Reference Values for Pediatric Atrial Volumes Assessed by Steady-State Free-Precession Magnetic Resonance Imaging Using Monoplane and Biplane Area-Length Methods

Abstract

Background: Measurement of atrial volumes by MRI is becoming increasingly important in pediatric cardiac disorders. However, MRI normal values for atrial volumes in children are lacking.

Purpose: To establish pediatric reference values for atrial volumes.

Study type: Retrospective.

Subjects: A total of 155 healthy children from two large institutions (103 male, age 13.9 ± 2.8 years, range 4-18 years).

Field strength/sequence: A 1.5 T; balanced steady-state free precession (bSSFP) sequence.

Assessment: The monoplane and biplane area-length methods were used to measure minimal and maximal left and right atrial volumes (LA_min , LA_max , RA_min , and RA_max ) from four-chamber (4ch) and two-chamber (2ch) MR cine images. Centile charts and tables for atrial volumes were created.

Statistical tests: Descriptive statistics, lambda-mu-sigma (LMS)-method of Cole and Green, univariable and multivariable linear regression models. A P value < 0.05 was considered to be statistically significant.

Results: In the multivariable linear model, body surface area was significantly associated with all atrial volumes and sex was significantly associated with RA volumes, LA volumes measured in the 2ch-view as well as biplane LA_max. Average atrial volumes measured: monoplane 4ch: LA_min 13.1 ± 4.8 mL/m² , LA_max 33.4 ± 8.8 mL/m² , RA_min 18.5 ± 6.8 mL/m² , RA_max 33.2 ± 9.6 mL/m² ; monoplane 2ch: LA_min 12.7 ± 4.9 mL/m² , LA_max 30.5 ± 9.5 mL/m² ; biplane: LA_min 12.3 ± 4.5 mL/m² , LA_max 30.9 ± 8.7 mL/m² .

Data conclusion: Pediatric MRI reference values for atrial volumes have been provided.

Technical efficacy: 2 EVIDENCE LEVEL: 4.

Keywords: cardiac MRI; children; left atrium; normative; reference values.