Patient rotation chest X-rays and the consequences of misinterpretation in paediatric radiology

Purpose: We aimed to demonstrate the consequences of rotation on neonatal chest radiographs and how it affects diagnosis. In addition, we demonstrate methods for determining the presence and direction of rotation.

Background: Patient rotation is common in chest X-rays of neonates. Rotation is present in over half of chest X-rays from the ICU, contributed to by unwillingness of technologists to reposition new-borns for fear of dislodging lines and tubes. There are six main effects of rotation on supine paediatric chest X-rays: 1) unilateral hyperlucency of the side that the patient is rotated towards; 2) the side 'up' appears larger; 3) apparent deviation of the cardiomediastinal shadow in the direction that the chest is rotated towards; 4) apparent cardiomegaly; 5) distorted cardio-mediastinal configuration; and 6) reversed position of the tips of the umbilical artery and vein catheters with rotation to the left. These effects can cause diagnostic errors due to misinterpretation, including air-trapping, atelectasis, cardiomegaly, and pleural effusions, or disease may be masked. We demonstrate the methods of evaluating rotation with examples, including a 3D model of the bony thorax as a guide. In addition, multiple examples of the effects of rotation are provided including examples where disease was misinterpreted, underestimated or masked.

Conclusion: Rotation is often unavoidable in neonatal chest X-rays, especially in the ICU. It is therefore important for physicians to recognise rotation and its effects, and to be aware that it can mimic or mask disease.