Technological advances modified actual trends in pediatric imaging. Up 25 years ago thoracic X-ray was the only resource in pediatric radiology. The introduction of CT, digital radiography, sonography and magnetic resonance and then of psitron emission tomography, led to a new dimension in thoracic pediatric imaging. In the future, new technological perspectives will make the functional study of the lung ventilation possible with techniques such as the 3-He hyperpolarized.