Impact of left ventricular trabeculations and papillary muscles on measures of cavity volume and ejection fraction
© Chuang et al; licensee BioMed Central Ltd. 2011
Published: 2 February 2011
Left ventricular (LV) trabeculations are typically considered LV cavity volume (i.e. ignored) when analyzing cardiac magnetic resonance (CMR) images as they are difficult to manually segment, but they are not actually part of the LV bloodpool. The treatment of papillary muscles is more variable, but they too have often been considered bloodpool.
To assess the impact of LV trabeculations and papillary muscles on LV volumes and ejection fraction (EF) determined from CMR images using automated segmentation software.
Contiguous 10-mm thick cine CMR images encompassing the left ventricle in the short-axis orientation (SSFP: TR/TE/FA=3.2ms/1.6ms/60°, 208x256 matrix, 400-mm FOV; 1.5-T scanner, Philips Healthcare, Best, the Netherlands) from 1494 adults (aged 64±9 yrs, 795 women) in the Framingham Heart Study Offspring cohort were analyzed using semi-automated epi- and endocardial LV border detection to determine LV end-diastolic and end-systolic volumes (EDV, ESV), EF and LV mass (LVM) before and after “adjustment” (ADJ) for trabeculations and papillary muscles. ADJ was fully automated and used fuzzy grayscale thresholding capable of accounting for partial volume effects (Cardiac Explorer, Philips Healthcare). Two-sample t-test was used to assess between-sex differences and paired t-test was used to evaluate effect of ADJ. Intra-class correlation (ICC) was used to assess reproducibility on 48 randomly selected participants from equal strata of sex and age-tertile.
M vs. W
M vs. W
LV trabeculations and papillary muscles occupy 22% of the putative LV blood pool in both sexes. Adjustment for trabecular and papillary muscle volume results in increased LV ejection fraction. Automated segmentation of LV trabeculations and papillary muscles is highly reproducible.
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