Incidental Findings on Pediatric Abdominal Magnetic Resonance Angiography

Abdominal magnetic resonance angiography (MRA) has gained favor in pediatric patients owing to its lack of ionizing radiation and noninvasive nature. Reports exist regarding incidental findings on body MRA in adult patients. However, the incidental findings in pediatric abdominal MRA have not been previously reported. Our study aims to determine the frequencies, characteristics, and categories of incidental findings in pediatric patients undergoing abdominal MRA.

Retrospective study was performed in 78 consecutive contrast-enhanced abdominal MRA of patients between ages 0 and 20 years over a 7-year time period. The presence of incidental vascular and extravascular findings was noted. Reports were categorized in consensus by two radiologists as no incidental finding (group A), normal or normal variants or nonsignificant incidental common findings (group B), or abnormal incidental findings (group C). Group C was reviewed to determine whether additional management was performed.

A total of 40 boys and 38 girls (51%:49%) were reported, with a mean age of 12.3 years (standard deviation ±5.6 years, range 7 days to 20 years). Three most common indications for MRA were renal artery stenosis (24.4%), vasculitis (21.8%), and suspected intra-abdominal venous thrombosis (14.1%). We identified a total of 92 incidental findings in 50 of 78 patients; 60 findings in 29 patients in group B, and 32 findings in 21 patients in group C. Atelectasis at the lung bases was the most common incidental finding in group B (14 of 78 patients). The most common findings in group C were ascites, scoliosis, and splenomegaly. There were three abnormal incidental findings that led to causative workup and/or further management (moderate ascites, pericardial and pleural effusion, and venous malformation). The remaining cases with abnormal findings received treatment of their primary conditions only.

Pediatric abdominal MRA revealed a large number of incidental findings. The large majority were findings without clinical significance. Basal lung atelectasis was the most common overall incidental and nonsignificant finding, whereas ascites was the most common abnormal incidental finding. Although not all abnormal incidental findings affected management, appropriate identification and communication of relevant findings would improve patient care.