How can the left atrial strain be correctly determined by cardiovascular magnetic resonance feature tracking?

Figures

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  Figure 1. Optimized planning along the main axes of the left atrium to assess volume, strain and strain rates. (A) Standard cine SSFP 4-chamber view at end-systole. (B) Standard cine SSFP 2-chamber view at end-systole. (C) Additional end-systolic cine SSFP view depicting the mitral valve and both the right upper pulmonary vein and the right lower pulmonary vein, which represents the longest extent of the left atrium. The three-point planning tool was used to define the optimized 4-chamber view (yellow stars and the blue star) and the optimized 2-chamber view (red stars and the blue star).

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  Figure 2. Illustration of the most distant position (arrow), typically best represented by the valley between the right upper pulmonary vein and the right lower pulmonary vein, to visualize the main axis of the left atrium using a 3D model. Heart segmentation including surface rendering using the whole heart analysis software IntelliSpace Portal (Version 12.1, Philips Medical Systems, Best, The Netherlands). For the reason of simplicity, only the left ventricle (LV) and the left atrium (LA) are shown to illustrate the spatial position of the two chambers. RLPV, right lower pulmonary vein; RUPV, right upper pulmonary vein; LLPV, left lower pulmonary vein; LUPV, left upper pulmonary vein.

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  Figure 3. Strain analysis applying the optimized planning procedure to correctly evaluate the strain, strain rate as well as the left atrial volumes. (A,B) Strain illustration by boundary points in a 4-chamber and 2-chamber view, respectively, in a 53-year-old women with sarcoidosis. Accordingly, (C) the strain-to-time curve and (D) the corresponding strain rate-to-time curve are displayed.

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  Figure 4. (A,B) Left atrial strain evaluation by standard planning or optimized planning. In case of standard planning (2-chamber and 4-chamber view aligned along the main axis of the left ventricle), the longest extent of the left atrium is usually not correctly captured (see red line), resulting in overestimations of strain and in underestimations of volumes. In contrast, by applying the optimized planning procedure, a correct definition of the longest LA extent is achieved, which improves the accuracy of left atrial strain, strain rate and volume values.