Table 1.
Techniques Under Investigation For Clinical Studies in Young Children, and the Status of Their Validation
| Assessment | Age group | Disease severity (structural or functional changes assessed) | Type of evidence | MCID defined | Test frequency | Safety aspects | Status of standardization (reproducibility, validity) | Cost of equipment |
|---|---|---|---|---|---|---|---|---|
| Infant pulmonary function testing (RVRTC)11–18 | <3 years of age | Detection of early functional changes | Well validated | No | Unrestricted | Oral sedation | Well defined | Moderate to high |
| MBW/LCI4,19–35 | All | All | Limited | No | Unrestricted | Oral sedation (optional for young children) | Required for each trial | Moderate to high |
| CT scans25,36,45–58,60–63 | For all ages | Early and advanced structural changes | Well validated | Yes/No | Restricted | Radiation | Well defined and required for each trial | Moderate |
| MRI40–42,57,66–78 | All (depending on local expertise) | All (morphology and function) | Moderately well validated | No | Unrestricted | Only when contrast media injection is used | Required for each trial | High |
| PET scan43,44,79–86 | For children ≥6 years of age | Detection of structural changes as for CT, in addition detection of active inflammation | Few studies in CF available | No | Restricted | Radiation | In development | High |
| Mucociliary clearance87–93,95 | >6 years of age | Early or advanced | Not validated | No | Restricted (4–6 scans per year) | Radiation | Standardized between few sites | Moderate |
| NPD119–134 | All, specialized at young age | Not applicable | Well validated | No | Unrestricted | Minimal | Well established | Moderate, requires expertise |
| ICM135–142 | All | Not applicable | Limited | No | Restricted | Requires rectal biopsy | Reasonably standardized | Moderate, requires expertise |
| Sweat chloride5,120–122,143–149 | All | Not applicable | Well validated | No | Unrestricted | None | Well established | Low |
CF, cystic fibrosis; CT, computed tomography; FDA, Food and Drug Administration; ICM, intestinal current measurement; LCI, lung clearance index; MBW, multiple breath washout; MCID, minimal clinically important difference; MRI, magenetic resonance imaging; NPD, nasal potential difference; PET, positron emission tomography; RVRTC, raised volume rapid thoracoabdominal compression.