Normal values for paediatric atrial volumes assessed by steady-state free-precession cardiovascular magnetic resonance

Background Measurement of atrial volumes by steady-state free precession (SSFP)cardiovascular magnetic resonance (CMR) is becoming increasingly important in the treatment and follow-up of paediatric congenital heart disease. It has prognostic value in terms of heart failure and cardiovascular death. However, CMR normal values for the clinically often used mono- and biplane area-length method in children are lacking. Aims We sought to create paediatric normal values for atrial volumes using the mono- and biplane area-length method. Methods In a retrospective study design, CMR data sets of 157 healthy children with an age range between 4 and 18 years from two centers in the UK and Germany were evaluated. In a four-chamber (4ch-) view, left and right atrial (LA, RA) endocardial borders were segmented during end-diastole and end-systole to calculate minimal and maximal atrial volumes (LAmin, LAmax, RAmin, RAmax) using the monoplane area-length method. Additionally, end-diastolic and end-systolic LA endocardial borders were segmented in a two-chamber (2ch-) view. Using the measurements from the 2ch- and 4ch-views, minimal and maximal LA volumes were calculated using the biplane area-length method. Atrial volumes were normalized for body surface area (BSA in m2). Sex-specific reference curves were created using the lambda mu sigma method. Results The median age was 13.8±2.81 years (53 girls). In children from 4–10 years average atrial volumes measured: monoplane 4ch: LAmin 10.2±3.5 ml/m2, LAmax 28.8±7.4 ml/m2, RAmin 14.1±6.3 ml/m2, RAmax 27.0±11.4 ml/m2; monoplane 2ch: LAmin 10.9±4.1 ml/m2, LAmax 27.0±6.1 ml/m2; biplane: LAmin 10.2±3.3 ml/m2, LAmax 27.4±5.7 ml/m2. In children from 11–18 years average atrial volumes measured: monoplane 4ch: LAmin 13.6±4.9 ml/m2, LAmax 34.1±9.1 ml/m2, RAmin 19.2±6.8 ml/m2, RAmax 34.2±9.6 ml/m2; monoplane 2ch: LAmin 13.2±4.9 ml/m2, LAmax 31.4±9.7 ml/m2; biplane: LAmin 12.9±4.4 ml/m2, LAmax 31.8±8.8 ml/m2. Separate centile charts and centile tables for boys and girls for all volumetric parameters were created. Conclusion We provide paediatric CMR reference values for atrial volumes. They can be used in the diagnosis and follow-up of congenital or acquired heart disease in children and for research purposes. Funding Acknowledgement Type of funding sources: None.