Fast magnetic resonance imaging (MRI) acquisitions with high frame rates can mitigate artefacts caused by physiological motion and bulk patient movement, enabling motion-resolved imaging.

This study aims to evaluate the detection performance of triplanar real-time cine fast imaging employing steady-state acquisition (FIESTA), compared to conventional MRI sequences.

This retrospective study included 53 children (median age, 1.9 years; range, 1 day–7.1 years) who underwent clinically indicated 1.5-T chest MRI in sedation between January and December 2024. Findings on triplanar real-time cine FIESTA sequences, acquired in up to 1 min, were compared to the findings obtained by dedicated lung sequences (fast spin echo, zero echo time, perfusion imaging) as reference. Detection of extrapulmonary findings (of the chest wall, diaphragm, pleura, mediastinum), lung parenchymal findings (consolidation, atelectasis, bronchial wall thickening, hyperinflation, cysts), and cardiovascular findings by real-time cine FIESTA are presented with descriptive statistics.

Real-time MRI provided diagnostic, motion-artefact-free thoracic images in the sedated but freely breathing patients. Diaphragmatic motion abnormalities were detected in one out of one case (100%), visible only on real-time cine FIESTA and not on the dedicated static sequences. Pleural effusion was present in 16 out of 17 cases (94%), and mediastinal masses were present in five out of five cases (100%). Lung pathologies, including consolidation and atelectasis, were identified in 40 out of 44 cases (91%). However, bronchial wall thickening was missed in all 20 cases (0%). Hyperinflation or air-filled cysts were detected in four out of four cases (100%). Cardiovascular abnormalities were identified in six out of eight cases (75%).

Real-time cine FIESTA imaging demonstrated high accuracy in detecting pleural effusion, pulmonary consolidation, cysts, and gross cardiovascular abnormalities in paediatric patients. However, airway pathologies were not identified. Clinical indications for real-time cine chest MRI need to be defined. Feasibility and performance of real-time imaging in unsedated children warrant further study.