Table 1.

Overview on outcome measures for investigation of early CF lung disease discussed in this review.

Technique	Investigated Aspect of CF Lung Disease	Applicable Age Range	Advantages	Disadvantages
Spirometry	lung function	≥3 years	good availability	necessitates cooperation insensitive for mild changes
MBW	lung function	from infancy on (requiring sedation in some young patients)	performed in tidal breathing with minimal cooperation detects early ventilation inhomogeneities	only available at specialized centers harmonization between devices, tracer gases and protocols pending
CT	lung structure	from infancy on (requiring sedation in some young patients)	good availability short duration of performance high resolution images detecting early morphological changes	ionizing radiation (limiting repeatability) no information on lung function
MRI	lung structure lung function	from infancy on (requiring sedation in young patients)	sensitive to early CF lung disease can be repeated in short time (no radiation)	performed at specialized centers investigation takes longer than CT lower resolution than CT
BAL	infection inflammation	from infancy on (requiring anesthesia in young patients)	only way to properly investigate colonization of the lower airways and to measure inflammatory markers	invasive BAL-directed therapy has shown no advantage over standard therapy

Definitions of abbreviations: CF = cystic fibrosis; MBW = multiple-breath washout; CT = computed tomography; MRI = magnetic resonance imaging; BAL = bronchoalveolar lavage.