pulmonary vein stump (arrow).

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  Fig. 2. 2D images of contrast-enhanced MRA and 4D flow MRI. The upper row presents a contrast-enhanced MRA images and the lower row shows the velocity map derived from 4D flow MRI. Each pulmonary vein can be seen in the figure [right superior pulmonary vein (RSPV), right inferior pulmonary vein (RIPV), left inferior pulmonary vein (LIPV), left superior pulmonary vein (LSPV)]. Decreased flow is seen at LSPV stump and around the junction between the left atrium and the LSPV.

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  Fig. 3. Blood flow velocity at five points; junction between the left atrium (LA) and right superior pulmonary vein (RSPV) (①), right inferior pulmonary vein (RIPV) (②), left inferior pulmonary vein (LIPV) (③) and left superior pulmonary vein (LSPV) (④), and the LSPV stump (⑤). Diagram shows the quantitative blood flow distribution at each of the five points. The blood flow velocity is the highest at the junction between the LA and RSPV, and slower at the LA–LSPV junction and LSPV stump than in other regions.

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  Fig. 4. Pathline analysis of 4D flow MRI. Color-coded pathlines show the flow pattern in the left atrium. The green area represents blood from each of the right superior pulmonary vein (RIPV), right superior pulmonary vein (RSPV) and left inferior pulmonary vein (LIPV). The red area represents the left superior pulmonary vein (LSPV) stump. Pathlines are drawn from the VOI of each of three pulmonary veins (RSPV, RIPV and LIPV). The yellow arrows indicate the direction of the blood flow. All of the pathlines are directed to the mitral valve; there is no flow directed to the junction between the left atrium and the LSPV.