[A critical study of technetium 99m and xenon 133 lung scintigraphy in patients with cystic fibrosis].

During investigations for cystic fibrosis, 41 children, most of whom were aged 0 to 7 years, were submitted to lung scintigraphy with technetium 99m first and xenon 133 subsequently. This procedure ensured accurate location of pulmonary lesions. The reliability of the radio-isotopic study was assessed through comparison to conventional clinical and radiological criteria, arterial blood gas determinations and pulmonary function tests. Perfusion scintigraphy with technetium 99m labelled macroaggregated albumin (n = 90) was compared to functional parametrical xenon, 133 study (n = 25) (perfusion-ventilation). The degree of lung disease was evaluated during serial examinations in order to improve prognostic prediction. Technetium 99m scintigraphy proves a reliable and sensitive procedure which accurately reflects the patients' clinical status when it is performed in the absence of patent pulmonary superinfection. Xenon 133 scintigraphy, which is more difficult to perform and interpret, has the advantage of providing a topographic and quantitative evaluation of pulmonary blood flow and ventilatory efficiency.