New Method for Estimating Left Atrial Volume Based on an Irregular Base Cylinder Model using Magnetic Resonance Imaging: Comparison with the Area-Length Method

pp. 20-24

Abstract

Background: Left atrial volume quantification is of great importance in various pathologies. For this purpose, models derived from echocardiography have been applied in magnetic resonance imaging, although they may not be completely accurate.

Objective: To validate a new method for estimating left atrial volume that is practical and more accurate than the method most commonly used at present.

Methods: Images of patients included in a cardiac magnetic resonance imaging database were used. Direct volumetric quantification and volumetric estimates using the area-length (AL) method and the irregular base cylinder (cilindro de base irregular, CBI) method were performed to measure correlation.

Results: Studies from 25 patients were analyzed. The mean age was 44 ± 15 years; 52% were male and 84% were studied on an outpatient basis. Pearson's correlation coefficient was higher for the CBI method (r=0.93; p <0.001) than for the AL method (r=0.83; p <0.001). The Bland-Altman analysis showed lower dispersion for the CBI method [-5.73 mL (18.6 to -30.11)] than for the AL method [-1.18 mL (43.82 to -46.17)]. Interobserver variability was lower for the CBI method [4.94 mL (44.76 to -34.88)] than for the LA method [19.7 mL (65.91 to -26.51)].

Conclusions: The CBI model showed better correlation than the AL model. We consider it a valid alternative that is equally simple and more accurate than the AL method for estimating left atrial volume by magnetic resonance imaging.