Clinical applications of radionuclide lung scanning in infants and children.

Krypton 81m ventilation and technetium 99m perfusion lung scans in anterior, posterior and oblique views in 86 children (age range 14 days to 15 years) with various paediatric problems were obtained. On reviewing these studies we found four main areas of clinical usefulness. (a) Establishing the diagnosis; in a relatively small number of patients the lung scan was essential for either establishing the exact diagnosis or directing attention to the abnormal area. (b) Refuting a diagnosis: the two main groups in this category include possible bronchiectasis and inhaled foreign body. (c) Establishing the extent of the disease; radionuclide studies enable one to assess and follow up the extent of the disease in children with lower respiratory problems; a lung scan may obviate the need for bronchography in bronchiectatics failing to respond to medical treatment and for whom surgery is being considered. Repeat studies are useful in following the natural history or the response to treatment of various lung conditions. (d) Assessing the success of surgical procedures on the heart and on abnormal pulmonary arteries. We indicate that 81Krm ventilation/99Tcm perfusion scanning are particularly useful in small children in whom tests of overall pulmonary function cannot be carried out because of lact of co-operation.